质量控制图在化工厂污水管理中的应用

介绍了将质量控制图应用于化工污水管理的过程。通过对化工厂污水中化学需氧量的浓度做单值－移动极差控制图,结果表明该化工厂的污水处理过程处于统计控制状态,污水处理工序过程能力符合要求,应用单值－移动极差控制图能够快速灵敏地反映工序的异常情况。     

BP模型在水泥行业清洁生产评价案例中的应用

基于BP神经网络的原理与算法,建立清洁生产多指标综合评价模型,采用隶属度函数对评价指标进行描述。以避免评价过程中的人为失误,达到客观评价的目的。用该模型对重庆某水泥厂进行清洁生产评价,结果表明：该评价方法操作性强、准确性高、可为实现清洁生产的客观评价提供科学依据和技术方法。     

糯扎渡水电站施工期环境影响监测讨论

特大型水电站建设中的环境影响监测有特定的地理、时效、多支流影响、施工期长等不可重现的特殊性.本文以糯扎渡水电站为例,利用多年监测数据,结合实际情况,探讨了监测因子、优化布点等内容.     

浅析《建设项目环境影响评价管理名录》在环境影响评价工作中的实际应用

环境保护部令第2号《建设项目环境影响评价管理名录》(以下简称《名录》)自2008年10月1日施行,各级环保部门据此对建设项目的环境影响评价实行分类管理。本文结合工作实际,浅析如何准确灵活把握《名录》,促进社会经济和谐发展。     

金属离子掺杂TiO_2薄膜光催化去除气相中甲醛

采用溶胶-凝胶法在普通玻璃表面制备TiO2,Fe3+/TiO2,La3+/TiO2三种光催化剂,研究了煅烧温度、煅烧时间、涂膜层数、Fe3+和La3+加入量等因素对光催化剂降解气相甲醛的影响。结果表明,La3+/TiO2光催化性能略好于TiO2,Fe3+/TiO2光催化性能最佳。当掺Fe3+的TiO2催化剂煅烧温度为450℃,煅烧时间为2h,Fe:T(imol)=0.3%,涂覆层数为4层,光催化反应3h,实验封闭体系中甲醛的降解率可达49.24%。     

Pretreatment of heterocyclic pesticide wastewater using ultrasonic/ozone combined process

Ultrasonic/O3 combined process was employed to pretreat heterocyclic pesticide wastewater for increasing biodegradability and reducing biological toxicity. Influences of ultrasonic frequency, ultrasonic power, probe diameter, initial pH and O3 dosage on the COD removal were studied. The results showed that the ultrasonic/O3 process significantly improved the biodegradability and reduced the biological toxicity of the wastewater. The ratio of BOD5/COD was increased from 0.03 to 0.55 and the EC50 increased from 11% to 52% under ultrasonic/O3 treatment. Low ultrasonic frequency brought better COD removal. Initial pH was found to have a high influence on the COD removal and alkaline conditions were more favorable. The influences of ultrasonic power and probe diameter were small. With an increase in O3 dosage, COD removal was e ectively improved. The optimal operational parameters for the combined process on COD removal were ultrasonic frequency 20 kHz, initial pH 9.00, ultrasonic power 300Wand dosage of O3 454.8 mg/(L min), under which the e ciency of COD removal reached 67.2%.     

桐乡市城市污水处理厂A~2/O工艺净化水质效果及影响因素研究

以采用A2/O工艺的桐乡城市污水处理厂净化城市污水为研究对象,介绍了该污水处理厂工艺设计、进水水质特征和水质净化效果,分析了温度、有机物负荷、氮负荷、磷负荷、可生化性、碳氮比、碳磷比、污泥产率、重金属离子浓度等因素对该污水处理厂运行的影响。结果表明:该污水厂进水水温适宜,可生化性好,碳源充足,同步脱氮除磷效果好,使该污水处理厂出水水质稳定达GB 18918-2002《城镇污水厂污染物排放标准》一级B标准。分析发现,该A2/O工艺对水中不同的重金属离子、表面活性剂、石油类有去除效果。重金属离子在活性污泥中产生富集现象,应重视污泥的处置等问题。     

纸浆造纸废水与城市污水厂进水混合处理的试验研究

采用SBR工艺模拟污水厂活性污泥法处理纸浆造纸废水。试验结果表明,活性污泥法处理纸浆造纸废水效果良好,对NH3-N、TP、SS、COD以及BOD5的去除率分别达到99%,88%,99%,93%,97%。证明纸浆造纸废水与城市污水混合处理是可行的。     

Effects of two forest types on the dynamics of four base cations along with rainfall partitioning in middle subtropical forests北大核心CSCD

盐基离子随穿透雨和树干茎流的迁移成为森林元素输入的重要组成部分.在迁移过程中,冠层淋溶、树干冲刷等改变了盐基离子含量,而不同林型的林冠特征、树皮性质等存在差异,因此盐基离子含量在不同林型中可能存在差异对米槠次生林和杉木人工林穿透雨、树干茎流进行为期4年的监测,对比研究4种盐基离子(K+、Ca2+、Na+、Mg2+)浓度和输入量的动态特征.结果显示:(1)米槠次生林树干茎流Ca2+、Mg2+浓度显著低于杉木人工林而K+浓度显著高于杉木人工林;穿透雨除Na+浓度外均为米槠次生林显著高于杉木人工林.穿透雨和树干茎流Na+浓度林型差异不显著.(2)两种林型盐基离子季节动态变化基本一致,在雨季旱季各有一个峰值,雨季浓度普遍低于旱季.米槠次生林盐基离子浓度稳定性普遍高于杉木人工林.(3)分析盐基离子浓度与降雨强度的关系发现:Ca2+、K+、Mg2+浓度随雨量级的增加而降低,Na+浓度随雨量级的增加而增加.(4)观测期间米槠次生林穿透雨累计输入Ca2+、K+、Mg2+和Na+总量分别为47.97、35.17、7.15和12.94 kg/hm2,树干茎流累计输入Ca2+、K+、Mg2+和Na+总量分别为11.38、6.21、1.54和3.00 kg/hm2;杉木人工林穿透雨累计输入Ca2+、K+、Mg2+和Na+总量分别为47.24、26.63、6.43和11.55 kg/hm2,树干茎流累计输入Ca2+、K+、Mg2+和Na+总量分别为4.11、1.20、0.50和0.83 kg/hm2.米槠次生林的林内雨盐基离子输入量大于杉木人工林.总体而言,米槠次生林比杉木人工林有更高的养分输入,能更好地维持生态系统养分的供应;上述结果有助于进一步认识森林物质随水文过程的流动,可为人工林经营管理提供一定科学基础数据.(图6表1参36)     

A novel proton-gradient-transfer acid complexes as an efficient and reusable catalyst for fatty acid esterification

In this work, a series of novel proton-gradient-transfer acid complexes (PGTACs) were developed. Their physicochemical properties, including thermal stability, melting point, and Hammett acidity, were measured. The effects of catalyst loading, reaction temperature, and substrate expansion on the catalytic performance were systematically studied. It is found that the combination of bidentate N-heterocycle and H2SO4 (1:2 M ratio) could form simultaneously N–H covalent bond and N…H hydrogen bond, which makes the PGTACs excellent catalysts integrate the advantages of strong acids (high catalytic activity) and ionic liquids (phase separation) in the esterification reaction. Moreover, these PGTACs can be reused by convenient phase separation without obvious diminution of catalytic activity. It is concluded that these PGTACs are potential alternative candidates for esterification reaction in the process of industrial catalysis.