磷酸铁生产过程中产生的母液废水具有较高的硫酸根含量、总磷（TP）、铵根含量及总硬度，为防止废水回用处理时发生结垢，必须进行有效的预处理。采用化学沉淀法研究不同药剂对废水中易结垢的阴离子和阳离子的去除效果。结果表明：向废水中投加氢氧化钙量为22.5 g/L（pH=9.0）时，TP为0.14 mg/L、去除率达到99.97%、硫酸根质量浓度降至1 525 mg/L、去除率为97.07%；向废水中投加磷酸根并用氨水调节pH，当磷酸根投加量为2 500 mg/L（pH=8.5）时，总硬度为110 mg/L、总硬度去除率达到97.82%、TP约为20 mg/L、绝干污泥量为7.32 g/L。投加氢氧化钙药剂可降低磷酸根、硫酸根等结垢阴离子和总溶解性固体含量，投加磷酸根和氨水可降低废水总硬度，即降低阳离子量。以上两种加药方式实现了对磷酸铁废水的有效预处理，避免废水在膜浓缩和零排放过程中结垢，是一种可行的磷酸铁废水预处理方法，同时应用ASPEN PLUS软件模拟向废水中投加氢氧化钙反应生成硫酸钙的过程并分析硫酸钙的比热容。

The mother liquor wastewater generated during the production of iron phosphate had high sulfate ions，total phosphorus（TP），ammonium ions，and total hardness.To prevent scaling of wastewater during reuse treatment，effective pre⁃treatment was necessary.The removal effect of different agents on the easily scaling anions and cations in wastewater was studied by chemical precipitation method.The results showed that when 22.5 g/L（pH=9.0） calcium hydroxide was added to the wastewater，TP was 0.14 mg/L，and the removal rate reached 99.97%.The sulfate ion concentration dropped to 1 525 mg/L，with a removal rate of 97.07%.Phosphate ions were added to the wastewater and pH was adjusted with ammonia water.When the amount of phosphate ions added was 2 500 mg/L（pH=8.5），the total hardness was 110 mg/L，the total hardness removal rate reached 97.82%，TP was about 20 mg/L，and the absolute dry sludge amount was 7.32 g/L.The addition of calcium hydroxide could reduce the amount of scale anions and TDS such as phosphate and sulfate ions，while the addition of phosphate and ammonia could reduce the total hardness of wastewater，which was the amount of cations.The above two dosing methods achieved effective pretreatment of iron phosphate wastewater，avoiding scaling during membrane concentration and zero discharge processes，and were feasible methods for pretreatment of iron phosphate wastewater.And ASPEN PLUS software was used to simulate the process of adding calcium hydroxide to wastewater to generate calcium sulfate and analyze the specific heat capacity of calcium sulfate.