Purifying waste waters contg low-valent sulphur cpds - by acidifying and treating with cultures of thiobacillus thiooxidans and or ferrooxidans

摘要

Process for reducing the O2-consuming properties of low-valent S cpd.-contg. waste waters is carried out by setting the waste water to pH 5 and treating with bacteria cultures of Thiobacillus thiooxidans and/or Thiobacillus ferrooxidans. Intensive contact of waste water with air or aeration accelerates process. Used for treating waste waters contg. sulphides, polysulphides, thiosulphates, sulphites or S, e.g. from prodn. of accelerators, fungicides, flotation auxiliaries on thiocarbamate basis, from cellulose industry and esp. from flotation of sulphidic ores. Soluble thiosulphates and polysulphides are converted to sulphates or H2SO4.O2-requirement can be reduced, e.g. from 100 mg/l, for waste water from sulphide ore flotation, to zero. Acid pH, esp. 1.5-4, favours activity of bacteria used.