Full-scale blending treatment of fresh MSWI leachate with municipal wastewater in a wastewater treatment plant

Fresh leachate, generated in municipal solid waste incineration (MSWI) plants, contains various pollutants with extremely high strength organics, which usually requires expensive and complex treatment processes. This study investigated the feasibility of blending treatment of MSWI leachate with municipal wastewater. Fresh MSWI leachate was pretreated by coagulation–flocculation with FeCl₃ 2 g/L and CaO 25 g/L, plate-and-frame filter press, followed by ammonia stripping at pH above 12. After that, blending treatment was carried out in a full-scale municipal wastewater treatment plant (WWTP) for approximately 3 months. Different operational modes consisting of different pretreated leachate and methanol addition levels were tested, and their performances were evaluated. Results showed that throughout the experimental period, monitored parameters in the WWTP effluent, including COD (<60 mg/L), BOD₅ (<20 mg/L), ammonium (<8 mg/L), phosphorus (<1.5 mg/L) and heavy metals, generally complied with the Chinese sewage discharged standard. Under the experimental conditions, a certain amount of methanol was needed to fulfill TN removal. An estimation of the operation cost revealed that the expenditure of blending treatment was much lower than the total costs of respective treatment of MSWI leachate and municipal wastewater. The outcomes indicated that blending treatment could not only improve the treatability of the MSWI leachate, but also reduce the treatment cost of the two different wastewaters.     

一种简便高效的土壤石油烃提取方法的建立

通过开展单因子实验与正交实验,考察不同参数下超声萃取法对土壤中总石油烃(TPH)的提取效率,并对比了超声萃取法、超声-索氏萃取法及传统索氏萃取法对不同原油污染土壤的提取效果。结果表明:超声萃取法的最优工作参数为20 m L二氯甲烷,超声10 min,4000 r/min离心10 min,萃取4次。3种提取方法中,超声萃取法对石油烃平均回收率最高,为100.95%,而传统的索氏萃取法最低,仅为94.54%。可见,超声萃取法操作简单,效率高,可广泛用于土壤中总石油烃含量的提取测定。     

菌渣中阿维菌素残留检测方法及其无害化工艺研究

文章建立了简单、快速的阿维菌素菌渣中阿维菌素残留量高校液相色谱检测方法以及利用水热法处理阿维菌素菌渣。采用固相萃取-高效液相色谱检测方法测定阿维菌素菌渣中阿维菌素残留量,提取剂为乙腈/水=4/1(V/V),采用HLB固相萃取柱进行净化。加标回收率90.3%~107.3%,相对标准偏差(RSD)为3.00%~5.69%,阿维2菌素标准曲线线性相关系数R~2=0.999 6,线性范围为1.0~1 000 mg/L。利用正交实验,水热法处理阿维菌素菌渣,在190℃的温度下处理2 h后,菌渣中阿维菌素残留量由991.30降至0.84 mg/kg,去除率达99.92%。处理前后的菌渣与有机肥标准作对比,除含水率外其余检测指标均达到有机肥标准要求。该项研究为阿维菌素菌渣的资源化利用提供了理论依据。     

电晕放电辐射信号的特征提取和模式识别方法研究

目的研究电晕放电辐射信号的特征提取和模式识别方法。方法在分析信号特征提取方法的基础上,对实测的电晕放电辐射信号特征提取,利用概率神经网络开展电晕放电辐射信号目标识别,检验特征提取的有效性。结果以奇异值作为输入特征量的PNN在整体上效果更优,稳定性好,对两类不同放电辐射信号的正确识别率均可达到80%以上,并且当输入特征量个数达到10个时,对实测样本的正确识别率均达到了最高值。电晕放电的正确识别率为96.7%,火花放电的正确识别率为93.3%。结论该方法能基本满足实际放电信号的识别应用。     

某城市污水处理厂二期污水处理工程设计研究

详细介绍了某城市第一污水处理厂在现有工程的基础上二期工程的工艺设计以及构筑物、设备参数;二期工程充分利用原有工程场地,本着现有、新建运行管理便捷统一原则,采用改良型A/A/O生化池作为二级处理主体工艺;二期工程投入运营后,某城市污水处理厂达到20×104 m3/d的污水设计规模.最终污水厂出水水质达到了《城镇污水处理厂污染物排放标准》(GB 18918-2002)一级 A排放标准.污水处理厂运营后,经济效益显著,可保本经营,并具有企业自我发展的能力.     

