Sewage
The most commonly used method is introduce sewage processing pool, join chemical (like bleaching powder or other chloric preparation) undertake alexipharmic, dosage inspects sewage to measure and decide, general 1 litre of sewage use 2 grams ～ 5 grams bleaching powder.
Pick from: 2007.12.09.05 edition " Chinese pasturage vet signs up for "