Bisphenol A removal from water by biomass-based carbon:isotherms, kinetics and thermodynamics studies

Abstract Biomass-based carbon was modified and used as an efficient bisphenol A (BPA) sorbent. The simple and environmentally friendly modification method produced sorbent with a capacity of 41.5 mg/g. The raw material was modified with FeCl₃ (Fe-CR), treated with hydrochloric acid (H-CR) or modified with CaCl₂ (Ca-CR). Batch sorption experiments were performed to evaluate the effects of the initial pH, sorbent dosage, temperature, and contact time on BPA removal. BPA removal with modified carbons was notably higher than that with unmodified carbon. All sorbent materials exhibited very high sorption capacities and compared favourably to materials reported in the literature. Several isotherms were applied to describe the experimental results of Fe-CR, H-CR, and Ca-CR modified carbon residues and the Sips model showed the best fit for all sorbents. Kinetic studies for the best sorbent material (Fe-CR) showed that the sorption process follows Elovich kinetics. Desorption cycles were implemented, and sorption capacity remained with three cycles

Preparation of novel Fe catalysts from industrial by-products:catalytic wet peroxide oxidation of bisphenol A

Abstract Biomass-based carbon residue (CR) was used as a support material for iron catalysts to degrade bisphenol A (BPA) in catalytic wet peroxide oxidation (CWPO). According to the results, CR and Fe/CR catalysts are suitable materials for CWPO. The Fe catalysts were prepared by either incipient wet impregnation or wet impregnation methods with an iron chloride solution. The specific surface area of the prepared catalysts was 17–91 m² g⁻¹, and it remained the same after the oxidation experiments. The CWPO experiments were carried out batch-wise at c(BPA) =60 mg L⁻¹, c(H₂O₂) =1.5 g L⁻¹, c(catalyst) =1–2 g L⁻¹, T = 50 °C and at the initial pH. The 5.0Fe/CR catalyst was found to be active with BPA removal and total organic carbon (TOC) conversion of 83 and 64%, respectively, and was the most stable catalyst with negligible iron leaching during the 3 h experiment

Biomass-based composite catalysts for catalytic wet peroxide oxidation of bisphenol A:preparation and characterization studies

Abstract The wet granulation process was used to prepare new, efficient, and cost-effective granular biomass-based composite catalysts for catalytic wet peroxide oxidation (CWPO) of bisphenol A (BPA). The most stable composite granules was prepared by mixing biomass-based carbon residue (CR) with metakaolin (MK) combined with calcium oxide (CaO) or cement and a solvent (NaOH or KOH). For all the prepared composite granules, the optimized binding agents to carbon ratio was 0.3, the solvent to carbon ratio 1.2, and the agitation rate 1200 rpm. The specific surface area of the prepared catalysts was 152–205 m2/g. The composite granular catalyst (CR + MK + CaO + NaOH) had the most durable and stable structure (compressive strength of 27 N) and the most basic surface (15 mmol/g) measured with temperature programmed desorption. This catalyst was the most active in CWPO of BPA and total organic carbon removal of 50% and 48%, respectively

Preparation of granulated biomass carbon catalysts:structure tailoring, characterization, and use in catalytic wet air oxidation of bisphenol A

Abstract New carbonized biomass–metakaolin (PSD/MK_Fe) granular composite catalyst materials were manufactured for the catalytic wet air oxidation (CWAO) of bisphenol A (BPA). These catalysts were characterized using different analytical and spectroscopic techniques, and results showed that the catalysts’ final properties were influenced by the addition of metakaolin (MK), polyvinyl alcohol, boric acid, and iron. Under the optimal CWAO experimental conditions (p: 20 bar, T: 160 °C, initial pH: 5–6, c[catalyst]: 1.0 g/L), nearly complete BPA conversion (>98%) and total organic carbon (TOC) conversion of 70% were reached. A key factor behind the enhanced catalytic activity was high specific surface area, although catalytic activity was also affected by surface acidity. These results confirmed the high efficiency of the current BPA conversion process involving the use of the easily separable and reusable PSD/MK_Fe catalyst. Therefore, biomass composite catalysts can be regarded as efficient catalysts for the oxidation of BPA during the CWAO process