水污染分析校准用汞溶液的研制

研制了水污染分析校准用汞溶液。采用原子荧光光谱法对样品进行了均匀性和稳定性检验,对样品的量值进行了验证并进行了不确定度评定。检验结果表明:汞溶液均匀性良好,室温条件下可稳定36个月以上;样品的标准值为100 mg/L,扩展不确定度为2 mg/L。样品量值与美国AccuStandard公司同种标准物质具有一致性。可用于水中汞检测的测定标准、质量控制、分析方法研究以及实验室能力验证等方面。     

5种不同晶型的纳米二氧化钛对金属铜生物积累的影响

纳米二氧化钛(nTiO_2)作为一种具有独特物理化学性质的纳米材料被广泛应用。然而,在生产、使用的过程中,nTiO_2会不可避免地进入于水环境中。重金属是水体中常见的污染物之一,nTiO_2进入水体后是否会与水体中的重金属发生相互作用,进而影响重金属的生物积累,目前相关报道还很少。本论文以大型溞为模式生物,考察了5种不同晶型nTiO_2对常见的重金属铜生物积累影响。结果表明,nTiO_2对Cu2+的吸附降低了试验液中Cu2+浓度。但5种不同晶型nTiO_2的吸附能力并不一样,其中锐钛矿晶型(A-S)的吸附能力最高,这可能是由于结构缺陷和表面羟基的存在,为Cu2+提供了更多的结合位点,从而提高了A-S的吸附能力。nTiO_2的存在降低了金属铜在大型溞体内的积累,这可能是由于nTiO_2对金属铜的吸附,降低了自由Cu2+的生物可利用性。由于nTiO_2样品之间比表面积的差异,不同晶型之间单位nTiO_2引起的铜积累有显著性差异性(P0.05),其中锐钛矿和金红石之比为4:1混合晶型(M1)最高,A-S最低。     

An investigation of a heat pump system using CO2/propane mixture as a working fluid

In order to decrease the heat rejection pressure of heat pump using pure working fluid, CO₂ or R744, other natural component including hydrocarbons (R290, R600a, R600, R1270, R170, R601) and dimethyl ether (RE170) is added to CO₂, respectively, and then six binary mixtures are achieved. By environmental and thermodynamic comparisons, R290 is selected to be the most appropriate component candidate to mix with CO₂, and meanwhile to weaken the flammability and explosivity for pure R290. Then, the system performances of heat pump using mixture of CO₂ and R290 were experimentally studied when R290 is added to CO₂ with a small fraction, and compared with that of the pure CO₂. The experimental test rig is designed and set up for the transcritical heat pump system. When the refrigerant charge is variable, the heating coefficient performance, optimum heat rejection pressure, compressor power, mass flow rate of refrigerant, and total heat coefficient of gas cooler were researched. The variation ratios of heating coefficient performance and heating capacity with deviation from the optimum refrigerant charge were also investigated. The optimum refrigerant charge of CO₂/R290 is obtained and the research results show that the addition of R290 to CO₂ can efficiently reduce the heat rejection pressure and improve the system performance. The results in the present work could provide useful guidelines for the design and operation of heat pump system using CO₂-based mixture.     

超声波处理剩余污泥有机物、氮和磷的释放特性研究

以生活污水处理厂污泥为研究对象.采用超声波技术研究了污泥破解过程中有机物、氮和磷的释放规律.结果表明,在声能密度为0.167、0.330、0.500 W/mL的条件下,污泥中的有机物、氮和磷的释放均随超声时间而增加;破解后污泥释放出的有机物以分子量(MW)≤2 000的物质为主,且上清液BOD5/COD>0.33;所释放的氮以有机氮为主,其次是氨氮,污泥破解液COD/凯氏氮平均值为11,适合于生物法脱氮;污泥破解所释放的正磷酸盐约占污泥总磷质量的6.0%～18.2%.利用沉淀结晶法将其回收,可减轻原污水处理工艺的磷负荷.     

Modeling the atmospheric transport and deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans in North America

The atmospheric fate of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) was simulated for the year 2000 in North America using a SMOKE/CMAQ-based chemical transport model that was modified for this purpose. The 1999 USEPA emission inventories of PCDD/Fs and criteria pollutants were used. The 1995 Canadian emission inventory of criteria pollutants and the 1995 Canadian area source emissions for PCDD/Fs were used with the 2000 Canadian point source emissions. Modifications to CMAQ involved coupling it with dual organic matter (OM) absorption and black carbon (BC) adsorption models to calculate PCDD/F gas–particle partitioning. The model satisfactorily reproduced the particle bound fractions at all rural sites for which there were measured data and across the whole domain, the modeled vs. measured differences in particle bound fractions were less than 20% for nearly all congeners. The model predicted ambient air PCDD/F concentrations were also consistent with measurements. Simulated deposition fluxes were within 58% of direct measurements. PCDD/F atmospheric depositions to each of the Great Lakes were estimated for the year 2000. The results indicate that approximately 76% of the total deposition of PCDD/Fs to the Great Lakes (in W-TEQ, or toxic equivalent units as defined by the World Health Organization) is attributed to PCDD/Fs absorbed into OM in aerosol. For all of the lakes, more than 92% of all deposition is particle phase wet deposition and only 5–8% is particle phase dry deposition. Wet deposition from the gas phase is negligible. Of the 17 toxic PCDD/F congeners, the Cl_4–5DD/F compounds contribute approximately 70% to the total atmospheric deposition to the Great Lakes. The seasonal changes in the PCDD/F deposition flux track variations in ambient temperature.     

