挂膜沸石覆盖层持续抑制底泥氨氮释放的影响因素研究

Sustainable inhibition of ammonium release from sediments by capping of bio-zeolite

通过多轮底泥修复实验研究了沸石类型、覆盖密度及上覆水氨氮浓度对挂膜沸石覆盖层持续抑制底泥氨氮释放、改善水质的影响.结果表明:沸石类型直接决定挂膜沸石覆盖层能否持续有效抑制底泥氨氮释放,孔径在8 nm左右的沸石F1表面才能附着有效降解氨氮的微生物,从而具有较强的原位再生能力,通过不断削减底泥氨氮(各轮底泥氨氮削减量为23~30mg)和上覆水氨氮(削减量达18 mg)来持续抑制底泥氨氮释放,将上覆水氨氮浓度控制在0.4~0.8 mg/L,达到地表水III类水体水质标准.挂膜沸石能否持续抑制底泥氨氮释放也与沸石覆盖密度和上覆水氨氮浓度有关,当覆盖密度大于1.46 kg/m2时、上覆水氨氮浓度低于4.28 mg/L时,覆盖挂膜沸石F1能够持续抑制底泥氨氮释放,使水体氨氮浓度满足地表水III类水体水质标准.

The effect of zeolite type, coverage density and ammonium concentration of overlying water on sustainable inhibition ofammonium release from sediments and improvement of water quality by capping bio-zeolites were studied. The results showed thatthe sediment ammonium release can be sustainably inhibited depending on zeolite types directly. The surface of zeolite F1 whoseaperture was at around 8 nm was conducive to adsorption of microorganism which can degrade ammonium efficiently, so bio-zeoliteF1 has strong ability of regeneration in situ. Through continuous cutting sediment ammonium (sediment ammonium reductionamount of each round was 23~30 mg) and overlying water ammonium (reduction amount was up to 18 mg) ,bio-zeolite F1 cansuppress the sediment ammonium release sustainably so that the concentration of ammonium in the overlying water was 0.4 mg/L^0.8 mg/L in capping bio-zeolite F1 system, to meet surface water quality standard of class III. In addition, the sustainable inhibitionof ammonium release by bio-zeolite F1 was affected by coverage density and ammonium concentration of overlying water. Therelease of ammonium was inhibited sustainably so the concentration of ammonium in the overlying water met the surface waterquality standard of class III when the coverage density of bio-zeolite F1 was greater than 1.46 kg/m2 and ammonium concentration ofoverlying water was lower than 4.28 mg/L.