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741.
A novel approach to rapid detection of acute water toxicity and its policy implications for grassroots sustainable environmental monitoring 总被引:1,自引:0,他引:1
Unknown chemicals, emerging contaminants, and the resulting reactions among them make early detection and warning of acute water toxicity extremely challenging. The conventional approach using small fish for toxicity monitoring normally requires a designated species of fish and over a week's time to complete, including dilution of the wastewater, a pre-test, and a full test. It often increases chances for error and delays emergency management. This paper reports a novel approach, based on grassroots knowledge and field and lab experience in Jilin, China. This approach uses a combination of different species of aquarium fish to achieve fast and reliable monitoring. It tests the original source water directly without going through the dilution procedure, while paying attention to the time factor. The approach does not require a pre-test and may shorten the time needed for detecting acute toxicity to a few minutes, using a new classification of aquatic toxicity levels. It is inexpensive to use and may be easily adopted by grassroots organizations. The approach is "greener" and more financially and socially sustainable than traditional approaches. The wide use of the approach has the potential to encourage policy innovations for making toxicity monitoring grassroots based and more effective in reducing acute contamination emergencies. 相似文献
742.
Heavy metal pollution is an increasing environmental problem in Chinese regions undergoing rapid economic and industrial development, such as the Pearl River Delta (PRD), southern China. We determined heavy metal concentrations in surface soils from the PRD. The soils were polluted with heavy metals, as defined by the Chinese soil quality standard grade II criteria. The degree of pollution decreased in the order Cd?>?Cu?>?Ni?>?Zn?>?As?>?Cr?>?Hg?>?Pb. The degree of heavy metal pollution by land use decreased in the order waste treatment plants (WP)?>?urban land (UL)?>?manufacturing industries (MI)?>?agricultural land (AL)?>?woodland (WL)?>?water sources (WS). Pollution with some of the metals, including Cd, Cu, Ni, and Zn, was attributed to the recent rapid development of the electronics and electroplating industries. Cd, Hg, and Pb (especially Cd) pose high potential ecological risks in all of the zones studied. The soils posing significantly high and high potential ecological risks from Cd covered 73.3 % of UL, 50 % of MI and WP land, and 48.5 % of AL. The potential ecological risks from heavy metals by land use decreased in the order UL?>?MI?>?AL?>?WP?>?WL?>?WS. The control of Cd, Hg, and Pb should be prioritized in the PRD, and emissions in wastewater, residue, and gas discharges from the electronics and electroplating industry should be decreased urgently. The use of chemical fertilizers and pesticides should also be decreased. 相似文献
743.
通过阀切换并联式双系统,建立了一套测定土壤样品中7种芳磺酸的反相离子对液相色谱法。该方法采用2根色谱柱,一根色谱柱分析的同时,另一根色谱柱通过阀切换实现平衡,节约了38.5%的分析时间。方法使用Dikma Diamonsil C18(150 mm×4.6 mm×5μm)色谱柱,以离子对试剂(四丁基硫酸氢铵)和乙腈为流动相,检测波长为226、235、258 nm。各组分线性关系良好,线性相关系数均在0.999 9以上。随机抽取样品进行重新提取、检测,得到各组分的相对标准偏差均小于7%,且定量限最高不超过0.181 2μg/g,重复性和定量限均能满足实验要求。 相似文献
744.
Emergy-based evaluation of system sustainability and ecosystem value of a large-scale constructed wetland in North China 总被引:2,自引:0,他引:2
Yiran Zhang Jian Liu Jian Zhang Renqing Wang 《Environmental monitoring and assessment》2013,185(7):5595-5609
Constructed wetland has been widely adopted to deal with degraded natural wetlands and water bodies; thus, more attention should be focused on ecological–economic sustainability and ecological efficiency of these projects for long-term success. Emergy accounting was conducted to investigate the energy and resource flows in constructed wetlands during the restoration process. Emergy-based indexes were adopted to evaluate the sustainability of a pilot large-scale constructed wetland in a large wetland restoration project in North China, carried out to enhance the river water quality and offset the degradation of natural wetland. Emergy and emdollar values for ecosystem services and natural capital were also calculated. The results showed that when outflow was considered as the product, the studied large-scale constructed wetland was more self-supporting and could be operated with lesser financial investment, although the waste treatment efficiency and the sustainability index were lower than conventional small-scale treatment constructed wetlands. Compared with natural wetlands, more visits from tourists and lesser financial investment coming in as feedback into the wetland would reduce system environment loading and promote system self-support ability, ultimately generating sustainability. In addition, the studied large-scale constructed wetland can effectively simulate energy and resource flows of natural wetland ecosystem and contribute a roughly equal value of ecosystem services in term of gross primary production. The studied large-scale constructed wetland can successfully achieve ecosystem functions as replacement for natural wetland and hasten the restoration process, although the restoration effectiveness of ecosystem structures in terms of living biomass and water using emergy-value accounting is still inconclusive. 相似文献
745.
