| 摘要 |
Water contg. sulphides is purified by oxidising in a reactor using sludge contg. aerobic bacteria. The sludge load (w.r.t. the sulphide oxidising part of the sludge) is at least 10 mg sulphide per Mg N in the sludge per hr.. Pref. the sludge load is at least 20 mg (at least 35 mg) sulphide per mg N. The sludge is in the form of biofilms bound to a carrier. The O2 concn. in the reactor is 0.1-9.0 (4) mg/l. The sulphide concn. in the effluent is kept at 0.5-30 mg/l. The sulphide surface load is at least 10 g/sq. m. The sulphide load is at least 50 (at least 100) mg S/l.h. In a two-stage process sulphide is (partially) oxidised to S and then, in a second reactor S and remaining sulphide oxidised to sulphate. The first oxidn. pref. uses a sulphide load of at least 26 mg S/l.h. (at least 50) (100-1000) mg S/l.h. S cpds. may first be anaerobically reduced to sulphide. The S cpds. are esp. sulphates, sulphites or thiosulphate. Purified water may be recycled to keep the S content below 800 (below 350) mg/l during anaerobic treatment. |
