Removal Of Dyestuffs Research Articles

Investigation of the Usability of Perlite Waste for Dyestuff Removal from Aqueous Solution

In this study, unexpended perlite waste obtained from a factory producing expanded perlite was used as adsorbent. Malachite green (MY), which is a cationic dyestuff, was used as adsorbed material. The pore properties including the BET surface area, pore volume and average pore diameter were characterized. The chemical composition of the perlite was analysed by XRF. The effects of initial pH, the amount of adsorbent, contact time and initial dyestuff concentration were examined. The adsorption kinetics of dyestuff obeys the pseudo second-order kinetic model. The experimental data indicated that the adsorption isotherms are well described by the Langmuir isotherm equation. 99% dyestuff removal was obtained under optimum conditions. As a result, it was found that perlite waste was a suitable adsorbent for malachite green dyestuff.

One-step synthesis of an environment-friendly cyclodextrin-based nanosponge and its applications for the removal of dyestuff from aqueous solutions

Cyclodextrin-based nanosponges (CDNS) are a novel kind of polymers belonged to cross-linked derivatives of cyclodextrins, and they are safe, biodegradable materials with appreciable toxicity to the environment. In this work, CDNS were fabricated in one-step solvothermal method by β-cyclodextrin (β-CD) and diphenyl carbonate (DPC), for the removal of dyestuffs from wastewater using two of the familiar dyes as the model contaminant. It was systematically investigated by the influence of the amount of adsorbent, the molar ratio of β-CD and DPC, pH, time, and initial concentration. Experimental results showed the maximum adsorption capacities of Basic red 46 and Rhodamine B were 101.43 mg/g and 52.33 mg/g, the adsorption behavior of two contaminants followed pseudo-second-order model and the Langmuir monolayer adsorption models. The differences in adsorption capacities on two model contaminants might due to the influence of dye structure. In conclusion, cyclodextrin-based nanosponges are a promising kind of environment-friendly materials in water treatment.

Ion-exchange mediated removal of cationic dye-stuffs from water using ammonium phosphomolybdate

Composition and morphology of micro-sized ammonium phosphomolybdate (APM) particles synthesized under ambient conditions was established using powder X-ray diffraction, fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. Further, the ability of APM particles to remove dye from dye-contaminated water was monitored with respect to nature of incident radiation, concentration, pH and nature of dye. APM could effectively remove cationic dyes from water as long as the pH range permitted the dye to retain its cationic behaviour. This specificity suggested that the removal of dye-stuffs could be attributed to ion-exchange between ammonium ions in APM with cationic dye moieties. APM could be reused several times without affecting its efficiency. Removal efficiency of 94.6% could be retained upto 16th cycle and sensitivity to pH enabled APM to reverse the cation exchange process. The ion-exchange process was not dependent on exposure of APM particles to irradiation which confirmed that the mode of action of APM was not photocatalytic in nature.

Cinnamon bark as low-cost and eco-friendly adsorbent for the removal of indigo carmine and malachite green dyestuffs

ABSTRACT This study aims to determine the adsorption potential of the cinnamon bark (CB), which is an agricultural waste, as an adsorbent for the removal of dyestuffs such as indigo carmine (IC) and malachite green (MG) from aqueous solution. Additionally, it includes the application of ‘univariate and multivariate techniques’ for determining the effects of key factors on adsorption process. The results obtained from experiments performed according to Central Composite Design (CCD) were evaluated with the Response Surface Methodology (RSM) approach. In optimum conditions (pH = 2, m = 1.80 g, t = 90 min, Co = 85 mg/L for IC and pH = 7, m = 0.45 g, Co = 30 mg/L for MG), the removal efficiencies of IC and MG adsorption onto CB were found as 84% ± 2 and 98.2% ± 0.2, with standard deviations (N = 3), respectively. The concordance of experimental data with pseudo-second-order kinetic model demonstrated that the adsorption was chemically controlled and an endothermic process that ongoing with increasing randomness on the adsorbent/adsorbate interface for both dyestuff removal. However, IC adsorption was non-spontaneous; MG adsorption was spontaneous. Because the equilibrium data were well explained to by Temkin isotherm model, the nature of adsorption was defined by the assumption that the binding energies of adsorption had a uniform distribution.