基于实测光谱的叶绿素a估测模型

为了有效地监测太湖湖区的富营养化程度,建立一种最佳的估测模型。对太湖水体进行了连续监测,获得了从2004年10月20～29日的实测光谱数据和水质数据。通过实测光谱反射率和叶绿素a浓度的相关分析,得到了叶绿素a反演的最佳波段,并通过比值法、反射峰位置法、峰谷距离法、峰高法和一阶微分法建立了基于实测光谱的叶绿素a浓度的估测模型。通过14个检验点,分别对5种模型进行了对比分析,结果发现,通过比值法建立的估测模型总体误差最小,估测精度最高,其695 nm附近反射峰与677 nm反射谷的比值与叶绿素a浓度之间具有良好的相关性,可决系数R²可达0.7433,可以作为整个湖区叶绿素a浓度的最佳估测模型。最后,应用该模型对该季节湖区的营养化程度做出了总体评价。     

Aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing in Guangzhou during the 2006 Pearl River Delta campaign

Optical and chemical aerosol measurements were obtained from 2 to 31 July 2006 at an urban site in the metropolitan area of Guangzhou (China) as part of the Program of Regional Integrated Experiment of Air Quality over Pearl River Delta (PRIDE-PRD2006) to investigate aerosol chemistry and the effect of aerosol water content on visibility impairment and radiative forcing. During the PRIDE-PRD2006 campaign, the average contributions of ammonium sulfate, organic mass by carbon (OMC), elemental carbon (EC), and sea salt (SS) to total PM_2.5 mass were measured to be 36.5%, 5.7%, 27.1%, 7.8%, and 3.7%, respectively. Compared with the clean marine period, (NH₄)₂SO₄, NH₄NO₃, and OMC were all greatly enhanced (by up to 430%) during local haze periods via the accumulation of a secondary aerosol component. The OMC dominance increased when high levels of biomass burning influenced the measurement site while (NH₄)₂SO₄ and OMC did when both biomass burning and industrial emissions influenced it. The effect of aerosol water content on the total light-extinction coefficient was estimated to be 34.2%, of which 25.8% was due to aerosol water in (NH₄)₂SO₄, 5.1% that in NH₄NO₃, and 3.3% that in SS. The average mass-scattering efficiency (MSE) of PM₁₀ particles was determined to be 2.2 ± 0.6 and 4.6 ± 1.7 m² g⁻¹ under dry (RH < 40%) and ambient conditions, respectively. The average single-scattering albedo (SSA) was 0.80 ± 0.08 and 0.90 ± 0.04 under dry and ambient conditions, respectively. Not only are the extinction and scattering coefficients greatly enhanced by aerosol water content, but MSE and SSA are also highly sensitive. It can be concluded that sulfate and carbonaceous aerosol, as well as aerosol water content, play important roles in the processes that determine visibility impairment and radiative forcing in the ambient atmosphere of the Guangzhou urban area.     

钻井废液毒性检测与评价研究

以几种典型钻井液体系为研究对象,分别选用成熟可靠的检测方法对其生物毒性、化学毒性和重金属含量进行分析,结果表明:部分钻井废液具有一定生物和化学毒性,其中,磺化体系钻井液在生物毒性和化学毒性方面均超标,应重点加强管理;低密度无固相体系和磺化体系钻井液中Hg和Cr元素存在不同程度的超标。     

型煤燃烧特性初探

本文使用热重分析仪对型煤的燃烧特性进行了初步探讨。煤灯样品在升温过程中,发生两次快速失重,对应的温度分别为Ｔ１和Ｔ２。由于制备型煤时,添加了无机粘结剂和无机固硫剂等无机物,导致制备型煤用的混合料的Ｔ１比原煤降低,而刷烈燃烧温度Ｔ２却比原煤升高。     

潮汐循环影响下上覆水环境因子和氮营养盐的变化及其相关关系

潮汐循环对水体理化特征的短期影响是潮汐河口各种理化参数变化的一个重要原因。通过崇明东旺沙堤外低潮滩和东海农场低潮滩采样及环境因子分析，发现崇明东滩各环境因子之间（除浊度外）相关性较好，均呈宽 “U”型变化；东海农场各环境因子之间相关性较差，变化不一致，且盐度、电导率变化与崇明东滩变化相反；受潮汐循环影响，崇明东滩涨潮初期各形态氮有明显释放过程，而东海农场的近底层水体在涨潮初期NH4+ N急剧下降，NOX- N缓慢下降；无论是在崇明东滩还是在东海农场，营养盐浓度受环境因子的共同影响，整个潮汐循环过程中总无机氮（TIN）与盐度呈显著线性负相关，这与整个长江口近岸水体的营养盐负荷相一致，长江上游淡水带来的高负荷营养盐流经河口进入海洋。