| The Membrane bioreactor (MBR) was a new water treatment process which combined the membrane separation technology with the traditional biological treatment one. MBR has the advantages such as simple process, small area occupied high quality effluent, and lower excess sludge production and so on. After the development of several decades, it has been developing and broadening its application fields, and has got more and more attention of the experts. But, the characteristics of the membrane components such as the very high cost and easily polluted have been influenced the further promotion and application of the MBR which lead it to be a situation of high efficient with high cost currently.The decontamination effect of SIDMBR treat the emulsified oil wastewater was investigated and the optimum conditions of the reactor within a certain range were discovered through the laboratory experiments in this paper. The treatment effects of the emulsified oil wastewater were also studied under stable operation, and the process feasibility and operational efficiency of the reactor were investigated after with the addition of the fly ash.In this study, the140meshes stainless steel cloth was selected as the membrane module to tructure a new MBR process:Sequencing Inclined Dynamic Membrane Biological Reactor (SIDMBR), which retained all the advantages of the traditional membrane bioreactor and even better than it. The selected membrane module has good performance which was verified by studying the mechanism of the membrane fouling, and it has effectively solved the defects of the expensive membrane materials and the membrane fouling which limited the development and application of the membrane technology. It provided some scientific reference basis for the process in the further popularization and application in the processing of the small-scale industrial wastewater treatment.The test results showed that the stainless steel mesh (140meshes) had much better practical performances than those of the nylon mesh and the industrial fabric. So, the stainless steel (140meshes) was selected as the membrane components in this study. The removal efficiencies of the COD, -N and total oil under the conditions of the HRT was24h (anaerobic4h, aerobic20h), influent oil concentration was150mg/L and the DO concentration was3mg/L reached94.4%,93.7%and99.2%, respectively. Water quality fully could fully meet the requirements of the first grade Sewage Discharge Standard (GB8978-1996). So, the conditions above were identified as the optimum ones of the experiments. The reactor had very good treatment effect in the case of the stable operation, and the average removal rates of the COD, NH4+-N and the total oil were93.9%,93.5%and99.0%, respectivly.Studies on the adsorption properties and dosing quantity of the fly ash to the emulsified oil wastewater showed that the fly ash had a good adsorption effect to the total oil and the COD, with rates of0.39and4.00mg/L·min, respectively; but the adsorption to the NH4+-N was negative, with a rate of-0.13mg/L·min; three of them had the same adsorption equilibrium of40min; the total oil adsorption isotherm line conformed to S-type adsorption isotherm basically; the COD adsorption isotherm was irregular; NH4T-N adsorption isotherm located below horizontal axis entirely; with the increasing quantity of the emulsified oil wastewater, adsorption amount of total oil and COD would also increase, and the maximum amount of total oil and COD were1.44and11.4mg/g; NH4T-N adsorption capacity was the smallest and even negative adsorption; the dosage of fly ash from0to2.4mg/L, and optimum dosage of1.6g/L which had the highest removal rate of total oil and COD, effluent concentrations were3.3and40mg/L, and the removal of NHU4+-N was84.6%, its effluent concentration was11.2mg/L at the moment.The influence of fly ash to structure and composition of dynamic membrane were also conducted during the experiment. Influence to membrane structure study showed that when adding0-1.6g/L fly ash, membrane flux increased with the increase of dosage, adding1.6-2.4g/L fly ash, flux decreased while increasing fly ash. The total volume of cake layer biofilm decreased with the increase of fly ash, the gel layer biofilm decreased with the dosage of fly ash less than1.6g/L, but increased with the dosage of fly ash more than1.6g/L. Size of particle attaching dynamic membrane increased with the adding of fly ash, and when the dosage was2.4g/L, something similar to gel appeared on the surface structure of dynamic membrane, connected particles. Influence to membrane components study showed that the amount of LB, TB and EPS in reactor decreased under different dosage of fly ash, but the component content and ratio of TB and EPS decreased first and then increased with the adding of fly ash, they reached their lowest when the dosage was1.6g/L. The infrared spectrum characteristic peaks of dynamic membrane were almost the same, but differ slightly in adsorption intensity under different dosage of fly ash. |
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