Research On Slow Rate Land Treatment System And Improved Experiment

This paper mainly discussed the design of slow rate land treatment system and plants choosing, fitting field, land area and hydraulic load designing . In order to solve the problem of hydraulic load of slow rate land treatment system, this paper carried through experimental research to increase hydraulic load of land treatment system, namely sewage irrigation and effluent reuse. The system fixed drainage device that could control drainage and collect discharged water, and the system could dispose a large of sewage with less land area and could use nitrogen, phosphor, organic substance of sewage to realize sewage disposal and sewage irrigation . All kinds of contaminations could be disposed effectively through controlling hydraulic load and drainage process, water quality discharged could satisfied with other usage standards. Experimental results showed:1. This experimental sewage which came from living area was lower than the standard listed of 《Vsurface water quality standard》; Water quality was improved obviously through disposing. The removal rate of consistence of suspended substance , ammonia nitrogen, BOD5, the index of hypermanganate, total phosphor was higher than 90%, and the removal rate of total nitrogen was between 80% and 90%.2. Dry land crops and water plants were contrasted in this experiment, hydraulic load of water plants was higher than dry land crops'. Experimental results showed that water plants system is superior to dry land crops system in disposing sewage. Two kind of systems was not notable in removing suspended substance , ammonia nitrogen, BOD5, the index of hypermanganate, total phosphor, but notable in total nitrogen .3. Land samples was gathered to test the indexes of ammonia nitrogen saltpeter nitrogen , total phosphor before and after system running. Results showed that three substance did not cumulate in soil and system running did not increase the contents of nitrogen, phosphor in soil and did not effect soil properties , so the system was sustained.The system could not only dispose sewage but also use sewage to irrigate and could remove effectively all kinds of contaminations; the system need not complicated technology and running expenses was low, so this technique could be widely applied...