Removal of Acid Blue 92 by Using Amino‐Functionalized Silica‐Pillared Clay as a New Nano‐Adsorbent: Equilibrium, Kinetic and Thermodynamic Parameters

Phosphorus removal and recovery: state of the science and challenges

Phosphorus is one of the main nutrients required for all life. Phosphorus as phosphate form plays an important role in different cellular processes. Entrance of phosphorus in the environment leads to serious ecological problems including water quality problems and soil pollution. Furthermore, it may cause eutrophication as well as harmful algae blooms (HABs) in aquatic environments. Several physical, chemical, and biological methods have been presented for phosphorus removal and recovery. In this review, there is an overview of phosphorus role in nature provided, available removal processes are discussed, and each of them is explained in detail. Chemical precipitation, ion exchange, membrane separation, and adsorption can be listed as the most used methods. Identifying advantages of these technologies will allow the performance of phosphorus removal systems to be updated, optimized, evaluate the treatment cost and benefits, and support select directions for further action. Two main applications of biochar and nanoscale materials are recommended.

Removal of arsenic by metal organic framework/chitosan/carbon nanocomposites: Modeling, optimization, and adsorption studies

In this work removal of the arsenic (As) spiked in water through adsorption using synthesized nanocomposites as a adsorbent. The Zn-BDC@chitosan/carbon nanotube (Zn-BDC@CT/CNT) and Zn-BDC@chitosan/graphene oxide (Zn-BDC@CT/GO) were synthesized from metal organic framework, carbon nanotube/graphene oxide and natural polysaccharide. Results of adsorption experiments showed that the Zn-BDC@CT/GO possessed a higher adsorption capacity than that of the Zn-BDC@CT/CNT. A study on the adsorption of As onto Zn-BDC@CT/GO was conducted and the process parameters were optimized by response surface methodology (RSM). A five-level, four-factor central composite design (CCD) has been used to determine the effect of various process parameters on As uptake from aqueous solution. By using this design a total of 20 adsorption experimental data were fitted. The regression analysis showed good fit of the experimental data to the second-order polynomial model with coefficient of determination (R²) value of 0.9997 and model F-value of 1099.97. The adsorption matched with the pseudo-second-order model and the Freundlich model. The thermodynamic parameters revealed that the nature of adsorption was feasible, spontaneous and endothermic process. Adsorption of As in the presence of other competitive ions was not significantly affected The effective adsorption performance also sustained even after ten adsorption-desorption cycles, indicating favorable reusability.