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281.
282.
Neomysis awatschensis was collected on the west coast of Jiaozhou Bay,Qingdao in 1992 and acclimated in the laboratory conditions.The acute toxicity method using 4 ~6 day juvenile mysid of this species is studied.The species is compared with M.bahia in taxonomy,geographic distribution,morphology,as well as the sensitivity to reference toxins,Based on the results,we recommend N.awatschensis to be a standard marine organism for toxicity test in China and the method to be applied in toxicity evaluation of drilling fluids.In this paper,we report the results of the above studies and the application of the method in the evaluation of several drilling fluid products. 相似文献
283.
光催化降解分解水中污染有机物 总被引:1,自引:0,他引:1
一、引言人类对自然资源的开发增加了废弃物的排放,大部分废弃物是有机物。有机物的污染问题在一些地方变得十分严重,除草剂和杀虫剂的广泛应用及其残余物的蔓延就是一例。有些工厂还不断向河流排出或泄漏有机物。环保当局固然可以制定更严格的排放标准以限制排放,因而工厂也会被迫对排放严加控制。但许多情况下需要对水再加处理,这些费用最终将转移到消费者头上,人们为干净的环境付出的代价是高昂的。因此,如何用更经济的方法达到这个目的而不限制生产是对人类智力的挑战。地表水和地下水的有机物污染是个严重的问题。在美国,一半人是从地下水获得饮用水。目前在美国有数千口井因有害化学品超标而被关闭,在中国这个问题更为严重。在美国从饮用水中检出了700余种有害化学物,在美国和欧洲,水中已普遍受到卤代烃的污染。这种污染部分来自事故,也由于饮用 相似文献
284.
Ultraviolet absorbance titration for the determination of conditional stability constants of Hg(Ⅱ) and dissolved organic matter 总被引:1,自引:0,他引:1
Strong interaction between natural dissolved organic matter (DOM) and Hg(Ⅱ) may influence the transport, conversion, toxicity and bio-validity of mercury in the environment. In this paper ultraviolet (UV) absorbance titration was employed for the first time for the determination of the conditional stability constants of Hg(Ⅱ) and (DOM). With increasing Hg(Ⅱ) concentrations, the UV absorbance of fulvic acid, humic acid, and DOM in river increases progressively. By linear and non-linear model fitting, the conditional stability constants (lgK) of Hg(Ⅱ) and DOM were worked out to be 3.54-4.93 and 3.64-4.85, respectively. The results are consistent with those acquired by the typical fluorescence quenching titration method, with the maximum relative error of lgK being 2.6% and the average relative error being 0.2%. The UV absorbance titration method has the advantages of rapid determination, simple performance, and it will probably become a new approach to studying interactions between DOM and trace metallic ions. 相似文献
285.
雪冰中微量有机物的生物地球化学研究进展 总被引:2,自引:0,他引:2
雪冰中微量有机物的生物地球化学研究进展龙江平,秦大河(中国科学院冰川冻土研究所,兰州730000)关键词雪冰,有机物,生物地球化学雪冰中微量有机物的生物地球化学主要研究雪冰中有天然来源的微量有机物和由人类活动、工业化发展带来的人为污染有机物。通过雪冰... 相似文献
286.
长江口溶解有机物光漂白和光矿化表观量子产率 总被引:3,自引:1,他引:2
溶解有机物(DOM)经太阳光照射导致其吸光度(光漂白)和溶解有机碳(光矿化)损失,从而影响水体生态系统光学特性及碳循环。本文通过测定冬季长江口及其邻近海域DOM光降解表观量子产率(AQY),初步探讨了DOM光反应活性在河口及陆架海的变化特征。DOM光降解AQY由口内至口外逐渐递减,且有色溶解有机物(CDOM)光漂白速率是溶解有机碳(DOC)光矿化速率的10倍。Φble(CDOM光漂白表观量子产率)和Φmin(DOC光矿化平均量子产率)在最大浑浊带以东海域与盐度和SUVA254分别呈显著的线性负相关与正相关,表明DOM光反应活性在长江口外受物理混合影响为主,且陆源DOM光反应活性比海源高。此外,最大浑浊带下游DOM光降解AQY显著低于上游。DOM光降解速率随波长的变化呈现非高斯分布,且峰值出现在330 nm,积分结果表明UVA是DOM光降解的主要贡献者。本研究结果将为完善我国东海碳通量模型提供帮助。 相似文献
287.
