Land Infiltration System To Remove Sewage Tn Pilot Study

Aiming at the growing of sewage discharge, the poor sewerage pipeline network, living in dispersion in rural, it is significantly imperative to research new technology, treating decentralize domestic wastewater to solve water pollution problem. Land infiltration system, as one kind of decentralize domestic wastewater treatment technologies, often selects pure soil as filling, low hydraulic loading and large area. Therefore two apparatus were established in a pilot laboratory with cinder, strong absorption capability, and red soil. 1 apparatus was loaded by the mediums of 55% cinder and 45% red soil mixed completely, 2 apparatus was loaded by red soil and cinder in delamination, focusing on the crucial problems in infiltration system, such as packing media, hydraulic loading, hydraulic loading cycle and adding glucose. The following conclusions were obtained:1) The performance of the filling materials, cinder and red soil, were evaluated comprehensively on surface characteristics, absorption property, nitrification and denitrification intensity. The results showed that the main component of cinder was silicate ferromanganese mineral with lots of pores which liked honeycomb. In red soil, pore space was smooth, and the main component was SiO2. The absorption capability of cinder to ammonia and phosphorus was stronger than red soil. The absorption saturation time of cinder to phosphorus was longer than red soil, and the time to ammonia was shorter than red soil. After a period of time, water binding capacity and VSS and nitrification and denitrification process of thin cinder were best, because of its proper proportion of solid-liquid-vapor.2) The removal effect of contaminants of two apparatus was compared in different hydraulic loading. It found that the average removal efficiency of COD, NH4+-N, TP were all above 80%. The removal effect was better in 2 apparatus with layers of red soil and cinder. The removal of NH4+-N and TN was affected seriously by the increase of hydraulic loading. However, hydraulic loading had a little impact on TP and organic popullant removal.3) The removal mechanisms in 2 apparatus were analyzed at shorter hydraulic loading cycle. The way of shorter hydraulic loading cycle could improve removal of COD and TN, were enhanced to 91.8% and 38.3%. Short hydraulic loading was conductive to remove contaminants.4) The nitrogen removal effect was studied when the apparatus was conducted in glucose added in influent to improve nitrogen removal. The average removal efficiency of COD, TP, NH4+-N and TN were obtained 78.1%, 90.5%, 40.8%, 46.5%, respectively. When adding glucose, the effluent concentrations of TP and NH4+-N were increased. Adding glucose did not improve denitrification greatly because apparatus had operated long time.