The Influence Of Polyaluminium Chloride Dosing Period On The Formation Of Aerobic Granular Sludge

Sewage treatment by aerobic granular sludge has dense microstructure, fast sedimenttion rate, easy degradation, higher removal rate of organic pollutants and many other advantages, but the technology to get the process of practical application is limited, because there is a long time to cultivating bacteria. In order to improve the formation of aerobic granular sludge. I was dosing coagulant Polyaluminium Chloride(Polyaluminium Chloride, PAC) at different stage of microbial growth to analyse the formation process of aerobic granular sludge and the sludge characteristics, the influence of the results are as follows:(1) With glucose as substrate, the sewage factory(A2/0 process) return sludge for the inoculation sludge pond, the sequencing batch type activated sludge reactor(SBR) cultivation of microorganisms in 1 ~ 7 d in the adjustment period, 8 ~ 14 d in logarithmic growth. The reactor the first 35 days completely granular sludge in normal conditions.(2) I compared the different influence of the dosage of polyaluminium chloride(PAC) to that the formation of aerobic granules and The influence of microorganism dehydrogenase activity. Then I finally identified the best PAC dosing quantity range is about 500 mg/L.(3) The timing of PAC dosing has a very big influence on the speed of the particles formed and the characteristics of the mature particle. Experiments show that the reactor of logarithmic phase when adding PAC in the microbial mature particles formed in the 21 d, respectively, than the adaptation dosing PAC and control group in advance the 9 d and 14 d; Logarithmic phase dosing PAC particles formed bystrength, specific gravity, moisture content(98.53%, 1.0591, 92.76%) was better than the adaptation of dosing PAC(97.81%, 1.0455, 95.04%) and control group(97.68%, 1.0380, 94.36%). As you can see, choose to reactor dosing PAC in logarithmic phase strengthening granulation can significantly accelerate the graining process, and improve the stability and settleability of the sludge particles.(4) The stable operation of reactor, the logarithmic phase of dosing PAC formation of aerobic granular sludge to average removal rate of COD and NH4 +N by about 94% and 75%, respectively, and the adaptation dosing PAC and the decontamination effect of aerobic granular sludge in the control group. Experiments show that the PAC concentration of 500 mg/L in any period when adding the decontamination ability of granular sludge.