Ultrasonic fabrication of SO42− doped g-C3N4/Ag3PO4 composite applied for effective removal of dyestuffs and antibiotics

SO42− doped g-C3N4/Ag3PO4 composite photocatalyst was synthesized by ultrasonic irradiation. Some characterization techniques, e.g. X-ray powder diffraction, N2 physical adsorption, Scanning electron microscopy, Transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, UV–vis diffuse reflectance spectroscopy, transient photocurrent response and electrochemical impedance spectra were applied to investigate the physicochemical property of the as-prepared samples. Coupling of 7 wt% g-C3N4 can effectively enhance the separation of electrons/holes and elevate the specific surface area. Subsequently, doping SO42− leads to the shortening of the bond length of P–O bond, and further augments the carrier concentration. The produced SO42–C3N4/Ag3PO4 shows an excellent photocatalytic performance for RhB and ciprofloxacin degradation. The degradation rates of dye and ciprofloxacin over U–SO42–C3N4/Ag3PO4 were 3.9 and 2.0 times higher than those of bare Ag3PO4.

Z-scheme CdIn2S4/BiOCl nanosheet face-to-face heterostructure: in-situ synthesis and enhanced interfacial charge transfer for high-efficient photocatalytic performance

In this work, a novel Z-scheme CdIn2S4 nano-octahedron/BiOCl nanosheet (CIS/BOC) heterostructure was successfully designed and synthesized via a facile in-situ hydrothermal process, where the CdIn2S4 nano-octahedra grew on the surfaces of tiny BiOCl nanosheets in a face-to-face way. The structure, morphology and optical properties of as-prepared samples were characterized through various technologies. The photocatalytic activities were systematically evaluated by the degradation of methyl orange (MO), tetracycline hydrochloride (TCH) and rhodamine B (RhB) under simulated solar light irradiation. The degradation results displayed that all CIS/BOC composites exhibited significantly enhanced photocatalytic activities toward MO degradation in comparison with the bare CdIn2S4 and BiOCl. Simultaneously, the obtained CIS/BOC-2 with 6 wt.% BiOCl nanosheets loaded possessed the optimal photocatalytic performance, and its rate constant was about 3.6 and 2.59 times as high as those of bare CdIn2S4 and BiOCl. Furthermore, the CIS/BOC-2 nanocomposite with superior photostability and repeatability also presented high photocatalytic activities for the removal of both antibiotics (TCH) and dyestuff (RhB). The unique Z-scheme face-to-face heterostructure with intimate contacted interface in CIS/BOC-x nanocomposites provided more charge transfer nanochannels, shortened the migration distance and boosted the separation of photoinduced charge carriers, resulting in the excellent photocatalytic activities. Our study may provide a promising strategy to develop and synthesize other Z-scheme face-to-face composite photocatalysts with good photocatalytic performance.

A new alternative to use soybean hulls on the adsorptive removal of aqueous dyestuff

This work aimed to use raw soybean hulls (RSH) as an adsorbent on the removal of BF-4B reactive red dye. Kinetic and equilibrium experiments were performed using the best conditions obtained from preliminary tests. Kinetic data were better represented by the pseudo-second order model, evidencing three well-differentiated mass transfer regions. By a statistical analysis of the fit of 7 equilibrium models and 2 model combinations to experimental data, it was observed that the adsorption occurred in a single molecule monolayer for final dye concentrations lower than ~63 mg L−1. After this concentration, a possible multimolecular monolayer was verified, evidencing the formation of aggregates or micelles, since the Langmuir-BET model was the best fit. The maximum adsorption capacity estimated was about 19 mg g−1. The results have proved that the soybean hulls could be used as an alternative adsorbent in the treatment of textile effluents, without the need for a pretreatment.

