A systematic review of biomass-derived materials for wastewater remediation of contaminants

Introduction

Water is one of the most precious and important natural resources on the earth. It is very crucial for all living creatures in its pure state because it constitutes the majority of living tissues and the concept of life is impossible without water. Water is also known as a universal solvent because of its good solubility power. It plays an indispensable role in the world economy. The need for pure water is continuously increasing. With growing population and industrialization, the obtainable supplies are speedily diminishing. Water contamination is a recent issue of concern for the whole world. According to the central pollution control board, the gross per capita water availability would decrease by 2050 (Central Pollution Control Board MINARS/36/2013-14), and the total demand for fresh water would be rising rapidly and creating water stress. Further, drinking water is not accessible in many regions of the world even though 70% of the earth is covered by water. The quality of water resources has degraded at a very fast rate due to various organic and inorganic pollutants released from anthropogenic as well as natural sources. Water contamination is a serious concern as it affects living entities from recreation, domestic, fishing, transportation, and other commercial activities (Yadav et al., 2019). Water pollution is caused by many factors like inadequate sewage treatment, chemical wastes, industrial effluents, petroleum refining wastes, marine dumping issues, fertilizers and pesticides used in agricultural activities radioactive waste material, thermal power plants, Animal excreta in rural areas, etc. The contaminated water contains various inorganic and organic contaminants, some of which are highly persistent, toxic, and carcinogenic. In water, more than 700 chemical contaminants have been reported (Yadav et al., 2019). Major toxic organic pollutants include pesticides, polynuclear aromatic hydrocarbons (PAHs), plasticizers, phenols, polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), fertilizers, greases, oils, nitrogen, bleach salts, biological contaminants like viruses, bacteria, protozoan, parasites, and drug residues, primary inorganic pollutants include arsenic, lead, cadmium, mercury, chromium, and many other (toxic) metals, along with nutrients such as nitrate and phosphate. Waste water regulations are established in some countries to reduce human and environmental exposure to hazardous chemicals. In the same line, the Central Pollution Control Board (India) set various standards for the discharge of waste water effluents into the any water body, for example biochemical oxygen demand 30 ppm, chemical oxygen demand (COD) 250 ppm, pH 5.5-9.0, manganese (mg/L): 1.0, chromium (mg/L): 0.05, copper (mg/L): 2.0, and iron (mg/L): 3.0 (Maity et al., 2019). Many studies have been carried out for the purification of wastewater and to preserve freshwater sources. Many techniques have been demonstrated as efficient to eliminate pollutants from wastewater (Buruga et al., 2019). Among the various water treatment techniques adsorption is considered to be one of the most successful techniques in the field of separation technology, particularly in wastewater treatment processes. Therefore, the main objective of this review article is to provide information on the application of various sustainable low-cost alternative adsorbents such as agricultural solid waste materials in the removal of heavy metal and dye from contaminated water. This review article also provides various research results and a compilation of up-to-date development on the current state of knowledge on various agricultural solid waste-based adsorbents and their application in the broad field of separation and purification of water and wastewater pollutants. This review is focused on two major contaminants like dyes and heavy metals. Dyes are the coloring agents that have two components chromospheres and auxochromes, chromospheres are responsible for producing color, and auxochromes are responsible for the solubility of molecules in water and enhance the affinity of dye molecules towards the fibers. Dyes are classified in several ways based on their chemical structure, color, application, and particle charge in the solution. Each class of dye has a very unique chemistry; some dyes react chemically while some are held by physical forces. Usually, dyes are divided into two classes, natural dyes, and synthetic dyes. The sources of natural dyes are animals and minerals. With the rapid growth of industrial activities, natural dyes couldn't meet the needs of people's demand, so synthetic dyes are developed and used particularly in fabrics and textile industries. Synthetic dyes include ionic dyes (cationic and anionic) and non-ionic dyes (vat and disperse) based on their particle charge upon dissolution in aqueous application medium. Classification based on chemical structure includes Azo, Anthraquinone, Indigoid, Nitroso, Nitro, Triarylmethane dyes. Soluble dyes are classified as acidic, mordant, metal complex, direct, basic, and reactive. Insoluble dyes are azoic, sulfur, vat, and disperse dye. Among all these dyes azo dyes are widely used and account for 65-70% of the total dyes produced. The annual production of dyes about 5×10 5 tonnes has been estimated and usually employed in various industries like papers, plastics, processing of food, cosmetics, tannins of textiles, pharmaceutical etc (Goodman et al., 2018). Approximately 100 tonnes/year dyes are discharged in water streams. Srivastava et al reported that most of Indian textile industries have been consuming more than 100L of water for the processing of 1 kg textile thus they discharge a huge amount of coloured wastewater in the environment that causes pollution of surface and ground water resources (Aruna et al., 2021). According to WHO and UNICEF, 2000 report approximately 70-80% of all illnesses in developing countries are caused by different water contaminants, particularly affecting women and children (WHO and UNICEF, 2000). The toxicity of dyes are due to their components like aromatics, amines and trace of heavy metals such as Cd, Cu, Pb, Zn and Co (Zhou et al., 2019). The presence of organic compounds in dyes cause the reduction in penetration of sun light in water that may affect the photosynthesis of aquatic life (Pearce et al., 2003). Most of dyes are carcinogenic, mutagenic, or teratogenic to all living beings which affects the many functions of human body like dysfunction of kidney, liver, brain and reproductive system and central nervous system (Kadirvelu et al., 2003). Acid red used in food and textile industries, colour photography which is Carcinogenic and affects the marine life also toxic to flora and fauna (Behnajady et al., 2007). Acid yellow used in dyeing wool, silk, leather and polyamide fibers and harmful to the environment (dos Santos et al., 2017). Crystal violet used in paper and textile industries, temporary hair colorant responsible for pollution of the groundwater in basel which causes vomiting, jaundice, quadriplegia & tissunecrosis (Appusamy et al., 2014;Li, 2010;X. Tan et al., 2016). Eriochrome Black T which degrades the water quality, causes eye and skin allergies (Srivastava et al., 2017). Methylene blue and Azo dyes which are majorly used in various industries like dyeing cotton, wood, silk and food industry (chilli powders, eggs, garlic curry sauce, and palm oils) are mutagenic & carcinogenic to humans causes eye burns or sometimes permanent injury to the eyes, nausea, vomiting, and mental confusion, liver and urinary bladder tumours in mammals (Daud et al., 2019).

Heavy metals belong to class of inorganic pollutants having atomic weight between 63.5 to 200.6 and specific gravity greater than 5, present in sludge, fertilizers, municipal waste, pesticides, mines residues and smelting industries (Halim et al., 2003). Industrial wastewater contains heavy metals like lead, chromium, mercury, uranium, selenium, zinc, arsenic, cadmium, silver, gold, and nickel. Among these, lead, cadmium, mercury and arsenic heavy metals show carcinogenic effects on human health. These may damage central nervous function, the cardiovascular and gastrointestinal systems, lungs, kidneys, liver, endocrine glands, bones, stomach cramps, skin irritations, vomiting, nausea, respiratory disorders, anaemia and mental fever. Heavy metal causes various types of cancers Parkinson's disease, multiple sclerosis, muscular dystrophy and Alzheimer's disease.

