Study On SBR Treatment Of Garlic-processed Wastewater

Garlic has the effectiveness of stimulating the appetite,anti-inflammation,Sterilization and staying caducity.Therefore,the deep-processing enterprises of garlic agricultural products expanded unceasingly in recent years,which also produced a large number of sewages.At present,there is little research about the treatment of the wastewaters.This article is focus on the research of purification technology for garlic-processed wastewaters by means of SBR and solid adsorption.The activated sludge for garlic-processed wastewaters was cultivated successfully. Selected activated sludge form sewage plants,fertilizer plants and friendship River to culture the activated sludge for garlic-processed wastewaters.After training,the removal rate of COD of the first two reached 97.88%,99.56%and the COD of the wastewaters which had dealt with attained the state's first-class standard for the environmental quality of surface water.But the activated sludge from friendship River was not suitable for the culture.During the process of cultivating activated sludge,the temperature,nutrients and other factors were examined,the results proved that the inorganic matter was in proportion with organic matter in the wastewaters.It was not very helpful to add nutrients to the wastewater for the degradation of COD.However,the temperature on the cultivation of activated sludge affected significantly.The removal rate of COD increased with the increasing temperature. Experiment also showed that the activated sludge became expanded when the temperature was 15℃.Based on an overall consideration of various factors,we found that 25℃was the best temperature for training the activated sludge.In SBR experiment,the impact of influent time,reaction time,sedimentation time, drainage time and idle time on the treatment effect was studied.The results showed that the best system parameters for the culture as the follows.Influent time:Omin;reaction time:7h, sedimentation time:1h;drainage time:1h.Under the conditions,the removal rate of COD reached 94.45%,and the system was running stable.The COD of the wastewaters which had dealt with attained the state's first-class standard for the environmental quality of surface water.Observe the types of the microbe in the activated sludge under a microscope.At the early stage of cultivating,we couldn't find any protozoa and the structure of zoogloea was incompact,the removal rate of COD was about 40%;In the medium term,sludge concentration increased gradually,We could find some ciliates,such as Paramecium, Trachelophyllum pusillum and a small amount of Vorticellas,the first two were the main microbes.The removal rate of COD exceeded 60%.At the late stage of cultivating,a large number of protozoas and micro-Metazoas appeared,such as rotifer,Epistylis,Vorticella and some microbes which had to be further study.Vorticella was the main microbe.The removal rate of COD exceeded 90%.The efficiency of sewage treatment was good.Adsorption treatments of garlic-processed wastewaters were carried out by activated carbon.Effect of adsorbent quantity,time,temperature,and pretreatment method of wastewater,and so on to adsorption operation was discussed.Experimental results from adsorption directly by activated carbon to these wastewaters are not very ideal.Its removal ratio of COD is less than 35%.However,through pretreatment of the garlic wastewaters by appropriate activated sludge,perfect treatment effect was obtained further by activated carbon. The removal ratio of COD approaches 93%,and the effluent has less than 23 mg/L in COD and may be discharged and be reused.