Effective treatment of industrial wastewater applying SBA-15 mesoporous silica modified with graphene oxide and hematite nanoparticles

Abstract Owing to the global water shortage, wastewater treatment becomes an urgent necessity. Herein, an effective fixed-bed column for its treatment is presented. Through the in-situ process, graphene oxide or hematite nanoparticles were loaded into mesoporous silica (SBA-15/GO or SBA-15/α-Fe2O3) and identified by FTIR, XRD, Raman, BET, and TEM. Such materials were used as adsorbents with different fillers as thermally-treated rice husk (SRHA), red brick waste (RB-waste), or fumed silica (F-silica) to remove various pollutants from industrial wastewater. In the presence of RB-waste, the adsorption results showed impressive efficacy for SBA-15/GO in the removal of color (94.80%), TSS (94.36%), TOC (97.02%), COD (98.66%), turbidity (99.24%), nitrate (98.35%), TP (96.43%) and BOD5 (98.46%). While SBA-15/α-Fe2O3, along with other pollutants, remove about 79.02% and 64.59% of ammonia in the presence of RB-waste and SRHA. These composites with all fillers demonstrated excellent removal of heavy elements. The optimum pH for COD, BOD5, TN, TP, NH3, and TOC elimination was the original pH of the collected wastewater. The effectiveness of the column containing SBA-15/α-Fe2O3 and RB-waste in removing NH3 and COD was assessed through the breakthrough curves. Thomas and Yoon-Nelson kinetic models were more appropriate for evaluating the experimental results. The application of RB-waste and SRHA as fillers implies an environmental requirement regarding the recycling of agriculture and industrial wastes to mitigate its accumulation and reduce wastewater treatment costs. Due to the high efficiency and effective reusability of the column, the large-scale implementation of the current separation system should be recommended for future wastewater treatment.