The Study Of Constructed Wetland Filler Selection And Treatment Of Low Polluted River Water

Filler is of an important part of the constructed wetland, filler either as a plant’ssupport, and can provide places for microbial attached, also can remove directlybonded contaminants. The study of the filler adsorption performance is important.Select five kinds of constructed wetland test fillers: flyash ceramisite, biologicalceramisite, zeolite, gravel, cinders. To these five fillers for the isothermal adsorptiontest of nitrogen and phosphorus. Through this concluded that the five kinds ofconstructed wetland of filler of nitrogen and phosphorus adsorption and absorptiontheory biggest strength, and to make the screening. And to zeolite was modified,through the modification to improve phosphorus adsorption performance of zeolite.Establish the vertical flow constructed wetland simulation system at differentoperation conditions of the treatment effect of the sewage.The isothermal adsorption of phosphorus in test, on biological ceramisitespeaking, Langmuir isothermal equation can be better than Frenundlich isothermalequations describe the adsorption of phosphorus performance. The other four kindsof fillers (flyash ceramisite, zeolite, gravel, cinders,) of adsorption performance canalso through the Langmuir isothermal equation and Frenundlich isothermal equationdescribing the correlation coefficient basic greater than0.9, according to Langmuirisothermal equation, and concludes that the five kinds of filler of phosphorusadsorption quantity biggest theory (Xm), from big to small is as follows: cinders>> flyash ceramisite> biological ceramisite> zeolite> gravel. One of the biggestphosphorus slag heap theory of the adsorption quantity can be up to20.12mg/g, is254times of the gravel; Flyash Ceramisite of phosphorus adsorption quantitybiggest theory of1.37mg/g, is the gravel17, in Frenundlich isothermal equations, ncan be used to rough packing adsorption strength said, it is generally thought that,when n in2-10range, said easy to adsorption, n <0.5, says difficult to adsorption.N value is, the bigger the adsorption ability is strong. Four kinds of filler (notincluding biological ceramisite, because its correlation coefficient smaller) onphosphorus adsorption ability is as follows: flyash ceramisite> zeolite> cindersgravel. In of ammonia nitrogen isothermal adsorption experiment, with Langmuirfitting equation and Frenundlich fitting equation can be very good fitting zeolite ofammonia nitrogen adsorption, two fitting the correlation coefficient equation aregreater than0.9; And flyash ceramisite, biological ceramisite, gravel, cinders, canbe made by Frenundlich fitting equation better fitting its of ammonia nitrogenadsorption situation, the correlation coefficient reached more than0.9. Five of thepacking of ammonia nitrogen adsorption quantity biggest theory (Xm), from big tosmall is zeolite> biological ceramisite> flyash ceramisite> cinder> gravel. Onezeolite of ammonia nitrogen theory’s largest adsorption of31.25mg/g,34times isgravel. Five kinds of filler of ammonia nitrogen adsorption ability is as follows:zeolite> gravel>coal cinder> biological ceramisite> flyash ceramisite.Through the comprehensive comparison, to experiment with the five kinds ofpacking and zeolite ceramsite in more suitable for packing as artificial wetland. Atthe same time for zeolite was modified test, according to Langmuir isothermequation, get modified zeolite of phosphorus adsorption quantity biggest theory of1.24mg/g, it is about before modification (0.11mg/g)11times.The vertical flow on the construction of artificial wetland simulation systemfor8months (October2011to June2012) long-term monitoring, the whole systemfor COD, ammonia nitrogen and phosphorus removal effect is good, the averagerespectively removal rate:54%-68%,85%-89%,40%-72%. Because the wholesystem into water COD is low, denitrifying process to realize, so the whole systemof nitrate nitrogen accumulation, total nitrogen removal efficiency is low, theaverage total nitrogen removal in between14%and26%. Four treatment unit intowater of ammonia nitrogen content for46.66%,52.23%nitrate nitrogen, and1.11%nitrate nitrogen, filler depth in about10cm when most of ammonia nitrogen intonitrate nitrogen, and a few and nitrate nitrogen. Four processing unit in nitratenitrogen content along the riser above90%, and4#processing unit,the nitratenitrogen also appeared accumulation, the whole system have no obviousdenitrifying process.