【作者】 范彩安；

【导师】 彭永臻；

【作者基本信息】 北京工业大学 ， 环境工程， 2003， 硕士

【摘要】 全面分析了制药废水性质及制药厂曾使用过的废水处理工艺存在的问题，选择两段SBR（TSSBR）作为试验反应器，研究运行参数和以DO、pH在线监测为基础的过程控制。旨在针对制药废水改造CASS工艺使出水达标，并实现主体的实时控制。TSSBR是COD降解与硝化反应在不同的反应器——SBR1、SBR2中依次进行的工艺，避免了高碳氮比（C/N）引起的活性污泥中硝化菌所占比例太少的问题；同时根据DO、pH在线监测、控制反应过程，避免了曝气时间过短、硝化不充分的问题，还保证了亚硝酸型硝化。经TSSBR处理的制药废水CODcr<100mg/L，NH3-N<1mg/L，NOx-N<2mg/L，优于化学制药工业废水CODcr<150 mg/L，NH3-N、NOx-N无要求的排放标准。对于TSSBR的过程控制，首先确定了DO、pH的一般变化规律。TSSBR的SBR1，DO在曝气初始跃升至一个平衡点后以较小的速率减小，pH则会增加；易降解COD分解结束时，DO陡升、pH减小。SBR2中，硝化时DO的变化同SBR1，只是pH是从减小突然增加。经调节池、水解酸化池处理后的制药废水性质稳定，以上规律始终未发现特例，因此利用DO、pH在线监测并控制处理过程是可靠的。然后在TSSBR优化控制研究中，得出以下结果：初始条件（尤指曝气量）相同时，预曝气试验的平衡DO比无预曝气试验的小，反应过程中DO的微小波动也少，说明预曝气可以增强微生物活性，加快反应速率。在无预曝气恒定DO与有预曝气恒定DO的情况下，以2.00mg/L的DO作为生物反应限制因子的标准不合适，对于前者此标准偏低，对于后者则偏高。恒定DO运行可以在节约能量的前提下提高反应速率。根据制药废水处理中平衡DO是随时间以一定速率减小的直线，假设在平衡DO阶段按一定速率增加曝气量可控制DO恒定，DO是过程反馈参数，pH是反应结束反馈参数。调整曝气量的方式有连续、间歇两种方法。<WP=4>药品性能要求药物对生物作用的微量高效性，DO可灵敏反应微生物的活性，这两者奠定了DO在线监测判断制药废水毒性的理论依据。有毒的制药废水的DO曲线出现特有的周期性波动，DO曲线的周期性波动为活性污泥微生物对底物无毒化与分解的周期性交替。SBR1延时曝气减小了TSSBR的平均反应速率；减小了 SBR2中有机物含量而不能维持一定比例的异养菌，故反硝化菌失活，凝聚性能较差的硝化菌流失。形成亚硝酸型硝化（短程硝化）的原因：25℃是保证短程硝化稳定的温度界限，大于25℃的温度对提高硝化速率作用不大；长期通过pH、DO信号控制亚硝化反应终点，保证系统中硝化菌的比例很低；药厂的主要产品及副产品抑制硝化菌，但浓度较高对亚硝化菌也抑制。在这些协同因素下，偶然的低温运行、延时曝气、水质波动不会破坏亚硝酸型硝化。在SBR2的一个周期里调节曝气量改变DO，观察pH的变化规律，克服了微生物活性时变性导致的干扰因素。曝气量、DO、pH都是随时间平行的曲线。pH决定了污水仅存在碳酸一级电离，碱度仅由HCO3-构成，所以从碳酸一级电离平衡角度分析了硝化过程pH下降，增大曝气量pH升高，减小曝气量pH下降的现象。最后，利用TSSBR的实验结果，首次提出CASS-LINPOR工艺用于改造制药厂废水处理工艺。将原CASS预反应区改为缺氧运行，作为前置反硝化单元；主体反应区依然是好氧运行，降解反硝化后剩余的碳源和硝化，并投加多孔悬浮填料以增加硝化菌的比例。运行采用半连续进水、间歇排水的方式。一个周期分为充水—反应、不充水—反应、不充水—沉淀、不充水—滗水、充水—闲置五个阶段；在这五个阶段都不停止好氧池向缺氧池的污泥回流，回流比是变化的；并且对每个阶段都应用了自动控制。更多还原

【Abstract】 After the quality of pharmaceutical wastewater and the problems of its treatment processes used were analyzed completely, two-stage SBR (TSSBR) as a trial reactor was selected. The operating parameters and the automatic control process with DO and pH as on-line feedback variables were studied. To make the effluent meet standard and carry out real-time control, the CASS was transformed.TSSBR was the process that organic material and nitrogen were removed in different reactors—SBR1、SBR2 in turn, which avoided the problem that the proportion of nitrifiers was too few in the activated sludge caused by higher rate of Carbon and Nitrogen. At the same time, the control of the reaction course by online detecting the DO and pH, ensured nitrification-denitrification via nitrite and avoided the problem of deficient nitrification owing to the shorter aeration time. After treatment, the effluent concentrations of CODcr, NH3-N and NOx-N were less than 100mg/L, 1mg/L and 2mg/L respectively, which were below the pharmaceutical chemically wastewater effluent standard that CODcr was less than 100mg/L, NH3-N and NOx-N were not required.Firstly, for the control of TSSBR, the common variation rule of DO and pH were confirmed. In SBR1, DO decreased with a smaller speed after leaping to an equilibrium point while pH increased; when decomposable organic material was used up, DO increased suddenly and pH decreased. In SBR2 during nitrification, the law of DO was the same as that of SBR1, while pH did not decrease but increase suddenly. The laws referred to above had not special case because the quality of pharmaceutical wastewater through adjusting tank and hydrolysis tank was stable, therefore the use of DO and pH as parameters that on-line monitored and controlled the treatment process of pharmaceutical wastewater was reliable.Secondly some conclusions were drawn in the study on the optimizing control：Under the same initial conditions, the balanced DO with pre-aeration was lower than that without pre-aeration, and the small fluctuations of DO in the course of reaction were also seldom. This showed that pre-aeration could strengthen the activity of microorganism and quicken reaction. It was not suitable for constant DO experiments with or without pre-aeration that 2.00mg/L DO was regarded as the restriction factor standard of microorganism reaction. The standard was on the low side for the former and on the high side for the latter.In the operational condition of constant DO, reaction speed could be raised under the precondition of saving energy. According to the rule that balance DO during the pharmaceutical wastewater treatment was a straight line whose numerical value reduced at a fixed speed with time passing, increasing the aeration at a fixed speed<WP=6>could make DO constant in the stage of balance DO. DO was the feedback parameter of the reaction course and pH was that of the end. There were two kinds of methods to adjust aeration—the continuous and the intermittent. Drug had to drop high performance to the organism and DO can sensitively respond the microorganism activity, both of which formed the theory basis that DO could be used to on-line monitor and judge the toxicity of pharmaceutical wastewater. DO curve of poisonous pharmaceutical wastewater appeared the peculiar periodicity fluctuation, which was the seasonal alternation between detoxification and decomposition of organic matter by activated sludge microorganisms.Extended aeration of SBR1 reduced the average reaction speed of TSSBR and the organic matter of SBR2 which made the low-agglomeration nitrifier lose, because nitrifier could not be kept without the heterotrophic bacteria, and made the bacteria of denitification lose activity.The reasons that formed nitrification via nitrite were that: 25℃ was the critical limit of stabilization, and the nitrification speed could not be raised too much when the temperature is higher than 25℃; Controlling the reaction terminal point by pH and DO in long term made the proport更多还原