人工湿地处理炼油废水的生态效益研究(英文)

Ecological effectiveness of constructed wetlands in treating oil refined wastewater

来自茂名石化公司的炼油废水含有较高浓度的污染物 ,超过广东省规定的排放标准 ,未经处理不能直接排放。 4种草本植物 ,香根草、芦苇、宽叶香蒲和蒲草被用来测试建植人工湿地的效果以及所建植的人工湿地处理炼油废水的效果。在为期 2个月的处理过程中 ,人工湿地在前期对炼油废水的净化效率很高 ,它们对第一批高浓度废水中氨氮、COD、BOD和油的去除率分别是 97.7%、78.2 %、91 .4%和 95 .3% ,对第一批低浓度污水分别是 97.1 %、71 .5 %、73.7%和 89.8%。但是 ,随着时间的推移 ,湿地的净化效果会有一定程度的下降 ,然后逐渐趋于稳定。湿地对氨氮、COD、BOD和油类的去除效率始终表现为氨氮 >油类 >BOD>COD,但植物对它们的净去除量却是 COD>BOD>氨氮和油类。湿地建植之初 ,植物的净化功能很弱 ,但随植物的生长和生物量的增加而逐渐增强。然而 ,不同植物种对废水的净化率很接近 ,基本上无显著性差异。被测试的 4种植物在污水湿地中的生长表现都好过在清水湿地中的 ,但香根草、芦苇和宽叶香蒲在高浓度废水的分蘖数比在低浓度的废水少些 ,而蒲草相反 ,表明高浓度污水相对于低浓度污水而言已经对前面 3个种产生了伤害 ,却仍促进蒲草生长。在清水培养阶段 ,香根草产生分蘖的速度是 4个种中最低的 ;

Wastewater produced from the oil refinery of the Maoming Petro-Chemical Company, China Petro-Chemical Corporation contains high concentrations of organic and inorganic pollutants, therefore it cannot be discharged directly into river or sea unless being treated first. Four plant species, Vetiveria zizanioides, Phragmites australis, Typha latifolia, and Lepironia articutala were planted in large containers as constructed vertical flow wetland to test their efficiencies in the purification of oil refined wastewater and their growth in wetlands soaked with oil refined wastewater. The results gotten from a 2-month treatment indicated that the purifying rates of constructed wetlands for oil refined wastewater were all very high at the beginning, which removed 97.7% of ammonia N, 78.2% of COD, 91.4% of BOD, and 95.3% of oil in the first batch of highly-concentrated wastewater (HCW), and 97.1% of ammonia N, 71.5% of COD, 73.7% of BOD, and 89.8% of oil in the first batch of low-concentrated wastewater (LCW). But the performance of wetlands was decreased and became basically stable as time passed. The efficiency of wetlands in removing the pollutants was always in order of ammonia N > oil > BOD > COD, but the net removal of plants to them was ranked as COD > BOD > oil and ammonia N. In the beginning, the purifying function of plants was quite weak, but it gradually increased with the acceleration of plants growth. However, there was almost no significant difference in the removal efficiencies among the four species. The four tested species produced better growth in wetlands with HCW or LCW than with clean water, but V. zizanioides, P. australis, T. latifolia produced fewer tillers in HCW than those in LCW, while this was contrary to L. articutala. This inferred that HCW might damage the first three species, and promote the growth of L. articutala. During the period of clean water cultivation, the new tiller producing rate of V. zizanioides was the lowest among the four species, but it gradually rose during the period of treatment water soak, while the tiller-producing rates of the other three species were distinctly lowered. It was therefore suggested that V. zizanioides might have a stronger adaptation to the harsh environment than other species tested in the experiment, especially in the situation of long time of adaptation to the environment. However, the above results remains to be further verified due to the limited observation time of only two months.