聚硅硫酸钛-羧化壳聚糖复配絮凝剂对颤藻的絮凝性能研究  

Study on the Flocculation Performance of Poly Silicate Titanium-Carboxylated Chitosan Composite Flocculant on Oscillatoria

作　　者：韦毅 李川溪 张炜 陈元涛 WEI Yi;LI Chuanxi;ZHANG Wei;CHEN Yuantao(School of Chemistry and Chemical Engineering,Qinghai Normal University,Xining 810000,China)

机构地区：[1]青海师范大学化学化工学院,青海西宁810000

出　　处：《水处理技术》2024年第9期75-79,90,共6页Technology of Water Treatment

基　　金：青海省科技成果转化专项项目-高原人工湿地生态平衡构建与应用示范(2021-SF-139)。

摘　　要：研究采用硫酸钛和聚硅酸合成了复合絮凝剂聚硅硫酸钛(PTSIS),并引入羧化壳聚糖(CPCTS)为助凝剂,通过一系列的絮凝实验,以颤藻水体的残余浊度、UV_(254)与叶绿素a浓度(Chl-a)的去除率为评价指标,研究了絮凝剂对颤藻水体处理的絮凝性能。结果显示,Si/Ti摩尔比为0.05、Ti投加量达到30 mg/L时的PTSIS絮凝性能最优,残余浊度为2.61 NTU,UV_(254)与叶绿素a浓度(Chl-a)的去除率分别为79.1%与84.1%。引入羧化壳聚糖的量为1.6 mg/L并复合使用PTSIS后残余浊度进一步降低为0.67 NTU,UV_(254)与叶绿素a浓度(Chl-a)的去除率分别为89.1%与95.7%,絮凝效果提升。pH对絮凝性能的影响结果显示,PTSIS最佳絮凝pH为6,复合使用后絮凝剂在pH=5~7时均有良好的絮凝效果。Zeta电位的分析结果表明,网捕卷扫与吸附架桥作用是PTSIS拥有较好絮凝效果的主要原因。引入羧化壳聚糖后,Zeta电位值升高,电性中和能力提高,进一步提高了絮凝性能且电性中和、网捕卷扫与吸附架桥的协同作用为复配絮凝剂絮凝的主要机制。In this study,titanium polysilicate sulfate(PTSIS)was synthesized by titanium sulfate and polysilicate acid,and carboxylated chitosan(CPCTS)was introduced as coagulant aid.Through a series of flocculation experiments,The residual turbidity,the removal rate of UV_(254)and chlorophyll-a concentration(Chl-a)were used as evaluation indexes to study the flocculation performance of the water treated by flocculants.The results showed that when the Si/Ti molar ratio was 0.05 and the dosage reached 30 mg/L,the flocculation performance of PTSIS was the best,the residual turbidity was 2.61 NTU,and the removal rates of UV_(254)and chlorophyll a concentration(Chl-a)were 79.1%and 84.1%,respectively.After the amount of carboxylated chitosan was 1.6 mg/L and combined with PTSIS,the residual turbidity was further reduced to 0.67 NTU,the removal rates of UV_(254)and chlorophyll a concentration(Chl-a)were 89.1%and 95.7%,respectively,and the flocculation effect was improved.The effect of pH on flocculation performance showed that the optimal pH of PTSIS was 6,and the flocculant had good flocculation effect at pH=5~7.The results of Zeta potential analysis show that the effect of net sweep and adsorption bridging is the main reason for the good flocculation effect of PTSIS.After the introduction of carboxylated chitosan,the Zeta potential value increased,the electrical neutralization ability increased,and the flocculation performance was further improved.The synergistic effect of electrical neutralization,net sweeping and adsorption bridge was the main mechanism of the flocculation of the composite flocculant.

关 键 词：絮凝剂 聚硅硫酸钛 羧化壳聚糖 颤藻 

分 类 号：X703.1[环境科学与工程—环境工程]