Biomass-Based Adsorbents for Removal of Dyes From Wastewater: A Review

In the paper

“Coal-derived activated carbon was supposed to be the most efficient type of activated carbon in adsorption.The efficiency of treatment is 99.8%, and it can treat various types of dyes (Yeow et al., 2021).”

What the sources say

• Supported

  The Conclusions state that coal-derived activated carbon is the most efficient type for adsorption, give a treatment efficiency of 99.8%, and say it can treat various dyes. Section 4.1 also describes its capacity to remove various types of dye. (LLM, conf=0.95)

  cites Yeow et al., 2021 source

In the paper

“Excessive exposure to dye causes skin irritation, respiratory problems and some dyes even increase the risk of cancer in humans (Amirza et al., 2017).”

What the sources say

• Partly supported

  The Introduction (page not provided) says dyes can cause skin irritation and describes potential carcinogenic effects, including effects on human cells. It does not mention respiratory problems or establish an exposure threshold for these harms; it also frames carcinogenicity as potential rather than a demonstrated increase in human cancer risk. (LLM, conf=0.88)

  cites Amirza et al., 2017 sourceExperimental — accuracy not yet measured

In the paper

“To satisfy the modern need, it is assessed that 0.7-1.6 million tons of dyes are delivered yearly and 10-15% of this volume is disposed of as wastewater, making it major water pollutants (Bhatia et al., 2017;Varghese et al., 2019;Syafiuddin and Fulazzaky, 2020).”

What the sources say

• ?Not checked — no full text of the sourcecites Bhatia et al., 2017 source
• ?Not checked — no full text of the sourcecites Varghese et al., 2019 source
• Partly supported

  The Introduction (page not supplied) reports approximately 700,000 metric tons of annual dye production and a 10–15% loss of colorants during dyeing. It also describes environmental harm from dyes released into water, but does not give the 1.6-million-ton upper estimate or state that all of the 10–15% loss is disposed of as wastewater. (LLM, conf=0.87)

  cites Syafiuddin and Fulazzaky, 2020 sourceExperimental — accuracy not yet measured

In the paper

“Dyes are usually classified based on their chemical structure, such as anionic, cationic, and nonionic; reactive dyes are stable and anionic, and display resistance toward light (Heidari et al., 2019;Dai et al., 2018).”

What the sources say

• Supported

  The Introduction explicitly describes reactive dyes as stable, anionic, and resistant to light. This directly supports the attributed claim. (LLM, conf=0.95)

  cites Heidari et al., 2019 source
• ?Not checked — no full text of the sourcecites Dai et al., 2018 source

In the paper

“Biotreatment of dyecontaining wastewater effluent by fungal cell was provided a cost-effective, easily applicable, eco-friendly (Salem et al., 2019;(Argumedo-Delira et al., 2021), and absence of nutrient needs (Ghany et al., 2019).”

What the sources say

• Supported

  The Introduction describes biological treatment as low-cost and eco-friendly and says fungi are easy to manipulate, supporting the qualities attributed to Salem et al. The separate claim about having no nutrient needs is cited to Ghany et al., not Salem et al., so it is not part of this verdict. (LLM, conf=0.88)

  cites Salem et al., 2019 source
• Partly supported

  The Introduction says biological dye-removal methods, including fungal treatments, are less costly than chemical methods and are eco-friendly. It does not establish that fungal-cell treatment is easily applicable. The separate claim about having no nutrient needs is attributed to Ghany et al., not to this source. (LLM, conf=0.84)

  cites Argumedo-Delira et al., 2021 sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites Ghany et al., 2019 source

In the paper

“Also worthy of note are disadvantages, among which the one linked to the high cost of disposal of the remaining concentrated residue following the separation, the high management costs and the inability to deal with high flow rates, and frequent clogging of membrane pores by the dye molecules (Collivignarelli et al., 2019).”