Yen-Chang Chen Jih-Hung Liu Jan-Tai Kuo Cheng-Fang Lin 《Environmental monitoring and assessment》2013,185(7):5653-5672
Reservoirs in Taiwan are inundated with nutrients that result in algal growth, and thus also reservoir eutrophication. Controlling the phosphorus load has always been the most crucial issue for maintaining reservoir water quality. Numerous agricultural activities, especially the production of tea in riparian areas, are conducted in watersheds in Taiwan. Nutrients from such activities, including phosphorus, are typically flushed into rivers during flooding, when over 90 % of the yearly total amount of phosphorous enters reservoirs. Excessive or enhanced soil erosion from rainstorms can dramatically increase the river sediment load and the amount of particulate phosphorus flushed into rivers. When flow rates are high, particulate phosphorus is the dominant form of phosphorus, but sediment and discharge measurements are difficult during flooding, which makes estimating phosphorus flux in rivers difficult. This study determines total amounts of phosphorus transport by measuring flood discharge and phosphorous levels during flooding. Changes in particulate phosphorus, dissolved phosphorus, and their adsorption behavior during a 24-h period are analyzed owing to the fact that the time for particulate phosphorus adsorption and desorption approaching equilibrium is about 16 h. Erosion of the reservoir watershed was caused by adsorption and desorption of suspended solids in the river, a process which can be summarily described using the Lagmuir isotherm. A method for estimating the phosphorus flux in the Daiyujay Creek during Typhoon Bilis in 2006 is presented in this study. Both sediment and phosphorus are affected by the drastic discharge during flooding. Water quality data were collected during two flood events, flood in June 9, 2006 and Typhoon Bilis, to show the concentrations of suspended solids and total phosphorus during floods are much higher than normal stages. Therefore, the drastic changes of total phosphorus, particulate phosphorus, and dissolved phosphorus in rivers during flooding should be monitored to evaluate the loading of phosphorus more precisely. The results show that monitoring and controlling phosphorus transport during flooding can help prevent the eutrophication of a reservoir. 相似文献
746.
Fengyu Liu Wei Li Fusheng Li Shiguo Sun 《Environmental monitoring and assessment》2013,185(5):4153-4158
Considering of the basic properties and also the two nitrogen atoms in the structure, hydrazine hydrate was employed to be an amine additive candidate, to build a Ru(bpy) 3 2+ /hydrazine electrochemiluminescence (ECL) system, and ECL of Ru(bpy) 3 2+ has been employed for the determination of hydrazine hydrate in the paper. The result demonstrated that the logarithmic ECL increasing (ΔECL?=?ECLafter addition of hydrazine???ECLbefore addition of hydrazine) versus the logarithmic concentration of hydrazine hydrate is linear over a concentration range of 1.0?×?10?9 to 1.0?×?10?5?mol/L, on both glassy carbon and Pt electrodes in a pH 9 phosphate buffer. The hydrazine hydrate detection limit was down to 1.0?×?10?9?mol/L, comparatively lower than other detection methods. To check its applicability, the proposed method was applied to the determination of hydrazine hydrate added into a tap water sample with good reproducibility and stability. All these provide a possibility to develop a novel ECL detection method for hydrazine in water. 相似文献
747.
