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941.
Soudek P Petrová S Benešová D Dvořáková M Vaněk T 《Journal of environmental radioactivity》2011,102(6):598-604
Hydroponicaly cultivated plants were grown on medium containing uranium. The appropriate concentrations of uranium for the experiments were selected on the basis of a standard ecotoxicity test. The most sensitive plant species was determined to be Lactuca sativa with an EC50 value about 0.1 mM. Cucumis sativa represented the most resistant plant to uranium (EC50 = 0.71 mM). Therefore, we used the uranium in a concentration range from 0.1 to 1 mM.Twenty different plant species were tested in hydroponic solution supplemented by 0.1 mM or 0.5 mM uranium concentration. The uranium accumulation of these plants varied from 0.16 mg/g DW to 0.011 mg/g DW. The highest uranium uptake was determined for Zea mays and the lowest for Arabidopsis thaliana. The amount of accumulated uranium was strongly influenced by uranium concentration in the cultivation medium. Autoradiography showed that uranium is mainly localized in the root system of the plants tested. Additional experiments demonstrated the possibility of influencing the uranium uptake from the cultivation medium by amendments. Tartaric acid was able to increase uranium uptake by Brassica oleracea and Sinapis alba up to 2.8 times or 1.9 times, respectively. Phosphate deficiency increased uranium uptake up to 4.5 times or 3.9 times, respectively, by Brassica oleracea and S. alba. In the case of deficiency of iron or presence of cadmium ions we did not find any increase in uranium accumulation. 相似文献
942.
采用穿透渗漏实验方法研究了经水泥固化的重金属废物的长期渗漏行为。用由Pb^2+、Zn^2+、Cu^2+、Ni^2+和Cr^6+5种重金属组成的合成废物样品进行2组实验。实验研究了渗漏实验液流速、PH的变化和金属渗漏能力对固体废物长期渗漏行为的影响。 相似文献
943.
Assessment of Several Test Methods for the Determination of the Anaerobic Biodegradability of Polymers 总被引:1,自引:0,他引:1
Stefan Gartiser Mathis Wallrabenstein Gabi Stiene 《Journal of Polymers and the Environment》1998,6(3):159-173
Anaerobic degradation of eight commercially available biodegradable polymers was compared in two anaerobic tests using digestion sludge, according to ISO 11734 and ASTM D.5210-91. Cotton, polyhydroxybutyrate/hydroxyvalerate copolymer (PHB/PHV), starch blend, thermoplastic cellulose acetate, and cellulose acetate fibers proved to be anaerobically degradable, but only a low extent of degradation was found for polylactide, polyvinylalcohol, and polycaprolactone. Both test methods gave the same overall results, but with the ISO medium, longer lag phases and greater ranges of variation in the results were observed. These effects are presumably due to low concentrations of carbon dioxide in the ISO medium. Carbon dioxide has been demonstrated to be essential for the growth of various anaerobic bacteria, notably homoacetogenic and methanogenic bacteria. 相似文献
944.
Salih Katırcıoğlu Sami Fethi Demet Beton Kalmaz Dilber Çağlar 《International Journal of Green Energy》2016,13(10):1059-1074
This study investigates the empirical relationship between energy consumption, international trade, and real income in Canada which has an important role in global energy and trade. It employs bound tests to level relationships and conditional error correction models through ARDL specification to a new version of the Solow Growth model. Using annual data of the 1960–2010 period, results reveal a long-term relationship between energy consumption, international trade, and real income in Canada. It is also found that energy exporting activity is the determinant (driver) of energy consumption through the channel of real income and energy consumption is the determinant (driver) of exports through the channel of real income in the long term of the Canadian economy. Exports and energy use are the determinants (drivers) of real income in the long term of the Canadian economy; therefore, as conditional Granger causality tests suggest there is feedback relationship between energy consumption, international trade, and real income in the long term of the Canadian economy. The present study suggests that any energy conservation policies are likely to have negative influence on output and international trade in Canada. 相似文献
945.
