| Pickling wastewater is the water from production processes using salt as the main ingredient. Pickling wastewater has characteristics of high organic matter, phosphorus and nitrogen characteristics, especially the features that it has a high salt inhibiting conventional biological treatment process, which makesitmore difficult to treat pickling wastewater. This researchhas carried out the factors of salted wastewater pretreatment (flotation, coagulation and sedimentation), biological treatment (MBR) and advanced treatment (activated carbon adsorption, ultraviolet disinfection).What’s more,it has isolated and purifiedtolerant bacteria of removing contaminants from mature domesticated salt activated sludge in biochemical processes.In order to achieve efficient processing of high salinity, high concentrations of organic wastewater and provide technical support for the practical application of engineering technology,theresearch has studied strain characteristics which is of significance for technology industry application and promotion.This researchhas investigatedtreatment effect of flotation method for salted wastewater to determine that flotation wastewater treatment is the best way if aeration rate is 4L/h and at this time, effluent COD and SS removal rates were 26.6% and 65%.This research examined the effect of coagulation and sedimentation method for processing Pickling wastewater, through experimental study to determine the optimum coagulant, the optimal dosage, and the optimum pH value of wastewater. When selected PAC as the coagulant PAC, 100mg/L dosage, waste water pH value about 8.5, the wastewater treatment works is best, when wastewater COD, SS removal rate is 36.1% and 30.9%.This researchhas investigated thepickling effect of membrane bioreactor (MBR) wastewater treatment process and after testing to determine the optimumdissolved oxygen (DO), the optimum hydraulic retention time (HRT) of MBR. Wastewater treatment works bestwhen DO PAC is 1～1.5mg/L, HRT is 12h, at which time,the COD removal efficiency was about 92%.This researchhas investigatedthepickling effect by activated carbon adsorption to treat salted wastewater, and after biological treatment,determinedthe optimumfiltration rate of activated carbon adsorption. Whenthe filtration rate is 4.2m/h, wastewater treatment works best, and at this point the COD removal efficiency is 34%.This researchhas investigated thepickling effect of UV germicidal to treat salted wastewater and by the test to determine the optimum length of time, the limit water turbidity. When the irradiation time is 2min and the wastewater turbidity is 8NTU, wastewater treatment effect is up to the optimum, and at this time, the total coliform bacteria in the water were less than 100/L.With activated sludge of mature domesticated as bacteria source, the research has isolated 12 Salt efficient bacteria by screening.After morphological, physiological and biochemical tests, PCR amplification and 16SrRNA sequencing, it has identified 12 tolerant salt bacteria are Halomonas sp.By examining the growth characteristics of the strainwhen the salinity is 9%,15%,18% and 21%, the researchhas investigated that the 12 strainsgrowth is in good condition when salinityrange was 5% to 15%,and after inoculation it can quickly enter the logarithmic growth phase with the salinity of 15%.At different salinities (6%,9%,15%), the strains divided into three groups can remove COD more than 75%, remove ammoniamore than 62%. Through investigating factors for three sets of strain,we found that under certain conditions of neutral pH of 7 to 8, the temperature 30～35℃,the three strains pollutant removal efficiency is to the best level. And at this time,the three strains removal COD efficiency is between 80% and 90%. |
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