The removal of dye from textile industry wastewater using a photo-Fenton like catalyst system was investigated wherein the removal efficiency of phenol and chemical oxygen demand (COD) was studied by varying various parameters of pH (3–11), reaction time (1–50 min), activated Carbon/CoFe₂O₄ (AC/CFO) nanocomposite dosage (0.1–0.9 g/L), and persulfate amount (1–9 mM/L). The highest removal rates of reactive red 198 and COD were found to be 100% and 98%, respectively, for real wastewater under the optimal conditions of pH = 6.5, AC/CFO nanocomposite dosage (0.3 g/L), reaction time, 25 min, and persulfate dose of 5 mM/L up on constant UV light irradiation (30 W) at ambient room temperature. The result showed that this system is a viable and highly efficient remediation protocol relative to other advanced oxidation processes; inexpensive nature, the ease of operation, use of earth-abundant materials, and reusability for removal of organic pollutants being the salient attributes.

The biosorption process using natural materials has found widespread applications than to their inexpensiveness, availability, and reusability. The aim of this research is to investigate the efficiency of psyllium seed powder in removal of reactive orange 16 dye. The impacts of various influential parameters such as initial pH, contact time, adsorbent dose, temperature and dye concentration were evaluated using a batch biosorption method. Data analysis was conducted by SPSS 19. The removal efficiency of reactive dye 16 using the natural adsorbent psyllium was obtained to be 94% in optimal conditions (pH 4, contact time = 40 min, and adsorbent dose = 2 g/L). Biosorption equilibrium experiments indicated that the best fit was achieved with Langmuir isotherm model. Maximum adsorption capacity was found to be 206.6 mg/g at 303 K. Kinetic analysis revealed that adsorption experimental data were best fitted by pseudo-second-order model. Free energy of adsorption (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) changes were calculated to predict the nature of adsorption. Thermodynamic evaluation indicates that a spontaneous process has occurred. Inexpensive, locally available, and effective materials could be used for dye removal in wastewater treatment processes. Undoubtedly low-cost adsorbent benefits for commercial purposes in the future.

Phenol is classified as priority pollutant. Phenol and its derivatives are stable in water, environmental contamination, and health concerns that are used as raw material in many chemical industries. This study investigated the removal of phenol by electro-H2O2/UV system. The response surface methodology (RSM) using central composite design (CCD) was used to modeling and optimization of experimental parameters such as pH, contact time, initial concentration of phenol, concentration of hydrogen peroxide, and current density. The obtained results demonstrated that the efficiency of the electro-H2O2/UV system was maximum (>99%) under the optimal conditions for the phenol removal from aqueous solutions, 2 mM of hydrogen peroxide concentration, 50 mg/L of initial phenol concentration, pH of 5, 10 mA/cm2 of current density, reaction time of 25 min and 2.1 kW h/m3 of energy consumption. Therefore, the electro-H2O2/UV system is an efficient method for the removal of organic compounds from industrial wastewater.

This study investigated the removal of phenol from steel industry wastewater by three dimensional electrochemical (TDE) process using CoFe₂O₄ nanobiocomposite based activated carbon in the presence of H₂O₂ (EC-CoFe₂O₄@AC-H₂O₂). In this study, CoFe₂O₄ nanobiocomposite-foundation activated carbon (CoFe₂O₄@AC) was used as microelectrode, adsorbent, and activator for peroxide hydrogen. The removal efficiency of phenol and COD was investigated through the parameters of pH, contact time, CoFe₂O₄@AC dosage, current density, and H₂O₂ concentration. The highest removal rates of phenol and COD were >99% and 98%, respectively. Also, steel plant wastewater under the optimal conditions of pH = 6.5, current density = 15 mA cm⁻², contact time = 25 min, H₂O₂ concentration of 1.0 mM, and CoFe₂O₄@AC dose = 0.3 g L⁻¹. Kinetic analysis revealed that the adsorption experimental data was best fitted by the pseudo-first-order model.

Phenol and its derivatives are available in various industries such as refineries, coking plants, steel mills, drugs, pesticides, paints, plastics, explosives and herbicides industries. This substance is carcinogenic and highly toxic to humans. The purpose of the study was to investigate the removal of phenol from wastewater of the steel industry using the Electro Coagulation–Photo Fenton (EC-PF) process. Phenol and chemical oxygen demand (COD) removal efficiency were investigated using the parameters pH, Fe⁺²/H₂O₂, reaction time and current density. The highest removal efficiency rates of phenol and COD were 100 and 98%, respectively, for real wastewater under optimal conditions of pH = 4, current density = 1.5 mA/cm², Fe⁺²/H₂O₂ = 1.5 and reaction time of 25 min. Combination of the two effective methods for the removal of phenol and COD, photocatalytic electrocoagulation photo-Fenton process is a suitable alternative for the removal of organic pollutants in industry wastewater because of the low consumption of chemicals, absence of sludge and other side products, and its high efficiency.

Removal of natural organic matter (NOM) is one of the most important objectives of water treatment plants but reducing these pollutants either present in water as dissolved or suspended form is not as efficient as is required in conventional treatment plants. The purpose of this study was comparison performance of composite polyaluminum silicate chloride (PASiC) and electrocoagulation (EC) process by aluminum electrodes in NOM removal from raw surface water. In this study, the effects of turbidity, total organic compounds (carbons) (TOC), adsorption at a wavelength of 254 nm (UV254), chemical oxygen demand (COD), alkalinity, residual aluminum in finished water by application of EC process and PASiC were investigated. The results demonstrate that PASiC coagulant at optimum concentration of 1–5 ml/L was capable of removing TOC, COD, U.V., and turbidity from raw water by 93.77, 93.5, 63 and 95 %, respectively. In contrast, EC process, removed TOC, COD, UV and turbidity from raw water by 89, 99.75, 37 and 50%, respectively. The pilot-scale results demonstrated the significant advantage of PASiC compared to EC process in removal of NOM and turbidity form raw water. Residual aluminum in finished water was below the recommended WHO guidelines 0.2 mg/L for both processes. Finally it can be concluded that PASiC and EC process are reliable, efficient and cost-effective methods for removal of NOM from surface water.