What the sources say

• ?Could not verify

  The available copy contains a repository listing and PDF link, but no article passage discussing membrane technologies. Searches for concentrated-residue disposal, management costs, high flow rates, and dye-related pore clogging returned no relevant text, so the attributed disadvantages cannot be verified from this copy. (LLM, conf=0.77)

  cites Collivignarelli et al., 2019 sourceExperimental — accuracy not yet measured

In the paper

“Algae are considered one of the sources of the most favorable types of bio-sorbents because they have high biosorption capacity and are easily available in large amounts (Singh and Singh, 2017;Azam et al., 2020).”

What the sources say

• Partly supported

  The Biosorption section describes algae as potent biosorbents, citing their availability in fresh and salt water, relatively high surface area, and high binding affinity. It does not establish that algae are easily available in large amounts; availability across habitats is not evidence of quantity. (LLM, conf=0.83)

  cites Singh and Singh, 2017 sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites Azam et al., 2020 source

In the paper

“Adsorption is found to be a very effective, cheap, and commonly used method among all available dye removal techniques (Kandisa and Saibaba KV, 2016).”

What the sources say

• Supported

  The Abstract calls adsorption a very effective and cheap dye-removal method. The Conclusion says it has low capital and operating costs and is commonly used to remove pollutants from industrial wastewater. (LLM, conf=0.94)

  cites Kandisa and Saibaba KV, 2016 source

In the paper

“Sludge production in the case of Fenton reagent, formation of toxic byproduct in the case of photocatalyst, and high cost due to the use of expensive reagents (for example, H 2 O 2 ) and energy consumption (generation of O 3 or UV radiation) are the major drawback of AOPs for dye removal (Cuerda-Correa et al., 2020;Moosavi et al., 2020).”

What the sources say

• Partly supported

  The paper identifies Fenton sludge in its Conclusions and states that expensive reagents such as H₂O₂ and energy for ozone or UV make AOPs costly. It also warns that AOPs can produce toxic byproducts, but does not establish this specifically as a drawback of photocatalysis for dye removal; the review focuses on antibiotics in water. The cited passages have no page numbers in our copy. (LLM, conf=0.88)

  cites Cuerda-Correa et al., 2020 sourceExperimental — accuracy not yet measured
• Partly supported

  Table 1 in the Introduction identifies sludge production as a disadvantage of Fenton reagents, toxic byproduct formation for photocatalysts, and high operational cost for ozonation. It does not attribute AOP costs to H₂O₂, ozone generation, or UV radiation; it instead lists low-cost reagents for Fenton treatment and low operational cost for photocatalysis. (LLM, conf=0.89)

  cites Moosavi et al., 2020 sourceExperimental — accuracy not yet measured

In the paper

“Potato peel biochar was considered a promising adsorbent for removing Cibacron Blue dye.The sorption ability of this waste follows the order: calcined > activated > native materials (Bouhadjra et al., 2021).”

What the sources say

• Supported

  The Abstract directly identifies potato peel biochar (PPc) as a promising adsorbent and states that Cibacron Blue sorption follows the order calcined > activated > native materials. The Conclusion also reports higher adsorption capacity for PPc than for activated or native potato peels. (LLM, conf=0.95)

  cites Bouhadjra et al., 2021 source

In the paper

“For example, phosphoric acid stimulates bond cleavage in agricultural waste biomass to increase the carbon yield (Bello et al., 2019).Phosphoric acid promoted dye biosorption by grafting phosphate functions onto the biomass and enhancing the acid functions involved in dye fixation (Benabbas et al., 2021).”

What the sources say

• Supported

  The Preparation of functionalized activated carbon section states that orthophosphoric acid promotes bond cleavage in agricultural waste biomass and increases carbon yield. The separate statement about phosphate functions and dye fixation is attributed to Benabbas et al. (2021), not to Bello et al. (2019). (LLM, conf=0.95)

  cites Bello et al., 2019 source
• ?Not checked — no full text of the sourcecites Benabbas et al., 2021 source

In the paper

“Some authors stated that the recovery step of powder-activated carbons is very costly, time-consuming, and not very efficient so that they are not suitable for industrial applications (Moosavi et al., 2020), and more particularly reusability is almost impossible for low-cost products (Saha et al., 2020).”

