UV/TiO2薄膜体系光降解酞酸酯研究

采用自制玻璃负载TiO2薄膜,研究了UV-V is/TiO2以及UV/TiO2/H2O2体系对2种酞酸酯DBP和DEHP的光催化降解情况。研究结果表明,TiO2在暗处对酞酸酯没有降解作用;UV/TiO2体系能有效光降解DBP和DEHP,TiO2具有明显的光催化作用,增强因子分别为fDBP=2.06,fDEHP=1.53;在一定浓度范围内DBP在UV/TiO2体系中的降解速率与其初始浓度成负一级动力学关系;UV/TiO2/H2O2体系对DBP的光降解能力远大于UV/TiO2和UV/H2O2体系,H2O2能显著提高TiO2的光催化活性。     

Sorption and desorption kinetics of phthalates and phenol on water/sediment interface

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Biodegradability of blends of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) with cellulose acetate esters in activated sludge

Blends of the bacterially produced polyester poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with cellulose acetate esters (CAE) further substituted with propionyl or butyryl groups (degree of substitution: 2.60 propionyl and 0.36 acetyl or 2.59 butyryl and 0.36 acetyl, respectively) were exposed for 4 months to activated sludge to determine their biodegradability. Samples of such blends made by solution-mixing and solvent-casting had complex morphologies in which both individual components as well as a miscible blend phase were present. Additionally, the two opposite surfaces of solvent-cast films showed both physical and chemical differences. After 2 months, samples of pure PHBV had degraded by more than 98% (15 mg/cm² of surface area), whereas a pure CAE sample had degraded less than 1% (<0.2 mg/cm²). Samples containing 25% CAE lost less than 40% of their initial weights (6 mg/cm²) over the total 4-month period. Samples with 50% CAE lost up to 16% weight (2 mg/cm²), whereas those containing 75% CAE lost only slightly more weight than corresponding sterile control samples (1 mg/cm²). NMR results confirm that weight loss from samples containing 25% CAE resulted only from degradation of PHBV and that the surface of samples became enriched in CAE. Solvent-cast film samples containing equal amounts of PHBV and CAE degraded preferentially on the surface which formed at the polymer-air interface. Scanning electron microscopy and attenuated total reflectance infrared spectroscopy revealed this surface to have a rougher texture and a greater PHBV content.     

A2O小试系统与实际工艺单元中OPEs去除的比较

污水处理厂出水是环境中OPEs的重要来源,且污水处理厂的生物处理单元可去除部分OPEs.为了更好的研究污水处理厂工况条件,以达到优化去除宏量有机物和微量有机物的目的,良好的小试装置必不可少.本研究在实验室设计并安装了一套A²O小试装置,根据有机磷酸酯的结构特点,在进水中投加了3种代表性的有机磷酸酯.比较了小试装置中与实际工艺单元中这3种有机磷酸酯的去除规律,发现OPEs在A²O小试中的去除规律与实际工艺单元中相似,磷酸三丁氧酯（TBEP）在两种工况下去除效果均较好,总去除率分别为84.6%与83.6%,磷酸三（1-氯-2-丙基）酯（TCPP）去除效果均较差.在不同处理单元中,由于厌氧池中主要发生水解作用,TCPP在两种工况下的厌氧池中都可去除,且在A²O小试厌氧池中的去除率（57.7%）优于实际工艺（25.5%）.TBEP的去除主要发生在好氧池中,且A²O小试二沉池可以有效去除TBEP（67.9%）,优于实际工艺的二沉池.两种工况下,好氧池曝气强度较大,引入磷酸三（1-氯-2-丙基）酯（TCPP）不易降解,TCPP在好氧池去除效果较差.除此之外,优化了小试装置的OPEs的检测取样量保证检测的准确性.     

