Kinetics and Performance of Biological Activated Carbon Reactor for Advanced Treatment of Textile Dye Wastewater

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.

Preparation Method of Iron Oxyhydroxide Nanosheets for Treating Organic Dyes

Considering the promoted purification requirement for industry sewage, the discharge of azo dye wastewater will have a serious impact on the environment, iron oxyhydroxide nanosheets were designed and prepared, and the purification effects and application conditions were investigated in this work. We have used its structural advantages to perform adsorption tests on Congo red (CR). It found that it has very excellent properties. It has strong adsorption capacity for Congo red under the condition of low dosage and no adjustment of PH. By employing iron oxyhydroxide nanosheets with optimized molar ratio of reducing agent to Fe, it was found that the adsorption efficiency increase in the removal percentage for CR from industry sewage could be achieved at the large specific surface area and pore volume of B-Fe Nanosheets.

A robust and renewable solar steam generator for high concentration dye wastewater purification

As an eco-friendly and sustainable technology, the solar-driven interfacial evaporation for water purification garners widespread attention. In the field of dye wastewater purification, some solar steam generators with catalytic degradation...