Need for water remediation

According to United Nations estimation, three is ten people deficit ingress to clean drinking water. Contaminated drinking water cause many diarrhoeal deaths per year. Only 3% of ground water is present in pure form and can be used for drinking and domestic purpose (Senthil Kumar et al., 2019). The amount of various new type contaminants ever increasing in hydrological environments and the availability of pure water is shrinking continuously that's why by 2025 half of the world population will be living in drinking water-deficient areas, so to avoid these difficulties and toxic effects, the water remediation becomes more challenging (Goodman et al., 2018).

Techniques for waste water treatment

It was more from 80s that people started giving much attention to the dye removal methods because of the hazardous effects of dyes on living things such as aquatic and human life. In the late 90's, there were two dye removal methods contained only preliminary water purification processes such as equalization and sedimentation. Because at that time there were no dye effluents discharge limit and the selection of dyes application and uses were not given a major attention to their environmental impact. At that time the chemical composition of most of the dyes used in the industry was unknown. After primary processes like equalization and sedimentation secondary treatments such as the use of filter beds for biodegradation comes in picture. There are several waste water treatment techniques to treat the waste water containing dyes and heavy metals. The major classes of these technologies are (i) Physical (ii) Chemical (iii) Biological (Fig. 2). All of these techniques are discussed below with their positive and negative aspects.

Biological methods

Numerous microorganisms like enzymes, fungi, algae, bacteria are studied for biodegradation and bioaccumulation of dye particles. These microorganisms have ability to biodegrade and bioaccumulate the dye particles. Various conventional biological dye removal methods are adsorption by microbial biomass, algae degradation, enzyme degradation, fungal cultures, microbial cultures as well as pure and mixed culture. Microbial biomass like mixture of organic living organisms fashioned to adsorb only selected dye molecules not all dyes. In algae degradation method algae consumes dye particles for selfgrowth. In enzyme degradation method extracted enzyme used to degrade dye molecules. This method have advantages like cost effective, high efficiency, non-toxic, reusability but its use is limited due to unreliable amount of enzyme production. Based on oxygen demand, biological methods divide in two classes, aerobic and anaerobic. In aerobic conditions, bacteria secret the enzymes to breakdown the organic compounds present in the wastewater. Some of the aerobic bacteria used for dye removal are Bacillus sp., Enterococcus sp., Pseudomonas sp. It has been found that a number of Triphenylmethane dyes, such as magenta, pararosaniline, crystal violet, malachite green, brilliant green and ethyl violet can be efficiently decolorized (92-100%) by the strain Kurthia sp. (Sani & Banerjee, 1999). (Delee et al., 1998;Forgacs et al., 2004) demonstrate the po tential of anaerobic treatment applications for the degradation of a wide variety of synthetic dyes present in waste water. Some of anaerobic bacteria used for dye removal are Escherichia coli, Clostridium sp. (Bhatia et al., 2017;Sarayu & Sandhya, 2012). (Razo-Flores et al., 1997) reported that the two azo dyes mordant orange 1 and azodisalicylate can be reduced and decolorized using methanogenic granular sludge under anaerobic conditions and (Van der Zee et al., 2001) gives the feasibility of decolourization of 20 azo dyes by the application of anaerobic granular sludge. The efficiency of biological treatment system is highly affected by many factors like sensitivity of microorganism towards seasonal changes, toxicity of some chemicals and requirement of large land areas for construction of bioreactors.

Chemical methods

Various conventional chemical contaminants removal methods are advanced oxidation process, fenton reaction dye removal, electrochemical destruction, oxidation, ozonation, photochemical and ultraviolet irradiation. All of these methods have many advantages and disadvantages discussed in the text below (Katheresan et al., 2018). In ultraviolet irradiation method UV light is used to decompose the dye particles in wastewater and this method produce no sludge, weakens foul odours but having drawbacks like energy depletion, high cost, limited treatment times. Ozonation is an effective dye removal method in which the ozone produced from oxygen is utilize to remove contaminant particles, it can be used in its gaseous state, doesn't increase wastewater volume, no sludge generation, quick reaction. But have limitations like extremely short half-life, high cost, and produce toxic by-products. Oxidation is the common chemical dye removal method in which, many oxidising agents are use to treat dye effluents, these oxidising agents completely convert complex structure of dye molecules in to carbon dioxide and water. Usage of catalyst with oxidising agents can increase the rate of process and take short time to complete the reaction. This method have disadvantages like not cost effective, the activation of hydrogen peroxide agent is difficult, pH dependent process and requires catalyst for efficient removal. In fenton reaction method Fenton's reagent (mixture of catalyst and hydrogen peroxide) are used to remove dye particles from wastewater, can remove soluble and insoluble dyes and all toxins from effluents which contain solid contents also. Negative aspects of this method are like it cannot remove disperse and vat dyes, produce high iron sludge, take long time. Electro-coagulation or non-soluble anodes are use in electrochemical destruction method to treat the dye wastewater. Advantages of this method are no sludge production, used chemical don't get consumed and disadvantages are production of additional hazardous material, high cost of electricity, high flow rate as compared to other methods. Advanced oxidation process involves multiple oxidation process done simultaneously to remove dye particles and toxic materials but it is expansive and non-flexible method. It produced undesirable by-products and pH dependent method. Chemical dye removal methods are commercially unattractive because these are costly as compared to physical and biological dye removal methods, requires high electrical energy for power equipment or reactors in which chemical dye removal take place, requirement of chemicals as well as reagents at large scale is an issue. Another undesirable characteristic of this method is the generation of toxic secondary pollution resulting at the end of a chemical dye removal process presenting an additional disposal problem.

Physical methods

Among the three methods, physical dye removal methods are simple, flexible and efficient. These are the most commonly used and straightforward methods and accomplished by the mass transfer mechanism. Various conventional physical dye removal methods are adsorption, coagulation or flocculation, ion exchange, irradiation, membrane filtration, nano filtration or ultra-filtration, reverse osmosis, and many more. All of these methods require the least amount of chemicals compare to the biological or chemical dye removal meth ods (N. A. Khan et al., 2018) and removal percentage of dyes ranging from 86.8 to 99%. Reverse osmosis is the pressure driven system in which water is passed through an extremely thin membrane leaving contaminants on one side and water on the other. Used for recycling, decolouring and desalting the water and produced pure water but its use is limited by its high cost and high pressure (Katheresan et al., 2018). Membrane filtration method is effective for water recovery but costly initial investment, Easy membrane fouling and concentrated sludge production make its use limited (Koyuncu & Güney, 2013). Irradiation method uses the radiation to remove dye molecules from dye wastewater and effective at laboratory scale, but it is expansive process and require a huge amount of dissolved oxygen. Ion exchange technique produced high quality treated water but it is effective for selected contaminants (Katheresan et al., 2018). Coagulation and flocculation is economical and robust method which is suitable only for removal of disperse, sulphur and vat dye effluents but this method have disadvantages like high sludge production and not effective for disperse, sulphur and vat dye effluents, pH dependent and sometimes expensive due to use of some special chemicals (Holkar et al., 2016). Most of these techniques have disadvantages like high sludge production, handling and disposal problems, high pressure, expensive, technical constraints, economically unfeasible, high energy cost, chemicals required (N. Gupta et al., 2016;V. K. Gupta et al., 2011), etc. Among these remediation methods adsorption techniques is efficient, eco-friendly, easy to operate and cost effective. It can remove a large number of contaminants such as organic, inorganic and biological substances including soluble and non-soluble compounds from waste water without producing toxic by-products (Hassan et al., 2020). The quality of water remains unchanged during adsorption process of water purification. Adsorption is the surface phenomenon in which substances from one phase adsorbed on the second phase adsorbent surface. A good adsorbent should have some important characteristics such as availability, low-cost technology, non-hazardous, high surface capacity, high abrasion resistance and stability in different environmental conditions (Shamsollahi & Partovinia, 2019). The adsorbents, which are generally used for dye wastewater treatment, are: Alumina, Silica gel, Zeolites, Activated carbon, Natural materials, low cost al-ternative adsorbents like (a) Natural materials such as peat, wood, coal, lignite etc. (b) Industrial/Agricultural/Domestic wastes or byproducts such as slag, sludge, fly ash, bagasse fly ash, red mud etc. (c) Synthesized products.

