Study Of Comparative Test For Treating Micro-Polluted Source Water With Biological Filter And Membrane Bioreactor

The continuous deterioration of water environment presents great difficulties and challenges to the capability and performance of conventional water treatment processes, therefore, broad concern has been obtained on biotreatment of micro-polluted source water. The research on the water quality of Songhuajiang river demonstrated that the main pollutants of this river are ammonia, permanganate index and styrene. In order to evaluate the efficiency on organic pollutant removal, three biotreatment processes, including bacterial activated carbon (BAC) filtration treatment, bacterial zeolite filtration treatment and membrane bioreactor (MBR), were employed in our experiments. In the mean time, application prospects of the two biotreatments, BAC filtration and MBR, were contrasted from angles of economic and technical.The results demonstrated that the efficiency of ammonia removal on bacterial zeolite filtration was higher than 90% during the start-up, along with the running time extension, the removal rate of ammonia decreased gradually, due to the adsorption and biodegradation of ammonia by bacterial, the removal rate kept at 20~30% after two-month running; the average removal rate on the permanganate index and styrene were 17.04% and 74.3%, respectively; there was almost no nitrobenzene removal rate on bacterial zeolite filtration. The removal rate of ammonia on BAC filtration kept at 40% around; compared to the bacterial zeolite filtration, BAC filtration had higher removal rate of permanganate index, styrene and nitrobenzene.Nitrite accumulation was studied in this paper. Influent NH4+-N concentration, pH value, and dissolved oxygen are three important influencing factors for nitrite accumulation. This paper will discuss the trends of nitrite generation affected by each of the three factors: when pH value is over 7.6, nitrite concentration increases in the column along the water-flow direction, and nitrite concentration arrives at the maximum value when pH is up to 8.0; nitrite accumulation could be observed obviously when NH4+-N concentration is higher than 4mg/L; in air-water cocurrent fashion, with the decrease of influent dissolved oxygen, the nitrite accumulation becomes gradually obvious, while in...