【作者】 黄娅琼；

【导师】 姜彬慧； 姜莉；

【作者基本信息】 东北大学 ， 环境工程， 2009， 硕士

【摘要】 选矿药剂厂的生产废水中含有极高浓度的黄原酸盐类化合物(俗称“黄药”),如果不进行处理随意排放会对生态环境产生极大的危害。研究表明：大量排放含有黄药的废水时,对水生动物胚胎会产生致畸作用。此外,黄药对人的神经系统和肝脏等器官也会产生毒害作用,而且在微酸性条件下黄药会分解产生二硫化碳(CS2),若进入大脑,会使神经系统产生病症；若进入血液,对造血系统也可产生不良影响。因此,寻找高效合理的黄药废水处理方法已迫在眉睫。目前,黄药废水的处理方法主要有吸附、分解、混凝沉降、化学沉淀法、生化、氧化等方法,但由于各种方法都存在着一定的弊端,处理结果不尽人意。针对这种现状,本研究首次利用膜生物反应器(MBR)对含有较高浓度的黄药废水进行处理研究,取得了较好的处理效果。在污泥驯化阶段,污泥颜色由开始时的灰褐色变为黄褐色。污泥浓度由接种时的6640mg/L最终增至9130mg/L,在驯化后期MLVSS/MLSS达到0.75。在反应器运行初期,反应器内混合液中的生物相主要为后生动物轮虫与钟虫等大量原生动物。而在驯化后期,由于黄药的生物毒性与入水pH值大于8,轮虫与钟虫均消失。经过33d的污泥驯化,容积负荷与污泥负荷分别上升至2.17kgCOD/(m3-d)和0.238kgCOD/(kgMLSS-d),黄药去除率>90%,COD去除率>80%,系统趋于稳定。针对水中惰性物质过多、活性污泥部分自身分解、污泥浓度降低这一问题,进行了反应器操作条件的优化实验。最终确定以0.5g/L的无水乙酸钠为外加碳源,水力停留时间24h,反应器温度保持在30。C的操作条件为优化条件。反应器运行至稳定状态后,出水水质良好,出水的COD平均为91.89mg/L, COD去除率>94%；出水的黄药浓度平均为1.452mg/L,黄药去除率>99.7%。达到较好的处理效果。此后,我们利用已稳定运行的MBR对铁岭选矿药剂厂的黄药生产废水进行了处理,系统出水的COD值平均为77.02mg/L,去除率均在94.5%以上,平均为95.71%。水质监测期内,出水COD值全部达到国家工业废水一级排放标准。出水黄药浓度平均为0.859mg/L,出水黄药含量最小值为0.707mg/L,最大值为0.974mg/L,去除率均在99.8%以上,平均为99.86%。已达到较好的去除效果,但仍未符合排放标准DB 21/1627-2008《辽宁省污水综合排放标准》,需进行后续处理。利用黄药在酸性条件下更为容易分解这一特性,本研究首先利用低浓度HC1调节出水pH值,然后采用双氧水为氧化剂,在酸性条件下处理MBR系统的出水。实验结果如下：黄药出水后续处理的最佳操作条件为,调节pH值至4左右,投加5mg/LH2O2,氧化40min,黄药浓度达到0.04mg/L,符合DB 21/1627-2008《辽宁省污水综合排放标准》。此外,反应器连续运行128d,仅在污泥驯化后期出现较为严重的膜污染现象。通过条件实验,将水力停留时间延长至24h,可大大降低膜污染程度。更多还原

【Abstract】 Waste water of pharmacy beneficiation plant contains high concentrations of xanthenes compounds; it could make a great deal of harm if we do not deal with emissions. Study shows that:a large number of wastewater containing xanthenes will have an important role in animals’embryo with teratogenic effects. In addition, the xanthenes also have a poisoning effect to nervous system and liver and other organs of human. Under slightly acidic conditions, carbon disulfide (CS2) will be produced. Nervous system will have the diseases under the condition of CS2 enter into the brain; if entering the blood, it will also have adverse effects on the hematopoietic system. Therefore, it is extremely important to find a reasonable and efficient method treatment of xanthenes wastewater immediately.At present, all kinds of method of treatments xanthenes wastewater mainly contains adsorption, decomposition, coagulation, chemical precipitation, biological and chemical, oxidation and other methods. Although these treatment technologies are mature, there are a variety of drawbacks which bring unsatisfactory treatment results. In view of this status quo, it is the first time to dispose high concentrations of xanthenes wastewater by membrane bioreactor (MBR). In this study, we obtain an excellent result.In the sludge acclimation phase, the color of sludge turned to gray brown. The concentration of sludge turns from 6640mg/L at the time of inoculation final to 9130mg/L. In addition, MLVSS/MLSS reached 0.75 in the late domestication. In the early running phase, biologic facies of mixture in reactor mainly included large number of metazoan, such as Brachionus and Vorticella. In the late domestication, as a result of toxicity of xanthenes and the pH value of water was more than 8, both the Brachionus and Vorticella disappeared. After 33d of sludge acclimation, the sludge load and load capacity rosed to 2.17kgCOD/(m3-d) and 0.238 kgCOD/(kgMLSS-d), respectively. At this time, the system stabilized. Xanthenes removal efficiency was more than 90%; COD removal efficiency was more than 80%. In allusion to the condition of too much inert material in the water and parts of activated sludge broke up, we operated a series of experiment to optimize the operating conditions. Finally, the best operating conditions were 0.5g/L of anhydrous sodium acetate added into wastewater as additional carbon source, HRT kept to 24h, reaction temperature maintained at 30℃. In the steady state, the water quality was good, the average effluent of COD was 91.88mg/L, COD removal efficiency was more than 94%; average of the xanthenes concentration in the water was 1.5mg/L, xanthenes removal efficiency was more than 99.7%. Since then, we used this stable MBR to treat producing pharmaceutical wastewater from Tieling xanthenes beneficiation plant. An average of the COD value of the effluent water was 77.02mg/L, the removal rate was more than 94.5%, and in average was 95.71%. In the period of water quality monitoring, all of the effluent COD values were lower than the national-level industrial wastewater discharge standards. An average of xanthenes concentration in the effluent water was 0.859mg/L, removal efficiency was more than 99.8%, and in average was 99.86%. However, due to xanthenes concentration failed to meet water emission standards, whose name is "Liaoning Province Integrated Wastewater Discharge Standard.", still needed follow-up.In virtue of easier decomposition in acidic conditions, in this study at first we used 0.1mol/L HCl to change water pH, and then used hydrogen peroxide as oxidant under acidic conditions to deal with the effluent water from the MBR system. The experimental results were as follows:the best operating conditions is pH value is 4 or so, the concentration of H2O2 is 5mg/L, and oxidation time is 40min. After this treatment, water met the emission standards entirely. At this moment, xanthenes concentration in the effluent water is 0.04mg/L.In addition, membrane fouling phenomenon only deteriorated in the period of late sludge acclimation when reactor operated continuous of 128d. Through the conditions experiments, when the HRT were extended to 24h, membrane fouling can greatly reduced.更多还原