Study On Constructed Wetland Treatment Technology For The Factory Moat Water Resource In Baosteel

According to the research content of the factory moat in Baosteel, the study constructs tow small-scale experiment facilities of Mn sand constructed wetland and gravel sand one, and one pilot-scale experiment facility of compounding filling constructed wetland, on the basis of which the study on treatment technology for water reuse by constructed wetland is made. The research content includes: ① investigation on water quality; ②the feasibility of water treatment by constructed wetland; ③the comparison between Mn sand constructed wetland and gravel sand constructed wetland; ④the infection by HRT and water temperature alteration; ⑤ the study on treatment efficiency on compounding filling constructed wetland to gain relative technical parameter. The result shows: There are many pollutants in the water. The Fe concentration is between 0.5-2.0mg/L and Mn concentration is between 0.2-1.0mg/L. The discharge point has much impact on the distribution of pollutants in the water. Water quality in Weiwu Lu seems much better. The regular between pollutants and season is not obvious. Technology of constructed wetland applied in the treatment of the factory moat is feasible. The treatment efficiency to Fe、 Mn、 organic pollutants and TP by Mn sand constructed wetland is high than that of gravel sand constructed wetland. But the efficiency to TN is lower. The two technologies can make up with each other. HRT and water temperature has no much impact on the treatment efficiency to Fe、 Mn、 organic pollutants 、 TP and NH₃-N, but has much impact to NO₃-N treatment. With the shorten of HRT and water temperature, the removal of NO₃-N becomes lower and lower. The treatment efficiency by compounding filling wetland is very great. The average removal rate is: turbidity, 88%; TFe, 93%; Mn, 83%, organic pollutant, 44%; NH₃-N, 80%. The effluent can meet the "Code for wastewater reclamation and reuse as industrial water". ●The design for the constructed wetland is proper and the HRT in winter could research 2 days, which could be shorter in summer.The factory moat water treatment by constructed wetland not only can solve the practical problem in the process of water reuse of iron and steel industry, but also exploits a new way for iron and steel wastewater reuse, it can improve water utility efficiency, help to achieve sustainable develop in iron and steel industry. This technology has a wide prospect in project application.