Research On The Treatment Process Of Small Scattered Piggery Wastewate

Small-scattered pig farms are mostly located in rural and suburban areas,it is impossible to establish perfect wastewater treatment system for wastewater treatment,because of the small size,low profits,its produces mostly of the piggery wastewater without effective treatment directly into water bodies,causing serious water environment pollution in rural and suburban areas.Therefore,development of appropriate wastewater treatment technology of small-scattered pig farms has become the key to solving rural and suburban pollution.The small-scattered piggery wastewater as the research object in this paper.through long-term monitoring of the piggery manure and sewage discharge characteristics.It is proposed to adopt biological septic tank + biological trickling filter + artificial wetland combination process to treatment small-scattered piggery wastewater.This paper focuses on study the biological septic tanks Study the volume load,residence time,temperature and other factors have effect on biological septic tank treatment effect.The best process parameters obtained by the test and provide the design basis and the stable operating conditions for the subsequent wastewater treatment process.The main research contents and results are as follows:(1)Through the monitoring of pig manure and wastewater discharge characteristics and we are informed of the characteristics of wastewater discharge.The water quality parameters of the wastewater are:COD is 9000～12000mg/L,TN is 0.71～0.92g/L,TP is 0.074～0.17g/L,SS is 1537～1748mg/L,pH is 6.59～7.68.The maximum amount of wastewater in summer.Each pig daily average volume of wastewater generated is 21.82L.(2)Study different volume loading have effect on biological septic tank operation effect.The results showed that the biological septic tank at high volume load on the removal of each pollutant is higher.HRT was 5d,influent organic load was 1.984～2.270 kgCOD · m-3·d-1,0.912～1.096 kgCOD·m-3·d-1,0.424～0.630 kgCOD·m-3·d-1,the COD removal rates were 52.5%,51.48%,42.55%;total nitrogen removal rates were 24.8%,6.78%,3.81%;total phosphorus removal rates were 47.56%,18.5%,zero removal;SS removal efficiency were 73.87%,57.36%,39.95%.This shows that the biological septic tank suitable for running at high influent load conditions.(3)Study the effect of different hydraulic residence time on the treatment effect of biological septic tank.The results showed that HRT was 5d and HRT was 3d,the biological septic tank is not much difference for each pollutant removal capabilities,and HRT was 2d biological septic tanks for each pollutant removal rate is low.HRT were 5d,3d,2d,COD removal rates were 75.56%,74.81%,58.04%;total nitrogen removal rates were 25.99%,22.54%,16.44%;total phosphorus removal rate were 59.57%,53.68%,39.42%;the removal rate of SS were 75.91%,72.90%and 68.37%.Ensure biological septic tank operation effect and maximize the reactor processing capacity.So make sure biological septic tank best HRT for 3 d.(4)Study the effect of temperatuure on biological septic tank operation effect.The results showed that temperature has a great influence on the COD treatment effect of biological septic tanks.In winter,the temperature around 0-10 ℃ reactor on the removal rate of COD is lower and the removal rate is up to 52.51%.In the spring,the temperature of 15-25 ℃ removal rate was high and the highest removal rate is 74.05%.(5)In order to improve the effect of biological septic tank treatment pig farm wastewater.By adding suspended filler,Study the filler added before and after the running effect of biological septic tank.The results showed that the addition of suspended filler does not help improve the performance of biological septic tank.During operation,due to the reason of suspension of filler and there was a lot of sludge floating phenomenon,resulting in a decline in water quality,so the selected fillers are not suitable for biological septic tank.So the packing is not suitable for biological septic tank.(6)According to the dynamics analysis of biological septic tanks COD degradation,the results showed that biological septic tanks on COD removal accords with zero order reaction kinetics.Get experience rate equation CA = CAO-390.93d-2773.6.In conclusion Biological septic tank on the nitrogen and phosphorus removal efficiency is low,but to have COD and SS have a certain Removing ability.Pig farm wastewater after biological septic tank treatment can alleviate the pressure of the subsequent processing.So biological septic tanks can be used in the pig farm wastewater pretreatment.