Mechanism of adsorption process

Adsorption mechanism depends on the properties of adsorbent and adsorbate, like nature of surface, functional sites on the surface, interaction behaviour of adsorbing molecule/ions (Siddiqui et al., 2019). Magnetic activated carbon/clay composite showed that the adsorption of Pb II , Cu II and Ni II heavy metal ions through ion exchange and electrostatic attraction took place because the positive charged ions of heavy metals attracted by the negatively charged functional groups present on the composite surface and the presence of Na + , Ca 2+ and Mg 2+ ions in the clay may be responsible for ion exchange mechanism (Le et al., 2019). The adsorption of arsenite on pine cone-magnetite composite took place by Inner sphere complex and ion exchange mechanism because in case of sphere complex formation the adsorption rate increase by adding salt and the value of ion exchange coefficient increase 0.05 to 0.51 that indicates the ion exchange between arsenite and nitrate ions on the surface (Ouma et al., 2018). MnO 2 /Black cumin seed composite adsorbed the methylene blue through electrostatic as well as hydrogen bonding because FT-IR spectra of methylene blue adsorbed composite shows shift in characteristic peaks of naked composite. The strength of electrostatic and hydrogen bonding was confirmed from the bonding energy determined from Temkin, and D-R models as well as thermodynamics studies (Wendler et al., 2010). The removal of arsenic by FeOH/CuO@waste bamboo cell took place by the synergistic effect of physical action and redox reaction mechanism. The type of adsorption mechanism can be probed with the help of FTIR which tells about shift in functional group peaks before and after the adsorption, XPS it tells about the change in binding energy peaks during adsorption process, XRD gives information about the change in crystal structure of adsorbate before and after adsorption, TEM-EDS, EDX (H. Liu et al., 2020).

Biosorbents derived from agricultural waste for dye and heavy metal removal

Agricultural waste is unwanted material obtained completely from agricultural operations directly connected to the growing of crops. Example of these waste materials are Rice husk, Sugarcane bagasse, Coconut husk, Corn stalk, peanut hull, Natural shell huts, Wheat husk, Barley husk, Coffee husk etc. These waste materials are produced in huge amount and create disposal problem. The reuse of these waste materials and development of an ideal adsorbent is an actual task in our present time. These agricultural waste materials can be used as adsorbents for water remediation because of their effectiveness, availability, unique chemical composition, chemical stability, low cost, renewable cycle, short regeneration cycle, environmental friendliness, and green energy. Their porous structure and large specific surface area makes it easy to adsorb heavy metals and dyes. The various functional groups like acetamido groups, carbonyl, phenolic, structural polysaccharides, amido, amino, sulphydryl, carboxyl, alcohols and esters present in agriculture waste material (Salleh et al., 2011;Zhou et al., 2015) can be replaced by many other functional groups such as amino, sulpha, carboxyl groups of dyes and many modifying reagents. For example chemical composition of Bamboo is lignin, pentosan and cellulose so it contains a huge amount of hydroxyl groups; peanut hull contains amino, carboxyl and hydroxyl groups which are responsible for adsorption. The activated carbon produced from agricultural wastes contains high carbon content, low inorganics, require mechanical strength, low levels of ash content and low cost (Chowdhury et al., 2011;Dias et al., 2007;Zhou et al., 2015). So the use of agricultural wastes as adsorbents in raw form or activated carbon form would provide an economic important value which helps to decrease the cost of disposal of waste and an alternative to solve environment problems. (Anastopoulos et al., 2020;Bhatnagar & Sillanpää, 2010;Dai et al., 2018;Ramesh, 2013;Zhou et al., 2015) have discussed the various low-cost adsorbents in a number of review articles for removal of heavy metals, dyes, phenols and pharmaceutical wastes. Many researchers used agriculture solid waste such as Beech saw dust , Bagasse fly ash, Wheat bran , Eucalyptus bark, Neem leaf powder, Rubber wood saw dust, Sugarcane bagasse, maize corn cob, jatropha oil cake, Raw rice bran for water contaminants removal (Sud et al., 2008). In this review, we aim to present biowaste as an environmentally benign, low-cost biosorbent for removal of various dyes and heavy metals from water effluents in raw form as well as modified form. The effect of biosorbents modification by physical, chemical and composite formation on the specific surface area and porosity was studied. Some of the advantages of using agricultural waste for wastewater treatment include simple technique, requires little processing, good adsorption capacity, selectivity for adsorption effluents, low cost, free availability and easy regeneration (Ngah & Hanafiah, 2008). Besides, the exhausted adsorbents can be disposed of by burning and the heat used for steam generation (V. K. Gupta & Suhas, 2009).

Physical modification of biosorbents

Biosorbents can modified by using different physical processes such as autoclaving cutting, grinding, thermal drying, milling, boiling, steaming, and carbonization these methods results change in adsorbent surface area and particle size (Ren et al., 2014). Utilization of physically modified biosorbents for heavy metal ions and dye removal discussed below. Cucumis sativa peel adsorbent after grinding modification may be suitably considered as nano biosorbent due to particles have spherical shape of variable sizes from 23 to 78 nm (Shakoor & Nasar, 2019). Adsorption of Congo red dye on sugarcane bagasse adsorbent took place intra-particle diffusion model in surface area of adsorbent value of range 0.58-0.66 m 2 /g while adsorption of methylene blue dye obeyed by multi-adsorption stages on surface area of adsorbent value of range 1.31-1.82 m 2 /g. Zhang et al., 2013 reported that milling of SB increase the surface area from 0.58 to 0.66 m 2 g -1 which resulted in increase in methylene blue dye removal efficiency by 5.6%, removing 96.6% of the dye (Z. Zhang et al., 2013). Moringa oleifera pod husk after grinding showed good adsorption capacity for crystal violet dye because grinding results in BET surface area and average diameter of pore values 2.097 m 2 /g and 66.268 Å (Keereerak & Chinpa, 2020). Grinding modification of fava bean peels results in macro porous adsorbent which have total surface area and total pore volume of value 0.2108 ± 0.0035 m 2 /g and .00067 cm 3 /g (Ba et al., 2020).

Removal of lead

Plastics, finishing tools, cathode ray tubes, ceramics, solders, pieces of lead flashing etc. are the major sources through which lead enter in the environment, concentration level of lead and duration of exposure control the various biological effects. In the environment it has strong affinity to bind with many particles like oil, sediments and sewage sludge which results its removal is of great concern. Kumar et al., 2016 ii.