Performance studies of a low heat rejection engine operated on non-volatile vegetable oils with exhaust gas recirculation

During recent decades, considerable effort has been expended world-wide to reduce dependency on petroleum fuels for power generation and transportation through the search for suitable alternative fuels that are environmentally friendly. In this respect, vegetable oils are a promising alternative to diesel fuel. However, the high viscosity, poor volatility and cold flow characteristics of vegetable oils can cause some problems such as injector coking, severe engine deposits, filter gumming and piston ring sticking and thickening of lubrication from long-term use in diesel engines. These problems can be eliminated or minimised by transesterification of the vegetable oils to form monoesters. Although transesterification improves the fuel properties of vegetable oil, the viscosity and volatility of biodiesel are still worse than those of petroleum diesel fuel. The performance of a diesel engine with such biodiesel operation can be improved further with the concept of the low heat rejection (LHR) engine. In the LHR engine, combustion surfaces on the pistons, cylinder walls and valves can be coated with ceramic materials. The objective of this study was to apply the LHR engine concept for improving engine performance when either honge biodiesel, known as honge oil methyl ester (HOME), or neem biodiesel, known as neem oil methyl ester (NOME) oils was used as an alternative fuel. For this purpose, experiments were conducted on a single cylinder, four-stroke, direct injection, water-cooled compression ignition engine using diesel, HOME and NOME oils at different injection timings of 19, 23 and 27° before top dead centre (BTDC) with and without the induction of exhaust gas recirculation (EGR). The percentage of EGR was varied from 5 to 20% in steps of 5%. The results showed that specific fuel consumption and brake thermal efficiency were improved for both of the biodiesel fuels in the LHR engine. An EGR of 10% resulted in better performance with trade-off between oxides of nitrogen and hydrocarbons/carbon monoxide emissions and hence 10% EGR is taken as the best of the range from 5 to 20%. However, readings with other EGR ratios are not reported.     

Combustion characteristics of a four-stroke CI engine operated on Honge and Jatropha oil methyl ester–ethanol blends when directly injected and dual fuelled with CNG induction

The demand for petroleum products in India has been increasing at a rate higher than the increase of domestic availability. At the same time, there is continuous pressure on emission control through periodically tightened regulations particularly in metropolitan cities. In the wake of this situation, there is an urgent need to promote the use of alternative fuels as substitutes for high-speed diesel. Dual-fuel mode of operation employing compressed natural gas (CNG) and plant oils such as Honge and Jatropha oils and their esters is an attractive option as our country has a large agriculture base that can be a feedstock to this fuel technology which can ease the burden on the economy by curtailing fuel imports. This paper presents the results of investigations carried out in studying the behaviour of Honge and Jatropha oil methyl esters and their blends with 15% ethanol and subsequent testing of these oils in a four-stroke, single-cylinder, water-cooled, direct-injection compression ignition engine in dual-fuel mode with CNG induction.     

胃肠模拟体外法的生理参数对室内灰尘中邻苯二甲酸酯与磷系阻燃剂的生物有效性的影响

室内灰尘吞食暴露是邻苯二甲酸酯与磷系阻燃剂的主要暴露途径,测定室内灰尘中该类有机污染物的生物有效性对其暴露风险评价至关重要.本研究选择胃肠模拟体外方法-生理原理提取法(PBET)法测定室内灰尘中邻苯二甲酸二正丁酯(Dibutyl phthalate,DBP)、邻苯二甲酸丁基苄基酯(Butyl benzyl phthalate,BBP)、邻苯二甲酸二(2-乙基己基)酯(Di(2-ethylhexyl)phthalate,DEHP)和三(2-氯乙基)磷酸酯(Tris(2-chloroethyl)phosphate,TCEP)的生物有效性.研究了PBET法中胆盐含量、模拟肠液p H值、液固比及同时摄入奶粉等生理参数对生物有效性的影响.结果表明,4种有机污染物的生物有效性从1.5%(DEHP)到52%(TCEP),随污染物辛醇水分配系数的增加而降低.随着模拟液胆盐含量增加,DBP、BBP与DEHP的生物有效性逐渐增加,并在10 g·L~(-1)附近达到最大值后趋于平稳.TCEP由于其较好的水溶性,生物有效性并未随着胆盐含量的增加而明显变化.奶粉含量的增加则显著增加了DBP、BBP、DEHP和TCEP的生物有效性,在10 g·L~(-1)附近达到最大值后普遍呈现下降趋势.随着液固比的增加,DBP和DEHP的生物有效性显著提升,然而BBP与TCEP的生物有效性却未发生明显改变.在p H 6~8范围内,均未对4种有机物的生物有效性产生显著影响.     

