School of Environment and Natural Resources, Doon University, Dehradun, 248012, India.
Department of Biotechnology and Medical Engineering, National Institute of Technology, Rourkela, Odisha, 769008, India.
Environ Sci Pollut Res Int. 2019 Nov;26(33):34177-34183. doi: 10.1007/s11356-018-3850-9. Epub 2018 Nov 29.
In this study, aqueous extracts of Musa paradisica (banana) peels and Dolichos lablab (Indian beans) seeds were prepared and tested as natural coagulants for turbidity removal from simulated turbid water. Effects of extraction time (15, 30, and 45 min), dosage (0.2 to 1.0 mL/L), and water pH on turbidity removals by the natural coagulants were evaluated. In both cases, the extraction time of 45 min for the preparation of aqueous extract and dosage of 0.6 mL/L gave the best results in terms of turbidity removal. Natural coagulants from M. paradisica peels powder could efficiently remove turbidity (> 83%) at all tested pH values (3.0 to 12.0) with maximum turbidity removal of 98.14% at pH 11. In the case of D. lablab seeds, low turbidity removal (71-74%) was observed at pH between 5.0 and 9.0. The maximum turbidity removal (98.84%) was obtained at pH 11. The scanning electron microscopy (SEM) analysis of the settled flocs revealed that more compact flocs formed using M. paradisica peels extract than those developed using D. lablab seeds extract. The chemical analysis and Fourier transform infrared (FTIR) spectroscopy of the extracts revealed that polymeric substances (carbohydrate and proteins) having functional groups -OH, C-N, C-C, -COOH, and N-H might be responsible for the coagulation activity. The zeta potential measurements of natural coagulants revealed that the possible coagulation mechanism would be adsorption and bridging between particles. This study demonstrated the potential use of aqueous extracts of M. paradisica peels and D. lablab seeds as low-cost natural coagulants for turbidity removal.
在这项研究中，制备了 Musa paradisica（香蕉）果皮和 Dolichos lablab（印度豆）种子的水提取物，并将其测试为用于去除模拟浊水浊度的天然混凝剂。评估了提取时间（15、30 和 45 分钟）、剂量（0.2 至 1.0 毫升/升）和水 pH 值对天然混凝剂去除浊度的影响。在这两种情况下，制备水提取物的提取时间为 45 分钟，剂量为 0.6 毫升/升，在去除浊度方面效果最佳。M. paradisica 果皮粉末的天然混凝剂可以在所有测试的 pH 值（3.0 至 12.0）下有效地去除浊度（>83%），在 pH 值为 11 时最大浊度去除率为 98.14%。对于 D. lablab 种子，在 pH 值为 5.0 至 9.0 之间观察到低浊度去除率（71-74%）。最大浊度去除率（98.84%）在 pH 值为 11 时获得。沉降絮体的扫描电子显微镜（SEM）分析表明，使用 M. paradisica 果皮提取物形成的絮体比使用 D. lablab 种子提取物形成的絮体更紧密。提取物的化学分析和傅里叶变换红外（FTIR）光谱分析表明，具有功能基团-OH、C-N、C-C、-COOH 和 N-H 的聚合物质（碳水化合物和蛋白质）可能是混凝活性的原因。天然混凝剂的 zeta 电位测量表明，可能的混凝机制是颗粒之间的吸附和桥接。这项研究表明，M. paradisica 果皮和 D. lablab 种子的水提取物可以用作去除浊度的低成本天然混凝剂。