Removal of chromium

Chromium is a toxic heavy metal occurs in various oxidation states but chromium (VI) and chromium (III) are of main environmental concern, which enters in to environment by many applications like tanning, wood preservation and pigments, dyes for plastic, paints, and textiles (Yu et al., 2000). Various agriculture biomass based adsorbents which used for the removal of chromium were Ficus nitida leaves (Ali & Alrafai, 2016), Olive bagasse (Demiral et al., 2008), Mango kernel (Mangifera indica) (Akram et al., 2017) [1] , Mosambi peel (Saha et al., 2013), Melaleuca diosmifolia leaf (Kuppusamy et al., 2016), Beech saw dust , Bagasse fly ash, Wheat bran , Eucalyptus bark , Neem leaf powder, Rubber wood saw dust, Sugarcane bagasse, maize corn cob, jatropha oil cake, Raw rice bran (Sud et al., 2008). Coconut shell used as adsorbent for Cr VI removal at optimum condition of pH , initial concentration, contact time, doses were 4.6, 10 -200 mg/L, 100 min, 1.5g/ L respectively with maximum adsorption capacity of value 40 mg/g, followed by Langmuir isotherm and pseudo second order kinetic model (Mohammed et al., 2014). Tadesse reported that teff straw act as an adsorbent for the removal of chromium metal with an adsorption capacity of value 3.51 mg/g at optimum pH , temperature , value was 2.0 , 298 K respectively and adsorption took place by chemisorption adsorption mechanism (Tadesse et al., 2015).

iii. Removal of cadmium, arsenic, nickel, copper, mercury, zinc Cadmium has more water solubility as compare to other heavy metals and it accumulates in environment from various sources but the long life time PVC-window frames, plastics and plating on steel are the basic sources and causes very harmful effects on human body. Nickel and its compounds have no characteristic odour or taste. The sources of nickel to the environment are nickel plating, colored ceramics, batteries, furnaces used to make alloys or from power plants and trash incinerators. Experiments were conducted on sequestration of heavy metals on various agriculture biowaste adsorbents and resulted in good removal efficiency. Peels of peas, fig leaves, broad beans, medlar peel , wheat bran , husk of black gram straw, bagasse fly ash , bagasse , wheat bran , hazelnut shell, orange peel, maize cob, peanut hulls, jack fruits , maple saw dust , tea waste, defatted rice bran, cottonseed hulls , pinus radiata bark, mango saw dust, mustard oil cake, are the adsorbents which were tried for the adsorption of heavy metals like cadmium, arsenic, mercury, nickel, copper etc. with adsorption efficiency of range 40-100% (Sud et al., 2008). Rice bran which is used for the removal of Pb (II), Cd (II), Cu (II), Zn (II) and showed more than 80% removal (Montanher et al., 2005) ( Montanher et al 2005). Najam et al 2016 reported that Raw walnut shell were used for removal of cadmium ions with adsorption capacity of value 7.29 mg/g at 6 pH by share or exchange electronics and chemisorptions adsorption mechanism (Najam & Andrabi, 2016). Sesame used as an adsorbent for removal of cadmium ions showed adsorption capacity of value 84.74 mg/g at optimum pH of value 6.0 and followed by chemisorptions mechanism (Cheraghi et al., 2015). Casuarinas fruit powder and Banana stem powder were used for the removal of copper ions showed adsorption capacity 4.55 and 6.49 mg/g at optimum conditions by chemisorption and physical adsorption mechanism (Mokkapati et al., 2016). Walnut shell were used for zinc ions removal showed adsorption capacity of value 7.48 mg/g at 5.0 pH and 313 K temperature by Ion exchange adsorption mechanism (Najam & Andrabi, 2016).

Chemical modification

Recently, more attention has been given for enhancing the effectiveness and adsorption capacity of biowaste adsorbents by modifying their specific properties using various techniques. Although various agriculture waste materials have been used as adsorbent for removal of water contaminants like heavy metals and dyes but the application of these untreated biosorbents causes several problems like low adsorption capacity, high chemical oxygen demand (COD) and bio-logical oxygen demand (BOD) as well as total organic carbon (TOC) due to release of soluble organic compounds contained in the agriculture wastes. So , the modification of these biosorbents required to avoid these problems because the pre-treatment of bio wastes using different kinds of modifying agents like many base solutions (sodium hydroxide, calcium hydroxide, sodium carbonate), mineral and organic acid solutions (hydrochloric acid, nitric acid, sulphuric acid, tartaric acid, citric acid, thioglycollic acid), organic compounds (ethylenediamine, formaldehyde, epichlorohydrin, methanol), oxidizing agent (hydrogen peroxide), dye (Reactive Orange 13) can extract soluble organic compounds and remove colour of aqueous solutions. These chemical modifications generally results in oxidation of functional groups present on the surface or introduce new functional groups on the surface of biosorbent which enhance chelating efficiency, surface area and porosity. For example, Hydrochloric acid, sodium carbonate, sodium hydroxide , tartaric acid and epichlorohydrin are commonly used for the chemical modification of rice husk which remove lignin, hemicellulose, reduce cellulose crystallinity and increase the porosity or surface area results more adsorption capacity for cadmium then unmodified rice husk (Ngah & Hanafiah, 2008). But sometimes these chemical modification results decrease in adsorption capacity, for ex-ample hydrochloric acid treated rice husk showed decrease in adsorption capacity for cadmium heavy metal ions then untreated rice husk because hydrochloric acid results in protonation of adsorption sites on adsorbent which leaves the heavy metal ions in the aqueous phase rather than being adsorbed on the adsorbent surface (U. Kumar & Bandyopadhyay, 2006). Esterification reaction between biosorbents of agriculture waste materials and acids results in increase functional groups. These extra functional groups on the surface are responsible for binding of the dye molecule and heavy metal ions which results in increase of adsorption efficiency but esterifies tartaric acid modified rice husk however significantly reduced the uptake of Cu and Pb because the chelators like nitrilotriacetic acid (NTA) and ethylenediaminetetraacetic acid (EDTA) caused significant suppressing effect on the uptake of Pb (Wong et al., 2003). Esterification of papaya seed increase the uptake of methylene blue dye from 200 mg/g to 250 mg/g but decrease for anionic congo red dye from 71.43 mg.g to 58.8 mg/g because the esterifies modification causes negative charge on the adsorbate surface (Nasuha et al., 2011). Modified orange peel adsorbent showed the maximum uptake capacity for Pb 2+ , Cd 2+ and Ni 2+ ions were 476.1, 293.3 and 162.6 mg g-1, respectively, which were about 4.2, 4.6 and 16.5 time higher than that of the unmodified biomass (Feng et al., 2011). Ortho-phosphoric acid treated Gmelina aborea leaf powder exhibited higher performance and showed a increase in adsorption capacity from 142.86 to 1000 mg/ L which proved that modification resulted in the creation of several pores on gmelina aborea leaf powder (Solomon et al., 2019). Chemical modifications of activated carbons using acids is the most studies technique that had been used for past several decades due to its simplicity, availability of oxidizing agents and the established nature of this technique. Which introduce acidic functional groups onto the surface of activated carbon. But an acid treatment gives different effects on the certain activated carbons either increasing or decreasing their adsorption capacities. This is control by the type of activating agents, precursors, activation methods and adsorbate. Hydrochloric acid modified oil palm shell-based activated carbon showed increase in adsorption capacity for methylene blue from 243.90 to 303.03 mg/g which was 24.24% higher than unmodified oil pal shell activated carbon. Due to the adsorption of negative ions (Cl - from HCl) on the positive sites on the carbon surface, which makes the surface negative and facilitating the adsorption of the positive charged molecules of methylene blue (I. A. W. Tan et al., 2008). Wang et al. reported that 2M hydrochloric acid and nitric acid modified commercial activated carbons (BDH, F100 and BPL) resulted in decrease in uptakes of methylene blue ions due to the removal of hydroxide groups by the acidic treatment which produced acidic oxygen functional groups on the carbon surface. Which reduced the interactions between methylene blue molecules and carbon (Wang et al., 2005). Ethylenediamine modified rice hull which adsorbed basic (basic blue) and reactive dyes (reactive orange) from single and binary solutions with good sorption capacity as compare to natural rice hull adsorbent. The maximum adsorption capacity in binary solution was increased by 4.5 and 2.4 times, respectively compared to those in single dye solutions. Chemical modifications also affect the point of zero charge (pH pzc ) of the adsorbent and behaviour of adsorbent towards solution pH. For phosphoric acid treated sugarcane bagasse, the dye adsorption was significantly remained almost 100% for all pH values. But for sugarcane bagasse carbon it was significantly changed over the pH value 3-6 showed lowest percentage of dye removal at pH 2 (52.2%) and at the pH range of 7-10 it remain constant. As the adsorption of dyes on modified sugarcane bagasse took place by ion-exchange mechanism that did not shows effect of pH on adsorption. But on unmodified sugar cane bagasse it took place by electrostatic attraction mechanism showed effect of solution pH. Phosphoric acid treated sugarcane bagasse showed more adsorption capacity as compare to unmodified sugar cane bagasse and untreated sugarcane bagasse carbon of values 48.42, 10.98 and 5.66 mg/g respectively (Saad et al., 2010). The pH pzc of the sugarcane bagasse and citric acid modified sugarcane bagasse adsorbents were 5.5 and 3.4 respectively. Point of zero charge of native, Polyethyleneimine treated and immobilized sugarcane bagasse was found to be 4.8, 5.8 and 5.3 respectively.

