The Experimental Research On Intracellular Carbon Source Of Biological Nitrogen And Phosphorus Removal In A~2/O Process

One of the hot points in sewage treatment research is to ensure the treating result as the premise, meanwhile realizing less cost and emission. This is the main aim of this paper. And the experiment steps are showed as follows:1) the nitrogen and phosphorus removal process needs carbon source, which comes from outside manual delivery usually. Different kind of carbon source will lead to different result. This paper use two kind of carbon source as comparison. One is sodium acetate, which is very common in experimental research as micro molecule carbon source. The other carbon source is wastewater, full of nutrient substance and energy, cheap, and easy to be obtained. The result shows that, when the main amount of energy coming from manually delivery is the same, appropriate aeration sludge shows better treating ability than over aeration sludge. In appropriate aeration sludge system, energy could be stored in sludge cells instead of being consumed. And wastewater is better for activated sludge to absorb, compared to micro molecule carbon source sodium acetate.2) Simulate the anaerobic, oxic procedure of A2/O process. Because different procedures need different oxygen and carbon concentrations, PHB amount will be varied. For there are some relations exist between the intracellular polymer PHB and extra cellular polymer, PHB can be the representation of the capacity of activated sludge. This experiment carries out in fixed oxygen atmosphere, and realizing by changing different aeration time. The best result was achieved when aerated time lasts for 6 hours to 10 hours. In these two reators, PHB synthesis and degradation process shows consistency with phosphorus removal and aggregation. So that they can maintain better effluent water quality. Too long aeration time (14h) will cause the sludge cell degenerated, while aerate 2 hours is too short for sludge cell to store energy. So these two inappropriate aeration time leads to low nutrient removal efficiency.3) This paper also analysis the key point of each sewage treatment plant, by monitoring the content of PHB, nitrogen, phosphorus, etc. The result is, without the anaerobic procedure, the A/O process couldn't synthesize PHB, which means there is no energy exists when the cell has to absorb phosphorus. So the A2/O process behaved better than A/O process, no matter in nitrogen, phosphorus removal aspect, or in energy storage aspect. Meanwhile, various sewage conditions cause different nutrient removal results in two A2/O process. If the sewage contains more phosphorus, its activated sludge can have stronger energy saving and phosphorus removal ability, and these two abilities will show a better linear correlation. The sewage of the other plant, which contains more nitrogen, shows stronger nitrogen removal ability other than dephosphorization.