MBBR-A2O/MBR处理农村生活污水动力学研究

采用MBBR-A2O/MBR(又称BCO-MBR)工艺,对水质特征呈现低碳源高氮磷、水质波动大和日变化系数大等特点的农村生活污水进行研究。对比MBBR-A2O/MBR工艺在5种不同水力停留时间下的(0.42 d、0.50 d、0.75 d、1.25 d、1.50 d)运行状况,挑选出最佳的水力停留时间,并利用Lawrence-McCarty模型构建该工艺的污染物降解动力学方程。结果表明,随着水力停留时间(HRT)的延长,MBBR-A2O/MBR工艺对污染物的去除效果逐渐提升。当HRT为1.25d,CODCr、NH3H、TN、TP平均进水质量浓度分别280.67mg/L、36.88 mg/L、50.59 mg/L、2.51 mg/L时,平均出水质量浓度分别为34.33 mg/L、3.19 mg/L、5.13 mg/L、0.63 mg/L,平均去除率分别可达87.86%、89.92%、89.85%、74.95%。CODCr、NH3H、TN出水质量浓度在城镇污水排放标准一级A限值以下,TP出水质量浓度达到一级B标准,因此确定最佳的HRT为1.25 d。污染物降解动力学计算所得模拟值与实际出水质量浓度测量值拟合度良好,其中CODCr模拟值与平均测量值一致性最高,相对误差在0.02~0.14,NH3H与TN的相对误差分别在0.19~0.60和0.1~0.33。这表明污染物降解动力学方程可以较好地模拟工艺出水的污染物质量浓度。CODCr降解动力学方程常数为Vmax=0.19 d-1,KS=82.97 mg/L;NH3H降解动力学方程常数为Vmax=0.02d-1,KS=8.49 mg/L;TN降解动力学方程常数为Vmax=0.024 d-1,KS=8.10 mg/L。研究的动力学常数与传统活性污泥法动力学常数相比,KS较高,而Vmax较低,导致Vmax较低的主要原因可能是测定的污泥质量浓度高于实际有效的质量浓度。研究对利用MBBR-A2O/MBR工艺处理农村生活污水和传统活性污泥工艺提标改造具有一定的应用参考价值。     

Simultaneous determination of 4-tert-octylphenol, 4-nonylphenol and bisphenol A in Guanting Reservoir using gas chromatography-mass spectrometry with selected ion monitoring

The wide occurrence of estrogenic compounds 4-tert-octylphenol, 4-nonylphenol, bisphenol A in surface water of Guanting Reservoir was successfully determined. The target compounds in water samples were preconcentrated by liquid-liquid extraction with dichloromethane, derivatized by trifluoroacetic anhydride, and quantified by gas chromatography-mass spectrometry(GC-MS) with selected ion monitoring(SlM). In the selected seven sampling sites(S1-S7), the concentration of NP in sample S7 was significantly higher than the other in reservoir. The status of pollution in S3 and S7 were much more serious. The concentrations of OP, NP and BPA were in the range of 44.5-48.8, 221.6-349.6 and 30.2-82.7 ng/L, respectively. The pollutants were mainly inputted from the upper river and released from sediments in Guanting Reservoir.     

智能报警系统的设计

采用单片机控制技术,利用现有电话座机,设计了拨号、信号发生器、自动摘挂机、信号音检测、语音录放等电路,并编制了相应的软件进行系统控制。由于该系统与电话线并用,易于实现,可较好地解决家庭、店铺、办公室及一些重要场所的防盗报警问题。经使用证明,该系统运行可靠,性价比较高。该智能报警系统的主要创新点是利用现有电话网络,采用单片机控制,具有较高的可靠性。     

A2/O系统受低C/N冲击及修复前后的微生物活性研究

利用2套A2/O工艺装置,通过在实际污水中添加铵盐的方式模拟低C/N冲击的不利情况,采取常规工艺调控措施进行修复,研究了冲击及修复前后的微生物活性变化.结果表明,A2/O系统在受到低C/N冲击之后,耗氧呼吸速率(OUR)、脱氢酶活性(DHA)、三磷酸腺苷(ATP)和聚β-羟基丁酸(PHB)4项指标迅速响应,降幅分别为81.8%,87.0%,90.5%和72.9%.提高污泥回流比和减小污泥龄都是有效的修复措施.修复期间,4项指标均呈现先快后慢的回升规律.提高污泥回流比是通过降低冲击负荷的方式实现OUR指标的基本回复,但DHA、ATP和PHB较受冲击前水平还有10%~20%不等的差距.减小污泥龄是通过逐步排出受损污泥来消除冲击的不利影响,过程中A2/O系统的处理效果不佳,但最后4项指标能够完全恢复.     