Table 1. Biosorbents utilization for dye removal using physical modifications

Adsorbent

The effect of chemical modification on the surface functional groups, specific surface area, volume and size of pores can be determined using characterisation techniques like Fourier transform infrared spectroscopy, Brunauer Emmett Teller (BET) analysis. SEM and Barret, Joyner, and Halenda (BJH) method is used for studying pore size distributions on the adsorbent surface. FTIR spectra of sodium hydroxide modified tea waste showed two new peaks formed at 2919 and 1427 corresponding to aliphatic C-H and NH 2 deformations but in case of raw rejected tea there were only remarkable shift in positions of -OH, C-O and -C-C-group peaks after adsorption, which showed methylene blue binding majorly at -OH and C-O groups. Also modified rejected tea has higher physical stability and surface activity as compare to raw tea. The changes in FTIR spectra after adsorption confirm the complexation of methylene blue with functional groups present in the adsorbents. SEM micrographs of modified rejected tea showed the surface of modified tea exhibited pores like honeycomb shape gaps and modification also did not change the actual surface texture of rejected tea and have a macro reticular with enhanced physical characteristic. The BET surface area, total pore volume and average pore diameter were measured to be 6.5 m 2 /g, 0.0064 cm 3 /g and 61˚A, respectively for modified rejected tea. The increase in adsorption capacity from 147 mg/g to 242.11 mg/g is due to formation of negative charge on rejected tea after modification with NaOH. Which increase the electrostatic attraction between adsorbent and adsorbate (Nasuha & Hameed, 2011). The Fourier transform infrared (FTIR) spectra of natural rice hull and oxalic acid modified rice hull results showed that carboxyl groups increased and there were an increase in the adsorption band corresponding to the stretch vibration of the carboxyl group (at 1736 cm -1 ), with the position of some peaks being changed after modification (Zou et al., 2011). NaOH activated prunus leaves showed more specific surface area of value 426.346 m 2 / g which was higher than the unmodified prunus (67.205 m 2 /g). NaOH treatments increase the pore volume of prunus leaves to 0.282 cm 3 / g and decrease the Pore diameter to 2.644 nm. Significant increase in surface area and pore volume for NaOH activated prunus leaves as compared to Dead leaves of Prunus Dulcis was attributed to removal of lignin from dead leaves of Prunus delcis due to NaOH treatment. Leading to development of pores and hence an increase in the surface area and pore volume (Jain & Gogate, 2018). XRD technique can be used to analyze the influence of the pre-treated process on the crystallinity of the cellulose. Retreatment process remove the amorphous components of lignin and hemicelluloses results increase in crystallinity after pre-treatment, (R. Liu et al., 2005). The pre-treatment of wheat straw with NaOH and HCl, which remove the hemicelluloses, lignin and pectin, resulted that the surface of Pre-WS was relatively wrinkled, and its average diameter decrease significantly to 7-10 μm (Hornsby et al., 1997). Grafting of wheat straw also resulted denser surface as compare to untreated wheat straw indicated that the surfaces was covered by the graft polymerization (Lin et al., 2017). Some of the chemical modifications of agriculture biowaste material biosorbents are given in Table 2 along with their maximum adsorption capacity and optimum conditions.

Conclusion

This review article started with brief presentation of classification of dyes, their toxic effects and several treatment techniques for waste water in which adsorption technique gain more emphasis. In adsorption technique various low cost adsorbents like agricultural solid waste materials used for removal of contaminants. Agricultural wastes materials have many functional groups which make them promising adsorbents for contaminants removal in their raw and modified form. The synthesis and applications of agricultural waste-based adsorbents for the removal of various types of heavy metals and dyes from water have been reviewed. Compare to other adsorbents agricultural wastebased composites are renewable, biodegradable, biocompatible, and economically viable. As evidenced by the literature reviewed in this paper, physical, chemical and composite modification can increase the uptake of contaminants by increasing number of active binding sites in the adsorbents, improving their ion exchange properties and form new functional groups. Effect of modification on adsorbents can be studied using various characterization techniques. Adsorption techniques using these nonconventional biomass adsorbents especially replace the use of expensive commercial activated carbon for the removal of toxic contaminants from water bodies and provide a green sustainable solution for treatment of contaminated water. These also contribute to an overall waste minimization strategy. Various composites of agriculture waste materials have been studied in which magnetic adsorbents are very helpful to recover adsorbents and control the adsorption process. Parameters such as adsorption mechanism for dyes and heavy metals removal, biosorption capacity of sorbent, temperature, biosorbent dose, initial concentration of contaminants, equilibrium time and pH of the solution were also presented. Various kinetic and thermodynamic models for adsorption process were studied. Several gaps that require attention, such as the enhancement of bio sorption capacity through the modification of adsorbents, assessment of adsorbents under multicomponent pollutants, validating these materials with real industrial effluents, recovery of metal ions and dyes, regeneration studies, continuous flow of studies, use of eco-friendly chemicals for adsorbents modification to avoid secondary pollution.

