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采用混凝沉淀法进行分散式饮水除砷试验。结果表明，当水样中五价砷［Ａｓ（Ⅴ）］含量为１．０ｍ ｇ／Ｌ时，不调节ｐＨ值（ｐＨ７．８２），直接投加５０ｍ ｇ／Ｌ硫酸铁，室温下沉淀静置１２ｈ，可使倾析液残留砷含量低于０．０５ｍ ｇ／Ｌ。如沉淀反应后静置３０～４０ ｍ ｉｎ 即过滤，则只需投加３０ｍ ｇ／Ｌ的硫酸铁或４０ｍ ｇ／Ｌ的硫酸铝即可达到同样的除砷效果。随着投加量的增加，２种混凝剂对砷的去除率均升高，当水样Ａｓ（Ⅴ）≤１．０ｍ ｇ／Ｌ和≤０．５ｍ ｇ／Ｌ时，分别投加３０ｍ ｇ／Ｌ 硫酸铁和硫酸铝，过滤后可使残留砷含量达到现行饮水卫生标准（＜０．０５ｍ ｇ／Ｌ）。在水样处于不同ｐＨ 值、水温、浊度、硬度等条件下硫酸铁的除砷性能较硫酸铝稳定。一般情况下，沉渣中的砷不会再次进入水中
Using coagulation sedimentation method to disperse arsenic in drinking water test. The results showed that when the content of pentavalent arsenic [As (Ⅴ)] was 1.0 m g / L, the pH value (pH7.82) was not adjusted. 50 m g / L ferric sulfate was directly added and the precipitate was precipitated at room temperature Set 12h, the decanter residual arsenic content of less than 0.05m g / L. If the precipitate after standing 30 ~ 40 m in that filter, just add 30m g / L of ferric sulfate or 40m g / L of aluminum sulfate to achieve the same effect of arsenic removal. With the increase of dosage, the arsenic removal rates of the two kinds of coagulants all increased. When the water samples were As (Ⅴ) ≤1.0m g / L and ≤0.5m g / L, 30m g / L ferric sulfate and aluminum sulfate. After filtration, the residual arsenic content can reach the current sanitary standard of drinking water (<0.05m g / L). Under the conditions of different pH value, water temperature, turbidity and hardness, the removal of arsenic from ferric sulfate is more stable than aluminum sulfate. Under normal circumstances, the arsenic in sediment will not re-enter the water