菲律宾蛤仔黏附污泥用于废水处理的生物絮凝剂特性研究

菲律宾蛤仔黏附污泥已被报道为一种新型的天然生物絮凝剂,适合淡水处理和海水处理。本文探究了菲律宾蛤仔黏附污泥在实际废水处理中的应用效果。结果表明:菲律宾蛤仔黏附污泥作为絮凝剂可以有效去除废水中悬浮物(SS),去除率可达49.3%,并能有效改善膨胀的活性污泥的沉降性能,促进光合细菌的挂膜,促进率为33.3%;另外,其还有效吸附去除水中的重金属,当重金属离子Cd^(2+)、Zn^(2+)、Cu^(2+)的浓度分别为5.09 mg/L、14.09 mg/L、255.81 mg/L时,去除率分别达72%、67%、92%。

一株大肠杆菌所产絮凝剂的特性研究

考察了一株大肠杆菌产生的絮凝剂的絮凝特性，研究表明，该菌产絮凝剂的活性成分主要存在于上清液中，且产絮凝剂的时间与菌生长相比，稍有些滞后，该絮凝剂絮凝高岭土悬浊液时，最适宜的pH范围为5.0-8.0，最佳的高岭土悬浊液浓度为2-4g/L；不同的金属阳离子都有不同程度的助凝作用。且Ca^2＋更具优越性，其适宜浓度为0.2-0.5g/L与其他生物絮凝剂及常用絮凝剂相比，其絮凝效果及絮凝剂用量展现出较好的优势 。

一株絮凝剂产生菌的筛选鉴定和培养条件优化

通过高岭土悬浊法考察微生物絮凝剂产生菌的絮凝活性,采用平板划线法从土壤样品中分离得到一株具有较高絮凝活性的菌株C412。根据菌落形态观察、生理生化实验和16S r DNA序列相似性比对,判定菌株C412为解淀粉芽孢杆菌。通过单因素法优化培养基,发现可溶性淀粉为最佳碳源;硫酸铵和牛肉膏复合为最佳氮源;添加适量的Na＋和Mg2＋有益菌株生长和絮凝活性提高。优化后的培养基组成为：15 g/L可溶性淀粉、1 g/L牛肉膏、3 g/L硫酸铵、1 g/L Na Cl、0.05 g/L Mg SO4·6H2O、5 g/L K2HPO4、2 g/L KH2PO4（p H=7）。菌株C412在此培养基中生长17 h后,菌体浓度（OD600）达到最大（3.18）,其最大絮凝活性可达95.53%。从发酵上清液中提取的生物絮凝剂耐热区间（4~60℃）和体系工作p H范围（4~13）较为广泛。

Screening of a Novel Bioflocculant-producing Strain and Research on Its Flocculation

[Objective] This study aimed to screen a bacterial strain capable of producing bioflocculant. [Method] A bacterial strain T-11 capable of producing bioflocculant was isolated from activated sludge. Detailed tests on the morphological, physiological and biochemical characteristics were carried out and identification was performed to identify the strain. Finally, the bioflocculant was isolated and purified, and the flocculating activity and chemical characteristics were measured. [Result] It was identified as Serratia plumuthica based on its morphological, physiological and biochemical characteristics. This strain secreted flocculant best in a culture medium which included sucrose and NaNO3. The maximal cell growth was achieved within 10 h and the flocculating activity paralleled to it. It was found to be effective for flocculation of kaolin suspension, when added at a final concentration of 0.7 mg/L, over a range of pHs （2-7）, and temperature （approximately 30-80 ℃）. Chemical analysis indicated that the bioflocculant was an acidic polysaccharide consisting of glucose, glucuronic acid and galactose, talose and altrose. Infrared spectrum analysis also revealed typical characteristics of polysaccharides. [Conclusion] The biofloccu- lants produced by strain T-11 can greatly improve the ability of activated sludge to settle.