Department of Environmental and Water Resources Engineering, School of Civil Engineering, Vellore Institute of Technology (VIT), Vellore, 632014, India.
Centre for Clean Environment, Vellore Institute of Technology (VIT), Vellore, 632014, India.
J Environ Manage. 2023 Oct 15;344:118388. doi: 10.1016/j.jenvman.2023.118388. Epub 2023 Jun 22.
Ciprofloxacin (CIP) and norfloxacin (NOR) belong to the organic contaminants of emerging concern (OCECs) that are frequently detected in wastewater matrices at ng/L to mg/L concentrations. This study investigates the potential of Scenedesmus obliquus in the treatment of CIP and NOR as a binary mixture from raw wastewater. Optimization of inoculum was done to find the required cell density concentration that has less inhibition and high removal. The optimum inoculum (cell density: 200 × 10 cells/mL and OD: 1.0) has shown 75% removal with no inhibition of growth. A pilot scale study was conducted in controlled environment using high-rate algal pond to investigate the contribution of abiotic and biotic removal. Abiotic removal is negligible in comparison with the biotic contribution of removal. The order of removal efficiency is observed as COD (88%) > NOR (84.8%) > CIP (84.6%) > NH (71.7%) with biodegradation as the major removal mechanism. Biotransformed products of CIP + NOR were identified inside the Scenedesmus obliquus. During the pilot-scale study, Biomass (3.70 ± 0.07 g/L) was harvested with carbohydrates (17.85 ± 0.1%), lipids (38.36 ± 0.13%), and proteins (28.18 ± 1.63%). Lipid productivity in binary mixture was 2.6 times higher than the lipid production in control condition. Transesterification of these lipids yielded good biofuel composition of 32.72% of saturated fatty acids and 21.7% of unsaturated fatty acids.
环丙沙星（CIP）和诺氟沙星（NOR）属于新兴关注的有机污染物（OCECs），经常以纳克/升至毫克/升的浓度在废水基质中被检测到。本研究探讨了斜生栅藻在处理原废水中 CIP 和 NOR 二元混合物方面的潜力。通过优化接种物，找到了抑制作用较小且去除率较高的所需细胞密度浓度。最佳接种物（细胞密度：200×10 个细胞/mL，OD：1.0）表现出 75%的去除率，且没有抑制生长。在控制环境中使用高速藻类塘进行了中试研究，以研究非生物和生物去除的贡献。与生物去除的贡献相比，非生物去除可以忽略不计。观察到去除效率的顺序为 COD（88%）>NOR（84.8%）>CIP（84.6%）>NH（71.7%），生物降解是主要的去除机制。在斜生栅藻体内鉴定出 CIP+NOR 的生物转化产物。在中试研究期间，收获了 3.70±0.07 g/L 的生物质，其中含有 17.85±0.1%的碳水化合物、38.36±0.13%的脂质和 28.18±1.63%的蛋白质。二元混合物中的脂质生产力比对照条件下的脂质生产力高 2.6 倍。对这些脂质进行酯交换得到了良好的生物燃料组成，其中饱和脂肪酸含量为 32.72%，不饱和脂肪酸含量为 21.7%。
