A Study On The Influence Of Sediment On The Reduction Of Pollutants In Water

Sediment, in the state of suspended and deposited in water, is an important part ofthe water environment in river. The suspended sediment which distributes widely inriver has great specific surface area because of its small particle size, at the same time,some active substances are adhered on the sediment surface, which on one hand, mayadsorb contaminants so as to reduce the concentration of pollutants in the water, on theother hand, may release contaminants to the aqueous phase and cause pollution whenthe water environment conditions or dynamic conditions change. Therefore, obviousdifferences of the pollutants migration and transformation occur between sedimentwater and water without sand.A series of simulation experiments were conducted on basis of summarizingexisting research results in this paper. Sediments in the Zhanghe River were used inthese experiments and isolated according to different particle size ranges. Ammonianitrogen and organism were the main pollutions in this research. Reduction laws ofammonia nitrogen and organism, in quiet water and on different conditions of impactfactors, were systematically studied in these series of experiments. The main researchcontents and results are as follows:(1) A series of experiments were designed to study the influence of sediment on thereduction process of the ammonia nitrogen under conditions of different sedimentconcentration, different particle size and different initial concentration of ammonianitrogen；(2) Experiments were conducted to research the effect on the degradation processof the organism caused by different concentration and the different particle size. Theresults showed that the organism degraded faster in sediment water than in waterwithout sand, and the higher the sediment concentration and smaller the particle size,the higher the degradation rate;(3) The first-order kinetics was tried to fit on the experiment results, and theinfluence of the sediment concentration and the particle size on the reaction rateconstant were discussed, thus to analyze the influence of sediment on the reductionprocess of ammonia nitrogen and organism;(4) Put forward corresponding suggestions for the management of sandy riversbased on the test results.