Ecological Purification And Effect Of Sewage In Town

Purple soil area in the upstream of Yangtze river valley is an important agr icultural economic zone in southwest China, and economic development rapidly,ecological environment is fragile, serious pollution problems,especially in untre ated and direct discharge of production and living waste water and fertilizer le aching of agricultural non-point source pollution asked question is particularly prominent,rich in nitrogen, phosphorus and other pollutants in water with rainf all runoff flow to the downstream enrichment, bring the serious eutrophication of water bodies and other environmental pressures to entire Yangtze river basin and the three gorges reservoir area. In this study, effective control nitrogen,ph osphorus and other non point source pollution, and protect the Yangtze River water environment for the purpose of, from ecological technology and bio-geog raphical direction of rural domestic sewage purification discharge, rooted in rur al domestic sewage are main contributor to water polluted, village as a small a rea less than 5% of land contribute about 30%- 40% of small watershed poll ution load of N and P.The study is based on the Chinese Academy of Sciences purple soil agro ecological experimental station, investigating in Linshan Township residents of Yanting County living and production rules, understand the residents sewage d ischarge way,using the natural condition of township geographical gap and clim ate humid, to build a set of economic, practical, operation of non point source pollution treatment and ecological control technology systems.in December 2014 to March 2014 wild continuous observation, sampling analysis such as nitrog en and phosphorus pollution concentration data as the foundation, with proven the stage and systematic purification mechanism and function of ecological c ontrol technology,includ vertical drop, medium enhanced pooland ecological dit ch vegetation interception and adsorption in. Studies have shown that（1） the daily emissions of domestic sewage in Linshan towns can reach 7.61m3, the monthly discharge is 22.82m3, the dry season is 4 months, the disch arge amount is 912.60m3, the annual discharge amount is 2737.80m3.（2）TN in Linshan domestic sewage, PN,NO₂^--N,TDN, NO₃^--N, and NH₄⁺-N,TP,DTP, PP, PO₄³⁺-P, DOC of daily discharge load respectively 611.73 g,83.58 g, 15.25 g,528.15 g, 0.77 g, 501.22 g, 46.50 g, 34.30 g, 12.21 g, 13.04 g, 221.19 g. And mo nthly load respectively 18.35 kg, 15.84 kg, 2.51 kg, 0.02 kg, 15.04 kg, 0.46 kg, 1.2k g, 1.03 kg, 0.37 kg, 0.39 kg, 6.64 kg, dry season four monthly load 73.41 kg, 63.38 kg, 10.03 kg, 0.09 kg, 60.15 kg, 1.83 kg, 5.58 kg, 4.12 kg, 1.46 kg and 1.57 kg, 26.54kg;（3） sewage convergence after a fall, medium pool, ditch vegetation, such a s purification section to export, TN, TDN, PN, NH₄⁺-N, NO₂^--N reduction rates w ere 81%, 83%, 74%, 86%, 82% in the whole system;TP, DTP, PP, PO43+-P red uction rates were 77%, 77%, 77% and 59%; doc reduction rate was up to 68%. Of TN, NH₄⁺-N, TP concentration respectively by bus entrance of 80.44 m g/L, 65.91 mg/L, 6.11 mg/L cut purification for the export of 31.65 mg/L, 19.40 mg/L, 2.96 mg/L, and reached second grade standard of national residents sewage discharge.（4） from the time scale in terms of pollutant migration and purification eff ect:noon > night> morning, may related to water flow velocity and temperat ure and plant growth habit; in the spatial scale of whole ecological purification（ can be subdivided into drop period,strengthening pool,vegetation period）syst em from J1（ entrance of waste water） to J6（Sewage outlet） with high purificati on efficiency, the village sewage in TN, TDN, PN, NH₄⁺-N, the concentration of NO₂^--N purification efficiency were 60.65%, 63.24%, 44.28%, 70.56%, 62.89%,of TP, DTP, PP and PO₄³⁺-P purification efficiency of 51.57%, 51.50%, 51.74% and 13.01% respectively, DOC of the purifying rate of 33.17%; the town se wage removal contribution rate as follows: vegetation period（perennial ryegrass,water celery, acid > flat bamboo leaves, calamus > Alternanthera philoxeroides,ore, bedrock, calamus > Canna > Thalia, Cyperus alternifolius） > strengthen ing pool > drop period.（5）under the influence of the pollutants in the dry season without rainfall condition, no matter in the time scale and spatial scale, overall concentration o f pollutants was decreased and decreased greatly, but the process is not is com pletely decline, but the increase has decreases;Dissolved accounted in the proce ss of migration of TN and TP were significantly higher than particulate form, T P in the dry season without（micro） under the condition of rainfall is main cut ting with dissolved in the process of migration, supplemented by particulate; TN to TDN, NH₄⁺-N as primary form cuts.