What the sources say

• Supported

  The Regeneration Technology section states that separating and recovering powdered activated carbon is costly, time-consuming, and inefficient, making it unsuitable for industrial applications. The separate claim about low-cost products is attributed to Saha et al., not Moosavi et al., and is outside this verdict. (LLM, conf=0.95)

  cites Moosavi et al., 2020 source
• ?Not checked — no full text of the sourcecites Saha et al., 2020 source

In the paper

“The pH of the solution affects both the chemistry of the aqueous solution and the binding sites present on the surface of adsorbents (Kumar et al., 2021).”

What the sources say

• Supported

  The section “Effect of initial pH concentration” (page not provided) states the claim verbatim and explains how pH affects ionization in solution and active sites on the adsorbent. (LLM, conf=0.95)

  cites Kumar et al., 2021 source

In the paper

“Most species of fungi potentially achieved more than 90% of a specific type of dye except Pleurotus ostreatus, Aspergillus flavus, and Diaporthe schini which had a removal efficiency of 53%, 53.62, and 87%, respectively.”

In the paper

“Table 4 revealed that Langmuir isotherm was fitted by most biosorption studies, indicating that the monolayer coverage adsorption was the dominant process.”

In the paper

“Table 4 revealed that Spirulina and Chlorella species are common types of microalgae studied and achieved up to 99% removal efficiency.”

In the paper

“Similarly, the pseudo-2 nd -order kinetic model showed the best model fit.”

In the paper

“Similarly, Sargassum species of macro algae are commonly studied and can remove more than 90% of dyes.”

In the paper

“The retrieved publications were found as adsorbents prepared from different biomasses activated and/or modified with various chemicals or techniques.”

In the paper

“Table 6 revealed that most studies showed the best fit for Langmuir isotherm and pseudo-second-order kinetic models, suggesting the dominance of monolayer chemoadsorption except some yeast species in which the Freundlich and Temkin isotherm models showed the best fit model.”

In the paper

“Although most biomasses achieved a good removal efficiency, each study reviewed has considered different parameters for efficiency determination.”

In the paper

“Among different available adsorbents, biomass-based treatments are found to be the recent materials employed at various sectors to remove dyes and other pollutants.”

In the paper

“The review reveals that the conventional dye treatment methods have some particular limitations related to operation efficiency, total cost, energy, and generation of toxic by-products, although they have good performances to a particular pollutant.”

In the paper

“Unfortunately, most studies on biomassbased adsorption have been conducted on the laboratory scale using simulated wastewater, so that the cost analysis of the biomass-based adsorbents is limited, particularly for microbial biomass.”

In the paper

“The bio-sorption process is affected by various environmental parameters such as pH, initial dye concentration, temperature, contact time, and adsorbent dose as well as the ways of the preparations of materials.”

In the paper

“Most of the studies on biomass-based adsorption concentrated on the removal of a single pollutant”

In the paper

“As it can be observed, publication counts from 2017 to 2020 are highly consistently increased suggested that the nonconventional adsorbents from biomass are recently attracting attention for dye removal.”

In the paper

“It has been observed that (Table 3) in low pH solutions, the removal rate of anionic dyes is increased while the removal rate of cationic dyes is lower.Conversely, a high pH solution increases the removal of the cationic dyes and causes a low removal percentage for anionic dyes (Ahmed and Ebrahim, 2020).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Ahmed and Ebrahim, 2020

In the paper

“Dyes from the industrial wastewater effluents are effectively removed by using activated carbon; however, it has some constraints such as capital cost, energy consumption, and loss of its ability after sorption-desorption cycles.”

In the paper

“Yeast is a single-celled organism, a member of the kingdom of fungi that have many favorable applications in the treatment of dye-containing solutions due to their high capacity to adsorb and accumulate pollutants, fast growth, faster decolorization than filamentous fungi, and the ability to survive unfavorable environments (Sen et al., 2016).”

What the sources say

• ?Not checked — no full text of the sourcecites Sen et al., 2016 source

In the paper

“For example, the bioadsorbents may be activated with acid/base (such as HCl, NaOH) and thermal activation, and also some are composited with inorganic and/or organic nanomaterials.”

In the paper

“It also blocks sunlight penetration thereby inhibiting photosynthesis (Bello et al., 2015;Dey et al., 2017).”

