Measurement of Fine Particles in Diesel Emissions Using a Real-Time Aerosol Monitor

Abstract

A real-time monitoring methodology to determine diesel fine particles in diesel emissions has been evaluated. The range of particle size captured by the monitor was ～0.1 μm to 1 μm. DustTrak real-time monitors were connected to the dilution tunnel of the vehicle exhaust to measure the emissions during the vehicle tests under both dynamic and steady-state driving conditions, and concentration data were recorded every 5 sec. Test variation of the real-time monitoring among different test days was similar to that measured by traditional filter-based gravi-metric method, whereas the repeatability of the monitor data within the same-day tests was better than that of gravimetric method. Correlations between the two methods were established for different fuels tested on a single light duty vehicle. When the emissions from the reference fuel was used to convert the monitor’s response to diesel fuels, the levels determined by the real-time monitor were consistent with those measured by gravimetric method among different fuels tested. Use of the real-time monitor could provide information on the levels of fine particles that is more relevant to the public health than the total particles.     

Effects of dimethoate on rotifer Brachionus calyciflorus using multigeneration toxicity tests

As important members of the zooplankton community and sources of food for fish, rotifers are used extensively in ecotoxicological research to assess the health of the environment and safety of compounds. However, most rotifer toxicity tests are only conducted using rotifer neonates derived from unexposed mothers, thus ignoring the potential transfer of contaminants from mother to offspring. To understand better the mother to offspring exposure, a multigenerational study was conducted using three successive generations (F₀, F₁ and F₂) of the common freshwater rotifer Brachionus calyciflorus to investigate the toxic effects of the widely used organophosphate pesticide, dimethoate (O, O-dimethyl S-methylcarbamoylmethyl phosphorodithioate). When the F₀ generation was exposed to five pesticide concentrations, the population growth rate (r) displayed symptoms of hormesis, characterized by the conversion of low-concentration stimulation to high-concentration inhibition. Despite this observation, the exposure to any given concentration of dimethoate reduced the population growth rates of the F₁ and F₂ generation rotifers. Significant differences existed between the F₀, F₁ and F₂ rotifers for the population growth rate under dimethoate stress: F₂ individuals were more sensitive than F₁, whereas the F₁ individuals were more sensitive than F₀. The results indicated that the parental exposure to a given toxic stress could result in increased sensitivity and decreased fitness in the offspring. This study illustrates the utility of multigenerational toxicity tests, which may better reflect and more accurately predict the effects of long-term pesticide exposure to aquatic organisms at the population level.     

烟气脱硫溶液中硫酸根的去除

分别采用石灰乳化学沉淀法和低温结晶法去除烟气脱硫溶液中的SO42-。实验结果表明：在室温、CaO溶液质量分数25%的条件下,石灰乳化学沉淀法对SO42-的去除率仅为59.51%,且向溶液中引入了Ca2+,产生的硫酸钙固体废物难以再生利用;采用低温结晶法处理烟气脱硫溶液,在结晶温度7 ℃、结晶时间3 h、NaOH加入量34.8 g/L的条件下,SO42-的去除率为82.04%、滤液中的ρ（Na+）为3.88 g/L。在现场工业应用试验中,采用低温结晶法去除烟气脱硫溶液中的SO42-,平均SO42-的去除率可达70.00%以上,滤液中的ρ（Na+）小于15.00 g/L。该法可有效抑制烟气脱硫溶液中SO42-含量的增加。     

混凝剂品种对混凝-超滤联合工艺膜污染的影响

本实验以工业化学合成聚合硫酸铁混凝剂和自制生物聚合硫酸铁为例,考察了铁系混凝剂品种对地表水浊度、TOC和UV254的去除效果,混凝剂品种对混凝-超滤联合工艺处理地表水过程中超滤膜污染的影响。混凝实验结果表明,在10 mg/L(以Fe3+计)最佳投加量下,两类混凝剂对浊度、TOC和UV254的去除率基本相同。超滤膜污染实验结果表明,生物聚合铁预处理水样通量衰减速度略大于化学聚合铁预处理水样;膜污染阻力分析结果显示,随着循环次数的增加,工业化学合成聚合铁预处理水样造成的不可逆污染阻力逐渐增加,而生物聚合铁预处理水样造成的不可逆污染阻力却略有下降;膜污染机理分析表明,2组过滤过程的膜污染类型基本相似,由最初的膜孔堵塞过渡到最终的滤饼层污染。SEM分析表明,生物聚合铁预处理水样的膜污染较为严重。     

SBR处理模拟氯苯废水

在SBR中利用光合细菌球形红细菌污泥颗粒进行模拟氯苯废水处理的初步研究,结果表明,采用球形红细菌污泥颗粒处理模拟氯苯废水的SBR系统是可行的,其降解氯苯过程符合Monod一级反应动力学方程。当进水氯苯浓度在125～187.5 mg/L变化时,处理效率都能稳定在90.5%～95.6%之间;其最佳工艺条件为反应时间6 h、DO 4.75～5.0 mg/L、沉淀时间1.5 h、污泥颗粒浓度4 000～6 000 mg/L。在污泥颗粒浓度4 000 mg/L、DO 5.0 mg/L、反应时间6 h的最佳条件下,当进水COD为748.1 mg/L、氯苯浓度100 mg/L时,COD的去除率达90.9%,处理后出水COD满足国家一级排放标准要求。     