Bacterial abundance, phytoplankton community structure and environmental parameters were investigated to study the relationships between bacteria and phytoplankton during giant jellyfish Nemopilema nomurai blooms in the central Yellow Sea during 2013. N. nomurai appeared in June, increased in August, reached a peak and began to degrade in September 2013. Results showed that phosphate was possible a key nutrient for both phytoplankton and bacteria in June, but it changed to nitrate in August and September. Phytoplankton composition significantly changed that pico-phytoplankton relative biomass significantly increased, whereas other size phytoplankton significantly decreased during jellyfish bloom. In June, a significantly positive correlation was observed between chlorophyll a concentration and bacterial abundance(r=0.67, P0.001, n=34).During jellyfish outbreak in August, there was no significant correlation between phytoplankton and bacteria(r=0.11, P0.05, n=25), but the relationship(r=0.71, P0.001, n=31) was rebuilt with jellyfish degradation in September. In August, small size phytoplankton occupied the mixed layer in offshore stations, while bacteria almost distributed evenly in vertical. Chlorophyll a concentration significantly increased from(0.42±0.056) μg/L in June to(0.74±0.174) μg/L in August, while bacterial abundance just slightly increased. Additionally, the negative net community production indicated that community respiration was not entirely determined by the local primary productivity in August. These results indicated that jellyfish blooms potentially affect coupling of phytoplankton and bacteria in marine ecosystems. 相似文献
288.
固相萃取-气相色谱/质谱法测定地面水中半挥发性有机物 总被引:1,自引:0,他引:1
利用XAD-2和XAD-8树脂吸附富集、有机溶剂洗脱、气相色谱/质谱法分析测定了福建九龙江流域水体中半挥发性有机化合物,共检出有机化合物138种,其中属于美国联邦环保总署和中国国家环保总局规定的优先控制有机污染物有20种。 相似文献
289.
Genetic Classification of Natural Gases in the Oil—Gas Zone and Its Application in the Sichuan Basin
黄籍中 《中国地球化学学报》1993,12(1):71-83
On the basis of the carbon isotopic compositions of methane(CH4) and its homologues and the differences in isotopic values for CH4 and ethane (C2H6) and the correlation and compositional char-acteristics of hydrocarbon gases, the author has proposed a genetic classification of natural gases in the oil-gas zone.They are classified as biogenetic and abiogenetic gases in terms of the types of hydrocarbon-generating precursors (or parent materials) and their thermal evolution stages.Biogenetic gases can also be further divided into two series: biochemical and thermochemical gases,with the lat-ter formed at different evolution stages.Gases generated from type-I and -II1 organic matter are called oil-series gases, those from type-III, coal -series ,and those type -II2,mixture-type gases.Gases generated from two or more than two types of precursors are called mixture-source gases.According to those mentioned above, natural gases from the major oil-gas pools in the Sichuan Basin have been discriminantly analyzed,and the results are concordant with the distribution and de-velopment of hydrocarbon-source rocks as well as with their characteristics, indicating a prospective application. 相似文献
290.
有效地管理地下水系统需要论述和预测该系统中污染质的运移和消亡情况,以便能更好地运用数学模型准确地描述系统的物理现象。影响许多有机污染物运移的最明显现象是在固(土壤)和液(地下水)两相之间的分配现象。污染物的分配趋势大体可以用对辛醇的基本性质的测量值进行估计,即取决于污染物的水分配系数和土壤的有机碳含量。这个粗略估计是定性评价的基础,但对系统的定量描述就不行,特别是所考虑的问题是非线性平衡吸附问题,分配取决于动力条件或是不可逆的,或者滞后相的分布现象等。准确地进行溶质运移模拟常常需要结合动力学参数和非线性吸附方法才能正确地确定质量守恒方程中的溶质运移现象。实验的方法可以用来确定重要的吸附因子,有机溶质和土壤系统的动力学性质及平衡分配关系。因此利用这种方法能够更准确地模拟污染质的迁移情况。 相似文献