[Treatment studies of industrial rainoff with a new type of constructed wetland].

According to water characteristics of industrial rain runoff in a catchment of Tongsha reservoir, Dongguan city, an improved baffled constructed wetland (BCW) was used for purification experiment study of simulated and on-the-spot rain runoff. The purification effects of simulated rain runoff were compared in different operated phases of BCW. Meanwhile, the variation of the pollutants (COD, SS, TN, TP, NH4(+) -N, Pb, Zn, Cu) along the BCW and their removal mechanism were analyzed and discussed, respectively. In the simulated experiment, the effluent water quality of BCW system met the needs of Environmental Quality Standard for Surface Water( GB 3838-2002) III, besides TN met IV, and most of the pollutants were removed in the front of the BCW. In the purification study of on-the-spot rain runoff, removal rate of COD, SS, TN, TP and NH4(+) -N were 90.9%, 97.0%, 83.4%, 92.2% and 90.0%, respectively; removal rate of Pb, Zn and Cu were 98.4%, 94.1% and 93.6%, respectively. The effluent met the grade III. Results showed that there was remarkable treatment performance of industrial catchment rain runoff when BCW system was used, which also can withstand strong shock load. Moreover, a modest variation of temperature affected the removal of pollutants in the BCW insignificantly.