短波长X射线衍射技术及在环境工程中的应用展望

介绍了短波长特征X射线衍射无损检测分析原理和方法,无损地测定了预拉伸铝板、高强钢孔挤压件、铝合金搅拌摩擦焊接件等材料部件的内部残余应力、内部物相、内部织构及其分布,并分析讨论了测试结果。该仪器具有体积小,投资少、使用维护方便等优势,展望了该无损检测分析技术在装备环境工程中的应用前景。     

La3+掺杂对吸附相反应制备TiO2复合催化剂的结晶过程及弱紫外光下活性的影响

利用吸附相反应技术制备弱紫外光响应的高效催化剂,并通过XRD、XPS以及HRTEM探索了不同焙烧温度下La3+掺杂量对TiO2结晶过程的影响.结合弱紫外光下甲基橙的降解反应,深入研究催化剂结晶过程的变化对弱紫外光下催化剂活性的影响.结果表明,La3+掺杂会抑制TiO2的结晶过程.当焙烧温度或者掺杂量较低时,La3+不能进入TiO2的晶格结构但会轻微地抑制TiO2的结晶过程;未进入晶格结构的La3+存在会引入光生载流子的浅能级捕获中心,在弱光体系中极大提升了催化剂的活性.当La3+的掺杂量为0.05%(原子分数)时,经过900℃焙烧后催化剂降解能力最高,其活性超过商用P25的2倍多.在较高La3+掺杂量(超过0.20%)时,900℃焙烧后一定量La3+进入TiO2的晶格结构而大大抑制了TiO2结晶;这种强烈的抑制作用使得催化剂中存在大量无定形结构TiO2,无定形TiO2甚至多于700℃焙烧后的催化剂,反而大大抑制了弱光体系中催化剂活性.     

沉积物中雌激素及壬基酚、辛基酚、双酚A的测定

近些年来雌激素及烷基酚类化合物由于其对水生生物的内分泌干扰作用越来越受到广泛关注.沉积物作为环境中有机污染物的重要储存库,研究目标物在其中的浓度分布对于探明此类物质在环境中的迁移转化具有重要意义.但沉积物中基质组成复杂而雌激素又痕量存在,这增加了前处理的难度.本研究从雌激素及烷基酚类化合物的理化性质入手,采用碱液提取、液液萃取和LC-MS/MS分析测定沉积物样品中的雌激素及壬基酚、辛基酚、双酚A.结果表明,经过优化的方法对7种目标物的回收率介于61.9%～93.7%之间.该方法能有效去除沉积物中那些不溶于强碱和既溶于酸又溶于碱的有机污染物,同时操作简单、成本低,但回收率高、检出限低,可广泛适用于河流沉积物样品及土壤样品的前处理.     

Application of comprehensive two-dimensional gas chromatography with mass spectrometric detection for the analysis of selected drug residues in wastewater and surface water

Pharmaceutical residues have become tightly controlled environmental contaminants in recent years, due to their increasing concentration in environmental components. This is mainly caused by their high level of production and everyday consumption. Therefore there is a need to apply new and sufficiently sensitive analytical methods, which can detect the presence of these contaminants even in very low concentrations. This study is focused on the application of a reliable analytical method for the analysis of 10 selected drug residues, mainly from the group of non-steroidal anti-inflammatory drugs (salicylic acid, acetylsalicylic acid, clofibric acid, ibuprofen, acetaminophen, caffeine, naproxen, mefenamic acid, ketoprofen, and dicofenac), in wastewaters and surface waters. This analytical method is based on solid phase extraction, derivatization by N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and finally analysis by comprehensive two-dimensional gas chromatography with Time-of-Flight mass spectrometric detection (GC×GC- TOF MS). Detection limits ranged from 0.18 to 5 ng/L depending on the compound and selected matrix. The method was successfully applied for detection of the presence of selected pharmaceuticals in the Svratka River and in wastewater from the wastewater treatment plant in Brno-Modrice, Czech Republic. The concentration of pharmaceuticals varied from one to several hundreds of ng/L in surface water and from one to several tens of μg/L in wastewater.     

LNAPLs污染物在层状非均质多孔介质中的运移试验研究

文章通过室内试验研究层状非均质多孔介质中轻非水相液体(Light Non-Aqueous Phase Liquid,LNAPL)的运移机制与分布特性。首先,在二维砂槽上进行LNAPL的入渗试验,试验过程中用数码相机进行拍照,把LANPL的扩散过程以图像的形式记录下来;然后,用AutoCAD对图片进行分析处理,得出不同时刻LNAPL的入渗锋面变化图。结果发现,介质结构突变面改变了LNAPL的迁移模式。在LNAPL由中砂进入细砂层后,由于受到毛细作用的增强,其运移速度加快;而由中砂进入粗砂,受粗砂介质阻滞作用增强的影响,LNAPL运移速度变小。当LNAPL由干砂进入湿润砂体时,由于孔隙水浮托力增大,LNAPL先产生纵向运移,随后以横向迁移的形式在地下水位上部聚积。当达到一定厚度后,LNAPL的压头足以克服浮托力,驱替孔隙水进入砂土孔隙。另外,LNAPL的厚度足够大时,方可克服饱水层受到的浮托力,在地下水位上形成LNAPL池,并因孔隙水向周围砂体排泄,LNAPL池周围的水位上升。