References

1. Akram M, Bhatti HN, Iqbal M, Noreen S, Sadaf S. Biocomposite efficiency for Cr (VI) adsorption: Kinetic, equilibrium and thermodynamics studies. Journal of Environmental Chemical Engineering. 2017;5(1):400-411. Ali IH, Alrafai HA. Kinetic, isotherm and thermodynamic Waste Management. 2020;0123456789. Amer H, El-Gendy A, El-Haggar S. Removal of lead (II) from aqueous solutions using rice straw. Water Science and Technology. 2017;76(5):1011-1021. Anastopoulos I, Pashalidis I, Orfanos AG, Manariotis ID, Tatarchuk T, Sellaoui L, Bonilla-Petriciolet A, Mittal A, Núñez-Delgado A. Removal of caffeine, nicotine and amoxicillin from (waste) waters by various adsorbents. A review. Journal of Environmental Management. 2020;261:110236. Appusamy A, John I, Ponnusamy K, Ramalingam A. Removal of crystal violet dye from aqueous solution using triton X-114 surfactant via cloud point extraction. Engineering Science and Technology, an International Journal. 2014;17(3):137-144. Argun ME, Dursun S, Ozdemir C, Karatas M. Heavy metal adsorption by modified oak sawdust: Thermodynamics and kinetics. 2007;141:77-85. Aruna, Bagotia N, Sharma AK, Kumar S. A review on modified sugarcane bagasse biosorbent for removal of dyes. Chemosphere. 2021;268:129309. Ba OS, Ka H, Shoe T, Ya H, Yo N. Novel approach for effective removal of methylene blue dye from water using fava bean peel waste. 2020:1-10. Behnajady MA, Modirshahla N, Daneshvar N, Rabbani M. Photocatalytic degradation of CI Acid Red 27 by immobilized ZnO on glass plates in continuous-mode. Journal of Hazardous Materials. 2007;140(12):257-263. Bhatia D, Sharma NR, Singh J, Kanwar RS. Biological methods for textile dye removal from wastewater: A review. Critical Reviews in Environmental Science and Technology. 2017;47(19):1836-1876. Bhatnagar A, Sillanpää M. Utilization of agro-industrial and municipal waste materials as potential adsorbents for water treatment-a review. Chemical Engineering Journal. 2010;157(2-3):277-296. Buruga K, Song H, Shang J, Bolan N, Jagannathan TK, Kim KH. A review on functional polymer-clay based nanocomposite membranes for treatment of water. Journal of Hazardous Materials. 2019;379.
2. Cheraghi E, Ameri E, Moheb A. Adsorption of cadmium ions from aqueous solutions using sesame as a low-cost biosorbent: kinetics and equilibrium studies. International Journal of Environmental Science and Technology. 2015;12(8):2579-2592.
3. Cheruiyot GK, Wanyonyi WC, Kiplimo JJ, Maina EN. Adsorption of toxic crystal violet dye using coffee husks: Equilibrium , kinetics and thermodynamics study. 2019;5:1-11.
4. Chowdhury S, Mishra R, Saha P, Kushwaha P. Adsorption thermodynamics, kinetics and isosteric heat of adsorption of malachite green onto chemically modified rice husk. Desalination. 2011;265(1-3):159-168. Dai Y, Sun Q, Wang W, Lu L, Liu M, Li J, Yang S, Sun Y, Zhang K, Xu J. Utilizations of agricultural waste as adsorbent for the removal of contaminants: A review. Chemosphere. 2018;211:235-253. Daud M, Hai A, Banat F, Wazir MB, Habib M, Bharath G, Al-Harthi MA. A review on the recent advances, challenges and future aspect of layered double hydroxides (LDH)-Containing hybrids as promising adsorbents for dyes removal. Journal of Molecular Liquids. 2019;288:110989. Delee W, O'Neill C, Hawkes FR, Pinheiro HM. Anaerobic treatment of textile effluents: a review. Journal of Chemical Technology & Biotechnology: International Research in Process, Environmental AND Clean Technology. 1998;73(4):323-335. Demiral H, Demiral I, Tümsek F, Karabacakoğlu B. Adsorption of chromium (VI) from aqueous solution by activated carbon derived from olive bagasse and applicability of different adsorption models. Chemical Engineering Journal. 2008;144(2):188-196. Dias JM, Alvim-Ferraz MCM, Almeida MF, Rivera-Utrilla J, Sánchez-Polo M. Waste materials for activated carbon preparation and its use in aqueous-phase treatment: a review. Journal of Environmental Management. 2007;85(4):833-846. dos Santos RMM, Gonçalves RGL, Constantino VRL, Santilli CV, Borges PD, Tronto J, Pinto FG. Adsorption of Acid Yellow 42 dye on calcined layered double hydroxide: Effect of time, concentration, pH and temperature. Applied Clay Science. 2017;140:132-139. El S, Zahira A, Abdeltif B, Soufiane R, Abdellatif T, Fouad A. Brown Seaweed Sargassum muticum as Low -Cost Biosorbent of Methylene Blue. International Journal of Environmental Research. 2018;0123456789. Feng N, Guo X, Liang S, Zhu Y, Liu J. Biosorption of heavy metals from aqueous solutions by chemically modified orange peel. Journal of Hazardous Materials. 2011;185(1):49-54. Forgacs E, Cserháti T, Oros G. Removal of synthetic dyes from wastewaters: A review. Environment International. 2004;30(7):953-971. Gemici BT, Ozel HU, Ozel HB. Adsorption behaviors of crystal violet from aqueous solution using Anatolian black pine ( Pinus nigra Arnold .): kinetic and equilibrium studies. Separation Science and Technology. 2019;0(0):1-9. Gong R, Jin Y, Chen J, Hu Y, Sun J. Removal of basic dyes from aqueous solution by sorption on phosphoric acid modified rice straw. 2007;73:332-337. . 1994;48:251-255. Goodman SM, Bura R, Dichiara AB. Facile Impregnation of Graphene into Porous Wood Filters for the Dynamic Removal and Recovery of Dyes from Aqueous Solutions. ACS Applied Nano Materials. 2018;1(10):5682-5690.
5. Guo J, Li B, Liu L, Lv K. Chemosphere Removal of methylene blue from aqueous solutions by chemically modified bamboo. CHEMOSPHERE. 2014;111:225-231. Gupta N, Kushwaha AK, Chattopadhyaya MC. Application of potato (Solanum tuberosum) plant wastes for the removal of methylene blue and malachite green dye from aqueous solution. Arabian Journal of Chemistry. 2016;9:S707-S716. Gupta VK, Gupta B, Rastogi A, Agarwal S, Nayak A. A comparative investigation on adsorption performances of mesoporous activated carbon prepared from waste rubber tire and activated carbon for a hazardous azo dye-Acid Blue 113. Journal of Hazardous Materials. 2011;186(1):891-901.
6. Gupta VK, Suhas. Application of low-cost adsorbents for dye removal -A review. Journal of Environmental Management. 2009;90(8):2313-2342. Halim M, Conte P, Piccolo A. Potential availability of heavy metals to phytoextraction from contaminated soils induced by exogenous humic substances. Chemosphere. 2003;52(1):265-275. Hassan M, Naidu R, Du J, Liu Y, Qi F. Critical review of magnetic biosorbents: Their preparation, application, and regeneration for wastewater treatment. Science of the Total Environment. 2020;702. Holkar CR, Jadhav AJ, Pinjari DV, Mahamuni NM, Pandit AB. A critical review on textile wastewater treatments: possible approaches. Journal of Environmental Management. 2016;182:351-366. Hornsby PR, Hinrichsen E, Tarverdi K. Preparation and properties of polypropylene composites reinforced with wheat and flax straw fibres: part I fibre characterization. Journal of Materials Science. 1997;32(2):443-449.
