scholarly journals Effect of operating parameters on dye wastewater treatment using Prosopis cineraria and kinetic modeling

2019 ◽  
Vol 25 (5) ◽  
pp. 788-793 ◽  
Author(s):  
Rajamohan Natarajan ◽  
Rajasimman Manivasagan

Textile dye effluent treatment was investigated using a novel biosorbent synthesized from Prosopis cineraria. The influence of operating variables, namely initial COD of the effluent (352-1,303 mg/L) and adsorbent dosage (0.25-4.0 g/L) on the removal efficiency was studied. The results of the biosorption experiments indicated that the equilibrium COD removal efficiency attained was 68% and COD uptake achieved was 90.52 mg/g at an optimal sorbent dose (2.0 g/L). Pseudo second order model fitted well to the experimental data and the rate constant was estimated as 0.098 x 10<sup>-5</sup> g /(mg min) .Chemisorption was identified as the removal mechanism involved. Power function model represented the kinetic data in selected range of COD and kinetic constants were estimated. XRF analysis of the biosorbent confirmed the presence of potassium oxide and calcium oxide as the two major components.

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Mebrahtu Gebrezgiher ◽  
Zebene Kiflie

Textile industries generate large quantities of dye containing wastewater which pose a serious environmental problem. Currently, biosorbents have become desirable for the removal of dyes from textile effluents. In this study, batch experiments were conducted to investigate the biosorption characteristics of cactus peel on the removal of reactive red dye from aqueous solutions. The effects of solution pH, biosorbent dosage, contact time, and initial concentration were studied. The interaction effects of process variables were analysed using response surface methodology. The results showed that removal efficiency increased as initial dye concentration and solution pH decreased and as biosorbent dosage and contact time increased. The highest removal efficiency (99.43%) was achieved at solution pH, initial dye concentration, biosorbent dose, and contact time of 3.0, 40 mg/l, 6 g, and 120 min, respectively. From regression analysis, the Langmuir isotherm was found to better (R2 = 0.9935) represent the biosorption process as compared with the Freundlich isotherm (R2 = 0.9722). Similarly, the pseudo-second-order model was seen to represent very well the biosorption kinetics. The results show that cactus peel has good potential for the removal of reactive red dye.


2013 ◽  
Vol 65 (1) ◽  
Author(s):  
Norzita Ngadi ◽  
Chin Chiek Ee ◽  
Nor Aida Yusoff

Dyes contain carcinogenic materials which can cause serious hazards to aquatic life and the users of water. Textile industry is the main source of dye wastewater which results in environmental pollution. Many studies have been conducted to investigate the use of low cost adsorbent as an alternative technique for the adsorption of dye. The objective of this study is to determine the potential of eggshell powder as an adsorbent for methylene blue removal and find out the best operating conditions for the color adsorption at laboratory scale. The adsorption of cationic methylene blue from aqueous solution onto the eggshell powder was carried out by varying the operating parameters which were contact time, pH, dosage of eggshell powder and temperature in order to study their effect in adsorption capacity of eggshell powder. The results obtained showed that the best operating condition for removal of methylene blue was at pH 10 (78.98 %) and temperature 50°C (47.37 %) by using 2 g of eggshell powder (57.03 %) with 30 minutes equilibrium time (41.36 %). The kinetic studies indicated that pseudo-second-order model best described the adsorption process.


Author(s):  
Mohammad Akter Hossain ◽  
Md. Nazmul Kayes ◽  
Md. Mufazzal Hossain

The nanoparticles of ZnO (n-ZnO) have been synthesized by a sol-gel method and characterized by UV-visible and FTIR spectroscopy, scanning electron microscopy (SEM), energy dispersive X-Ray spectrometry (EDX) and powder X-ray diffractometry (XRD). Precursor of n-ZnO particles were prepared via a non-aqueous route, which was calcined at 500oC. These particles were then deposited on a glass substrate for adsorption and photodegradation of a typical textile dye, Remazol Red R (RRR). Especially, the high surface to volume ratio of nanoparticles has appealed much attention to use these particles both as an adsorbent and a photocatalyst. A comparative study was carried out between n-ZnO and a commercially available ZnO (c-ZnO) to investigate the removal efficiency of RRR from its aqueous solution under different conditions. The removal efficiency has been optimized by varying several operating variables and the highest performance has been obtained with 0.115 g/slide of ZnO and 0.5 × 10-4 M aqueous solution of RRR under sunlight irradiation. It is important to note that the use of the films of ZnO in the presence of solar light makes it suitable for recycling and causes no secondary environmental pollution.


Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 129
Author(s):  
Yen-Hui Lin ◽  
Bing-Han Ho

The kinetics and performance of a biological activated carbon (BAC) reactor were evaluated to validate the proposed kinetic model. The Freundlich adsorption capacity (Ka) and adsorption intensity constants (n) obtained from the batch experiments were 1.023 ± 0.134 (mg/g) (L/mg)1/n and 2.036 ± 0.785, respectively. The effective diffusivity (Ds) of the substrate within the activated carbon was determined by comparing the adsorption model value with the experimental data to find the best fit value (4.3 × 10–4 cm2/d). The batch tests revealed that the yield coefficient (Y) was 0.18 mg VSS/mg COD. Monod and Haldane kinetics were applied to fit the experimental data and determine the biokinetic constants, such as the maximum specific utilization rate (k), half-saturation constant (KS), inhibition constant (Ki), and biomass death rate coefficient (kd). The results revealed that the Haldane kinetics fit the experimental data better than the Monod kinetics. The values of k, KS, Ki, and kdwere 3.52 mg COD/mg VSS-d, 71.7 mg COD/L, 81.63 mg COD/L, and 4.9 × 10−3 1/d, respectively. The BAC reactor had a high COD removal efficiency of 94.45% at a steady state. The average influent color was found to be 62 ± 22 ADMI color units, and the color removal efficiency was 73‒100% (average 92.3 ± 10.2%). The removal efficiency for ammonium was 73.9 ± 24.4%, while the residual concentration of ammonium in the effluent was 1.91 ± 2.04 mg/L. The effluent quality from the BAC reactor could meet the discharge standard and satisfy the reuse requirements of textile dye wastewater.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Tzan-Chain Lee ◽  
Shumao Wang ◽  
Zonggui Huang ◽  
Zhongxing Mo ◽  
Gangxing Wang ◽  
...  

The potentiality of tea stem for the adsorption of methylene blue (MB) from aqueous phase was investigated. A series of operating factors, including the initial MB concentration, contact time, pH of solution, dose of tea stem, and ionic strength of solution, were conducted to understand the effect of adsorption of MB onto tea stem. Adsorption isotherm, kinetic models, thermodynamic investigation, and regenerability of tea stem were systematically investigated in this study. The experiment results revealed that the removal efficiency decreased with MB concentration and the equilibrium time of adsorption at different initial MB concentrations was approximately at 60 min. The appropriate dose of tea stem powder was found to be 4 g/L. The pHzpc of tea stem was evaluated and was observed to be 6.0 ± 0.2. The removal efficiency increased with pH ranging from 3.0 to 5.0 and remained constantly at the pH range of 5.0–11.0. The pH affected the adsorption because of the repellent power between H+ and dye cation. The ionic strength was found to have a negligible effect on the adsorption. The Langmuir and Temkin isotherm models were found to be the best isotherm models to elucidate the adsorption mechanism between MB and tea stem powder. The maximum adsorption capacity of 103.09 mg/g derived from the Langmuir model was much close to the experimental result. From the kinetic analysis, the pseudo-second-order model was found to be the suitable model to describe the adsorption behavior. The calculated adsorption capacities at different temperatures derived from the pseudo-second-order model ranging from 68.91 to 69.8 mg/g were well close to the experimental data. The intraparticle diffusion of MB molecules into pore structures of tea stem powder is the rate-limiting step for the adsorption process in this study. Evaluation of thermodynamic parameters including changes in enthalpy, entropy, and Gibb’s free energy indicated the adsorption mechanism between MB and tea stem powder was a spontaneous and exothermic process. The regeneration/adsorption experiments indicated that the tea stem powder efficiently remained more than 97% after five cycles using NaOH as a desorbing agent and thus be used for many times. On the basis of experimental results obtained, it is concluded that the tea stem has a considerable potential as a low-cost sorbent for removing MB from the aqueous phase.


RSC Advances ◽  
2016 ◽  
Vol 6 (82) ◽  
pp. 78936-78946 ◽  
Author(s):  
Song Cheng ◽  
Libo Zhang ◽  
Hongying Xia ◽  
Jinhui Peng ◽  
Jianhua Shu ◽  
...  

A and B are Langmuir isotherm and pseudo-second-order model. We conclude that MB adsorption capacity of Fe-activated carbon is bigger than raw activated carbon, indicating that Fe-activated carbon has better MB removal efficiency.