Synthesis of β-Cyclodextrin Immobilized Starch and Its Application for the Removal of Dyestuff from Waste-Water

A natural polymeric adsorbent, β-cyclodextrin immobilized starch (CS-βCD) was prepared by introducing host functional molecule β-cyclodextrin (β-CD) onto starch in presence of citric acid. The immobilization conditions were optimized to: m CA:m CS = 1:2, reaction time of 2 h and reaction temperature at 120 °C, by varying the input levels of the reactant, CS-βCD with a series of immobilization ratio (IR) and carboxyl content (CC) could be obtained. The FT-IR and 13C-NMR analysis indicated the β-CD molecules have been immobilized onto starch via the formation of ester linkages. The XRD and SEM analysis showed CS-βCD had more looser structure and more irregular surface compared with native starch. The GPC analysis showed CS-βCD had a reduced molecular weight but a more complicated molecular configuration. The adsorbing capacities of CS-βCD to three cationic dyes (methylene blue, methyl purple and basic fuchsin) were significantly improved compared with native starch, diatomite and zeolite. The adsorption behaviors of CS-βCD to the three dyes had high fitting degrees to both Langmuir and Freundlich models (R2 > 0.98). The decolourization ratio of CS-βCD to the mixed dyestuff waste-water had reached 88.75%, which was much higher than other absorbents. The results indicated the CS-βCD would become a high-efficiency dyestuff adsorbent, and would have a promising application in the industrial dyestuff waste-water treatment.

Utilization of Activated Carbon Prepared from Pumpkin Seed Shell for the Removal of Dyestuff from Aqueous Solutions and Wastewater by Microwave Radiation

In this study, the aim was to investigate the removal of the cationic (Methylene Blue, MB) and anionic (Acid Blue 193, AB) dyestuff from aqueous solutions and wastewater (synthetic) using activated carbon prepared from pumpkin seed shell as adsorbent (as catalyst) by the microwave-assisted (MW) method. This process is the combination of MW irradiation, MW adsorbent (as catalyst) and oxidant. The effects of radiation time, dosages of adsorbent and oxidant and initial dyestuff concentration on the removal efficiency were investigated. With the initial dyestuff concentration of 100 mg/L, a 99 % dyestuff removal percentage was obtained applying low power in 3 min using 0.2 g activated carbon and 0.5 mL hydrogen peroxide for MB and a 90% removal percentage was obtained applying low power in 3 min using 0.6 g activated carbon and 0.5 mL hydrogen peroxide for AB. Results suggest that the prepared activated carbon from pumpkin seed shell has potential in remediation of dyestuff contaminated waters. Keywords : Activated carbon, Dyestuff, Aqueous solution, Wastewater, Microwave radiation DOI : 10.7176/JSTR/5-2-08

Design of a Zwitter-Ionic Nanocomposite for Dyestuff Removal

Today, with the increasing awareness of environmental conservation, many scientists are directing their work on environmental improvements. In the textile industry, dyestuff load of wastewater increases, and improvements are made to reduce this load. As a contribution to these improvements, a nanocomposite is designed with clay, chitosan and its modifications, which are totally natural. As a preliminary study, the clay was modified and treated with dyestuff solutions to investigate the absorption properties of Methylene Blue with various clay types. According to the results obtained by UV visible spectrophotometer, Cloisite 30B, which is the clay with the best absorption property, has been determined as the reference material. With the lights of preliminary study, a nanocomposite was designed to adsorb dyestuffs from textile waste waters using modified clay and modified chitosan. With the anionic modification of chitosan, it can be converted into carboxymethylchitosan (CMCTS) and it can also have affinity to cationic structures. With this structure, colored composites are obtained while contributing to recycling and environment by providing adsorption of dyestuff. According to UV-vis and FT-IR results, CMCTS that is modified with Butanetetracarboxylic acid (BTCA) has better adsorption from textile wastewaters.

Catalytic Degradation of Orange II by MnIII(TPPS) in Basic Hydrogen Peroxide Medium: A Detailed Kinetic Analysis

The presence of dyes from inter alia textile industry in wastewater, poses a serious threat for the environment. New methods for the removal of persistent dyestuffs from effluent streams still attract much attention. In this report the application of MnIII(TPPS) [where TPPS = 5,10,15,20‐tetrakis(4‐sulfonatophenyl) –21 H,23H‐porphyrin] as suitable catalyst for the oxidative degradation of a model substrate, Orange II (ORII), was studied. The MnIII(TPPS)/H2O2 system was found to degrade ORII with high efficiency under ambient conditions in carbonate buffer solutions. In order to gain further insight into the degradation mechanism, detailed kinetic studies using rapid‐scan spectrophotometry as a function of [H2O2], [MnIII(TPPS)] and pH, were performed. Evidence for the participation of peroxocarbonate ions (HCO4– and CO42–) as efficient oxidants in carbonate buffer was found. The experimental results suggest rapid formation of an intermediate (TPPS)MnV=O complex, followed by the subsequent degradation of ORII. The reaction showed maximum reactivity at pH ≈ 11. Spectroscopic data demonstrated that the catalytic cycle could be repeated several times without any significant loss in catalytic activity.

