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991.
海岸带是一个在地理意义上和社会经济意义上独具特征的区域。这种条带状的区域,包含着巨大的环境价值和经济价值,因而受到沿海国家的重视,并已形成一种“海岸带”的社会意识。随着生产和科学技术的发展,海岸带的研究领域愈来愈广阔,自然资源综合研究与日俱增。近年来,美国海岸带的研究,在环境、社会经济和海岸工程的基础上,特别强调资源、生态系统、计划和管理法规等方面,出版了有关海岸带技术、环境、社会  相似文献   
992.
生命周期评价在工程分析中的运用   总被引:2,自引:0,他引:2  
项平  薛军 《环境导报》1999,(5):28-29
工程分析是建设项目环境影响评价的关键所在。就目前工程分析存在的问题进行讨论,介绍生命周期评价的基本过程,提出将生命周期评价引入工程分析,以提高工程分析的科学性,为项目决策提供科学依据。‘’  相似文献   
993.
煤矿矿井水资源化与循环经济   总被引:13,自引:0,他引:13  
运用循环经济原理,讨论了不同类型矿井水的处理、回用和存在的问题,对国内煤矿矿井水资源化进行了环境代价可行性分析。矿井水循环利用有利于解决我国矿区水污染与水资源短缺问题,具有广阔的应用前景。  相似文献   
994.
研究了超声场降解水溶液中叔丁醇的行为,并探讨了反应动力学模式。实验表明.在本实验条件下超声波降解叔丁醇能够达到较好的降解效果。叔丁醇的去除率随着超声辐射时间的延长而提高,在频率为20kHz、功率为1500W的超声场下,作用80min能够达到90%左右的去除率。反映体系的降解速率随着反应温度的提高而升高,随着初始浓度的增大而降低:反应体系的pH值对叔丁醇的降解率影响不大:溶液中溶解气体的种类对降解效果有一定影响。反应速率常数按照由快到慢的顺序为ko2〉k未作处理〉kN2。在一定的初始浓度条件下,超声波降解叔丁醇的反应符合假一级反应动力学模式。  相似文献   
995.
颗粒活性炭对UASB处理垃圾渗滤液促进作用的研究   总被引:1,自引:0,他引:1  
通过对比研究,考查了用UASB处理垃圾渗滤液时,投加颗粒活性炭对加速UASB反应器中污泥颗粒化进程、缩短启动时间、提高处理效果的影响。结果显示:启动时间缩短了近1/3,最大有机负荷提高近40%且出现了更大颗粒污泥,但COD去除效率没有明显提高。  相似文献   
996.
脱卤球菌(Dehalococcoidia,Dia)纲是绿弯菌门下属八大纲之一.迄今为止,脱卤球菌纲中包含3个能进行严格厌氧有机卤化物呼吸的菌属:脱卤拟球菌(Dehalococcoides,Dhc)、脱卤单胞菌(Dehalogenimonas,Dhgm)及尚未正式命名的Candidatus"Dehalobium".当前关于脱卤拟球菌和脱卤单胞菌生理学、生物化学和生态学方面的研究,主要集中在从有机氯污染场地中富集或者分离出来的菌株方面.而越来越多的研究证据表明,能进行有机卤化物呼吸的脱卤球菌纲微生物不仅仅只存在于污染物产地,在各种环境(如海洋、淡水、陆地)中也能经常被检测和鉴定到.但脱卤球菌纲微生物在自然界生态系统中起到的重要作用尚未被完全揭示.本文旨在介绍和讨论被低估且未被充分研究的脱卤球菌纲微生物的生理生态特征及其潜在的生态学功能,从而引起研究人员更广泛的关注,鼓励跨学科研究来揭示这一类特殊微生物在有机卤化物生物地球化学循环中的重要作用.  相似文献   
997.
剩余污泥的处理与处置是个世界性的难题。目前的处置方法中,土地利用逐渐被各国所广泛采用。通过对秦皇岛第三、第四污水处理厂的剩余污泥的基本性质进行测试,以此为基础对污泥的农用价值及其应用前景进行分析和展望。  相似文献   
998.
