【作者】 郑志伟；

【导师】 呼世斌；

【作者基本信息】 西北农林科技大学 ， 环境工程， 2008， 硕士

【摘要】 浓缩果汁生产废水属高浓度有机废水,具有固体杂质多,有机物含量高,水质变化大等特点,如不处理就直接排放,将会对天然水体造成严重污染。目前,我国一般采用物化+生化处理的方法对果汁废水进行处理。由于果汁产业是近年新兴工业,果汁废水处理的研究相对于啤酒废水、酒精废水、淀粉废水等其它高浓度有机废水处理的研究来说有些滞后,相关的研究报道和工程实例也较少,已有工艺大多仿照其它高浓度有机废水的处理工艺设计,由于没有考虑到果汁废水的自身特点,很多都在启动和运转过程中产生了一系列问题,因此,有必要对果汁废水处理的工艺及工艺运行参数进行试验研究,提出可行的工艺和最佳的控制参数。本研究根据果汁废水COD值高、SS值高的特点,采用水解酸化—SBR这一组合工艺对果汁废水处理进行试验研究,通过分析废水COD、BOD5、SS等指标的去除效果和变化规律,探索了该组合工艺在启动和运行过程中的最佳控制参数,研究结果如下:1.采用低负荷接种挂膜法对水解酸化池进行启动,经过22天的调试运行,水解酸化反应器挂膜成功,处理效果趋于稳定,COD去除率保持在42.2%～47.3%之间,SS去除率保持在76.2%～82.4%之间。短时间完成启动过程的现象表明果汁废水具有良好的水解酸化处理活性。2.通过单因素试验得到水解酸化反应器处理果汁废水的适宜参数控制条件为:HRT为8h,搅拌间隔2h。在此条件下,当进水COD浓度为3838～4310mg/L时,水解酸化工艺对果汁废水COD、BOD5和SS的去除率分别稳定在45%、28%和78%左右。表明以水解酸化工艺作为前处理单元,可高效去除果汁废水SS,使BOD5/COD值由处理前的0.45～0.53提高到处理后的0.60～0.66,可为后续SBR工艺的稳定运行创造有利条件,提高组合工艺的整体效果和稳定性。3.采用好氧活性污泥工艺处理较高浓度的有机废水时,活性污泥的培养驯化是处理系统取得成功的一个必要手段,试验中通过24天的连续培养驯化过程,得到了活性较高的污泥,外观呈黄褐色,絮状,SV30在20%～35%之间,SVI在70～100之间,可承受较大范围内的COD负荷。4.采用SBR工艺进行后处理时,通过单因素试验确定最其适的操作条件为:曝气时间7h,曝气量0.1m3/h,沉淀时间1h以及MLSS为3500～4000 mg/L,在此条件下SBR对水解酸化预处理后的果汁废水COD、BOD5及SS的去除率分别达到94.3%～97.1%、96.4%～98.1%和67.1%～73.2%,连续运行试验表明其稳定性较好。5.在分别得到各单元工艺的最佳控制条件后,进行了水解酸化—SBR组合工艺处理果汁废水的连续运行试验,并对其抗冲击负荷能力进行了分析研究。结果表明:组合工艺处理效果稳定、抗冲击负荷能力较强,当进水COD位4000mg/L左右时,出水COD、BOD5、SS去除率分别达到了96.7%～97.8%、97.7%～98.7%和92.4%～94.2%,最终出水可满足GB8978-1996二级排放标准。综上所述:水解酸化-SBR组合工艺对果汁废水具有较高的处理效率,同时,该组合工艺具有占地面积小、设备利用率高、过程控制灵活、耐冲击能力强等优点,对于实际推广有着十分重要的意义。更多还原

【Abstract】 Syrup wastewater belongs to a category of high concentrated organic wastewater. Having the unique charateristics such as high concentrated organic pollutant and solid impurity, changeable water quality and so on. If it is not properly treated, it could cause serious pollution to the environment. At present, combined technology of physic-chemical and biochemical treatment is usually adopted to sovle the problem. Since that syrup industry quickly developped only these years, research on syrup wastewater is fewer compare to other high concentrated organci waserwater as brewery wastewater, alcohol wastewater and starch wastewater. The existing projects are mainly designed following other high concentrated organic wasterwater treatment technology, without cnsidering the charaistics of syrup wastewater, many problems occur. So it is essential to make some research on technics of syrup wastewater treatment and quest for the suitable controlling parameters.In this research, an experimental study on syrup wastewater with hydrolytic acidification-SBR technology has been carried out, through analyzing the COD, BOD5 and SS removal effect of the combined technology, the optimal controlling parameters during the start-up and circulate of the combined technology is explored. The results showe that:1. When taking a methed of low load inoculated biofilm formation to startup the hydrolytic acidification reactor, 22 days of operation showed that the biofim growed well and that the removal rate of COD was between 42.2%~47.3%, the removal rate of SS was between 76.2%~82.4%. It took few days to complete the start-up process showed that syrup wastewater is easy to hydrolytic and acidificate.2. Results of the single factor experiment showed that when taking hydrolytic acidification reactor to treat syrup wastewater, the optimum HRT was 8h and the optimum agitation interval time is 2h. Under this condition, when the COD of influent was 3838~4310 mg/L, COD, BOD5 and SS removal rate of the wastewater stabilized at about 45%, 28% and 78%. It was demonstrated that the SS was removed mostly through the hydrolytic acidification process, BOD5/COD increased from 0.45~0.53 to 0.60~0.66, which can create a suitable condition for the subsequent SBR process and enhance the efficiency of the combined technology.3. The activated sludge domestication process was an essential step when using activated sludge technology to treat with higher concentrated organic wastewater. In this resrarch, some high efficiency activated sludge which could endure higher extension of COD loading was obtained through 24 days’domestication process, it was floccule and filemot, its SV30 was between 20%~35% and its SVI was between 70~100.4. Taking SBR process as the subsequent treatment after hydrolytic acidification process, it was proved that the optimal MLSS concentration of SBR was about 3500~4000mg/L, and the optimal aeration rate was 0.1m3/h, the times for aeration and settlement were 7h and 1h, respectively. Under this condition, COD, BOD5 and SS removal rate of the influent were between 94.3%~97.1%, 96.4%~98.1% and 67.1%~73.2%, the continuous operation experiment proved that the effect of SBR process was also stable.5. Having got the optimal controlling parameters of each unit technics, continuous operation experiment about syrup wastewater treatment with hydrolytic acidification-SBR technology was taken, and the anti-impact load ability was analyzed during this process. The results showed that the combined technology had stable removal effect and strong anti-impact. After treated by the combined technology, the removal rate of COD, BOD5 and SS were about 96.7%~97.8%, 97.7%~98.7% and 92.4%~94.2%, and the last effluent could reach the second standard of G8978-1996.In conclusion, when hydrolytic acidification technology is used in syrup wastewater treatment, the removal efficiency of organic contaminant is high, and the combined technology also has the unique charateristics of small covering size, high efficiency of equipment, flexible modulated operation, strong anti-impact and so on, so it can be popularized in actual application of ayrup wastewater or some other high concentrated organic wastewater.更多还原