Mesoporous Multi-Metal Citrates as Scavengers for Organic Dyes

In this work we have established excellent adsorption properties of Multi-metal citrate complexes for the capture of Organic dyes. These complexes exhibit mesoporous character with pore diameter ≈ 40A and narrow pore size distribution in their structure as demonstrated by fitting experimental adsorption data into Barrett, Joyner and Halenda (BJH) and Density Functional Theory (DFT) models. Thus these materials have the potential of being used as scavengers for dye stuff removal from industrial waste discharge in the water stream and may replace the high cost carbon adsorbents to capture dye molecules and curb water pollution with resultant toxic, carcinogenic and mutagenic effects of dye stuff on living beings. The mesoporous Zinc, Nickel, Iron, Copper multi-metal citrate complexes with different combinations of these metal ions and citric acid linker have been synthesized under mild hydrothermal conditions through green synthetic pathways. Because of their biocompatibility and non toxicity, these low cost mesoporous materials may prove boon for transport of dyes used as contrast agents during diagnostics applications due to their increased image contrast and chemical stability.

Electrochemical degradation of textile dyes in a flow reactor: effect of operating conditions and dyes chemical structure

In this study, electrochemical oxidation of five azo dyestuffs (Yellow D-5GN, Red D-B8, Ruby F-2B, Blue D-5RN, Black DN), that are widely used in the textile industry, was investigated in a flow reactor. BDD electrode with a high boron doping level (C/B = 10 000) was prepared and used. Two configurations of reactor were considered, i.e., one with the undivided cell, and the other with the cell divided by anodic and cathodic compartments. The effect of current density and the initial pH of the solution on the dyestuff degradation process was investigated. As expected, higher degradation rate was found for higher current density, while the effect of pH was marginal. Next, electrochemical oxidation of azo dyestuffs with different chemical structures was investigated. Based on the cyclic voltammetry measurements, the correlation between the dyestuff removal rate and the oxidation potential value of dyestuff was found. These results suggest that the direct oxidation of dyestuffs at the highly doped BDD anode plays a significant role in the electrochemical oxidation. Finally, the electrochemical removal of dyestuffs was carried out in two types of dyeing baths. The dyeing bath composition has a significant effect on the degradation efficiency. Chlorides in F-type dyeing bath accelerated electrochemical removal due to effective generation of Cl2/HOCl at the highly B-doped BDD anode. In contrast, OH− inhibited the D-type dyestuff removal from dyeing bath, because they acted as scavengers of ·OH radicals. Highly B-doped BDD anode is promising material to F-type dyestuff treatment in industrial wastewater.

Effect of thermal regeneration of diatomite adsorbent on its efficacy for removal of dye from water

Reduction in adsorption capacities of adsorbents is limiting of its wider application for water treatment. In this study, we developed a new approach for recycling diatomite to be used adsorbent. The laser scattering particle size analyzer, X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray and Brunauer–Emmett–Teller analysis were used to evaluate the structural characteristics of treated samples. The adsorption efficacy of raw and heated diatomite at 300, 600 and 900 °C for textile dyestuff removal from wastewater was investigated. The characterization results show insignificant changes except some deconstructions were occurred after treatment at 900 °C. The maximum adsorption capacities were obtained at pH 2 and adsorbent dosage of 4 g L−1. The required time to reach the equilibrium was 30 min, and diatomite treated at 600 °C is acted as an excellent adsorbent. The kinetic studies were better described by the pseudo-second-order kinetic model. The isotherms experimental data showed that the adsorption of dye onto raw diatomite, DH300 and DH600 follows the Brunauer–Emmett–Teller isotherm model, but its adsorption onto DH900 conforms well to Freundlich isotherm model. Recycling of diatomite using thermal treatment was useful. At 600 °C which is considered the best regeneration temperature, the adsorbed dye was completely despaired, and around 73% was restored after three regeneration cycles.

