Study On Anoxic And Biological Contact Oxidation Complex Process For Aquatic Products Processing Wastewater Treatment

The thesis was supported by the project of making and revising on nationalenvironmental protection standard–Effluent standard of pollutants for aquatic productsprocessing industry (No.2006-432). In this thesis, the aquatic product processingwastewater was treated by the Anoxic and Biological Contact Oxidation (A+BCO)complex process. The feasibility of effluent to meet the new standard and the dynamicmodel of pollutants removal by the complex process had been studied in this thesis.The Hydrolytic Acidification and Biological Contact Oxidation (HA+BCO)process has been widely used in middle or small aquatic products processing enterprisesat home. The process has good treatment effect about COD and NH3-N, but theconcentration of TN and TP in effluent is too high to meet the new standard. So theenterprises which used the HA+BCO process to treat their wastewater need to upgradetheir sewage treatment facilities.In order to improve the treatment effect of pollutants especially nitrogen andphosphorus in aquatic products processing wastewater, the way to optimize and reformthe sewage treatment facilities had been studied in this thesis: reform the hydrolysistank to anoxia tank and increase reflux equipments for it, then the HA+BCO processwill been reformed to the A+BCO complex process which with denitrification. Theresearch contents of this thesis includes:①Determine the best effluent quality of theaquatic product processing wastewater after treated by traditional HA+BCO process inlaboratory and determine if it could meet the new standard.②Determine severalparameters of complex process respectively when the effluent quality meet thestandards of existing or newly-built enterprise’s, such as the running condition, the fillratio of filler, the kind of coagulant and the dosing quantity of it. The treatment costincreased for meeting the new standard also been estimated in this thesis.③Study onthe kinetics of organics removal by two-phase microorganism in complex process andbuild the dynamic model which can fit A+BCO process.It is indicated that, in laboratory, the concentration of COD and NH3-N in theeffluent treated by traditional HA+BCO process could meet the standard of existing andnewly-built enterprise’s separately, but the removal effect of TN and TP is not good, theconcentration of them could not meet standards of existing enterprises’.To the A+BCO complex process, when the HRT is20h, the DO concentration is 5mg/L, the reflux ratio is400%and the sludge age is10d, the process will achieve thebest treatment effect. And at this condition, if1.0g cationic polyacrylamide(CPAM) and30g polyaluminium chloride (PAC)（or25g polymeric ferric sulfate (PFS)）been addedinto every cubic sewage, then the effluent quality of A+BCO process will meet theexisting enterprise effluent standards, and the treatment cost will increase0.46RMB/t; ifthe dosing quantity of coagulant is1.0g CPAM and50g PAC (or30g PFS), and the fillratio of the anoxic tank is52%, then the effluent quality will meet the standards ofnewly-built enterprise’s, and the treatment cost will increase0.5RMB/t.Two main parameters qm,nitr,spand qm,COD,spin the calculation model which based onASM1had been corrected in this word, and the kinetic equations of organics removalwhich could suitable for the A+BCO complex process and the YDT filler had been builtin this thesis. The precision of two kinetic equations had been tested: the precision ofthe kinetic model about NH3-N and COD removal are88%and92%.