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91.
Pharmaceuticals and personal care products found in the Great Lakes above concentrations of environmental concern 总被引:2,自引:0,他引:2
The monitoring of pharmaceuticals and personal care products (PPCPs) has focused on the distribution in rivers and small lakes, but data regarding their occurrence and effects in large lake systems, such as the Great Lakes, are sparse. Wastewater treatment processes have not been optimized to remove influent PPCPs and are a major source of PPCPs in the environment. Furthermore, PPCPs are not currently regulated in wastewater effluent. In this experiment we evaluated the concentration, and corresponding risk, of PPCPs from a wastewater effluent source at varying distances in Lake Michigan. Fifty-four PPCPs and hormones were assessed on six different dates over a two-year period from surface water and sediment samples up to 3.2 km from a wastewater treatment plant and at two sites within a harbor. Thirty-two PPCPs were detected in Lake Michigan and 30 were detected in the sediment, with numerous PPCPs being detected up to 3.2 km away from the shoreline. The most frequently detected PPCPs in Lake Michigan were metformin, caffeine, sulfamethoxazole, and triclosan. To determine the ecological risk, the maximum measured environmental concentrations were compared to the predicted no-effect concentration and 14 PPCPs were found to be of medium or high ecological risk. The environmental risk of PPCPs in large lake systems, such as the Great Lakes, has been questioned due to high dilution; however, the concentrations found in this study, and their corresponding risk quotient, indicate a significant threat by PPCPs to the health of the Great Lakes, particularly near shore organisms. 相似文献
92.
通过对7种废气自动监测系统的比较研究和现场测试,提出了非分散红外法、紫外差分法、紫外荧光法、化学发光法等多种SO2和NO x自动监测技术在低浓度范围实现准确定量监测的性能评价方法,定义了CEMS的系统检出限及其主要影响因素。建议采用系统检出限、线性误差等关键参数作为低浓度CEMS的性能评价方法,提出将全系统多点标准气体校准或加标回收率作为验收和质控监督的基本方法。 相似文献
93.
94.
用对二甲氨基苯甲醛分光光度法测定水中水合肼,将显色剂用量由5.0 m L降至3.0 m L,比色皿厚度由30 mm增至50 mm,水样酸度由1 mol/L降至0.5 mol/L,同时增加低浓度校准曲线,实现对其方法检出限的优化。结果表明,优化后方法检出限由0.007 8 mg/L降至0.001 0 mg/L,精密度及加标回收率均符合规范要求,能够保证低浓度水样的准确测定。 相似文献
95.
Zhu Dajian 《中国人口.资源与环境(英文版)》2012,10(2):24-30
The core issue for China transition development in the next 30 years is to shift from the quantity growth model to the quality improvement model. The paper introduces the research progress in three key areas of sustainable development studies since the 1990s. It is pointed out that there is a well-being thresh-old at which the margin utility of economic growth for human well-being will decline, that there is an ecological limit beyond which more economic growth in terms of physical scale will be impossible, and that the creation of human well-being is related not only to the amount but also to the structure and efficiency of public expenditure from government. After an in-depth discussion on facts, origins and policy implications of each issue, some theory and policy thinking with long-lasting significance are raised for the transition development of China. 相似文献
96.
三面受火的方钢管混凝土柱耐火极限 总被引:1,自引:0,他引:1
编制了预测方钢管混凝土柱三面火灾作用下高温反应的数值分析程序,并将之用于不同荷载比、截面边长、长细比、荷载偏心率、钢材和混凝土强度及含钢率共480种工况下方钢管混凝土柱耐火极限参数分析,得到了三面火灾作用下方钢管混凝土柱耐火极限的主要影响参数及其影响规律。基于参数分析结果,定量给出了该受火条件下方钢管混凝土柱耐火极限的简化计算方法。研究结果表明:荷载比、截面边长、长细比是三面火灾作用下方钢管混凝土柱耐火极限的主要影响参数,表现为截面边长越大,荷载比和长细比越小,构件的耐火极限越大。由于存在极强偏心,当荷载作用点偏于背火面时荷载偏心率亦有较大影响。 相似文献
97.