Utilization of modified Dioscorea opposita Thunb. as a novel biosorbent for the adsorption of indigo carmine in aqueous solutions.

It is important to identify efficient adsorbents for the removal of dyestuffs from aqueous solutions as this kind of pollution becomes more extensive. In this study, Dioscorea opposita Thunb. (DOT) was modified with polyethylene imine (DOT@PEI) as a novel biosorbent to remove the typical anionic dye indigo carmine (IC) from wastewater. The modified DOT@PEI biosorbent was characterized using BET (Brunauer–Emmett–Teller), SEM (scanning electron microscopy), EDS (energy dispersive spectroscopy), and FTIR (Fourier transform infrared spectroscopy) methods, and the results demonstrated that DOT@PEI is an excellent biosorbent. Batch adsorption studies showed that optimum adsorption parameters were pH 2.0, 1.0 g L−1 dosage, and temperature of 20 °C. The isothermal adsorption data showed good fitting to the Langmuir model, with a maximum adsorption capability of 344.83 mg g−1 for IC. Kinetic experiments showed that the experimental data fitted well to a pseudo-second-order kinetic model and the thermodynamic parameters indicated that adsorption is a spontaneous exothermic process. Adsorption–desorption experiments illustrated the good regeneration capability of DOT@PEI. These results demonstrate that DOT@PEI can be used as an effective biosorbent in water for the removal of anionic dyes such as required for environmental applications.

Core@double-shell structured magnetic halloysite nanotube nano-hybrid as efficient recyclable adsorbent for methylene blue removal

Design and fabrication of structurally optimized absorbents are important for wastewater treatment such as dyes and heavy metals removal. Herein, we reported the core@double-shell structured magnetic halloysite nanotube nano-hybrid absorbent with target micro-structure and high efficiency removal capacity of dyestuffs. Our core@double-shell structured absorbent consisted of a halloysite nanotube as skeleton, an intermediate magnetic nanoparticles coating with more specific surface area and magnetic separation property, and poly(DA+KH550) derivate layer outside provided active adsorption sites. This well-defined core@double-shell configuration was quite distinct from conventional core-shell or hybrid structures. The integrated advantages of HNTs skeleton, Fe3O4 nanoparticles inner shell and poly(DA+KH550) outside shell contributed to the high adsorption capacity of methylene blue (up to 714.29mgg−1) and excellent cycling stability. Furthermore, the novel core@double-shell structured absorbent exhibited better removal efficiency for methylene blue in solution with high pH, and the adsorption process can be described by using the pseudo-second-order model. More importantly, the recycling process of adsorbents was more energetically and economically sustainable by using a permanent magnet. The characteristic high removal capacity, cycling stability and easy separation made core@double-shell structured absorbent promising for the efficient removal of dyestuffs from the wastewater.

Adsorption of Basic and Acidic Dyes onto Agricultural Wastes

The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red (CR) dyes from aqueous solution was investigated. The adsorbent (ALP) was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of CV and CR dyes onto the adsorbent (ALP) was found to be: contact time (100mins), pH (10.0), temperature (343K) for an initial CV dye concentration of 50mg/L using adsorbent dose of 1.0g and contact time (100mins), pH (2.0), temperature (333K) for an initial CR dye concentration of 50mg/L using adsorbent dose 1.0g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for both CV and CR dyes adsorption. The maximum adsorption capacity of ALP was found to be 22.96mg/g and 7.77mg/g for the adsorption of CV and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0obtained for both dyes indicate the spontaneous nature of the adsorption process while the positive values of ΔH0and ΔS0obtained indicated the endothermic nature and increased randomness during the adsorption process respectively for the adsorption of CV and CR onto ALP. Based on the results obtained such as good adsorption capacity, rapid kinetics, and its low cost, ALP appears to be a promising adsorbent material for the removal of CV and CR dye stuff from aqueous media.

