Ag-CRG水处理剂的制备与抑菌缓蚀性能试验

Preparation and Properties of Ag-CRG as Water Treatment Agent

控制释放玻璃(Controlled-Release Glass, CRG)作为一种溶蚀控制型释放体系,能实现无机抗菌离子的0级反应动力学速率释放。可通过AgNO3溶液的平皿抑菌试验,确定了银离子在水中的最低有效抑菌浓度(MED)为5×10-3 mgL-1;通过旋转挂片试验,证明了水溶液中Ag+的存在会加剧碳钢的电偶腐蚀,而这一不利影响可通过投加微量聚磷酸盐得到有效控制。CRG样品的抑菌和缓蚀试验结果表明,磷酸盐含银控制释放玻璃(Ag-CRG)能按比例、稳定地释放出聚磷酸盐和银离子,同时具有明显的抑菌和缓蚀作用,可以成为集缓蚀、阻垢和杀菌等三种功能于一体的新型缓释水处理剂,适用于中小型工业循环冷却水和市政供水系统。

Controlled-Release Glass (CRG), which is a kind of erosion-controlled release systems, is an ideal carrier to realize 0-order release of inorganic ions. Phosphate CRG specimens containing Ag2O (Ag-CRG) and AgNO3 solutions of different concentration levels were prepared. The spread-plate test and rotating coupon test were conducted to investigate the antibacterial and corrosion behaviors of silver ions and the properties of Ag-CRG in aqueous environment. The tests with the AgNO3 solutions showed that silver ions had satisfactory and persistent bacteriostatic effect when its concentration was over its Minimum Effective Dosage (MED) level of 5×10-3 mgL-1 and that the galvanic corrosion of carbon steel was aggravated when the dosage of Ag+ was increased. But addition of 5 mgL-1 polyphosphate could effectively eliminate the unfavorable effect of Ag+ at its MED level. Further bacteriostatic and corrosion tests showed that when the Ag-CRG specimens were used, the fresh polyphosphates and silver ions were released congruently and continuously to yield the combined corrosion inhibition as well as antibacterial effects as the Ag-CRG specimens dissolved constantly in water. This study concluded that the Ag-CRG could find application as a multi-purpose agent with reduced administration in the treatment of cooling water, and drinking water systems.