... with ISO9001-2000 4.High Quality+Prompt Delivery Ferrous Sulphate HeptahydrateIn industry,ferrous sulphate is mainly used for water purification, sewage purification ... and so on. In addition with its cheap price, ferrous sulphate is preferred in the purification process of wastewater of ... 0.0005Pb≤0.004 Factory High Quality Industrial Grade Ferrous Sulphate Heptahydrate FeSO4.7H2O 98.0% Min Fe 19.7 ...