漳泽水库水体污染对黑斑蛙蝌蚪遗传毒性的野外调查研究

通过野外采集漳泽水库不同采样点的黑斑蛙蝌蚪,采用微核、核异常、彗星试验3种方法,研究了水体污染对蝌蚪红细胞微核率、核异常率和DNA断裂3种遗传毒性指标的影响。微核试验结果显示:各采样点红细胞微核率除泽头采样点外,均明显高于阴性对照(P0.01),其中水库入口店上采样点的微核率最高,为6.87‰,位于水库上、中、下游3个采样点的微核率逐渐下降,从大到小依次为:下韩(5.45‰)、台上(3.71‰)、泽头(2.33‰)。核异常试验结果显示:各采样点核异常率均明显高于阴性对照(P0.01),核异常率与微核率二者变化趋势趋于一致。彗星试验结果显示:各采样点红细胞尾长、尾矩与阴性对照相比差异均极显著(P0.01),尾长、尾矩的变化趋势与微核试验结果一致。对同样位于水库中游的采样点司徒和台上的4个指标进行多重比较分析发现:微核率、核异常率和彗星尾长差异均不显著(P0.05),而尾矩差异显著(P0.05)。综上可知,漳泽水库各采样点水体具有较高的遗传毒性,主要毒性作用为引起染色体(DNA)断裂;各采样点遗传毒性指标变化规律与水体污染物变化规律趋于一致,因此应用这3种方法可以有效地对水体遗传毒性进行检测。     

超声技术降解酸性红B废水

以酸性红Ｂ染料模拟废水为对象,考察了废水浓度、ｐＨ、超声时间、ＮａＣｌ投加量及曝气等因素对其超声降解效率的影响．实验结果表明：酸性红Ｂ降解率与超声时间基本上成线性关系;初始浓度高,降解率大;ｐＨ值增大,降解率减小;当溶液中ＮａＣｌ投加量从０ 增加到１ｇ／Ｌ,降解率从４３％ 增加到近９０％ ;再增加溶液中ＮａＣｌ的浓度,对其降解率影响不大;水浴温度升高,酸性红Ｂ降解率增大;曝气及Ｈ₂Ｏ₂ 投加量对其降解率的影响不大．     

NiB2O4 (B = Mn or Co) catalysts for NH3-SCR of NOx at low-temperature in microwave field

● Microwave-assisted catalytic NH₃-SCR reaction over spinel oxides is carried out. ● SCR reaction temperature is tremendously lowered in microwave field. ● NO conversion of NiMn₂O₄ is highly up to 90.6% at 70°C under microwave heating. Microwave-assisted selective catalytic reduction of nitrogen oxides (NO_x) was investigated over Ni-based metal oxides. The NiMn₂O₄ and NiCo₂O₄ catalysts were synthesized by the co-precipitation method and their activities were evaluated as potential candidate catalysts for low-temperature NH₃-SCR in a microwave field. The physicochemical properties and structures of the catalysts were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), N₂-physisorption, NO adsorption-desorption in the microwave field, H₂-temperature programmed reduction (H₂-TPR) and NH₃-temperature programmed desorption (NH₃-TPD). The results verified that microwave radiation reduced the reaction temperature required for NH₃-SCR compared to conventional heating, which needed less energy. For the NiMn₂O₄ catalyst, the catalytic efficiency exceeded 90% at 70 °C and reached 96.8% at 110 °C in the microwave field. Meanwhile, the NiMn₂O₄ also exhibited excellent low-temperature NH₃-SCR reaction performance under conventional heating conditions, which is due to the high BET specific surface area, more suitable redox property, good NO adsorption-desorption in the microwave field and rich acidic sites.     

CAS-BT复合反应器同步脱氮除磷试验研究

在CAST反应器中引入自制悬浮填料,构成了CAS-BT复合反应器,采用人工配制废水,对其同步脱氮除磷效果进行了试验研究.试验结果表明,当TN为178.05 mg/L、TP为28.32 mg/L时,CAS-BT工艺取得了很好的同步脱氮除磷效果,TN和TP的去除率分别达到97.55%和98.10%.进行同步脱氮除磷时,CAS-BT比其他的水处理工艺更具优势.     

