【作者】 宋凤敏；

【导师】 呼世斌；

【作者基本信息】 西北农林科技大学 ， 环境工程， 2004， 硕士

【摘要】 薯蓣皂素是一种药用价值很高的激素类药物原料，被广泛的应用于抗炎、避孕、镇痛、治疗冠心病等药物，国内外需求量很大。在这种市场需求的带动下，生产皂素的企业也不断增多。但是生产皂素过程中产生的废水却是一种色度大(7000 倍)，酸度高(pH1— 2)，污染物浓度高(COD20000— 60000mg/L)的有机废水。由于废水具有这些特点而使其处理难度大，处理费用高。目前尚无较好的处理方法，大多数生产企业将废水直接排放，对周围的水体及土壤造成很大程度的污染。因此，皂素生产废水成为废水处理行业的又一难点。 酵母菌是一种真菌。据其分布情况表明，经长期的自然选择，酵母菌对高糖、高碳、高渗透压等环境具有较强的适应性，这使其有可能应用于高浓度有机废水的处理，并由于其利用的碳源种类非常广泛，使其可应用于不同的有机废水的处理。而皂素生产废水属强酸性高浓度有机废水，其主要成分是盐酸、淀粉、五碳糖、六碳糖，且含糖量很大。可控制条件让酵母菌在皂素生产废水中生长，既达到废水处理的目的，又可回收酵母单细胞蛋白(SCP )，从而实现废水的资源化利用。 本研究主要是利用酵母菌对皂素生产废水进行了连续小试处理。通过批量生化试验对酵母菌在皂素生产废水中的生长条件进行了探索，并从多种组合菌株中筛选出一组处理效果最佳的酵母菌株组合。结果表明该菌株(卡尔斯伯酵母+深红酵母+热带假丝酵母)在 pH5.0，温度 28℃，处理时间 28 小时，接种量 10%的条件下，对皂素生产废水中 COD的去除率达到 70%以上。利用接种了该菌株的生物接触氧化反应器对皂素生产废水进行的连续小试结果表明：在恒温 28℃，水力停留时间 12 小时，DO 在 4.5mg/L 左右的条件下，COD 容积负荷为 2.0— 19.2Kg/m3.d 的范围内，COD 去除率稳定在 70%以上。另外发现，溶解氧的大小对 COD 去除率影响很大，系统一旦缺氧，COD去除率会很大幅度下降。对进出水 pH 和 COD 去除率的关系进行了探索，发现进水 pH 对 COD 去除率有一定的影响，但系统出水 pH 不受进水 pH 大小的影响，保持在 6.0— 7.0 范围内。酵母菌生长最佳 pH 是在 4.5— 5.5 间。处理后的出水中含有大量的酵母菌体，且菌体含量随进水有机物浓度(COD)升高而增加。将酵母菌反应器出水再经 EM 活性污泥反应器进行二级处理。利用 SBR 反应器使反应器中共存大量的好养和厌氧微生物共同发挥作用，废水在两级生物处理后 COD 去除率达 90%以上。 同时，对皂素生产废水混凝批量试验的净化研究进行了一系列的探索试验，结果表明，混凝处理对皂素生产废水的处理效果不大，故不宜采用混凝法来处理皂素生产废水。更多还原

【Abstract】 Diosgenin is the raw material of a kind of highly valuable hormone medicine, Whichis widely applied to these medicines of resisting inflammation、contraception、relievingpain、anesthetizing、curing coronary heart disease ,etc. The international market demands ofDiosgenin is very large ,which leads to the growth of the number of manufactures ofDiosgenin in China .However ,the Diosgenin production wastewater which is characterizedby high color(7000 times), low pH(1— 2) and high organic concentration(COD=20000— 60000mg/L) can be hardly treated in a reasonable cost .Most of the Diosgeninmanufactures discharge the wastewater directly because there is no totally feasible method oftreating it now. This has done great harm to the water and soil environment near themanufactures , The treatment of Diosgenin production wastewater becomes a new difficultyof industrial wastewater treatment . Yeast is a kind of fungi .Distributing of yeast indicates that after the natural selectionfor along time , yeast fit on the surroundings of containing high concentration sugar ,highconcentration carbon ,or high infiltration pressure, which makes it possible to apply to thetreatment of the high concentration organic wastewater ,And the Diosgenin productionwastewater has the characteristic of great acidity ,high organic matter concentration, whichmainly ingredients are hydrochloric acid ,starch ,moreover ,its content of sugar is reallyhigh .So in order to reduce the pollution degree of the organic waste and gain the SCP byusing the waste as a resource ,we can make the yeast grow in the Diosgenin productionwastewater by controlling the factors. In the study the laboratory-scale continuous treatments of the Diosgenin productionwastewater used yeast. The biochemistry test of yeast indicated that under thecondition:pH5.0,temperature 28℃　,handling time 28 hours ,inoculation 10% term, the CODof the wastewater removal rate is 70% finally, and selects the best yeast strains combinationfrom many kinds of mixed yeast strains, it includes: Sal.carlsbergensis Hanser , Rhodotorularubra(Demme)Lodder , Candida tropicalis. The best yeast strains were inoculated to abiological contact oxidation reactor, and the reactor was used to treat the Diosgeninproduction wastewater . Under the COD load range from 2.0-19.2kg/m.d ,28℃ ,HRT12h ,DO=4.5mg/L,the COD removal rate was over 70%.On other hand, the CODremoval rate will decrease sharply when the treatment system is in short of DO. Variation oforiginal wastewater pH has the important influence on the COD removal rate , but it seemedto have no apparent influence on the pH of effluent water, which keeps the rang of6.0— 7.0.The optimum pH for the growth of yeast was found to be in the rang of 4.5— 5.5.The effluent wastewater contained high concentration of yeast bodies, which content<WP=7>increased with the organic concentration (COD) of the wastewater . The effluent wastewaterusing yeast was treated by EM-Activated sludge, which contents great of aerobic andanaerobic microbiology .Using SBR reactor , the results showed that the COD removal ratecan reach 90% finally. Moreover , a series of exporting experiments of the coagulation purify study showed theeffect is small .So the Diosgenin wastewater treatment is not suitable to apply the coagulationpurify method .更多还原