Qian Y  Yin D  Li Y  Wang J  Zhang M  Hu S 《Chemosphere》2004,57(2):127-133
Four chlorobenzenes (chlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, p-chloro-methylbenzene) were administrated to the crucian carps (Carassius auratus) by peritoneal injections in the laboratory for 30 days. Serum testosterone and 17 beta-estradiol concentrations were detected using radioimmunology assay (RIA), and the activities of two hepatic microsome enzymes, glutathione s-transferase (GST) and UDP-glucuronosyltransferase (UDPGT), were measured using the modified methods as described by Habig and Owens. Results showed that the four chlorobenzenes caused significant increases in serum testosterone concentration in the crucian carps (P < 0.05) compared to the controls, but they caused no significant effect on 17 beta-estradiol level. All test chemicals caused a change in hepatic GST activity in crucian carps, with significant increases in enzyme activity (P < 0.05). Chlorobenzene, 1,3-dichlorobenzene and p-chloro-methylbenzene resulted in a marked inhibition to UDPGT activity in crucian carp (P < 0.05) except 1,4-dichlorobenzene. The changes in hepatic microsome enzyme activities may have resulted in the alterations of serum sex steroids levels in the crucian carps. The results indicated that these four chlorobenzenes may result in the changes of endocrine functions and may affect the reproductive success of this and other species.  相似文献   
999.
Effect of organic acids on adsorption and desorption of rare earth elements   总被引:12,自引:0,他引:12  
Shan XQ  Lian J  Wen B 《Chemosphere》2002,47(7):701-710
Effect of citric, malic, tartaric and acetic acids on adsorption of La, Ce, Pr and Nd by and desorption from four typical Chinese soils was studied. Generally, adsorption capacities of rare earth elements (REEs) were significantly correlated with the cation exchange capacity (CEC) of soils. In the presence of acetic acids adsorption of REEs was similar to that in the presence of Ca(NO3)2. However, in the presence of citric, malic and tartaric acids adsorption of REEs by Heilongjiang, Zhejiang and Guangdong soils decreased to varying extents if compared with that in the presence of nitrate and acetic acid. The significance of suppression followed the order of citric acid > malic acid > tartaric acid > acetic acid, which was consistent with the order of stability of complexes of REEs with these organic acids. However, the adsorption increased with increasing equilibrium solution pH. For Jiangxi soil with low soil pH, CEC and organic matter these organic acids exerted an even more serious suppression effect on the adsorption of REEs. Another feature of the relationship between the adsorption of REEs and equilibrium solution pH was that the adsorption of REEs decreased with increase of pH from 2 to 4.5 and then slightly increased with further increase of pH. Desorption of REEs varied with soils and with organic acids as well. REEs were released easily from Heilongjiang, Zhejiang and Guangdong soils in the presence of organic acid. Generally, desorption of REEs decreased with increasing equilibrium solution pH. Effect of organic acids on desorption of REEs from Jiangxi soil was more complicated. In the presence of citric and malic acids no decrement and/or slight increase in desorption of REEs were observed over the equilibrium solution pH from 3 to 6.5. The reasons for this were ascribed to the strong complexing capacity of citric and malic acids and low soil pH, CEC and organic matter of Jiangxi soil.  相似文献   
1000.
The present study reports on the mercury concentrations of the vestimentiferan worm, Lamellibrachia satsuma, (Annelida: Pogonophora) found near hydrothermal vents at a depth of 80-100 m in the northern parts of Kagoshima Bay. The vestimentiferan worms had total mercury concentrations of 238 ng/g in the anterior muscle of the body and 164 ng/g in the posterior trophosome. Methylmercury constituted only 7.6% of total mercury detected anteriorly and 16.3% posteriorly. The mean total mercury concentration in filtrated ambient seawater of the worm habitat was 1.1 ng/l. The worm should accumulate mercury in seawater by a one-step into the anterior and posterior parts as 2.2 x 10(%) and 1.5 x 10(5) times those of the filtered ambient seawater, respectively. The bioaccumulation factor of mercury by the worms with only their respiration would be actually larger than that by other marine animals through food webs. The high bioaccumulation factor of mercury in the worms suggest the following two possibilities: (i) the biological half-life of organomercury in the worm could be exceptionally long; or (ii) the lifetime of vestimentiferan worms examined in the present study could be extremely long. Various metals in one specimen of the worm were analyzed by using ICP-MS, and then gold as well as silver were detected in the worm. Gold was detected for the first time from marine animals.  相似文献   
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