Particulate Air Pollution in Mexico City: A Collaborative Research Project

ABSTRACT

PM₁₀, PM₂₅, precursor gas, and upper-air meteorological measurements were taken in Mexico City, Mexico, from February 23 to March 22, 1997, to understand concentrations and chemical compositions of the city's particulate matter (PM). Average 24-hr PM₁₀ concentrations over the period of study at the core sites in the city were 75 H g/m³. The 24-hr standard of 150 μ g/m³ was exceeded for seven samples taken during the study period; the maximum 24-hr concentration measured was 542 μ g/m³. Nearly half of the PM₁₀ was composed of fugitive dust from roadways, construction, and bare land. About 50% of the PM₁₀ consisted of PM_2.5, with higher percentages during the morning hours. Organic and black carbon constituted up to half of the PM_2.5. PM concentrations were highest during the early morning and after sunset, when the mixed layers were shallow. Meteorological measurements taken during the field campaign show that on most days air was transported out of the Mexico City basin during the afternoon with little day-to-day carryover.     

我国PPE市场探析

PPE（个体防护装备）的应用涉及到我国国民经济的许多领域．随着经济建设的快速发展和各级政府对安全防护工作的高度重视与资金投入．以及企事业单位对安全防护尤其对个体防护的意识普遍增强．对PPE的要求也越来越高。促使国内PPE市场需求也随之升温．面对十分看好的市场前景．众多厂商之间的竞争也愈加激烈。     

Leaf-air transfer of organochlorine pesticides from three selected vegetables

The leaf-air transfer of organochlorine pesticides (OCPs) in three kinds of vegetables, namely lettuce, romaine and garlic leaves was investigated. It was found that although the uptake of OCPs by the three selected vegetables was similar under controlled conditions, the depuration varied significantly among chemicals and plant species in terms of elimination rate, final residue of each OCPs, as well as the effect of temperature on the residue of OCPs in the vegetables. The results indicated that neither QCB nor HCB could be trapped tightly by any of the three selected vegetables, in contrast, p,p'-DDT could be retained effectively by all of them; the retainment of alpha-HCH, gamma-HCH, p,p'-DDE, was dependent on the vegetable species, of which the garlic leaf had the biggest ability to trap them. Our work provided insight into the behavior of OCPs in the agroecosystem.     

Behavior and fate of chlorpyrifos introduced into soil-crop systems by irrigation

The effect of chlorpyrifos added in irrigation water to a red soil from Central South China on the growth of wheat and oilseed rape seedlings, together with its uptake, was studied in a pot experiment. Addition of chlorpyrifos (1-10 microg g-1) in a single irrigation with distilled water resulted in absorption of chlorpyrifos by wheat (0.257-4.50 microg g-1) and also oilseed rape seedlings (0.249-2.02 microg g-1) during 20 d of plant growth. An initial concentration of chlorpyrifos in soil that is equivalent to or below 10 microg g-1 did not significantly influence the growth of wheat seedlings. Similarly, an initial concentration equivalent to or below 5 microg g-1 did not significantly influence the growth of oilseed rape seedlings. The degradation rate of chlorpyrifos was 1.4-4.2 times larger in oilseed rape rhizosphere soil than in unvegetated soil. The numbers of bacteria and fungi in oilseed rape rhizosphere soil were 3.18 times and 1.84 times larger, respectively, than those in unvegetated soil. This helps to explain the difference in degradation rates obtained.     

Synthesis evaluation with entire-array-polygon method to ecological economic system of Funing County in Jiangsu Province

Based on the theory of ecological footprint this paper analyzed the ecological economic system in Funing County in the view of demands of economic system to natural resource and supply of ecosystem for natural resources. It was proposed that the concept of ecological deficit (ecological remainder) per ten thousands yuan GDP be used to evaluate development of ecological economic system. With a synthesis appraisement to the ecological economic system using entire-array-polygon method combined with Ulanowicz development ability and with ecological deficit (ecological remainder) per ten thousands yuan GDP, it provids a theoretical base for reconstructing and managing of demonstration eco-region.     

水生植物化感作用应急处置海洋赤潮和淡水水华

近年来,植物化感作用逐渐成为控制藻类暴发的一种新技术。根据国内外的研究成果,着重从水生植物化感作用、化感抑藻物质、应急处置藻类方法、海洋赤潮和淡水水华的应急处置及机理进行评述,并对该技术今后的发展予以展望。