Efficiency And Microbial Ecology Characteristics Of Compound Crystal Seed Filter Treat Wastewater

Phosphorus is the key element of water eutrophication, at the same time, phosphorus isnon-renewable natural resource. The decrease of phosphorus reserve will be the limit factorfor economic development in the future. The compound crystal seed filter can not onlyachieve phosphorus removal but also can realize the recycling of phosphorus. The dominantpopulation in different stages was analysed by molecular biology techniques, treatmentefficiency and bacterial community composition characteristics of compound seed crystalfilter were studied.The research object of this subject was simulated domestic wastewater. Compared withthe pollutants removal efficiency and the succession rules of dominant population includedstarted-up and stable operation phase in four biologically aerated filters (BAF), with steel slagcompound media and slag compound media as the packings. The pollutants removalefficiency and microbial ecology characteristics of A/O alternate working BAFs wereinvestigated. Then the pollutants removal efficiency and microbial ecology characteristics oftwo compound crystal seed filters by adding CaCl2in anaerobic filters were investigated. Inthe condition of optimum n(Ca)/n(P) the pollutants removal efficiency and microbial ecologycharacteristics in an operation condition were studied.In stable operation stage the average COD removal rate are84.19%,83.50%,85.99%and84.19%respectively. The average ammonia nitrogen removal rate are96.98%,97.26%,95.06%and91.34%respectively. The average phosphorus removal rate are29.25%,29.41%,39.50%and37.94%respectively. Similarity analysis of DGGE show that the four BAFs showobviously succession rules of dominant population in different stages. The dominantpopulation of four filters in stable operation phase belong to Proteobacteria、Acidobacteria、Bacteroidetes, the number of Proteobacteria have absolute advantage. The amount ofepsilonproteobacteria reduced in stable stage.In A/O alternate working stage, the average COD removal rate of steel slag compoundmedia filter and slag compound media filter are83.56%and83.32%respectively; the averageremoval rate of ammonia nitrogen are56.15%and50.89%respectively; the average removal rate of phosphorus are68.07%and63.15%. SEM-EDS of crystal seed show a small amountof crystal has formed, it probably was Ca5(OH)(PO4)3.Otherwise, after A/O alternate workingdomesticate, the dominant population of four BAFs have little difference. Compared withsingle BAF, the population abundance decreased significantly. The dominant population ofcompound crystal seed filters is priority to Proteobacteria and Bacteroidetes, UnculturedDechloromonas sp.is widely reported preponderant polyphosphate accumulatingmicroorganisms (PAOs).The wastewater treatment efficiency of compound crystal seed filters strengtheningcrystal by adding CaCl2in anaerobic filters are investigated. By strengthening crystal, thesurface of crystal seed had formed spherical crystal, probably was Ca5(OH)(PO4)3, and crystalhad raised further. The activity of protozoan and metazoan are not influenced significantly bystrengthening crystal, but the similarity and Shannon index were decreased. The dominantpopulation of compound crystal seed filters strengthening crystal are Proteobacteria、Bacteroidetes and Acidobacteria. Uncultured Dechloromonas sp. is still the dominant PAOs,and strengthening crystal do not have negative effect on it.The research show that phosphorus removal rate of compound crystal seed filters andstrengthening crystal improve significantly compared with single BAF, the crystal can beCa5(OH)(PO4)3. The effect of phosphorus removal and recovery of compound crystal seedfilter are obvious. The dominant population show obvious succession rules. The studyprovides technical reference for stable operation of compound crystal seed filter.