非均相催化臭氧氧化深度处理炼油废水

采用非均相催化剂催化臭氧氧化处理炼油废水,考察了催化剂负载率、p H、催化剂投加量和臭氧投加量及反应时间对处理效果的影响。结果表明,组合工艺最佳工艺条件为:催化剂负载率2.1%、p H 9、催化剂投量80 g/L、臭氧投量8.1 mg/L、反应时间60 min,COD、石油类、NH3-N、硫化物和SS去除率分别为91.3%、92.7%、80.5%、34.5%和59%。处理炼油废水过程中组合工艺存在明显协同效应,协同因子为1.47。中间臭氧氧化和催化臭氧氧化在最优工艺条件下对炼油废水COD的降解均符合准一级动力学规律。基于叔丁醇的实验结果,结合降解动力学可以推测,降解炼油废水过程中非均相催化剂催化臭氧产生高活性羟基自由基是降解效率提高的主导因素。     

First-Person Effects of Emotional and Informational Messages in Strategic Environmental Communications Campaigns

This study examined the first- and third-person effects of emotional and informational messages, particularly relating to the critical issue areas of energy, the environment, and global warming. Due to intense political polarization on such issues, it also explored the role of political party identification. The results of an experiment indicated that informational messages about the environment produced third-person effects, while environmental advertisements meant to evoke emotion caused first-person effects. Moreover, emotional environmental advertisements appealed more to Republicans and those who did not support a political party. As such, indirect, emotional messages appear to represent an opportunity for strategic environmental communicators to design campaigns that resonate with potentially unreceptive audiences.     

空气中超细颗粒物检测方法的研究进展

颗粒物的健康损害效应已得到广泛的关注。尤其近年来,国内外学者们针对PM2.5等大颗粒开展了大量的人群流行病学和毒理学研究,健康损害效应的因果关系得到基本确认。然而比PM2.5粒径更小但数量更多的超细颗粒物(UFPs),其暴露特征及对健康影响的贡献值尚不清楚,缺乏统一的检测方法及策略是影响其健康评估的关键因素。因此,本文根据国内外文献,综述了目前超细颗粒物的检测方法、仪器及策略,总结了超细颗粒物评价方法的影响因素及其存在的不足,为超细颗粒物检测方法的进一步研究提供建议和帮助。     

中国各省环境效率及环境效率幻觉分析

为了更准确地了解我国经济发展质量,深刻理解环境效率的含义,本文以全新视角对中国各省环境效率进行测量、分析。首先,基于中国各省农业和工业生产要素投入、期望产出和非期望产出,利用二次型方向性距离函数和收益函数的对偶关系,测算2011年至2013年中国大陆31个省份污染物的影子价格。其次,利用影子价格衡量污染物减排边际成本的优点,根据世界可持续发展工商理事会(WBCSD)提出的环境效率测度公式,研究各省的环境负荷、环境效率,针对环境效率在衡量经济发展质量过程中的缺陷,提出环境效率幻觉概念,结合二者对全国各省进行综合评判,结果表明:全国范围内的各省环境效率值基本呈逐年递增趋势;整体上环境效率值在东中西部呈递减,但东北各省的环境效率值已普遍低于西南各省,且差距有扩大的趋势;出现环境效率幻觉的省份较少,但随着经济"新常态"的出现,其数量在增加。再次,利用环境效率的上升和环境效率幻觉的下降判断,中国仅二分之一的省份环境质量在真正好转。最后,环境效率影响因素的分析表明:全国范围内,产业结构、人均收入以及对外贸易水平与环境效率正相关,政府规制与环境效率负相关,对各地区的影响却呈现出较大差异;政府规制在东部和中部地区对环境效率具有促进作用,且东部大于中部,而西部地区却存在负效应;产业结构在中部和西部地区对环境效率具有积极的促进作用,且西部大于中部,但是东部地区却存在着负效应;对外贸易的继续增加对东中部地区环境效率具有消极的影响,且东部大于中部,对西部地区环境效率有积极的促进作用。     

Promotional effect of transition metal doping on the properties of KF/CaO catalyst for biodiesel synthesis

A series of heterogeneous KF/CaO catalysts modified with transition metals (lanthanum, cerium, and zirconium) were prepared via wet impregnation method and applied to the trsansesterification process of waste cooking oil (WCO) as feedstock with methanol to biodiesel production. The structure, performance of the solid catalysts was characterized by X-ray diffraction (XRD), temperature programmed desorption of CO₂ (CO₂-TPD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The effect of methanol/oil molar ratio, ¹reaction time, reaction temperature, catalyst amount, and stability was investigated. The results showed that 10 wt% of lanthanum, cerium, and zirconium improved the catalytic activity of KF/CaO catalyst. The maximum catalytic activity using the lanthanum doping of 10wt% on KF/CaO catalyst was reached 98.7% under the optimal reaction condition of methanol/oil molar ratio of 12:1, reaction for 1 h at reaction temperature of 65°C, and 4% (wt/wt oil) catalyst amount. In addition, the FAME yield of KF/CaO/La catalyst remained higher than 95% after 10 cycles. The promotional effect of lanthanum doping could be attributed to the enhancement of the basicity strength of KF/CaO catalyst and block the leach of Ca²⁺ in the transesterification reaction.     

