多基质土壤混合层技术系统(MSL)对猪场废水的处理效果

Treatment of piggery wastewater using multi-soil-layering system

通过室内试验模拟研究多基质土壤混合层技术系统(multi-soil-layering system,MSL)在水力负荷为50、100、200和300L.m-2.d-1条件下对猪场废水的处理效果,并初步探讨该系统对有机物、氮、磷的去除途径。结果表明:在4个水力负荷下,化学需氧量(CODCr)平均去除率分别为74.8%、72.6%、59.5%和33.4%,微生物分解是MSL系统去除有机物的主要途径;氨氮平均去除率分别为82.1%、71.0%、30.0%和18.9%,硝化/反硝化作用是MSL系统去除氮的主要途径;磷的平均去除率分别为61.4%、56.0%、39.1%和23.0%,基质吸附作用是MSL系统去除磷的主要途径;水力负荷对MSL系统处理养猪废水的效果特别是对氮的去除有很大影响,控制适当的水力负荷是提高MSL系统污水处理效果的重要手段。MSL系统对猪场废水的处理是一种高效无动力的处理技术,具有较高的实用价值。

A series of multi-soil-layering systems （MSL） in a lab scale was employed to study the efficiency and the mechanism of chemical oxygen demand （CODcr） of organic matter, N and P removal in the wastewater generated from piggery at the hydraulic loading rates of 50, 100, 200, and 300 L-m-2 - d 1 . The results showed that the mean removal rates of organic matter were 74.8% , 72.6% , 59.5% and 33.4% under the four hydraulic loading rates, respectively, microbial decomposition process being the main mechanism of organic matter removal. The mean removal rates of ammonium nitrogen were 82.1% , 71.0% , 30.0% , and 18.9%, respectively, and the nitrification / denitrification process could remarkably account for total nitrogen removal. The mean removal rates of phosphorus were 61.4% , 56.0%, 39.1% and 23.0% under the four hydraulic loading rates, respectively, and phosphorus removal was own to its strong adsorption onto substrates. This experiment also showed that hydraulic loading rate was an important factor affecting piggery wastewater treatment efficiency, especially the removal of nitrogen, suggesting that an appropriate hydraulic loading rate was maintained to obtain an optimum efficiency of CODcr, N and P removal. Results above indicate that an MSL system with little energy consumption could be practically adopted to treat piggery wastewater.