Abstract Four sprays of 0.05 ana 0.10% phosalone were given on chilli (Capsicum annuum Linn.) crop at an interval of 15 days starting from 21 days after transplanting. Residues were determined in the green chilli fruits by GLC after cleanup of extract on multiband thin‐layer plate. The half‐lives of residues were 1.55 and 1.68 days on chilli fruits from the crop treated with four sprays of 0.05 and 0.10% phosalone respectively. The time required to reach the tolerance limit of 1 ppm after last spray with 0.05 and 0.10 % emulsion was 4.75 and 7.62 days respectively. Washing of fruits under tap water was found effective in bringing down the level of phosalone residues by 21.64 to 75.11 %. 相似文献
98.
Sergio C. Nanita Melissa Ziegler Livio Giammarrusti Andreas Huber Elena Astor Janet C. Ruhl 《Journal of environmental science and health. Part. B》2013,48(7):640-648
An assessment of the error associated with conventional pesticide residue analysis has been conducted based on computer simulations and inter-laboratory residue analysis. Computational simulations were conducted based on (i) typical performance and regulatory acceptance criteria of analytical methods, and (ii) field residue distributions. In addition, field samples with incurred residues were sent to different private laboratories and the results compared. The relative difference in pesticide residues obtained when samples from the same field or produce lot are analyzed at separate laboratories was used to quantify the uncertainty associated with residue analyses performed using common analytical technology, and methods that are in compliance with current regulatory requirements. The study showed that differences of > 100% are common and should be expected when samples from the same crop are analyzed at different laboratories. The results also suggest that the error within residue measurements can be particularly detrimental when a result is reported near the maximum residue limit (MRL). 相似文献
99.
诸大建 《中国人口.资源与环境》2011,21(10)
从数量扩张的增长模式转向质量提升的发展模式,是中国未来30年转型发展的核心问题.本文介绍了20世纪90年代以来可持续发展在3个关键课题上的研究进展.在经济增长与社会富祉的关系上,指出经济增长对于社会富祉的贡献存在着门槛,跨过这个门槛经济增长对福利贡献的边际效用开始递减;在经济增长与资源环境的关系上,指出经济增长没有导致资源环境消耗的倒U型曲线,在自然资本存在限制的情况下无限的经济增长是不可能的;在政府支出与民生发展的关系上,指出公共支出增大并不必然导致社会福利的提高,而公共支出的结构与方式对民生发展却是极其重要的.在对每个问题分析事实依据、原因解释、政策意义的基础上,针对中国转型发展提出了一些具有长期意义的理论思考与政策思考. 相似文献
100.
The concentrations of indicator polychlorinated biphenyls (PCBs) and organochlorine insecticides were determined in bonito (Sardasarda L. 1758) and anchovy (Engraulisencrasicolus L. 1758) from the Black Sea, Turkey. Concentrations of total indicator PCBs ranged between <1-17.0 in bonito, and <1-17.5 ng/g fresh weight in anchovy, and total of 1,1,1-trichloro-2,2-bis-chlorophenyl-ethane and its metabolites’ (DDTs) concentrations ranged between 13.4-26.3, and 2.96-19.0 ng/g fresh weight in bonito and anchovy respectively. PCB 52, p,p′-DDE and endosulfan (α + β) were found dominant in both of the fish species. Except endosulfan, and some DDT metabolites, none of the studied organochlorine pesticides was detected in the fish samples. Concentrations of PCBs in anchovy were found higher than those in bonito, whereas DDT and endosulfan concentrations were found similar in both of the fish species. All of the fish samples had residue concentrations below the maximum residue limits (MRL) recommended by FAO/WHO Codex Alimentarius Commission. 相似文献