Adsorption of Basic and Acidic Dyes onto Agricultural Wastes

The potential of almond leaves powder, (ALP) for the removal of Crystal violet (CV) and Congo red (CR) dyes from aqueous solution was investigated. The adsorbent (ALP) was characterized by FTIR and SEM analysis. Batch adsorption studies were conducted and various parameters such as contact time, adsorbent dosage, initial dye concentration, pH and temperature were studied to observe their effects in the dyes adsorption process. The optimum conditions for the adsorption of CV and CR dyes onto the adsorbent (ALP) was found to be: contact time (100mins), pH (10.0), temperature (343K) for an initial CV dye concentration of 50mg/L using adsorbent dose of 1.0g and contact time (100mins), pH (2.0), temperature (333K) for an initial CR dye concentration of 50mg/L using adsorbent dose 1.0g respectively. The experimental equilibrium adsorption data fitted best and well to the Freundlich isotherm model for both CV and CR dyes adsorption. The maximum adsorption capacity of ALP was found to be 22.96mg/g and 7.77mg/g for the adsorption of CV and CR dyes respectively. The kinetic data conformed to the pseudo-second-order kinetic model. Thermodynamic quantities such as Gibbs free energy (ΔG0), enthalpy (ΔH0) and entropy (ΔS0) were evaluated and the negative values of ΔG0obtained for both dyes indicate the spontaneous nature of the adsorption process while the positive values of ΔH0and ΔS0obtained indicated the endothermic nature and increased randomness during the adsorption process respectively for the adsorption of CV and CR onto ALP. Based on the results obtained such as good adsorption capacity, rapid kinetics, and its low cost, ALP appears to be a promising adsorbent material for the removal of CV and CR dye stuff from aqueous media.

Magnetically recoverable cross-linked polyethylenimine as a novel adsorbent for removal of anionic dyes with different structures from aqueous solution

Herein, magnetically recoverable cross-linkedpolyethylenimine (MPEI) composites with porous structures, in which the magnetic carriers were embedded, were successfully synthesized via a simple chemical route. It was found that the obtained magnetic polymer exhibited significantly enhanced adsorption capability towards six anionic dyes with different structures and they could be magnetically separated from aqueous solution after adsorption. The batch experiments indicated that the sorption of anionic dyes by MPEI was selective, forceful, fast and pH-sensitive, better fitted to pseudo-second-order kinetics model, and was Langmuir monolayer adsorption. Meanwhile, the adsorption thermodynamics suggested an endothermic and spontaneous process for all the dyes. Considering the properties of both adsorbents and dyes, the sorption conditions, as well as the kinetics process, it was declared that the anionic dyes with −SO3− group were mainly adsorbed by the positively charged MPEI adsorbents via electrostatic interaction in a wide pH range and the number of negative charge and the size of organic dyes could significantly influence the adsorption behavior of model dyes. Also, the FT-IR and EDX spectra of dye-loaded MPEI convincingly confirmed the effective capture of anionic dyes by MPEI. More importantly, the as-prepared materials could act as efficient adsorbents for the treatment of model textile effluent and the regenerated adsorbents in alkaline medium could be utilized repeatedly. Such fascinating merits make MPEI suitable to be practically applied in removal of dyestuffs from industrial wastewater.

Study of Freeze-dried Chitosan Beads Encapsulating Live Lactic Acid Bacteria for Removal of Reactive Dyes

Water pollution by the discharge of dye residue has been polluting the planet for decades. Chitosan is one of the natural abundant biomasses that show excellent adsorption toward colorants. Nevertheless, sophisticated chemical modifications of chitosan are inevitable to enhance physical and chemical stabilities in practical applications. In the present study, simple freeze-drying has been adopted to chitosan (CHI) beads showing good stability at low levels of pH. The results show complete decolourisation of Reactive Blue 19 (RB19) within 2 hours at pH 3 and temperature of 37 ◦ C. The encapsulation of live bacterium Lactobacillus casei (L. casei) into chitosan beads for dyestuff removal is also evaluated. Kinetics studies show a faster initial rate of adsorption by L. casei-chitosan beads at pH 3 and temperature of 37 ◦ C. The adsorptions partially follow the intraparticle diffusion mechanism.