What the sources say

• ?Not checked — no full text of the sourcecites Bello et al., 2015 source
• ?Not checked — no full text of the sourcecites Dey et al., 2017 source

In the paper

“Surface chemistry, pH, initial dye concentration, temperature, contact time, and adsorbent dose as well as the ways of the preparations of materials affect the biosorption process.”

In the paper

“The sorbent had maximum sorption capacity for acridine orange (193.8 mg/g) but lower for malachite green (110.4 mg/ g) at 2 h contact time.”

What the sources say

• ?Not checked — no full text of the sourcecites Angelova et al., 2016 source

In the paper

“Dye removal from wastewater using bio-based adsorbents is a promising alternative.”

In the paper

“The removal of color by coagulation is strongly dependent on the structure of dye molecules (chromophores and auxochromes), so structural considerations of dyes are very important when choosing the most appropriate coagulant for dye removal (Mcyotto et al., 2021).”

What the sources say

• ?Not checked — no full text of the sourcecites Mcyotto et al., 2021 source

In the paper

“Advanced oxidation processes (AOPs) involve the generation of oxidizing species such as hydroxyl radicals and sulfate radicals in sufficient quantity to interact with the organic compounds of the medium (Wang and Wang, 2020;Duan et al., 2020).”

What the sources say

• ?Not checked — no full text of the sourcecites Wang and Wang, 2020 source
• ?Not checked — no full text of the sourcecites Duan et al., 2020 source

In the paper

“It has some advantages such as appreciable resistance to temperature, good resistance to adverse chemical environment, and excellent performance of color removal (Roy et al., 2018).”

What the sources say

• ?Not checked — no full text of the sourcecites Roy et al., 2018 source

In the paper

“Fungal biomasses are composed of sugars, proteins, and lipids, and different functional groups (alcohols, carboxyl, and alkanes) which provide it certain properties and applications as a biosorption in treatments of wastewater (Isaza-Pérez et al., 2020;Ahmed and Ebrahim, 2020).”

What the sources say

• ?Not checked — no full text of the sourcecites Isaza-Pérez et al., 2020 source
• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Ahmed and Ebrahim, 2020

In the paper

“Sludge generation, the extra operational cost for sludge disposal, and high maintenance costs are major challenges in applying this process.”

In the paper

“Coagulation-flocculation is among the most widespread physiochemical processes for the removal and distraction of coloring substances in wastewater.”

In the paper

“An optimum monolayer uptake capacity of 279.14 mg/g was reported for the modified algal adsorbent (Essekri et al., 2021).”

What the sources say

• ?Not checked — no full text of the sourcecites Essekri et al., 2021 source

In the paper

“Their small size, ubiquity, and capability to grow under varying environmental conditions make them good adsorbents (Singh et al., 2018).”

What the sources say

• ?Not checked — no full text of the sourcecites Singh et al., 2018 source

In the paper

“Anionic dyes are removed in acidic conditions and cationic dyes (e.g.MB) in alkaline conditions.”

In the paper

“The maximum sorption capacity for basic blue dye was found to be 139.74mg/g from the Langmuir adsorption isotherm.”

What the sources say

• ?Not checked — no full text of the sourcecites Kim et al., 2015 source

In the paper

“Various types of dyes and metal ions are the major pollutants encountered in wastewater effluent, which disturb the aquatic environment (Varghese et al., 2019;Saravanan et al., 2021).Dyes are organic compounds that are released from several industrial sources including textile, paper, leather, rubber, cosmetic, and printing industries (Piaskowski et al., 2018;Katheresan et al., 2018).”

What the sources say

• ?Not checked — no full text of the sourcecites Varghese et al., 2019 source
• ?Not checked — no full text of the sourcecites Saravanan et al., 2021 source
• ?Not checked — no full text of the sourcecites Piaskowski et al., 2018 source

In the paper

“Higher surface area, higher porosity, and low ash content lead to high adsorption capacity.”

