Study On Domestic Wastewater And Regeneration By The Small Airlift Contact Oxidation Decentralized Process

With the rapid industrialization and urbanization of our country, the more serious shortage of water resource and the deteriorating water pollution have aggravated the contradiction of demand and supply for water supply, which will be the key factor limiting the sustainable development in the future. If suitable water source in the establishing region or water diversion from other areas is unavailable, the regeneration and reuse of domestic wastewater will be the inevitable choice.The research works and conclusions of the paper:We select the small airlift bio-contact oxidation as the primary technical process to treat sanitary sewage and regeneration use decentralizedly, as the consideration of the quantity , the quality and the discharging characters of the sanitary sewage. The appropriate parameters were determined through experiment, and the operation stability, anti-impact loads and cost of the process were also analyzed, which provide designing and running parameters for practical projects in the future.The experiment showed: 80.1% COD and 58% NH₃-N can be removed by airlift bio-contact oxidation system under the conditions of air/water ration of 16.8 and the hydraulic loading of 4.8m³/(m³Â·d). In the effluent, COD, NH₃-N, TN, SS, pH value, turbidity and chromaticity met "the Water quality standard for urban miscellaneous water consumption"(GB/T 18920-2002). The unique design of airlift and media enhanced the anti-impact loading capability and the stability of the biological treatment system, moreover, the integration and serialization design brought convenient construction, low operation cost and simplified the traditional contact oxidation process. The underground installation, according with the ecological concept, was not involved with land occupying and house removing, thus had little effect on the environment layout.To improve the value of this equipment, AlCl₃ was chose to enhance chemical phosphorus removal. The HRT of sedimentation tank was 25-30min.The result indicated: when the concentration of TP in influent were 2-4mg/L and 6mg/L, the AlCl₃/TP ration were about 8.6 and 12 respectively, and the concentration of TP in effluent was Less than 0.5mg/L.Based on the design, operation and technical economic comparison of the...