METHOD OF CLEANING WASTE WATER FROM SULFATE IONS Russian patent published in 2004 - IPC

FIELD: cleaning of waste and natural water from sulfate ions; mining and chemical industries; cleaning galvanic runoffs of industrial plants.

SUBSTANCE: proposed method is based on neutralization of sulfate-containing waste water and introduction of reagent; prior to introducing reagent, water is subjected to neutralization to pH=8.5-12.1; used as reagent is mixture of lime with aluminum hydroxide of amorphous structure extracted from acid solution of aluminum salt and metered into neutralized water at subsequent additional neutralization of runoffs to pH=12.2-12.8; then water being cleaned is stirred to completion of settling of SO2-4

to solid phase. It is good practice to use mixture of line with aluminum hydroxide at ratio of CaO:Al(OH)₃ no less than 1:1.1. Proposed method ensures cleaning of waste water from sulfate ions to concentration not below 100 mg/cu dm stipulated by maximum permissible concentration.

EFFECT: reduction of cleaning time; enhanced efficiency.

2 cl, 1 tbl, 5 ex