ABSTRACT

Bioflocculant-producing bacteria were isolated from various water reservoirs and sediments of the water treatment plant. Four promising strains were identified by standard biochemical methods and 16s rRNA gene sequencing. Bioflocculants were produced in a batch bioreactor of 3 L under optimized conditions. Fourier transformed infrared spectroscopy and scanning electron microscopy (SEM) were used to confirm the chemical and morphological nature of bioflocculants. Anionic and cationic textile dyes congo red (CR) and rhodamine-B (RB) decolourization efficiency by ethanol precipitated bioflocculants were accessed under different values of pH, temperature, dose of flocculant and presence of monovalent, divalent and trivalent cations. Bioflocculants of all the four isolates were found to be highly efficient in decolourization of dye from an aqueous medium with the removal rate up to 99.56%. The removal rate of CR and RB from aqueous medium was largely influenced by the physiochemical condition of the solution viz. pH, temperature, concentration of ions and dose of flocculants. The microbial bioflocculants are biodegradable and highly stable as well as possess abroad range of pH, temperature and ions tolerance range. So, they may be economical and can be greener substitutes for the present harsh chemical-based wastewater effluent treatment methods.

摘要

从水处理厂的各种水库和沉积物中分离出产生生物絮凝剂的细菌。通过标准生化方法和 16s rRNA 基因测序鉴定了四种有前景的菌株。生物絮凝剂在 3 L 的间歇式生物反应器中在优化条件下生产。傅里叶变换红外光谱和扫描电子显微镜 (SEM) 用于确认生物絮凝剂的化学和形态性质。乙醇沉淀生物絮凝剂对阴离子和阳离子纺织染料刚果红 (CR) 和罗丹明-B (RB) 的脱色效率在不同的 pH 值、温度、絮凝剂剂量以及一价、二价和三价阳离子的存在下进行评估。发现所有四种分离物的生物絮凝剂都能高效地从水性介质中脱色染料，去除率高达 99.56%。从水性介质中去除 CR 和 RB 的速率在很大程度上受溶液的理化条件影响，即。pH、温度、离子浓度和絮凝剂剂量。微生物絮凝剂可生物降解，稳定性高，具有广泛的pH、温度和离子耐受范围。因此，它们可能是经济的，并且可以成为目前苛刻的基于化学物质的废水处理方法的更环保的替代品。微生物絮凝剂可生物降解，稳定性高，具有广泛的pH、温度和离子耐受范围。因此，它们可能是经济的，并且可以成为目前苛刻的基于化学物质的废水处理方法的更环保的替代品。微生物絮凝剂可生物降解，稳定性高，具有广泛的pH、温度和离子耐受范围。因此，它们可能是经济的，并且可以成为目前苛刻的基于化学品的废水处理方法的更环保的替代品。