底泥污染物释放动力学研究

采用模拟试验方式和新型微生物数量测定方法 ,研究了沼泽化湖泊底泥和受污染河流底泥在不同扰动状态下 ,底泥耗氧速率、氮和磷污染物释放动力学过程。结果表明 :( 1)底泥耗氧速率是同样条件下上覆水耗氧速率的 48倍 ,而在扰动状态下 ,底泥耗氧速率达到上覆水耗氧速率的 5 96— 93 6倍 ,扰动底泥显著增大其耗氧速率 ,底泥污染越严重 ,其耗氧速率越大 ,对水体产生的影响也越大。 ( 2 )扰动底泥可以显著增大底泥的氮磷释放速率 ,氮的释放受有机氮的氨化、氨氮的硝化、硝酸盐氮的反硝化以及氨氮被微生物吸收转化为有机氮等的影响 ;磷的释放过程受厌氧过程和底泥颗粒吸附的影响 ,耗氧速率高的底泥具有更大的氮磷释放潜力。 ( 3 )微生物数量在底泥污染物释放动力学中起着关键性作用 ,新型方法可以快速检测微生物总量。试验结果对于水环境的管理、受污染水体的修复 ,以及底泥的处理处置等都具有重要的指导意义

Kinetics of pollutants release from sediments

With laboratory test and a new microbial measurement method, this paper investigated sediments oxygen demand (SOD) rate and kinetics of pollutants release from sediments of both paludal lake and polluted river under different disturbance conditions. The results showed that: (1) SOD rate is 48 times of that of overlying water under the same condition, and 596-936 times when disturbed. Polluted sediments have higher SOD rates and larger impacts on water body. (2) Nitrogen and phosphorus release rates are greater when sediments were disturbed. The release of nitrogen is affected by amination, nitrification, denitrification and microorganism assimilation of ammonia nitrogen, while the phosphorus release is affected by anaerobic condition and adsorption of sediment particles. The sediments with higher SOD rates have greater phosphorus release potential. (3) Microbial amount plays a key role in kinetics of pollutants release from sediments. The new method can measure microorganism amount rapidly. These results are of significant importance to water management, polluted water restoration, sediment management and disposal.