In the paper

“Among the above three methods, steam activation is the best environmentally and economically viable option, while chemical activation results in the highest surface area and porosity (Rahimian and Zarinabadi, 2020).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Rahimian and Zarinabadi, 2020

In the paper

“The application of waste organic materials (e.g., compounds extracted from peels, leaves, barks) and microbial biomasses (fungus bio-sorbent, bacterial, and green algal biomasses) is gaining an increasing interest being effective, low-cost, and ecologically friendly sorbents.”

In the paper

“Recently, advanced oxidation processes (AOPs) have been effectively investigated in the removal of a variety of contaminants from water and wastewater.”

In the paper

“The carboxyl groups have a negative charge at a higher pH, which results in electrostatic binding of the cationic dyes.”

In the paper

“Activated carbon (AC) is a commonly used adsorbent that refers to a group of carbon materials with high oscillation and high internal surface which are unique because of their remarkable interior area, pore structure, high adsorption capacity, surface reactivity, and low cost compared to inorganic adsorbents such as zeolite (Hasanzadeh et al., 2020).”

What the sources say

• ?Not checked — no full text of the sourcecites Hasanzadeh et al., 2020 source

In the paper

“Adsorption using the nonconventional biomass-based sorbents is the greatest attractive alternatives because of their low cost, sustainability, availability, and eco-friendly.”

In the paper

“However, the limitations of most of these methods include the generation of toxic sludge, high operational and maintenance costs, and the intricate technique involved in the treatment (Yahiaoui et al., 2021).”

What the sources say

• ?Not checked — no full text of the sourcecites Yahiaoui et al., 2021 source

In the paper

“The adsorption involves valency forces through the sharing or exchange of electrons between the adsorbent and dye molecules by covalent forces and ion exchange (Mohd Nasir et al., 2021).”

What the sources say

• ?Not checked — no full text of the sourcecites Mohd Nasir et al., 2021 source

In the paper

“Activated carbon is undoubtedly considered a universal adsorbent for effluent treatment and is commonly used for the remo//val of several pollutants (Rahimian and Zarinabadi, 2020).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites Rahimian and Zarinabadi, 2020

In the paper

“The EC process is successful in the removal of organic dyes, fine suspended particles, heavy metals, and oil and grease (or other heavier hydrocarbons) from diverse industrial effluents (Mondal et al., 2018).”

What the sources say

• ?Not checked — no full text of the sourcecites Mondal et al., 2018 source

In the paper

“Algae, yeast, bacterial, fungal, agro-waste, and plant debris are potential bioadsorbent sources.”

In the paper

“When pH is greater than pH pzc , it is favorable for cationic dye adsorption due to the existence of functional groups (OH -, COO -), whereas anionic dye adsorption is favorable at pH less than pH pzc because the surfaces of adsorbents become positively charged (Zhou et al., 2019).”

What the sources say

• ?Not checked — no full text of the sourcecites Zhou et al., 2019 source

In the paper

“Owing to eco-friendly, low cost, and good surface characteristics, biomass-based adsorbents are attracting attention and are widely studied.”

In the paper

“The pore volume of the bioadsorbents and functional groups of dyes are the deciding factors in achieving high dye adsorption.”

In the paper

“They found 90.3 and 83.7% desorption for biomass and commercial AC, respectively, from dye-loaded adsorbents (Saha et al., 2020).Moreover, the adsorbents were effective up to two adsorption-desorption cycles.”

What the sources say

• ?Not checked — no full text of the sourcecites Saha et al., 2020 source

In the paper

“The common desorption methods include thermal treatment, acid (H 2 SO 4 , HNO 3 , HCl, H 3 PO 4 , NaOH) treatment, organic solvents (methanol and ethanol), biological methods, and vacuum methods (Hassan and Carr, 2021).”

What the sources say

• ?Not checked — no full text of the sourcecites Hassan and Carr, 2021 source

In the paper

“It was estimated that the cost of 1 g of adsorbent is ₹4.54, ₹0.91, and ₹0.97 for Coconut shell, Groundnut shell, and Rice husk, respectively, by considering operational costs including manufacturing costs, maintenance costs, feedstock costs, transportation costs, labor costs, and the distribution costs (Praveen et al., 2021).”

