Sewage treatment

摘要

A process for treating sewage comprises the addition of a water soluble compound of iron to sewage before the sewage is subjected to primary settlement or clarification. The iron compound is added at a rate between 0.2 and 4.0 mg per litre calculated as Fe. Preferred iron compounds are ferrous or ferric sulphate and a preferred method of addition utilises a saturator. The process reduces the quantity of hydrogen sulphide produced during sewage treatment and is more economical than known processes.