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1.
Environmental Science and Pollution Research - Recent research has shown a huge impact of non-renewable energy (NRE) production on environmental health. In this context, this work analyzes the...  相似文献   
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In this work we present the results of a 2-year survey of indoor radon variations in four cities of Lahijan, Ardabil, Sar-Ein and Namin in North and Northwest Iran. We used both passive and active measurements by solid state nuclear track detectors (SSNTDs) with CR-39 polycarbonate and PRASSI Portable radon Gas Surveyor. A total of 1124 samplers in Lahijan, Ardabil, Sar-Ein and Namin were installed. Sampling frequency was seasonal and sampling locations were randomly chosen based on dwelling structures, floors, geological formations, elevation and temperature variation parameters. For quality assurance, 281 active measurements and double sampling were carried out. Based on our results and the results of previous surveys, Ardabil and Lahijan have the second and third highest radon concentration in Iran, respectively (Ramsar is first). The average radon concentration during the year in Lahijan, Ardabil, Sar-Ein and Namin were 163, 240, 160 and 144 Bq/m(3) with medians of 160, 168, 124 and 133 Bq/m(3), respectively. These concentrations give rise to annual effective doses of 3.43 mSv/y for Lahijan and 5.00 mSv/y for Ardabil. The maximum recorded concentration was 2386 Bq/m(3) during winter in Ardabil and the minimum concentration was 55 Bq/m(3) during spring in Lahijan. Relationships between radon concentration and building materials and room ventilation were also studied. The dosimetry calculations showed that these four cities could be categorized as average natural radiation zones. The correlation coefficients relating warm and cold season radon variation data were obtained.  相似文献   
3.
Abstract

Chloroanilines are constituents of many agrochemicals and have been found to be metabolized to succinic acid conjugates, e.g., succinamides and succinimides. The mutagenic potential of five chloroanilines and their succinamides and succinimide derivatives have been tested with two strains of Salmonella typhimurium (TA98 and TA100) with and without rat hepatic micro‐somal fraction. None of the compounds produced a dose response effect with a two‐fold increase in revertants indicating that these compounds are not mutagens or promutagens in these assays.  相似文献   
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Five plants were examined for their ability to remove nutrients from aquaculture wastewater and suitability as fish feed: alfalfa, white clover, oat, fall rye, barley. The seeds were first germinated in water in a hydroponic system, and the plants were fed wastewater from Tilapia production facility. Clover and alfalfa seeds were infected with fungus shortly after germination, and their roots were completely destroyed by day 14. Oat, rye and barley had the fastest growth and showed greater tolerance to fungal disease compared with alfalfa and clover. Although substantial amounts of soluble and insoluble substances were released by the seeds during the germination period, the plants were able to remove all the pollutants in wastewater and significant portions of those released substances. The total reductions in total solids, COD, NO3-N, NO2-N, phosphate and potassium ranged from 54.7% to 91.0%, 56.0% to 91.5%, 82.9% to 98.1%, 95.9% to 99.5%, 54.5% to 93.6% and 99.6% to 99.8%, respectively. Oat, barley and rye grow well in this type of hydroponic system and can be used as a fish feed after being supplemented with fat, Ca, Na, Mn and Fe. Oil seeds and the chlorides of these elements could be added to these plants when formulating the fish feed. For a continuous operation, a two-unit system could be configured to allow for one week germination and one week cleaning and startup in one unit while the other unit is in operation.  相似文献   
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微藻富含油脂,可以用作合成生物柴油的原料,被认为是最具发展前景的生物质能源.微藻的光合培养体系往往是非纯培养体系,现有研究更多地关注微藻生物量的积累及其对废水环境的净化效果,而对体系中广泛存在的共栖细菌缺乏全面深入的认知.本文通过对棕鞭藻共栖细菌的16S rDNA基因进行高通量测序分析,研究棕鞭藻(Ochromonas)在生活废水、BG11及Glu+BG11(BG11中添加10 g·L-1葡萄糖)3种不同营养环境中共栖细菌的群落结构差异,进而阐明有机物及复杂废水环境对微藻共栖细菌群落结构的影响效果.结果表明,生活废水、BG11及Glu+BG11 3种营养环境中共栖细菌群落结构存在显著差异,生活废水体系中生物多样性显著高于BG11及Glu+BG11体系,生活废水中共栖细菌香浓(Shannon)多样性指数高达4.32,其次是BG11及Glu+BG11,Shannon指数分别为2.13、1.54.从共栖细菌群落的组成上看,3种营养环境中优势菌属差异显著,生活废水中优势菌属有芽殖杆菌属(Gemmobacter)、鞘脂单胞菌属(Sphingomonas)及玫瑰球菌属(Roseococcus),相对丰度分别为14.46%、14.9%、14.54%,其中,芽殖杆菌属只在生活废水中有较高丰度.BG11中寡养单胞菌属(Stenotrophomonas)与玫瑰球菌属的丰度分别高达26.86%、51.03%.Glu+BG11中寡养单胞菌属较BG11中显著增加,达到82.41%,而玫瑰球菌属较生活废水及BG11中则明显降低,菌群丰度仅为6.2%.对比3种营养环境,玫瑰球菌属均具有较高丰度,是棕鞭藻良好的共生菌.  相似文献   
7.
