Removal of Reactive Green Dye from Textile Waste Water by Photo Fenton Process: Modeling, Kinetic, and Thermodynamic.

This work investigated the removal of the reactive green (R.G) dye from wastewater using the photo-Fenton process. Batch experiments were carried out to research the role of the Impacts of operating parameters. The dosage of H2O2; dosage Fe+2; pH; temperature, and irradiation time were examined. Maximum decolorization efficiencies green dye were achieved at the [H2O2]=100 ppm; [Fe2+]=20 ppm; pH 3; temperature=56 °C and irradiation time=90 min. This research focuses on modeling, kinetics and thermodynamics of the removal of pollutant (reactive green dye) of water. The results showed that the decolorization kinetic of R.G followed pseudo-first-order reaction kinetic. Also the thermodynamic parameters ∆G˚, ∆H˚ and ∆S˚ were determined using the Van't Hoff equation for the oxidation processes. The changes in Gibbs free energy showed the oxidation process under normal conditions is non-spontaneous.

Chemometric characterization of textile waste waters from different processes

The aim of this work is focused on water quality classification of the textile waste water streams and evaluation of pollution. Data from the chemical characterization of the effluents were elaborated to identify a useful separation in potentially treatment for reuse. This was done with the aim of realizing a full scale characterization of effluents. In the two textile companies analyzed, machineries are used to carry out different production processes such as sizing and desizing, weaving, scouring, bleaching, mercerizing, carbonizing, fulling, dying and finishing. Different process effluents from the same machinery were found to be very diverse in pollution level. 25 and 49 samples of textile waste waters from two different textile companies were analysed and physical chemical measurements were performed. The following physicochemical and chemical water quality parameters were controlled: absorbance measured at three different wavelengths, pH, conductivity, turbidity, total suspended solids, volatile suspended solids, chemical oxygen demand, metals content (Ba, Ca, Cu, Mn, K, Sr, Fe, Al, Na) and total nitrogen content. For handling the results, basic statistical methods for the determination of mean and median values, standard deviations, minimal and maximal values of measured parameters and their mutual correlation coefficients, were performed. Different chemometric methods, namely, principal component analysis (PCA), cluster analysis (CA), and linear discriminant analysis (LDA) were used to find hidden information about textile waste water quality.

TREATMENT OF TEXTILE WASTE WATER AND SORPTION OF LEAD USING CHITOSAN FROM BIO-WASTE

Textile effluent contains different organic and inorganic pollutants, among these are COD and heavy metals such as lead (Pb), chromium (Cr), cadium (Cd), and copper (Cu) used for the production of color pigments. In this study the adsorption capacity of chitosan produced from snail shells as an adsorbent for the treatment of textile effluent and for the removal of lead (Pb2+) from waste water carried out. Batch experiments were performed to study the treatment of textile waste water and the adsorption of lead Pb2+ion unto chitosan. The effect of various experimental parameters (adsorbent dose, contact time and temperature) was studied, and optimal conditions were determined. Batch adsorption study on textile waste water showed 96.9 % COD removal was achieved for carbon dosage of 15mg carbon/100ml of textile wastewater solution. The equilibrium data were analyzed with Langmuir, Freundlich, Temkin, Elovich, Florry Huggins, Jovanovic, Harkin Jura and Dubinin–Radushkevich (DRK) adsorption models. Freundlich isotherm yielded the best fit to the experimental equilibrium adsorption data with a correlation coefficient (R2 ) of 0.991. The adsorption intensity is 1.68. This was closely followed by Langmuir Isotherm with a correlation coefficient (R2 ) of is 0.943. The maximum monolayer coverage (Qo) from Langmuir isotherm model was determined to be 50.51mg/g, KL (Langmuir isotherm constant) is 0.00374L/mg, RL (the separation factor) is 0.217 indicating that the equilibrium sorption was favorable. Adsorption kinetics data for sorption of Pb2+ion unto chitosan were analyzed using the pseudo first order, pseudo second order and intra particle diffusion models. The results indicated that the adsorption kinetic data were best described by pseudo secondorder model. For the thermodynamic studies, the enthalpy change, ΔH°, and the entropy change, ΔS°, for the adsorption processes are -18.10 kJ/mol and -0.0652KJ/mol K respectively. The free energy, ΔG° for the process are 2186.39 J/mol, 3071.761 J/mol, 3689.615J/mol and 4153.032 J/mol at 303K, 313K, 323 K and 333K respectively. The results of thermodynamic parameters evaluated showed that the process was non spontaneous and exothermic in nature. The results show that chitosan can be used as an alternative low-cost adsorbent for treatment of textile effluent and the removal of COD and lead from wastewater.

Treatment of Textile Dyeing Waste Water Using TiO2/Zn Electrode by Spray Pyrolysis in Electrocoagulation Process

An alternative form of treatment for the remediation of textile waste water, electrocoagulation (EC) methods are used. This work deals mainly with the treatment of waste water for textile dyeing preceded by the use of wastewater. The goal of the proposed study is to evaluate the efficiency of the electrocoagulation process using TiO2/Zn electrodes using TiCl3 via spray pyrolysis. The surface morphology of the electrode was studied by SEM, XRD and EDS analysis. The efficiency of electrocoagulation treatment process to treat synthetic waste water containing Coralene Navy RDRLSR, Coralene Red 3G, Rubru RD GLFI dye was studied. The effect of parameters such as current density, influence of effluent pH, supporting electrolyte NaCl concentration, and EC time on dye removal efficiency were investigated. The result indicates that this process is very efficient and was able to achieve color removal (99.5%) at pH 8.5 and 0.15 A in 10 minutes.