Bioremediation Of Urban Contaminated Riverway Water

At present, Aiming the status of eutrophication, people can sucessfuly remove nitrogen by using biology technique.But for phosphorus, can not carry satisfied effect for most reactors.To compose the problem, The experiment researches the affecting factor of biology removing the Phosphorus and effect in different craftworks in this project.Ceramic particle was mainly used for biofilm carrier and remediation of surface water, however, there are some problems of it, such as flow situation, washing back and the complex structure, inconvenient operation and management.In this project , using ceramic honeycomb carrier, Abundant microbiology formed on the carrier due to the special structure of ceramic carrier and the surface water according to experiments.On the other side, The microorganism attached on the carrier easily, and honeycomb shape promote oxygen transfer.First step, in-situbioremediation and ex-situbioremediation process were used for the treatment of the river-water of Caohejing.To research the effect of phosphorus removal under different reaction time.The result indicates that the phosphorus removal rate is fluctuating in -3.39%—50.51%, the effect is not good.Sequencing Biofilm Batch Reactor and A2/O process were used for the treatment of the simulated wastewater, specially for phosphorous removal, based on biofilm formed on ceramic honeycomb carrier. Anaerobic reaction section was 2.5 hours and 6 hours in aerobic reaction section, the influent COD/TP rate is 50-60, the density of phosphorus from the SBBR effluent is smaller than 0.5 mg/L, the removal efficiencies of total phosphorus be more than 85%, but the efficiencies from the A/O craft be less than 50%.Improving A/O process, research the removal effect on simulated water and the river-water by using the inflow reactor.The result indicates that the removal rate of TP,NH4+–N,CODCr were above 90%,90.10%,73.19% under the inflow is 5 mL/min and the circumfluence is 19 mL/min, or the hydraulic resident time (HRT) in anoxic reactor is 4.12 minutes, and is 38.48 minutes in anorobic reactor.This process overcome the disadvantage of high HRT in SBR process and save the treatment cost. When treatment the river-water, the removal rate of TP,NH4+–N were 56.09%,84.07%.The reason is that the low carbon can not satisfy the demand of phosphor bacterium growth.And the rate enhance rapidly and unstably when put into acetic acid.Furthermore, to identify bacterium genus of the biofilm by using PCR—DGGE. total microbial DNA was extracted from samples which were collected from anoxic reactor, anorobic reactor and the total outlet.16S rRNA fragments were amplified from the total DNA successfully using a pair of universal bacterial 16S rRNA primer , and then were used for denaturing gradient gel electrophoresis (DGGE) analysis. The bands in the gel were analyzed by statistical methods and excided from the gel for sequencing, and the sequences were used for homology analysis and then two phylogenetic trees were constructed using DNA Star software sources.The phylogenetic analysis based on partial 16S rDNA from anaerobic biofilm suggested that the strain DN was the closest relative to Aeromonas salmonicida bacterium,Enterobacter sakazakii bacterium,Escherichia coli with 94% of sequence similarity.And the 16S rDNA from aerobic biofilm suggested that the strain DN was the closest relative to Staphylococcus,Pseudomonas bacterium with 99%.