Department of Environmental Science, Periyar University, Salem, India.
Department of Biology and Applied Research Centre for Pearl River Delta Environment, Hong Kong Baptist University, Hong Kong SAR, People's Republic of China.
Environ Technol. 2023 Nov;44(26):4046-4059. doi: 10.1080/09593330.2022.2078672. Epub 2022 May 29.
The bioflocculant producing bacterial strain - UKD24 was isolated from the domestic sewage treatment plant. The isolated strain was identified as by using 16S rRNA gene sequencing. The UKD24 showed remarkable flocculation rates when grown with the carbon sources namely glucose, sucrose and lactose, and many commercial nitrogen sources. Furthermore, the fish waste extract (FE) was used to enhance the productivity of the bioflocculant as a nitrogen supplement and it showed a significant level of flocculation rate similar to the commercial nitrogen sources. The Box-Behnken experiments were designed to predict the optimal conditions for bioflocculant production and it suggested that glucose - 3.247 g L, FE - 0.5 g L and inoculum size - 1% are the suitable levels for bioflocculant production. The FTIR analysis of the bioflocculant showed the functional groups related to the polysaccharides and the EEM analysis showed the fluorescence components related to the proteins and humic acids. The biochemical composition of the bioflocculant was identified as polysaccharides (24.36 ± 1.5%) and protein (12.15 ± 0.2%). The tested optimum conditions of the bioflocculant to induce flocculation were tested in the kaolin wastewater and it showed that the optimum dosage of the flocculant was 5 mg L and the pH range was broad as 5-10. The cation dependency tests revealed that the monovalent and divalent cations are highly suitable for flocculation while the trivalent cations showed moderate flocculation. The Cr(VI) removal efficiency of the bioflocculant showed that ∼35% of heavy metal is trapped into flocks during the flocculation.
从生活污水处理厂分离到产生物絮凝剂的细菌菌株 UKD24。通过 16S rRNA 基因测序鉴定该分离菌株为。当以葡萄糖、蔗糖和乳糖等碳源和许多商业氮源作为生长基质时，UKD24 表现出显著的絮凝率。此外，使用鱼废提取物 (FE) 作为氮源补充物来提高生物絮凝剂的生产力，其絮凝率与商业氮源相当。采用 Box-Behnken 实验设计来预测生物絮凝剂生产的最佳条件，结果表明葡萄糖-3.247 g/L、FE-0.5 g/L 和接种量-1%是生物絮凝剂生产的适宜水平。生物絮凝剂的 FTIR 分析表明存在与多糖相关的功能基团，EEM 分析表明存在与蛋白质和腐殖酸相关的荧光成分。生物絮凝剂的生化组成鉴定为多糖（24.36±1.5%）和蛋白质（12.15±0.2%）。在高岭土废水中测试生物絮凝剂的最佳絮凝条件，结果表明最佳絮凝剂用量为 5 mg/L，pH 范围较宽为 5-10。阳离子依赖性测试表明一价和二价阳离子非常适合絮凝，而三价阳离子表现出中等的絮凝性。生物絮凝剂对 Cr(VI)的去除效率表明，在絮凝过程中约有 35%的重金属被捕获到絮体中。