A novel Dempster-Shafer theory-based approach with weighted average for failure mode and effects analysis under uncertainty

Risk priority number (RPN) is a commonly-used prioritization method in failure mode and effects analysis (FMEA) for systemic reliability and safety study. However, conventional RPN confronts wide criticisms, due to the neglect of the uncertainties of experts' opinions. It is important to handle the conflicts among experts' multi-opinions which could be described in imprecise, incomplete or crisp forms in lack of knowledge. In this paper, a novel method is proposed to alleviate and/or eliminate counter-intuitive behaviors against conflicts among multi-opinions under Dempster-Shafer theory. Firstly, the abnormity test for experts’ opinions is undertaken to identify and discard those distinct judgments. Then, an approach to determining the subjective weights of experts is proposed, which is used in weighted average for multi-opinions before calculating RPNs. Finally, the risk priority evaluation on main engine crankcase explosion failure on-board ship is implemented to verify the feasibility of the proposed approach.     

Behavior of the organophosphorus insecticide fenitrothion in stored faba beans and its biological effects towards experimental animals

Sound whole-seed faba beans were treated with (methyl-¹⁴C) fenitrothion [O, O-dimethyl-O-(3-methyl-4-nitrophenyl) phosphorothioate] at 5 and 10 mg insecticide/kg seeds, a dose normally used in practice. During the 30 weeks of storage period, the penetration and distribution of insecticide residues were studied. The amount of surface residues, internal residues and bound insecticide residues was estimated. Surface residues were found to decrease with the increase in time of storage, whereas internal residues showed a gradual increase with time apparently not dose dependent. Grain-bound residues increased with time and reached to its maximum (14–18%) after 24 weeks of storage. Chromatographic analysis of the internal extracts revealed the presence of the parent compound together with three main metabolites which were found in both free and conjugated form. Feeding mice for 90 days with a diet mixed with total internal fenitrothion residues in stored faba beans led to a reduction in body weight gain, and an appreciable decrease in cholinesterase activity of 32% for plasma and 15% for red blood cells (RBC_S) after two months of experiment. Also, a significant decrease was showed in both total protein and albumin concentration at the end of feeding period (90 days). Liver and kidney function, as well as lipid profile of treated mice significantly increased at the end of feeding period. After a one-month recovery period, all the examined blood parameters returned to about the control values except blood urea and serum triglyceride.     

硫化镍异相结晶法处理含镍废水

针对含络合剂的重金属废水,以含镍废水为例,探索了以气体硫化氢为结晶药剂的硫化镍异相结晶技术。废水以薄层液膜方式铺展于结晶载体表面,硫化氢气体穿过气液界面进入液相,硫离子与金属离子在载体表面异相结晶析出,重金属得以去除。以含酒石酸的模拟化学镀镍废水为对象,静态实验与动态实验均表明该技术具有可行性,硫化镍沉淀在结晶载体表面异相结晶析出,且附着稳定;络合剂对反应影响小;进水流速为4 mL/min,硫化钠流速为0.65 g/min,氮气流速为0.16 L/min时,出水镍浓度为49～53 mg/L,单位面积滤布表面结晶平均去除镍量为0.98 g/(m2.h)。     

非均相Fenton和非均相US-Fenton体系中甲基橙降解动力学

在初始pH=3的条件下研究了甲基橙在非均相Fenton体系和非均相US-Fenton体系中的降解动力学。研究内容包括表观动力学方程和活化能。研究表明,超声的引入可以提高甲基橙的降解效率和降解速率。对比非均相Fenton和非均相US-Fenton体系中的表观动力学方程表明超声的引入可以提高反应速率常数,此外,还可以提高H2O2的利用率。通过对比分析,超声的引入可以降低反应所需的活化能,在超声的存在下,甲基橙的氧化活化能为25.12 kJ/mol,而在没有超声的条件下,需要的活化能为41.49 kJ/mol。     

The effects of ammonium sulphate and urea upon egg hatching and miracidial survival of Schistosoma mansoni

Abstract

The effects of various concentrations of ammonium sulphate and urea on egg hatching and miracidial survival of S. mansoni were tested in order to determine if the use of these fertilizers in the ricelands of the Republic of Cameroon could affect the transmission of schistosomiasis. Results indicate that hatching of eggs and survival of miracidia varied with concentrations of tested chemicals and times of exposure. Exposure of S. mansoni eggs to 0.20%‐1.00% ammonium sulphate or to 0.50%‐4.00% urea reduced their ability to hatch and produce miracidia. A chemical concentration of 1.00% ammonium sulphate or 4.00% urea was found to be sufficient to produce complete inhibition of hatching. High concentrations of both chemicals not only inhibited miracidial emmergence but also may be ovocidal. Results obtained from miracidial survival tests indicated that LC₅, LC₅₀ and LC₉₅ values for ammonium sulphate were 0.07%, 0.80% and 10.61% after 2 hours of exposure; 0.03%, 0.16% and 0.90% after 4 hours of exposure; and 0.30%, 0.20% and 0.40% after 6 hours of exposure respectively. Similar statistical analyses revealed that the LC₅, LC₅₀ and LC₉₅ values for urea were 0.22%, 1.90% and 16.25% after 2 hours of exposure; 0.28%, 0.57% and 1.14% after 4 hours of exposure; and 0.13%, 0.27% and 0.57%” after 6 hours of exposure respectively. Although the two fertilizers exerted some adverse effects on S. mansoni eggs and miracidia at relatively high concentrations, neither of them was found to be of practical value. Ammonium sulphate and urea concentrations effective in killing S. mansoni eggs and miracidia were about one to two orders of magnitude greater than the actual field application rates.