With calcium chloride precipitant to eliminate the interference of PO43-, total nitrogen in compound fertilizer is determined by formol method.

用氯化钙作沉淀剂，消除磷酸根离子，用甲醛法测定复合肥中总氮。

Study the effect of nine kinds of coagulant aid and precipitant aid such as atlapulgite to coagulant aluminum salt dispose of organic wastewater of high concentration, then optimize and assemble.

研究了采用活性土等九种助凝助沉剂在铝盐混凝剂处理高浓度有水时作用,继而进行优化组合,结果良好,例如用微量聚丙烯酰胺和0。