Tengteng Liu Joris M. Koene Xiaoxiao Dong Rongshu Fu 《Environmental monitoring and assessment》2013,185(5):4183-4190
The concentration of heavy metals in the environment is normally low. We here address whether using the development of isolated pond snail Radix auricularia eggs would provide a more sensitive endpoint and whether the gelatinous matrix of the egg mass surrounding the eggs indeed protects the snail embryos. In the present study, artificial removal of the gelatinous matrix of egg masses greatly increased the sensitivity of developing eggs to a heavy metal (cadmium). The sensitivity of isolated eggs to cadmium was determined using several convenient endpoints, including mortality, hatching rate, and heart rate, with an acute toxicity test and a subchronic test. In the acute toxicity test, a 96-h LC50 value of 58.26 μg/L cadmium was determined. In the subchronic toxicity test, sublethal effects in terms of a significant reduction in hatching rate could be found in the 25-μg/L treatment, and a significant decrease of heart rate was observed in both treatments (5 and 25 μg/L). The high sensitivity of isolated eggs indicates that such tests can be efficient for toxicity assays and risk assessment, although one needs to keep in mind that the ecologically relevant measure of toxicity will be how eggs are affected when they are still inside the egg mass. 相似文献
748.
749.
Liangyun Liu Huan Tang Peter Caccetta Eric A. Lehmann Yong Hu Xiaoliang Wu 《Environmental monitoring and assessment》2013,185(12):9949-9965
The Three-North Shelter Forest Program is the largest afforestation reconstruction project in the world. Remote sensing is a crucial tool to map land use and land cover change, but it is still challenging to accurately quantify the change in forest extent from time-series satellite images. In this paper, 30 Landsat MSS/TM/ETM+ epochs from 1974 to 2012 were collected, and the high-quality ground surface reflectance (GSR) time-series images were processed by integrating the 6S atmosphere transfer model and a relative reflectance normalization algorithm. Subsequently, we developed a vegetation change tracking method to reconstruct the forest change history (afforestation and deforestation) from the time-series Landsat GSR images based on the integrated forest z-score (IFZ) model by Huang et al. (2009a), which was improved by multi-phenological IFZ models and the smoothing processing of IFZ data for afforestation mapping. The mapping result showed a large increase in the extent of forest, from 380,394 ha (14.8 % of total district area) in 1974 to 1,128,380 ha (43.9 %) in 2010. Finally, the land cover and forest change map was validated with an overall accuracy of 89.1 % and a kappa coefficient of 0.858. The forest change time was also successfully retrieved, with 22.2 % and 86.5 % of the change pixels attributed to the correct epoch and within three epochs, respectively. The results confirmed a great achievement of the ecological revegetation projects in Yulin district over the last 40 years and also illustrated the potential of the time-series of Landsat images for detecting forest changes and estimating tree age for the artificial forest in a semi-arid zone strongly influenced by human activities. 相似文献
750.
Fengzu Zhang Sufang Fan Shaowen Liu Xuesheng Li Canping Pan 《Environmental monitoring and assessment》2013,185(11):9101-9109
A modified LC-MS method for the analysis of mepiquat residue in wheat, potato, and soil was developed and validated. A hydrophilic interaction liquid chromatographic column has been successfully used to retain and separate the mepiquat. Mepiquat residue dynamics and final residues in supervised field trials at Good Agricultural Practice (GAP) conditions in wheat, potato, and soil were studied. The limits of quantification for mepiquat in all samples were all 0.007 mg kg?1, which were lower than their maximum residue limits. At fortification levels of 0.04, 0.2, and 2 mg kg?1 in all samples, recoveries ranged from 77.5 to 116.4 % with relative standard deviations of 0.4–7.9 % (n?=?5). The dissipation half-lives (T 1/2) of mepiquat in soil (wheat), wheat plants, soil (potato), and potato plants were 4.5–6.3, 3.0–5.6, 2.2–4.6, and 2.4–3.2 days, respectively. The final residues of mepiquat were below 0.153 mg kg?1 in soil (wheat), 0.052–1.900 mg kg?1 in wheat, below 0.072 mg kg?1 in soil (potato), and below 1.173 mg kg?1 in potato at harvest time. Moreover, pesticide risk assessment for all the detected residues was conducted. A maximum 0.0012 % of acceptable daily intake (150 mg kg?1) for national estimated daily intake indicated low dietary risk of these products. 相似文献