| Livestock wastewater has already become one of the main eutrophication water pollution sources in our country nowdays, which seriously influenced ecological environment, economical and social healthy development. Artificial wetland system is complex for wastewater treatment composed of matrix, emergent and submerged macrophytes, microbe and water body, which designed and constructed by analoged natural wetland according to ecology principle. The matrix, macrophytes and microbe of artificial wetland system could remove pollutants of wastewater, and the system is suited for the small and medium-sized towns and the countryside areaes with lower level econome development and energy shortage.In the experiment, the matrix components of artificial wetland system and the purification effect of plant kinks on livestock wastewater, and safety recirculation of water treated with matrix were studied for providing theory basis and technique support for slection of plant and matrix, and movement of artificial wetland system, and providing reference basis for reasonable use of livestock wastewater. The main results as following:1. The vertical current matrix of artificial wetland system was constructed using activated charcoal and the slag (1:3), ceramsite and volcanic rock respectively, and its effect of purifying livestock wastewater was studied. The results indicated that three kinds of matrix had good purification effect on the total phosphorus of wastewater, and the most elimination rate could reach 99.8%, 82.2% and 93.3% respectively, and the most elimination rate could reach 99.3%, 90.6% and 82.8% for turbidity of wastewater respectively. The mixed matrix of activated charcoal and slag had better elimination effect on biological oxygen demand (BOD) and total nitrogen than volcanic rock and ceramsite with more than 34.6% and 39.7% elimination rate for COD and 29.8% and 53.6% for total nitrogen respectively. The pollution indexes of wastewater of the artificial model reduced rapidly and remained steadly from 0 to 5 days treatment with matrix.2. The results from livestock wastewater purification with floating and submerged macrophytes showed that the floating duckweed had better purification effect on wastewater and elimination rates were 43.83% for COD and 95.95% for total phosphorus. The emergent plants of reed and the stem of cattail had 79.85% and 65.3% total phosphorus elimination rates, and 46.17% COD elimination rate for reed. The degeneration rate of ammonium nitrogen reached above 95% in the water purification incubators planted five kinds of plants. Submerged macrophyte Myriophyllum spicatum had the best elimination rate of total nitrogen with 76.4%, which was 29.29% and 46.77% higher than Potamogeton pectinatus and duckweed. Therefore, the different crops could be planted reasonably to make them play coordination role and obtain excellent purification of wastewater.3. The result of water safety recirculation research showed that it had a certain impact to the crop growth if livestock wastewater was directly irrigated to soil, which reduced germination percentage of vegetables of radish and anise, and root enlargement rate of radish. The impact was not great for the corn crop grew to a certain stage by livestock wastewater irrigation directly, howerer, it decreased obviously fresh weight per plant of radish. Water recirculation had the best comprehensive effect on crops irrigated with the artificial wetland system with vertical current matrix treatment.
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