Study On Polymeric Substances Internal And External Cellular At Catalyzed Iron Internal Electrolysis Coupling With Biological Threatment

The catalyzed iron inner electrolysis (CIIE) process is a new developed methodfor wastewater treatment, which was applied to industrial wastewater asbio-pretreatment successfully and combined the process of electro-chemistry with itsof bio-chemistry initially. Extracellular polymeric substances (EPS) and intracellularpolymeric substances (IPS), which are two important kinds of cellular polymericsubstances, play an important role in biological wastewater treatment. In this paper,studies on coupling technology of catalyzed iron method and aerobic bio-treatmentand law of formation and transformation of EPS and IPS, which will provide thebiological basis for developing coupling technology and further organically combinethe process of catalytic reduction with bio-chemistry reaction.Some extraction methods of EPS of three activated sludge were compared andextraction of cation exchange resin method (CER) was investigated here. The resultsshowed that heating to 80℃is very effective extraction method, which is effectivemethod for extrating activated sludge without contaminating EPS during theextraction procedure. Heating to 80℃was used to all experiments of this paper.The influence of bio-ferric process and bio-iron filling process on EPS wasstudied. Metal ion mainly distributed in suldge, and the content of Fe³⁺ and Cu²⁺ ishigher in EPS of coupling reactor than in the controlling one. In the catalyzed ironmethod, the production of ferric ion benefit the growth of microorganism and theproduction of EPS when the total content of ferric ion in the reactor was lowed than80mg/gSS. However, superfluous ferric ion, which content exceeded to 80mg/gSS,can inhibit the living activity of microorganism and produce negative effects of EPSformation.Furthermore, the results obtained through SEM, zetasizer and particle sizedistribution analyzer confirmed that coupling technology improved flocculation,settlement and dewatering of activated sludge and effected on conformation, frame,and dense of sludge to get compacting activated sludge. Also, the surface character of sludge was changed in coupling technology, such as zeta potential and particledistribution.The formation of IPS in bio-ferric process and bio-iron filling process wasinvestigated. The results showed that COD rapidly decreased in the initial aerationstage and the law of formation and consuming of IPS was changed. The production offerric ion in catalyzed iron method had effects on the formation and accumulation ofIPS, which influenced the efficiency of biological denitrification and phosphorusremoval indirectly. The capability of resisting sudden load change of couplingtechnology was stronger than its of controling recator, and the addition of iron andcopper had a great influence on phosphorus removal.The formation of EPS and IPS in biological treatment was surveyed. In the result,the content of PHB of IPS was far too higher than its of intraglucogen and EPS. Thecapacity of accumulation of IPS was the strongest among the three polymericsubstances in the coupling system. Competitive growth existed in EPS and IPS,especially in EPS and PHB. The existence of metal ion can change this competitivegrowth of extra-and intra-cellular polymeric substances.Take part in developing two coupling technology-catalyzed iron internalelectrolysis coupling with biofilm treatment and nitrogen removal in iron innerelectrolysis-biological coupling process. The removal of COD, chroma, TP and TNand simultaneous removal of nitrogen and phosphorus were investigated. The resultsshowed that the growth of microorganism in coupling reactor was better than incoupoling one. The removal effects of pollution factors in coupling reactors were allsuperior to those in coupling one, such as COD, chroma, TP and TN. At thetemperature of 25℃, the procedure of shortcut nitrification-denitrification producedeasily and the time of shortcut nitrification-denitrification can be decreased innitrogen removal in iron inner electrolysis-biological coupling process. The effect ofphosphorus removal was high in nitrogen removal in iron inner electrolysis-biologicalcoupling process, in which P was influenced greatly and P was reduced enormously insludge in coupling technology.