The Anti-clogging Study Of Strengthened Constructed Rapid Infiltration System In Rural Domestic Sewage

With the rapid urbanized development, the water environmental pollution becomes more and more severe. Due to lack of the urban infrastructure, the sewage directly discharge, so it results in bad environmental problem. In order to find a energy-saving and cost-reducing technology which combines nature treatment with manual treatment, we need to rely on the local environmental conditions. Constructed rapid infiltration(CRI) system is an ecological technology which mainly degrades pollutants by microorganism. Its key is that constructed filters with good penetrating quality, such as river sand, coal ganguer, replaces soil layer. As a result, its hydraulic loading improves very much. The working methodology of flooding and drying is also adopted. Therefore, the hydraulic loading cycle(HLC) is an important parameter in CRI`s design.In order to solve the clogging problem, this test perfects the sthenthened constuctued rapid infiltration(SCRI) system, which includes changing the surface of non-saturated layer with Sand medium layer, comparing with loofah sponge and corncob, especially exploring the removal efficiency of complex wastewater under large pollution loading.In consequence, the average removal rate of COD, NH3-N, TN and TP were 91.15%, 84%, 30% and 80%respectively, the mean effluent concentrations were respectively for 31.95mg/L, 2.5mg/L, 8.20mg/L, 0.40mg/L, it meet the "urban sewage treatment plant pollutant discharge standard"(GB 18918-2002) level of a standard under low pollution loading. Because Sand medium layer is used, it provides a powerful capacity oxygen reaeration, sthenthens biodegradation and prevents clogging.Meanwhile, it has a very high removal efficiency of complex wastewater under large pollution loading. But complex wastewater under large pollution loading may result in the intermittent clogging with 2# column, and 1# column puts off clogging and prevents from jam because of adopted Sand medium layer.comparing with loofah sponge and corncob in carbon source, loofah sponge has a small amount of carbon source every time, so that it guarantees a very high removal efficiency of complex wastewater under large pollution loading. As a result, we choose loofah sponge which is used in saturated layer.