生物反应器中投加含硅聚铁混凝剂的协同作用研究

比较了将含硅聚铁混凝剂分别投加到反应器和出水中两种工艺对COD和磷的去除效果.结果表明: 混凝剂投加量在40 mg/L以下时,前者出水中的磷低于后者,此时将混凝剂投加到反应器中具有生物协同作用,30 mg/L时协同作用最明显; 当混凝剂的投加量增加到50 mg/L时两种工艺出水中的磷没有明显差别,不再具有生物协同作用; 混凝剂投加量为10～50 mg/L时,两种工艺的出水COD差别不大,没有协同作用.将混凝剂直接投加到反应器中可省去混凝、沉淀所需的设备及构筑物,从而节约投资.因此为提高对TP和COD的去除效果,可直接将混凝剂投加到生物反应器中.

On synergetic effects of phosphorus removal by feeding polyferric silicate into bioreactor

The present study is aimed at comparing and analyzing the difference of phosphorus and COD removal effects between feeding coagulant into biological reactor and coagulating, settling the bioreactor effluent by using the polyferric silicate. The results of our experiments indicate that when the dosage of coagulant was less than 40 mg/L, the phosphorus concentration of effluent in former process was less than that in latter process, so there was synergetic effects in feeding coagulant into bioreactor. As is seen, in recent years, the eutrophication of water bodies has become a more and more serious problem, so that not only COD but also nitrogen and phosphorus are to be removed from wastewater. Since nitrogen removal and phosphorus removal need different conditions, there exist some contradictions between the two processes in single-activated sludge system. In addition, since nitrogen removal and phosphorus removal can hardly satisfy the environmental protection standards simultaneously in a traditional biological treatment system.. Nitrogen was only removed by biological treatment systems, so assistant phosphorus removal was usually used as chemical phosphorus removal. When the dosage of coagulant was increased to 50 mg/L, no evident difference were found between the two treatment processes and synergetic effects couldn't be found. The synergetic effects were most prominent when the dosage was 30 mg/L. For COD, the two feeding modes help to improve the removing effects of COD. However, no evident difference would be seen between them when the dosage was 10-50 mg/L. In conclusion, if the coagulant was directly fed into bioreactors, the expenses of coagulating and settling equipments can be saved, moreover, the removing effect of TP can be enhanced. Therefore, the coagulant can be directly fed into bioreactors so as to improve the removing effect of TP and COD,