The 7.6 magnitude (Richter scale) earthquake that struck northern Pakistan on 8 October 2005 was devastating. This paper gauges success in targeting vulnerable families during the transition from relief to reconstruction through cash assistance provided by the Livelihood Support Cash Grants (LSCG) programme. Families without a male member, with a disabled male member aged between 18 and 60 years or with more than five children, defined as vulnerable, were provided with USD 50 per month for six months via a bank transfer. The LSCG scheme enrolled around 750,000 families and selected 267,402 vulnerable families to whom it disbursed a total of USD 86.95 million. Using a community‐based survey, this paper assesses leakage and under‐coverage (exclusion). Approximately 30 per cent of families received the cash grant. However, only one in two was eligible for the benefit, and one in two deserving families was excluded. This is a matter of grave concern.  相似文献   
8.
A dynamic water balance model is created to examine the effects of different water conservation policies and recycled water use on water demand and supply in a region faced with water shortages and significant population growth, the Las Vegas Valley (LVV). The model, developed using system dynamics approach, includes an unusual component of the water system, return flow credits, where credits are accrued for returning treated wastewater to the water supply source. In LVV, Lake Mead serves as, both the drinking water source and the receiving body for treated wastewater. LVV has a consumptive use allocation from Lake Mead but return flow credits allow the water agency to pull out additional water equal to the amount returned as treated wastewater. This backdrop results in a scenario in which conservation may cause a decline in the available water supply. Current water use in LVV is 945 lpcd (250 gpcd), which the water agency aims to reduce to 752 lpcd (199 gpcd) by 2035, mainly through water conservation. Different conservation policies focused on indoor and outdoor water use, along with different population growth scenarios, are modeled for their effects on the water demand and supply. Major contribution of this study is in highlighting the importance of outdoor water conservation and the effectiveness of reducing population growth rate in addressing the future water shortages. The water agency target to decrease consumption, if met completely through outdoor conservation, coupled with lower population growth rate, can potentially satisfy the Valley’s water demands through 2035.  相似文献   
9.
Fresh water, coupled with soil salinization in many areas has resulted in an increased need forscreening of salt tolerant turf grasses. Relative salinity tolerance of eightwarm season turfgrass species were examined in this study in sand culture. Grasses were grown in a glasshouse, irrigated with either distilled water or saline sea water adjusted to 24, 48 or 72 dSm-1. Salt tolerances of the grasses were assessed on the basis of their shoot and root growth, leaf firing and turf quality. Regression analysis indicated that Zoysiajaponica (Japanese lawn grass) (JG), Stenotaphrum secundatum (St. Augustine) (SA), Cynodon dactylon (satiri) (BS), Zoysia teneuifolia (Korean grass) (KG), Digitaria didactyla (Serangoon grass) (SG), Cynodon dactylon (Tifdwarf) (TD), Paspalum notatum (Bahia grass) (BG) and Axonopus compressus(Pearl blue) (PB) suffered a 50% shoot growth reduction at 36.0, 31.8, 30.9, 28.4, 26.4, 25.7, 20.0 and 18.6 dSm1 of salinity, respectively and a root growth reduction at44.9, 43.7, 33.4, 31.0, 29.5 27.5, 21.5 and 21.4 dSm- of salinity, respectively. Leaf firing and turf quality of the selected species, as a whole, were also found to be affected harmoniously with the change in root and shoot growth. On the basis of the experimental results the selected species were ranked for salinity tolerance as JG>SA>BS>KG>SG >TD>BG>PB.  相似文献   
10.
Based on the data of 30 Chinese provinces for the period from 2004 to 2015, this paper expounds the carbon emissions effect of two-way foreign direct investment (FDI) from the perspective of scale effect and factor market distortions. This study uses Kaya identity to decompose carbon emission and construct simultaneous equations model to empirically examine the factor market distortion and the carbon emission scale effect of two-way FDI. The results show that the inward foreign direct investment (IFDI) increase regional carbon emission through scale effect and also exacerbates factor market distortion in China, whereas the outward FDI trends reduce carbon emission and reduces factor market distortions in China. The study also shows that human capital, research and development (R&D), trade openness, and capital accumulation are important determinants of two-way FDI. Therefore, the study proposes that IFDI policies should focus on acquiring green technologies. In addition, the domestic enterprises should be encouraged to participate in global business.  相似文献   
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