2016 ◽  
Vol 6 (4) ◽  
pp. 1045-1049
Author(s):  
N. Rajamohan ◽  
R. Rajesh Kannan ◽  
M. Rajasimman

Heavy metal pollution due to the contamination of Selenium above the tolerable limit in the natural environment is a challenging issue that environmental scientists face. This study is aimed at identifying ion exchange technology as a feasible solution to remove selenium ions using 001x7 resin. Parametric experiments were conducted to identify the optimal pH, sorbent dose and speed of agitation. Selenium removal efficiency of 85% was attained at pH 5.0 with 100 mg/L selenium concentration. The increase in resin dose was found to increase removal efficiency. However, metal uptake decreased. The experiments on the effect of concentration proved the negative effect of higher concentrations of selenium on removal efficiency. The ion exchange process was proved to be optimal at an agitation speed of 200 rpm and a temperature of 35 °C. Pseudo second order model was found to fit the kinetic data very well compared to the pseudo-first order model and the pseudo second order rate constant was estimated as 8.725x10-5 g mg-1 min-1 with a solution containing 100 mg/L selenium.


2019 ◽  
Vol 34 (2) ◽  
pp. 218-227
Author(s):  
Radouane Laib ◽  
Samira Amokrane-Nibou ◽  
Djamel Nibou ◽  
Mohamed Trari

Abstract A recycled newspaper pulp (NPP) was used in the adsorption of a basic textile dye (Sandocryl gold yellow, basic yellow 28: BY28). NPP was deinked and bleached for the homogeneity of the adsorbent and elimination of the anchor. The release of NPP was followed by measuring the absorbance and chemical oxygen demand (COD) in water. The NPP samples were characterized by X-ray diffraction and FT-IR spectroscopy while the morphology was visualized by the SEM technique and the chemical composition determined by the energy dispersive spectroscopy (EDS). The adsorption of BY28 on NPP was investigated by varying the contact time (0–160 min), pH (2–6), biosorbent dose (1–8 g) and initial BY28 concentration (25–200 mg L−1); the results show a good yield in the pH range (4–7). The adsorption isotherms were studied by the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Tempkin models. A maximal NPP adsorption capacity of 91.21 mg g−1 at 20 °C was obtained. The kinetic study showed that the best fit is obtained with the pseudo second order model that correlates suitably the experimental data well.


Author(s):  
Raja Balasaraswathi S and Kiruba T

The textile industry is one of the major industries contributing to water pollution. The wet processing of textiles involves the usage of a wide variety of chemicals and dyes. This water-intensive process can potentially affect the water bodies by its effluents. The treatment of dye effluents and reusing of the water could be the possible solution to reduce the impact. Adsorption is one of the most common methods used for textile effluent treatment. Various bio-adsorbents are explored to make the adsorption more sustainable. Nigella Sativa (Black cumin) seeds and its oil are having good medicinal value. The seed-waste left after the oil extraction is found to have active components that can be used as an effective bio-adsorbent. The dye removal efficiency of Nigella Sativa seed-waste is investigated under different experimental conditions (varied adsorbent dose, temperature, pH, and contact time) for reactive dyes. The maximum removal efficiency of 91% is obtained at the optimized experimental condition. Thus the study emphasizes that the no-cost Nigella Sativa seed-waste can be used as an effective bio-adsorbent for reactive dye removal from dye effluents.


2019 ◽  
Vol 35 (4) ◽  
pp. 1384-1391
Author(s):  
Abdur-Rahim Adebisi ◽  
Giwa Khadijat Ayanpeju ◽  
Abdulsalam Francois Wewers ◽  
Mary Adelaide Oladipo

The study investigates the effectiveness and mechanism of the adsorption of malachite green from single and mixed dyes aqueous solutions by an adsorbent prepared from acid-treated Parkia biglobosa sawdust. The adsorbent was characterized using different techniques, and the adsorption was conducted in single, binary, ternary and quaternary dye systems under different experimental conditions. Experimental results were subjected to different isotherm and kinetics models. The adsorption process was endothermic and thermodynamically feasible with the removal efficiency increasing with increase in adsorbent dosage, solution working pH, initial dye concentration and contact time. The rate of sorption of the dye was fast; it attained equilibrium within 180 minutes in both the single and mixed solute systems. Pseudo-second order model gives the best kinetics fit (R2 = 0.998). The adsorption isotherm in all solute systems have best fits for the Temkin model (R2 > 0.96).


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