高效液相色谱法测定水中两种邻苯二甲酸酯的不确定度研究

对高效液相色谱法测定水中两种邻苯二甲酸酯类化合物过程的不确定度及来源进行了分析和评定.通过数学模型计算分析过程中的各不确定度的分量,最后计算出相对合成不确定度和相对扩展不确定度.其中,邻苯二甲酸二丁酯和甲醇中邻苯二甲酸二(2-乙基己基)酯的相对合成不确定度分别为5.18%和3.93%.根据分析结果,在引起不确定度的因素中,由曲线拟合导致的不确定度分量最大,而样品前处理和方法回收率对不确定度的引入也有较大的影响.     

潍坊滨海经济技术开发区饮用水中有机磷酸酯的水平及人体暴露风险评估

采用固相萃取-气相色谱-三重四极杆质谱联用法(SPE-GC-MS/MS)分析了潍坊滨海经济技术开发区饮用水中的6种有机磷酸酯(organophosphate esters,OPEs)的浓度水平及组成特征,并分析了潍坊滨海经济技术开发区饮用水和当地居民混合血清中OPEs的相关性.采用美国环保署(US EPA)推荐的健康风险评价模型,评价了潍坊滨海经济技术开发区饮用水中OPEs的健康风险.结果表明,自来水样品中Σ_6 OPEs浓度水平为162~253 ng·L~(-1),而地下水中Σ_6 OPEs的浓度水平为3.52~13.9 ng·L~(-1),比自来水低两个数量级.自来水中磷酸三(2-氯)乙酯[tris(2-chloroethyl)phosphate,TCEP]的浓度水平最高,占Σ_6 OPEs的94.81%,地下水中含量最高的OPEs为磷酸三苯酯(triphenyl phosphate,TPh P),占Σ_6 OPEs的47.55%.2011年采集的潍坊滨海经济技术开发区居民混合血清中OPEs的分布与自来水中OPEs的分布间显著正相关(r=0.990,P0.01),2015年采集的居民混合血清中OPEs的分布与自来水中OPEs的分布间也显著正相关(r=0.997,P0.01),表明饮用水中的OPEs可能对人体血清中OPEs的污染水平有重要的贡献.不同人群通过饮用水摄入OPEs的日均暴露剂量(DI)为0.26~7.48 ng·(kg·d)-1,饮用水中各OPEs的非致癌性风险危害商(HQ)在10~(-5.81)~10~(-2.43)之间,通过饮用水摄入的OPEs非致癌性风险处于较低的水平.通过饮用水摄入的TCEP致癌性风险(Risk)在10~(-8.82)~10~(-6.79)之间,低于理论风险阈值(Risk=10~(-6.00)),但自来水中TCEP的致癌性风险相对高于地下水.     

西湖景区土壤中邻苯二甲酸酯污染水平、来源分析和空间分布特征

为考察杭州西湖景区土壤环境中邻苯二甲酸酯(phthalate esters,PAEs)的污染情况,本研究采集了西湖景区4种不同土地利用类型土壤共42个土壤样品,利用气相色谱三重四级杆质谱联用仪(GC-MS/MS)对所有样品中6种PAEs的含量水平和组成情况进行了分析,并采用主成分分析法和普通克里金插值法对不同土地利用类型土壤中PAEs的来源与空间分布进行了详细探讨.结果表明,西湖景区6种邻苯二甲酸酯累计含量(ΣPAEs)范围为597. 6～7 360. 1μg·kg~(-1),邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二正丁酯(DBP)和邻苯二甲酸二(2-乙基)己酯(DEHP)是3种主要的PAEs污染物,三者总含量平均值贡献率高达98. 43%,而DEHP作为含量最高的PAEs单体贡献率为66. 28%;不同土地利用类型土壤中的PAEs组成由于其来源不同而具有差异性,交通运输与游客活动是西湖景区内PAEs的主要来源; 6种PAEs主要分布在西湖景区的东北区域,呈现出由北向南、自东向西递减趋势.