添加氮损失抑制剂对蓝藻泥堆肥质量的影响

对脱水蓝藻进行大型生产性堆肥实验。研究堆肥过程中,氮损失抑制剂过磷酸钙的添加对堆肥物料各类理化性质的影响。研究结果表明,过磷酸钙加入的处理组与未加过磷酸钙的对照组堆制37 d后堆肥物料均可腐熟,且堆肥肥效均符合NY525-2002的相关要求。添加过磷酸钙处理组有机质含量为490 g/kg,全N、全P和全K含量分别为20.75、10.02和11.32 g/kg,总养分含量达到9.77%,堆肥品质明显优于对照处理。同时,在微生物的作用下,对照组中微囊藻毒素MC-RR与微囊藻毒素MC-LR去除率分别达到89.8%与78.3%。值得一提的是,添加过磷酸钙后,MC-RR和MC-LR的去除率得到进一步提高,分别达到了92.96%和100%,较好地保证了蓝藻堆肥农用的安全性,为脱水蓝藻好氧堆肥化提供了可行性依据。     

Determination of Steroid Estrogens in Wastewater Treatment Plant of A Controceptives Producing Factory

Steroid estrogens such as estrone (E1), 17β-estradiol (E2), estriol (E3), and 17α-ethynylestradiol (EE2) have been suspected to be the main contaminants, which can affect the endocrine system of animals. Many authors have investigated these chemicals in the domestic wastewater treatment plants (WTP). However, wastewater from industries producing steroid contraceptives has not got ample attention. From the environmental point of view, the four steroids are very significant because even very low concentrations (ng/L) can cause reproductive disturbances in human, livestock and wildlife. The main purpose of the present investigation was to develop an analytical method for the determination of the four steroid estrogens present in WTP of a pharmacy factory, mainly producing contraceptive medicine in Beijing, China. Analysis was performed by solid-phase extraction (SPE) system and liquid chromatography combined with tandem mass spectrometry (LC/MS/MS). The average recoveries from effluent samples ranged from 88% to 103% and the precision of the method ranged from 9% to 4%. Based on 0.5-L wastewater samples, the limit of quantification (LOQ) was determined at 0.7 ng/L for E1, 0.8 for E2, 0.9 ng/L for E3, and 0.5 ng/L for EE2 in influent, and 1.0 ng/L for E2 and EE2, and 2.0 ng/L for E1 and E3 in effluent. In the influent samples, average concentrations of 80, 85, 73 and 155 ng/L were determined for E1, E2, E3 and EE2, respectively, showing that they were removed in this WTP to the extent of 79, 73, 85 and 67%, respectively.     

特警战训服面料开发技术研究

本文介绍了以芳纶纤维为主要材料的我国新一代特警战训服面料的技术研发及达到的主要性能指标。通过试验研究,开发了具有高强防撕裂、永久阻燃、耐高温、防静电、防油拒水、防酸碱等具有集成防护功能的特警战训服系列面料。     

Leaching-induced migration and compositional form change of Cu,Zn, and Cd from sludge to loess

Land utilization of sewage sludge has become one of the major issues in environmental mitigation in China. This is particularly important in the Loess Plateau of Northwest China. Sludge enriched with organic matter and nutrients might effectively help to resolve the problems of silty loess soils as evidenced by porosity defect, structural alterations and absence of fertility. After sludge flows into the loess, irrigation water contains heavy metals that leach and migrate into sludge and consequently related human health risks may occur that raise concerns; and this situation needs to be rectified. The characteristics of the vertical migration and composition form change of Cu, Zn, and Cd from composted sludge to loess, and corresponding influencing factors, were investigated by performing a soil column simulation test under the leaching treatment of a one-year irrigation water capacity. Results demonstrated that: (1) composted sludge significantly improved loess fertility, and irrigation leaching transported only a small quantity of organic matter in sludge in the plough layer; (2) although some of the Cu, Zn, and Cd in composted sludge migrated to and concentrated in the middle and upper layers of the soil column during leaching, these metals were mostly retained in the plough layer; and (3) after the leaching treatment of the one-year irrigation water capacity, the compositions of Cu, Zn, and Cd (particularly Cu and Zn) in both plough layer and loess began to stabilize with low concentrations in the exudate. These findings confirmed the applicability of composted sludge in loess regions. This study provided a new insight into the sludge reuse in alkaline soils in arid and semi-arid region.     

磺化石墨烯对小麦幼苗生长及生理生化指标的影响

随着石墨烯生产量和使用量的不断增大,其对生态环境的风险逐渐引起了环境学家的关注。采用水培试验,探究了磺化石墨烯(SGO)对小麦幼苗的生长、抗氧化酶活性及脂质过氧化的影响。结果表明:在培养10 d后,低浓度磺化石墨烯对小麦根系的生长有显著促进作用(P0.05),200 mg·L-1浓度处理与对照处理相比提高了84.3%,随着浓度增加促进作用逐渐减弱,1 000 mg·L-1时与对照相比提高了19.9%。但对小麦地上部的生长没有影响。磺化石墨烯处理的小麦幼苗根系和叶片组织中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)及丙二醛(MDA)都呈现先下降后上升的趋势。当磺化石墨烯浓度低于200 mg·L-1时,处理组小麦抗氧化酶的活性及MDA含量相对于对照处理大都有所降低,说明低浓度时磺化石墨烯没有对小麦的生长产生氧化胁迫,这与磺化石墨烯可能具有一定的抗氧化能力有关,而高浓度时由于产生氧化胁迫使各项生理生化指标逐渐上升。本实验结果为石墨烯材料对植物的毒理学研究提供了基础数据。