What the sources say

• ?Not checked — no full text of the sourcecites Praveen et al., 2021 source

In the paper

“They found that the two biosorbents had a dye removal capacity of 8.66 mg/g and 7.96 mg/g respectively at a pH of 2 (Semião et al., 2020).”

What the sources say

• ?Not checked — no full text of the sourcecites Semião et al., 2020 source

In the paper

“Several authors reported that the cost of bioadsorbents prepared from microbes and forest and agricultural waste is low as compared with conventional treatment technologies, although they did not incorporate cost-benefit analysis in their study.”

In the paper

“One of the important features for the use of biomass-derived adsorbent for removal of dyes is that it can be used on a large scale because of its huge availability.”

In the paper

“Sewu et al. (2017) prepared biochar from Korean cabbage (KC), rice straw, and wood chip and can be used as an alternative to activated carbon to remove congo red and CV (Sewu et al., 2017), but KC had better absorption performance than others.”

What the sources say

• ?Not checked — no full text of the sourcecites Sewu et al., 2017 source

In the paper

“The adsorption capacity of the modified biochar was significantly enhanced from 78.18 to 523.12 mg/g at equilibrium.Up to 98% of AO7 was removed by triethylenetetramine-modified biochar, while 96% removal was achieved using unmodified biochar (El-Nemr et al., 2020).”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites El-Nemr et al., 2020

In the paper

“Groundnut shellbased biochar had maximum adsorption capacity (46.3 mg/g) as well as the least cost (₹0.91)per unit gram of Basic Red 09 dye removal.”

What the sources say

• ?Not checked — no full text of the sourcecites Praveen et al., 2021 source

In the paper

“Among all the adsorbents, the biomassderived adsorbent is preferred comparatively having the highest surface area, regardless of the activation techniques, depending on source types resulted in increasing the adsorption of the contaminants.”

In the paper

“After the adsorption process is accomplished, the desorption process is of great importance to regenerate and reuse those used adsorbents and to reduce the generation of waste as well as to keep the process price down (Zhou et al., 2019).”

What the sources say

• ?Not checked — no full text of the sourcecites Zhou et al., 2019 source

In the paper

“The sorption study revealed that the capacity of prepared watermelon biochars was ranged between 76.94 and 462.18 mg/g at pH of 1.0, contact time of 3 h, and room temperature, and more than 96% removal of AY11 was achieved.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites El Nemr et al., 2020

In the paper

“The potential solutions for safely disposing of the final effluent include stabilization and immobilization, for example, using a cement-based system as a binding agent (Dey et al., 2017).”

What the sources say

• ?Not checked — no full text of the sourcecites Dey et al., 2017 source

In the paper

“Consequently, difficulties are faced in the comparison among them.”

In the paper

“Agricultural and forestry wastes are generally rich in cellulose, hemicellulose, and lignin.Its surface comprises several active groups including hydroxyl, carboxyl, amino, carboxyl, methyl, and so on (Zhou et al., 2019).”

What the sources say

• ?Not checked — no full text of the sourcecites Zhou et al., 2019 source

In the paper

“Distinctive surface chemistry with the incorporation of several functional groups (alcohol, ketones, aldehydes, carboxylic, ether, phenol) makes those bio-sorbents with a high attraction toward dye and makes the biomass-based adsorbents effective material for dye removal.”

In the paper

“The maximum monolayer adsorption capacities of BYB for MB, MG, and SO were 212.05, 212.05, and 76.77 mg/g, respectively.”

What the sources say

• ?Not checked — no full text of the sourcecites Lin et al., 2019 source

In the paper

“Moreover, the biomass-derived adsorbents are commonly cellulose-based structures and can produce a good porous carbon that can adsorb various types of contaminants in the natural environment.”

What the sources say

• ?Not checked — no full text of the sourcecites Sherugar et al., 2022 source

In the paper

“Activated carbon provided from Persea Americana was suggested for basic yellow dye removal from wastewater with 98% removal.This activated carbon can substitute the commercially available adsorbents (Regti et al., 2017).”

What the sources say

• ?Not checked — no full text of the sourcecites Regti et al., 2017 source