不同材质对催化裂化装置催化剂粉尘粘附性能的试验研究

在三座DN150 mmX1600 mm有机玻璃塔试验装置上,考察了DN15的塑料拉西环、陶瓷拉西环和不锈钢拉西环三种材质填料对催化剂的粘附能力。在催化剂浓度5‰,液相负荷40 L/h,气相负荷80 m3/h的条件下,经过408h的连续运转,结果表明不同材质填料对催化剂的粘附能力均存在饱和状态,粘附在填料上的催化剂不随时间的持续增加而增多。其中,塑料填料对催化剂的粘附能力最强,增重0.125kg;不锈钢填料次之,增重为0.115kg;陶瓷填料最弱,增重为0.055kg。可为相关领域的工业应用提供借鉴和数据支撑。     

解析环境监测中3S技术的应用

伴随现代信息技术的发展,3S技术逐渐运用于生物环境的动态监测中,并发挥了其绝对的运用优势.本案通过对3S技术的特性进行着手分析,系统探究了3S技术在生物环境的动态监测中的具体运用.     

北运河中游沉积物对磷的吸附特性研究

研究了位于北京郊区的北运河中游9个断面的沉积物对磷的吸附行为,分析了沉积物组成及其理化性质与磷吸附特征的关系.实验结果表明,不同断面沉积物对磷的最大吸附量在0.11 ～9.45 mg/g之间,而各断面沉积物的临界平衡磷浓度(EPC0)范围在0.33～ 1.85 mg/L之间,统计分析显示EPC0与河水中的总磷和可溶性无机磷呈显著负相关,但与沉积物中的金属和有机质含量相关性较差;根据临界平衡磷浓度定义的推断,新华大街桥、玉带桥、运河大街桥、六环路桥、宋梁路桥、湿地和甘棠橡胶坝7个断面的沉积物表现为磷的“汇”,而丰子沟和减运沟2个点表现为磷的“源”,并且各点沉积物释放和吸附磷的趋势较大.     

芬顿氧化试验中残余双氧水对CODcr测定的影响研究

在采用Fenton高级氧化技术对垃圾压滤液进行处理时,作为氧化剂的双氧水经常不能完全消耗。而使用重铬酸钾法进行CODcr测定时,待测水体中残余的双氧水会表现出还原性而消耗重铬酸钾,对最终CODcr测定结果产生影响。本文分析了在垃圾压滤液中不同浓度双氧水对CODcr测定的影响大小,得出双氧水浓度对CODcr影响曲线,同时为消除双氧水对CODcr测定结果影响,在试验中投加过量硫酸亚铁与双氧水反应,当投加量达到理论反应量的1.0～1.2倍时,对双氧水去除效果最好,使后续的CODcr测定试验更加准确。     

地下水环境影响评价导则执行过程中遇到的问题及建议

对中国各地区地下水的水质情况进行了调查,分析了地下水环境管理和保护工作中的问题,指出地下水污染防治工作的重要性、迫切性。对《环境影响评价技术导则地下水环境》(HJ 610-2011)的工作等级划分、环境影响识别、环境现状调查、影响评价及污染防治等内容进行了简要介绍,汇总了评价导则执行后,对各类项目进行地下水评价过程中遇到的困难和问题,并在对各种问题进行分析的基础上,提出了有针对性的解决方法和建议。     

论灾害风险研究中的空间尺度耦合

作为人地关系中"地"对"人"负面作用的核心学科——灾害风险学存在着显著的地理空间尺度差异与尺度效应。本文提出灾害风险尺度耦合的概念与类型,从数据、方法和区划三个方面提出灾害风险研究中的空间降尺度和空间升尺度耦合思路,供同行学者参考。     

Preparation and coagulation efficiency of polyaluminium ferric silicate chloride composite coagulant from wastewater of high-purity graphite production

The aim of the present work was to produce a polyaluminium ferric silicate chloride (PAFSiC) coagulant from acidic and alkaline wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride (PAC). The PAFSiC coagulant was prepared by co-polymerization. The effects of (Al+Fe)/Si molar ratio, OH/(Al+Fe) molar ratio (i.e., value), coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand (COD), and total phosphate (TP). The PAFSiC with a value of 2.0 and (Al+Fe)/Si ratio of 5 (PAFSiC 2.0/5) showed excellent coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC 2.0/5 was 5.0–9.0, slightly wider than that of PAC (6.0–8.0). The process can be easily incorporated into high-purity graphite production plants, thereby reducing wastewater pollution and producing a valuable coagulant.     

Preliminary report on methane emissions from the Three Gorges Reservoir in the summer drainage period

Considerable variations may exist in CH4 emissions from the Three Gorges Reservoir.     

Biostability in distribution systems in one city in southern China：Characteristics, modeling and control strategy

This study investigated the bacterial regrowth in drinking water distribution systems receiving finished water from an advanced drinking water treatment plant in one city in southem China. Thirteen nodes in two water supply zones with different aged pipelines were selected to monitor water temperature, dissolved oxygen （DO）, chloramine residual, assimilable organic carbon （AOC）, and heterotrophic plate counts （HPC）. Regression and principal component analyses indicated that HPC had a strong correlation with chloramine residual. Based on Chick-Watson＇s Law and the Monod equation, biostability curves under different conditions were developed to achieve the goal of HPC 100 CFU/mL. The biostability curves could interpret the scenario under various AOC concentrations and predict the required chloramine residual concentration under the condition of high AOC level. The simulation was also carded out to predict the scenario with a stricter HPC goal （≤50 CFU/mL） and determine the required chloramine residual. The biological regrowth control strategy was assessed using biostability curve analysis. The results indicated that maintaining high chloramine residual concentration was the most practical way to achieve the goal of HPC ≤ 100 CFU/mL. Biostability curves could be a very useful tool for biostability control in distribution systems. This work could provide some new insights towards biostability control in real distribution systems.     

PM2.5和SO2复合暴露对大鼠心脏病理学及炎症因子表达的影响

将雄性SD大鼠分为对照组、1.5 mg·kg~(-1)PM_(2.5)组、5.6 mg·m-3SO_2组及1.5、6、24 mg·kg~(-1)PM_(2.5)和5.6 mg·m-3SO_2联合作用组.采用HE染色法、荧光实时定量PCR和ELISA等方法测定各组大鼠心脏组织病理学变化和炎症因子IL-1β、IL-6、TNF-α、i NOS基因表达及NO含量.结果表明,与对照组相比,SO_2(5.6 mg%m-3)或PM_(2.5)(1.5 mg·kg~(-1))单独作用没有引起明显的心肌细胞损伤,而PM_(2.5)和SO_2共同作用导致不同程度的心肌排列紊乱,细胞间隙增大及炎症细胞浸润和出血,比SO_2(5.6 mg%m-3)或PM_(2.5)(1.5 mg·kg~(-1))单独作用有严重的病理学损伤.1.5mg·kg~(-1)PM_(2.5)和SO_2引起4个基因表达和NO水平的变化与对照组相比没有统计学意义,而PM_(2.5)和SO_2联合处理引起大鼠心脏炎症因子表达水平比对照组显著增高,同时与SO_2组或PM_(2.5)组相比也有显著升高.提示在本实验条件下,相比于PM_(2.5)(1.5 mg·kg~(-1))和SO_2(5.6 mg·m-3)单独作用,二者复合暴露能引起心脏组织病理损伤和炎症因子高表达,这可能是PM_(2.5)和SO_2引发心脏疾病的重要机制.