7. Ibrahim S, Fatimah I, Ang H, Wang S. Adsorption of anionic dyes in aqueous solution using chemically modified barley straw. 2010:1177-1182. Imamoglu M, Şahin H, Aydın Ş, Tosunoğlu F, Yılmaz H, Yıldız SZ. biosorbent: Batch and column studies. Journal of Environmental Management. 2018;210:226-238. Kadirvelu K, Kavipriya M, Karthika C, Radhika M, Vennilamani N, Pattabhi S. Utilization of various agricultural wastes for activated carbon preparation and application for the removal of dyes and metal International Journal of Advanced Chemistry Research https://www.chemistryjournals.net 2664679X, 2026, 8(9), Downloaded from https://www.doi.org/10.33545/26646781.2026.v8.i9a.748 by International Journal of Advanced Chemistry Research on [24/09/2026]. See the Terms and Conditions (https://www.chemistryjournals.net) for rules of use; OA articles are governed by the applicable Creative Commons License 55 ions from aqueous solutions. Bioresource Technology. 2003;87(1):129-132. Katheresan V, Kansedo J, Lau SY. Journal of Environmental Chemical Engineering E ffi ciency of various recent wastewater dye removal methods: A review. 2018;6(May):4676-4697. Keereerak A, Chinpa W. A potential biosorbent from Moringa oleifera pod husk for crystal violet adsorption: Kinetics , isotherms , thermodynamic and desorption studies. 2020;46:186-194.
8. Khan MN, Wahab MF. Characterization of chemically modified corncobs and its application in the removal of metal ions from aqueous solution. 2007;141:237-244. Khan NA, Bhadra BN, Jhung SH. Heteropoly acid-loaded ionic liquid@ metal-organic frameworks: Effective and reusable adsorbents for the desulfurization of a liquid model fuel. Chemical Engineering Journal. 2018;334:2215-2221.
9. Koyuncu I, Güney K. Membrane-Based Treatment of Textile Industry Wastewaters. Encyclopedia of Membrane Science and Technology. 2013:1-12. Kumar B, Smita K, Sánchez E, Stael C, Cumbal L. Andean Sacha inchi (Plukenetia volubilis L.) shell biomass as new biosorbents for Pb 2+ and Cu 2+ ions. Ecological Engineering. 2016;93:152-158. Kumar KV, Kumaran A. Removal of methylene blue by mango seed kernel powder. Biochemical Engineering Journal. 2005;27(1):83-93. Kumar U, Bandyopadhyay M. Sorption of cadmium from aqueous solution using pretreated rice husk. Bioresource Technology. 2006;97(1):104-109. Kuppusamy S, Thavamani P, Megharaj M, Venkateswarlu K, Lee YB, Naidu R. Potential of Melaleuca diosmifolia leaf as a low-cost adsorbent for hexavalent chromium removal from contaminated water bodies. Process Safety and Environmental Protection. 2016;100:173-182.
10. Le VT, Tran TKN, Tran DL, Le HS, Doan VD, Bui QD, Nguyen HT. One-pot synthesis of a novel magnetic activated carbon/clay composite for removal of heavy metals from aqueous solution. Journal of Dispersion Science and Technology. 2019;40(12):1761-1776. -acrylamide-methacrylate) and amylose. Bioresource Technology. 2010;101(7):2197-2202. Lin Q, Wang K, Gao M, Bai Y, Chen L, Ma H. Effectively removal of cationic and anionic dyes by pH-sensitive amphoteric adsorbent derived from agricultural waste-wheat straw. Journal of the Taiwan Institute of Chemical Engineers. 2017;0:1-8. Liu H, Li P, Qiu F, Zhang T, Xu Bioproducts Processing. 2020;123:177-187.
11. Liu Q, Li Y, Chen H, Lu J, Yu G, Möslang M. Superior adsorption capacity of functionalised straw adsorbent for dyes and heavy-metal ions. Journal of Hazardous Materials. 2020;382(130):121040. Liu R, Yu H, Huang Y. Structure and morphology of cellulose in wheat straw. Cellulose. 2005;12(1):25-34. Luo M, Lin H, Li B, Dong Y, He Y, Wang L. A novel modification of lignin on corncob-based biochar to enhance removal of cadmium from water. Bioresource Technology. 2018;259:312-318. Maity S, Dubey A, Chakraborty S. A review on polypyrrole-coated bio-composites -cost biosorbent: kinetic and equilibrium studies. Applied Water Science. 2018;8(7):1-9.
12. Memić ŠAM, Sulejmanović EŠJ. Adsorptive removal of eight heavy metals from aqueous solution by unmodified and modified agricultural waste: tangerine peel. International Journal of Environmental Science and Technology. 2018;0123456789.
13. Mohammed MA, Shitu A, Tadda MA, Ngabura M. Utilization of various Agricultural waste materials in the treatment of Industrial wastewater containing Heavy metals: A Review. Int. Res. J. Environ. Sci. 2014;3(3):62-71. Mokkapati RP, Mokkapati J, Ratnakaram VN. Kinetic, isotherm and thermodynamics investigation on adsorption of divalent copper using agro-waste biomaterials, Musa acuminata, Casuarina equisetifolia L. and Sorghum bicolor. Polish Journal of Chemical Technology. 2016;18(2):6877.
14. Montanher SF, Oliveira EA, Rollemberg MC. Removal of metal ions from aqueous solutions by sorption onto rice bran. Journal of Hazardous Materials. 2005;117(2-3):207-211. Najam R, Andrabi SMA. Removal of Cu (II), Zn (II) and Cd (II) ions from aqueous solutions by adsorption on walnut shellEquilibrium and thermodynamic studies: treatment of effluents from electroplating industry. Desalination and Water Treatment. 2016;57(56):27363-27373. Nasuha N, Hameed BH. Adsorption of methylene blue from aqueous solution onto NaOH-modified rejected tea. Chemical Engineering Journal. 2011;166(2):783786. Nasuha N, Zurainan HZ, Maarof HI, Zubir NA, Amri N, Pauh P, Pinang P. Effect of cationic and anionic dye adsorption from aqueous solution by using chemically modified papaya seed. 2011;8:50-54. Ngah WSW, Hanafiah MAKM. Removal of heavy metal ions from wastewater by chemically modified plant wastes as adsorbents: A review. 2008;99:3935-3948. Okafor PC, Okon PU, Daniel EF, Ebenso EE. Adsorption capacity of coconut (Cocos nucifera L.) shell for lead, copper, cadmium and arsenic from aqueous solutions. International Journal of Electrochemical Science. 2012;7:12354-12369. Ong ST, Lee CK, Zainal Z. Removal of basic and reactive dyes using ethylenediamine modified rice hull. 2007;98:2792-2799. Oualid HA, Abdellaoui Y, Laabd M, Ouardi M El, Brahmi Y, Iazza M, Oualid JA. Eco-E ffi cient Green Seaweed Codium decorticatum Biosorbent for Textile Dyes: Characterization , Mechanism , Recyclability , and RSM Optimization. 2020. Ouma ILA, Naidoo EB, Ofomaja AE. Thermodynamic, kinetic and spectroscopic investigation of arsenite adsorption mechanism on pine cone-magnetite composite. Journal of Environmental Chemical Engineering. 2018;6(4):5409-5419. Özsin G, Kılıç M, Apaydın E, Ayşe V, Pütün E. Chemically activated carbon production from agricultural waste of chickpea and its application for heavy metal adsorption: equilibrium , kinetic , and thermodynamic studies. Applied Water Science. 2019. Pearce CI, Lloyd JR, Guthrie JT. The removal of colour from textile wastewater using whole bacterial cells: A review. Dyes and Pigments. 2003;58(3):179-196.
