| With the rapid development of agriculture,the demond for pesticides increasing in our country,a great deal of wastewater are produced in pesticide production.Due to the particularity of the raw materials and the technology,lead to the composition of wastewater is complex,poor biodegradability and difficult treatment,how to effectively and reasonable treatment of pesticide wastewater has become one of the most popular problems in the world.The experiment of this paper was conducted to treat pesticide wastewater by suspended ceramics with aerobic and anaerobic processes,the core of this process is adopted special ceramsite filler,the surface of ceramsite is rough and porous,water infiltration grain density is 0.9 to 1.1 g/cm3,particle size is between 8 to 16 mm and with high surface area,ceramisite will swell under the action of water flow,these features make it easy to microbial hang film on its face,ensure the ability of removing all kinds of pollutants in wastewater.Suspended ceramsite aeration biological filter as the slightly polluted source water biological pretreatment process has been applied in many practical engineering projects,and shows the advantages of good treatment effect,reduce the operation cost greatly.The test of this paper has applied to pesticide wastewater treatment process,then get the series parameters of stable operation and the result is good.Relevant test results are shown below:This experiment first carries on to the hydrolysis acidification pool,using waste water treatment plant's sludge to seed and completed in just 20 days,removal of CODcr is good.After the biofilm growth,the average removal rate of CODcr was 29.0%,the biological decomposition of the wastewater is enhanced after the treatment of hydrolysis acidification pool and creates the good condition for the aerobic treatment latter.The entire startup process of suspended ceramsite aeration fluidized reactor only takes 22 days.After the success of biofilm culturing,studied the water purification effect to determine the optimum parameters.with the filtration rate increases,removal of CODcr?NH3-N?TP and chroma is decreased;Three kinds of upflow filter gas-water radio had little effect on CODcr,NH3-N and chroma removal,but has certain influence on TP removal and the result is best when the upflow filter gas-water radio was 1.5:1;three kinds of reflux ratio also had little effect on NH3-N and chroma,removal of CODcr increased significantly when the reflux ratio from 50% to 100%,then rose to 150%,the removal rate without too big change.With the increase of reflux ratio,removal of TP presented earlier increase and later decrease trend,TP removal effect is best under the condition of reflux ratio is 100%.The backwash way is determined by observing the head loss and the removal of NH3-N: with the method of air-water backwash and the backwash cycle is 10 days.PAC and PAM were used as complex flocculent to further remove phosphorus,Considering running cost and removal efficiency,determining the phosphorus reagent dosage is PAFC 70mg/L and PAM 10mg/L.During the running of demonstration project,the process effluent CODcr<200mg/L,meet grade two of "The National Integrated Wastewater Discharge Standard"(GB8978-1996),the process effluent NH3-N<15mg/L,meet the first grade criteria of integrated wastewater discharge standard(GB8978-1996),the process effluent TP<2mg/L,can achieve the requirements of the sewage plant in the industrial park,the process effluent chromaticity<50 times,meet the first grade criteria of integrated wastewater discharge standard(GB8978-1996).The cost of wastewater treatment after the operation of demonstration project is1.49 yuan/m3,much lower than other pesticide wastewater treatment process. |
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