Hybrid Wastewater Treatment System for Water Reuse and P Recovery

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1) This research dealt with the coagulation characteristics of polysilicato-iron (PSI), a new inorganic polymer coagulant, when it was applied to coagulate algae and municipal wastewater. The experimental results obtained with jar tests indicate that PSI was more effective than PAC and AS in coagulating and separating Microcystis sp. and Stephanodiscus sp. When the jet mixed separator (JMS) was used as a unit of simultaneous flocculation and sedimentation, PSI had almost the same effect as PAC at the same dosage of 5 mg/l Al or Fe in coagulating municipal wastewater.2) This research has developed a novel membrane process in which ammonia oxidizers are fixed en the membrane disk. In this study, the characteristics of the membrane filtration resistance was investigated The results derived from this study were summarized as follows : (1) The magnitude of the filtration resistance was strongly affected by the initial inoculation. (2) The filtration resistance due to the accumulate cake was … More found to be dominant. (3) Increasing the disk rotational speed was found to be efficient for removing cake. About 3000 hours of the operation could be continued by only implementing this simple cleaning method every 500 hours. (4) Filtration resistance excluding the cake resistance seemed to be caused by humic substances and extracellular polymeric substance produced by biomass.3) The density of ammonia-oxidizers which formed dense cell cluster was about 5 times higher in the innermost biofilm than in the middle and surface of the biofilm. Due to the presence of ammonia-oxidizers throughout the biofilm, ammonium oxidation zone was expanded with increasing in oxygen penetration depth, which consequently resulted in an increase of the overall ammonium flux into the biofilm. Specific ammonium oxidation rate was dependent upon the density of ammonia-oxidizers.4) Phosphorus deficiency induces the synthesis of acid phosphatases in roots of lupin and other plant species. In this study we examined the induction of secretory acid phosphatase (S-Apase) at both the molecular and cellular levels. Lupin plants had increased levels of total acid phosphatase activity within two to five days after P was withered and levels approximately doubled by 15 days. Lateral roots and not main taproots were responsible for this increase in acid phosphatase activity. Immunoblot analysis using antibodies raised against a purified S-Apase showed that the synthesis of this protein was induced as early as 2 days in the P deficient treatment and that levels dramatically increased by 15 days. In contrast, no immunoreactive polypeptide was evident from crude extracts prepared from root tissues of-P treated plants. Less