15. Ramesh KSBS T. Removal of dyes using agricultural waste as low-cost adsorbents: a review. 2013:773-790. Rao PV, Pydiraju P, Madhuri V, Vineeth S, Rahimuddin S, Vangalapati M. Materials Today: Proceedings Removal of indigo carmine dye from aqueous solution by adsorption on biomass of Grevillea Robusta leaves. Materials Today: Proceedings. 2020;xxxx:2-5. RazoFlores E, Luijten M, Donlon BA, Lettinga G, Field JA. Complete biodegradation of the azo dye azodisalicylate under anaerobic conditions. Environmental Science & Technology. 1997;31(7):2098-2103.
16. Kong W, Sun R. Preparation of sugarcane bagasse/poly (acrylic acid-co-acrylamide) hydrogels and their application. BioResources. 2014;9(2):3290-3303. Rwiza MJ, Oh S, Kim K, Kim SD. Comparative sorption isotherms and removal studies for Pb(II) by physical and thermochemical modification of low-cost agro-wastes from Tanzania Mwemezi. ECSN, Ii. 2018. Saad SA, Isa KM, Bahari R. Chemically modified sugarcane bagasse as a potentially low-cost biosorbent for dye removal. Desalination. 2010;264(1):123-128.
17. Saha R, Mukherjee K, Saha I, Ghosh A, Ghosh SK, Saha B. Removal of hexavalent chromium from water by adsorption on mosambi (Citrus limetta) peel. Research on Chemical Intermediates. 2013;39(5):2245-2257. Salleh MAM, Mahmoud DK, Karim WAWA, Idris A. Cationic and anionic dye adsorption by agricultural solid wastes: a comprehensive review. Desalination. 2011;280(1-3):1-13.
18. Sani RK, Banerjee UC. Decolorization of triphenylmethane dyes and textile and dye-stuff effluent by Kurthia sp. Enzyme and Microbial Technology. 1999;24(7):433-437. Sarayu K, Sandhya S. Current technologies for biological treatment of textile wastewater-a review. Applied Biochemistry and Biotechnology. 2012;167(3):645-661.
19. Scheufele FB, Ueda MH, Ribeiro C, Steffen V, Borba CE, Kroumov AD. Biosorption of direct black dye by cassava root husks: Kinetics, equilibrium, thermodynamics and mechanism as International Journal of Advanced Chemistry Research https://www.chemistryjournals.net 2664679X, 2026, 8(9), Downloaded from https://www.doi.org/10.33545/26646781.2026.v8.i9a.748 by International Journal of Advanced Chemistry Research on [24/09/2026]. See the Terms and Conditions (https://www.chemistryjournals.net) for rules of use; OA articles are governed by the applicable Creative Commons License 56 sessment. Journal OfEnvironmental Chemical Engineering. 2019.
20. Senthil Kumar P, Janet Joshiba G, Femina CC, Varshini P, Priyadharshini S, Arun Karthick MS, Jothirani R. A critical review on recent developments in the low-cost adsorption of dyes from wastewater. Desalination and Water Treatment. 2019;172:395-416. Senthilkumaar S, Varadarajan PR, Porkodi K, Subbhuraam CV. Adsorption of methylene blue onto jute fiber carbon: kinetics and equilibrium studies. 2005;284:78-82.
21. Shakoor S, Nasar A. Utilization of Cucumis Sativus Peel as an Eco-Friendly Biosorbent for the Confiscation of Crystal Violet Dye from Artificially Contaminated Wastewater. 2019;7928.
22. Shamsollahi Z, Partovinia A. Recent advances on pollutants removal by rice husk as a bio-based adsorbent: A critical review. Journal of Environmental Management. 2019;246:314-323.
23. Siddiqui SI, Manzoor O, Mohsin M, Chaudhry SA. Nigella sativa seed based nanocomposite-MnO 2 /BC: An antibacterial material for photocatalytic degradation, and adsorptive removal of Methylene blue from water. Environmental Research. 2019;171:328-340. Singh S, Parveen N, Gupta H. Adsorptive decontamination of rhodamine-B from water using banana peel powder: a biosorbent. Environmental Technology & Innovation. 2018. Solomon O, Oluwadamilola E, Adesina K, Adewale S, Abosede A, Oluwasogo A. Heliyon Rhodamine B dye sequestration using Gmelina aborea leaf powder. Heliyon. 2019;5(November):e02872. Srivastava A, Verma N, Mistri A, Ranjan B, Nigam AK, Kumari U, Mittal S, Mittal AK. Alterations in the skin of Labeo rohita exposed to an azo dye, Eriochrome black T: a histopathological and enzyme biochemical investigation. Environmental Science and Pollution Research. 2017;24(9):8671-8681. Sud D, Mahajan G, Kaur MP. Agricultural waste material as potential adsorbent for sequestering heavy metal ions from aqueous solutions -A review. Bioresource Technology. 2008;99(14):6017-6027. Tadesse B, Teju E, Megersa N. The Teff straw: a novel low-cost adsorbent for quantitative removal of Cr (VI) from contaminated aqueous samples. Desalination and Water Treatment. 2015;56(11):29252936.
24. Tan IAW, Ahmad AL, Hameed BH. Enhancement of basic dye adsorption uptake from aqueous solutions using chemically modified oil palm shell activated carbon. 2008;318:88-96. Tan X, Liu Y, Gu Y, Liu S, Zeng G, Cai X, Hu X, Wang H, Liu S, Jiang L. Biochar pyrolyzed from MgAl-layered double hydroxides precoated ramie biomass (Boehmeria nivea (L.) Gaud.): characterization and application for crystal violet removal. Journal of Environmental Management. 2016;184:85-93.
25. Taylor P, Chieng HI, Lim LBL, Priyantha N. Enhancing adsorption capacity of toxic malachite green dye through chemically modified breadnut peel: equilibrium , thermodynamics , kinetics and regeneration studies. 2014;December:37-41.
26. Uddin T, Islam A, Mahmud S. sludge. Chemosphere. 2001;44(5):1169-1176. Wang S, Zhu ZH, Coomes A, Haghseresht F, Lu GQ. The physical and surface chemical characteristics of activated carbons and the adsorption of methylene blue from wastewater. Journal of Colloid and Interface Science. 2005;284(2):440-446.
27. Waranusantigul P, Pokethitiyook P, Kruatrachue M, Upatham ES. Kinetics of basic dye ( methylene blue ) biosorption by giant duckweed ( Spirodela polyrrhiza ). 2003;125:385-392. Wendler K, Thar J, Zahn S, Kirchner B. Estimating the hydrogen bond energy. The Journal of Physical Chemistry A. 2010;114(35):9529-9536. Wong KK, Lee CK, Low KS, Haron MJ. Naoh. Chemosphere. 2003;50(1):23-28. Yadav VB, Gadi R, Kalra S. Clay based nanocomposites for removal of heavy metals from water: A review. Journal of Environmental Management. 2019;232(November 2018):803-817. . 2010;181(1-3):52-56. Zhang W, Li H, Kan X, Dong L, Yan H, Jiang Z, Yang H. Bioresource Technology Adsorption of anionic dyes from aqueous solutions using chemically modified straw. BIORESOURCE TECHNOLOGY. 2012;117:40-47.