Study on Removal Effect of Organic Matters in Micro-polluted Raw Water by Substrate in Constructed Wetland

Surface flow constructed wetland,reciprocating flow constructed wetland and plug flow constructed wetland were built in Yuqing reservoir from Yellow River in Jinan.The removal effect of CODMn in micro-polluted raw water by constructed wetlands and the elimination of organic matters by the substrate were investigated.The results show that constructed wetlands have good removal effect of CODMn in micro-polluted raw water.The removal rates of CODMn by reciprocating flow constructed wetland,plug flow constructed wetland and surface flow constructed wetland are 31.37% to 58.12%,27.10% to 57.65% and 17.10% to 34.45% respectively.The combined effects of plants,microorganisms and substrate are the treatment mechanism of micro-polluted raw water,in which the substrate plays an important role.After the treatment by plug flow constructed wetland and reciprocating flow constructed wetland,the amount of carbon element on the substrate surface rises from 4.30% to 4.42% and 4.60%,the amount of nitrogen element rises from 4.10% to 6.58% and 6.70%,and the amount of phosphorus element rises from zero to 9.10% and 9.58% respectively.