A Research Into The Reason Why The Manganese Removal Efficiency Of The Biological Iron And Manganese Removal Filter Declines After Long-Time Operation

Manganese removal has been a difficult problem which has puzzled water quality engineers for over half a century, but now it has been solved preferably under the theory of biological manganese fixation and removal which has been matured through the last 20 years. Good theory which wanted to be consummate needs the verification of practice. Under the guidance of the theory, the technology of biological manganese removal has had a widely application and showed us great technical advantages. For example: the first considerable scale plant of ZhangShi development zone of ShenYang, DongFeng plant in JiLin, LanXi plant in HeiLongjiang Province, HunNan plant in ShenYang, DaLinghe plant in JinZhou and JiangBei plant in JaMusi and so on. The theory and technology has gained the recognition of the engineering bound, but it also has some disadvantages: for instance, the long time of the start-up of the bio-filter, which wastes a lot of time, manpower and money. The new problem occurred in the application: the first plant of ZhangShi development zone of ShenYang has operated stably for 4 years and been found out the effluent quality deteriorated in the end of the year 2005. Stability of the technology has been oppugned. In this paper, the reason why the efficiency of manganese removal of the bio-filter declines after running many years has been analyzed detailedly, and the rapid start-up of the bio-filter has gained preliminary research, according to the theory of biological manganese removal, under the plant and filter column experiments.According to the experiments from three major aspects which could affect the manganese removal efficiency of the bio-filter, we conclude that: the variety of the natural condition of exterior and human factor could impact the efficiency of the bio-filter, but it could recover depending on the microbe's self-adapted ability and reproduction through some time. However, the change of the inherent conditions impacted the efficiency of the bio-filter beyond retrieve. The filter media and filter configuration would evolved after long time running of the bio-filter, this is decided by the mechanism of the biological manganese removal. The HunNan center plant's bio-filter layer was cultured by mature filter material transplantation. It came out that: this method made the bio-filter have definite ability of manganese removal in the beginning, and the bio-filter can be mature in a short time, the effluent quality quickly come up to the standard, because the adaptation period of the microbe is short and the logarithmic phase arrived rapidly. So the microbe propagated quickly and the bio-filter matured soon. This is profited from that the microbe in the mature filter media of transplantation has a steady ecosystem and a similar living environments comparing the microbe cultured in labs.This research analyzed the reason why the effluent quality of the bio-filter of manganese removal deteriorated after long time operation, and suggested a simple and effective solution. This can offer reference to prevent the effluent quality deteriorating of the other bio-filter manganese removal plants which have running steadily, and make the mechanism of biological fixation and removal more perfective. This research also gives a preliminary exploration and attempt on the rapid start-up of the bio-filter. All these have a significant actual using value.