Anoxic phosphorus removal in a pilot scale anaerobic-anoxic oxidation ditch process

The anaerobic-anoxic oxidation ditch (A²/O OD) process is popularly used to eliminate nutrients from domestic wastewater. In order to identify the existence of denitrifying phosphorus removing bacteria (DPB), evaluate the contribution of DPB to biological nutrient removal, and enhance the denitrifying phosphorus removal in the A²/O OD process, a pilot-scale A²/O OD plant (375 L) was conducted. At the same time batch tests using sequence batch reactors (12 L and 4 L) were operated to reveal the significance of anoxic phosphorus removal. The results indicated that: The average removal efficiency of COD, NH4+, PO43-, and TN were 88.2%, 92.6%, 87.8%, and 73.1%, respectively, when the steady state of the pilot-scale A²/O OD plant was reached during 31-73 d, demonstrating a good denitrifying phosphorus removal performance. Phosphorus uptake took place in the anoxic zone by poly-phosphorus accumulating organisms NO2- could be used as electron receptors in denitrifying phosphorus removal, and the phosphorus uptake rate with NO2- as the electron receptor was higher than that with NO3- when the initial concentration of either NO2- or NO3- was 40 mg/L.     

Human-derived cell lines to study xenobiotic metabolism

In vitro systems make for rapid identification of xenobiotic effects and can be used to study cellular and subcellular toxicity mechanisms. In this report the metabolic competence of two human-derived cell lines, a hepatic (Hep G2) and a pulmonary one (A549) was tested. In the two cell systems the capability to activate Benzo[a]Pyrene through the cytochrome P450 enzyme system and to form reactive metabolites was analysed. ³H-BaP and the scintillation counting analysis were used to show the differences of the metabolic activity in Hep G2 and A549. A similar time course of ³H-BaP uptake was observed in the cell systems. Nevertheless, in the two cell lines the distribution of radioactive metabolites seemed to reflect a specific tissue response to toxicity.     

A/O法活性污泥系统计算机模拟研究

介绍了以活性污泥 1号模型 (ASM1 )和固体通量沉淀模型为基础 ,结合反应器原理 ,用VB6 .0计算机语言建立A/O法活性污泥模拟器的方法 ,探讨了A/O法活性污泥系统的模拟工艺流程、各组分的物料平衡关系和欧拉法数值积分的步长选取等问题。模拟器的校准结果表明 ,该模拟器建立的思路和方法完全正确 ,可以用于A/O法活性污泥系统的模拟和预测。     

MnO2-生物炭材料协同过一硫酸盐快速高效去除双酚A的行为和机理研究

通过化学共沉淀法与KMnO₄溶液反应制备得到了表面负载MnO₂的芦苇生物炭材料MnO₂-PAAC.同时,通过SEM、FTIR、XPS等一系列表征证明MnO₂成功负载在芦苇生物炭表面,且其具有较大的比表面积、丰富的官能团等特征.最后,在MnO₂-PAAC与过一硫酸盐复合物(PMS)系统中,评估了MnO₂-PAAC对双酚A的吸附和氧化性能,并系统研究了不同环境影响因素如投加量、环境温度、环境pH及共存阴离子的影响.结果表明,MnO₂-PAAC在PMS系统中提高了对双酚A的去除能力和效率,其去除机制由吸附和氧化降解(自由基和非自由基途径)两种路径共同参与,且降解后产物毒性明显变小.这些研究结果表明,MnO₂-PAAC可以作为一种快速高效的材料去除水环境中的双酚A.     

Dispersion modeling of LNG-Vapor on land – A CFD-Model evaluation study

Based on methane from renewable resources, LNG is an alternative fuel for heavy and long-distance traffic in land transport. Contrary to its positive properties, the fuel contains risks from an explosion and extremely low temperatures for personal and infrastructure safety. CFD-models are suitable for doing risk analyses for arbitrary scenarios. For examining how to model for risk research the dispersion of LNG-vapor, this paper contains a model variant study, with an evaluation by experiments.This paper describes the use of the CFD-code ANSYS Fluent for simulating experiments of the ‘LNG Safety Program Phase II‘. The content of the well-documented experiments was the research of the vaporization rate of LNG on land and the dispersion of LNG-vapor in the air. Based on the comparison to two experiments, overall 12 CFD-model variants with varying thermal and turbulence parameters were examined how they affect the transient LNG-vapor dispersion in air.The definition of turbulence-boundary-condition at the domain borders had the biggest impact on modeling, followed by the turbulence model. The most accurate model variant had been applied for observing the spreading behavior of LNG-vapor in the air after evaporation on land and analyzing the influence of the LNG-composition to the dispersion. The results show that the mixture of LNG-vapor and the air in the free field is cooler than the ambient air and spreads like a heavy gas on the ground.     

纳米金修饰分子印迹聚合膜电极检测双酚A

以纳米金修饰玻碳电极为基础电极,以双酚A为模板分子,以邻氨基苯硫酚为聚合单体,采用循环伏安法电聚合制备分子印迹聚合膜,利用循环伏安和交流阻抗法研究电极的电化学特性。结果表明,双酚A在修饰电极表面的反应是一个受吸附控制的等电子、质子转移的不可逆反应。采用差分脉冲伏安法检测双酚A,线性范围为5. 0×10~(-6)mol/L～4. 0×10~(-4)mol/L,检出限为2. 3×10~(-7)mol/L。将该电极用于自来水和牛奶样品的测定,结果均为未检出,加标回收率分别为93. 5%和95. 4%,3次测定结果的RSD分别为4. 0%和5. 7%。