本文结合湖北省自然科学基金项目"混凝土结构使役环境的智能模拟(2008CDB396)",在前期"211工程"项目"单轴约束可调式混凝土温度应力试验机"研究基础上,针对现有混凝土耐久性试验机在侵蚀溶液注入与氯离子浓度控制环境的空白,采用C51单片机为控制器,设计了一种混凝土结构使役环境中氯离子浓度控制系统,用于自动调节混凝土耐久性实验,模拟实验环境箱内的侵蚀溶液氯离子浓度,保证混凝土耐久性实验试件所处环境氯离子浓度稳定在设定的范围。系统采用溶液缓冲调节与循环注入方式,控制单元采用直读式离子浓度控制器,信号采集更方便。本系统不仅结构简洁,工作可靠性高,还能减少人力浪费,提高运行经济性。 相似文献
946.
947.
George F. Antonious 《Journal of environmental science and health. Part. B》2013,48(3):377-399
Abstract Levels of acephate (OrtheneR) and its principle metabolite, methamidophos, in/on greenhouse‐grown pepper and cucumber fruits and leaves in relation to the applied methamidophos were monitored. Dislodgeable and total residues of acephate and methamidophos were determined by gas‐liquid chromatography equipped with a flame ionization detector (GC‐FID) and were confirmed by nitrogen phosphorus detector (GC‐NPD). The dissipation curves of the residues followed first‐order kinetics (R2> 0.96). Initial residues of acephate on fruits varied between pepper (15.12 ppm) and cucumber (2.16 ppm) . Total residues in fruits and leaves determined at intervals following application revealed the greater persistence of acephate on pepper fruits (half‐life [t1/2] of 6 d) than on cucumber fruits (t1/2 was 3.7 d) . T1/2 values for the applied methamidophos were 4.7 and 5.3 d on pepper and cucumber fruits, respectively. Deacety‐lation of acephate (formation of its metabolite) was detectable 1 d following acephate treatment and reached a maximum of 2.05% of initial acephate residues 3 d after application on pepper fruits. On cucumber fruits, acephate metabolite reached a maximum of 2.12% one wk following application. No acephate residues were detected above the limit of detection of 0.001 ppm in pepper fruits 50 d following acephate application while its metabolite was detectable at that time (detectability limit was 0.0001 ppm). 相似文献
948.
基于生命周期分析的餐厨垃圾肥料化利用环境风险评价研究 总被引:1,自引:0,他引:1
餐厨垃圾肥料化利用过程的风险因子主要产生于原料运输与存储、预处理、堆肥、废物填埋和肥料化产品施用5个过程,其风险影响包括地表水和地下水污染、恶臭污染、土壤盐碱化和影响作物生长以及由此引起的人体健康损害.基于生命周期全过程分析,以好氧堆肥为代表的餐厨垃圾肥料化利用的环境风险为研究对象,系统地分析了餐厨垃圾堆肥过程中的潜在风险,归纳并提出风险源项估算以及环境风险影响评价的具体方法和相关参数,通过南京市餐厨垃圾示范性项目案例,说明餐厨垃圾肥料化利用风险评价方法的具体应用. 相似文献
949.
Shinji Sakurai Yoko Fujikawa Masumi Kakumoto Masataka Sugahara Tatsuhide Hamasaki Mikio Umeda 《Journal of environmental science and health. Part. B》2013,48(3):284-291
In this study, we investigated the behavior of estrogens in the rhizosphere of white clover (Trifolium repens, clover hereafter) with two different pot tests, using soil and agar as growth media. In a pot test using agar spiked with estrogen, the estrogen concentration in the agar with clover decreased to non-detectable levels within one month, while in the agar without clover, 60% of initially added estrogen remained after one month. The half-lives of estrone (E1) and 17β -estradiol (E2) in the agar with clover were 2.4–3.8 and 13.2 d, respectively. The dissipation of E1 followed first-order rate law, while that of E2 fitted a zero-order reaction, indicating that they had different mechanisms of dissipation from agar. In the soil pot test, the behavior of E1 and E2 was not influenced by clover. An initial rapid decrease in the amount of estrogen extracted by methanol/acetic acid was followed by persistence for 1–3 months, regardless of presence of clover. Moreover, in three weeks E1 and E2 were only partly degraded by microbes extracted from the soil used in the pot test. In this study, abiotic degradation of estrogens and sorption of estrogen to soil, rather than the effects of soil microbes and clover, contributed to the initial rapid dissipation of estrogens in the soil. However, the results of the agar pot test suggested that vegetation such as clover may significantly contribute to removal of estrogens when estrogens in aqueous phase are discharged with surface runoff and preferential flow after heavy rain in agricultural fields, or when present in soils with low estrogen sorptivity. 相似文献
950.