Laser-induced breakdown spectroscopy application in environmental monitoring of water quality: a review

Water quality monitoring is a critical part of environmental management and protection, and to be able to qualitatively and quantitatively determine contamination and impurity levels in water is especially important. Compared to the currently available water quality monitoring methods and techniques, laser-induced breakdown spectroscopy (LIBS) has several advantages, including no need for sample pre-preparation, fast and easy operation, and chemical free during the process. Therefore, it is of great importance to understand the fundamentals of aqueous LIBS analysis and effectively apply this technique to environmental monitoring. This article reviews the research conducted on LIBS analysis for liquid samples, and the article content includes LIBS theory, history and applications, quantitative analysis of metallic species in liquids, LIBS signal enhancement methods and data processing, characteristics of plasma generated by laser in water, and the factors affecting accuracy of analysis results. Although there have been many research works focusing on aqueous LIBS analysis, detection limit and stability of this technique still need to be improved to satisfy the requirements of environmental monitoring standard. In addition, determination of nonmetallic species in liquid by LIBS is equally important and needs immediate attention from the community. This comprehensive review will assist the readers to better understand the aqueous LIBS technique and help to identify current research needs for environmental monitoring of water quality.     

锡林浩特市露采煤炭区土地利用的扰动分析

利用锡林浩特市周边3个时期(2005,2009和2015年)的Landsat系列遥感影像,采用监督分类及人机交互解译的方法,将研究区土地利用类型分为露天采场、剥离区、排土场、矿山工业场地、农用地、城市建设用地和草地7类,对土地利用和土地覆被变化(Land-Use and Land-Cover Change,LUCC)进行分析。结果表明,草原区露天煤矿开发对草原生态系统扰动剧烈,采矿作业区(露天采场、剥离区、排土场、矿山工业场地)的面积及占比呈上升趋势,草地的面积及占比不断减少;土地利用变化转移矩阵表明,采矿扰动因素中,排土场对LUCC影响较大,对排土场进行有效复垦,可减缓生态环境破坏速度,对保护脆弱的草原生态系统具有重要意义;提出草原露采煤炭区LUCC的遥感监测可以准确反映矿区土地利用变化的动态过程和发展趋势,为矿区生态重建提供科学支持。     

淡水水体中微囊藻毒素的监测技术

随着水体富营养化的日益加剧 ,有毒蓝藻水华在世界范围内频繁发生。有毒蓝藻产生的毒素对人类和动物有潜在的危害 ,迫切要求对水体中特别是饮用水源中的蓝藻毒素进行监测。微囊藻毒素是蓝藻产生的一类环状七肽 ,可以抑制蛋白磷酸酶 1和 2 A。微量微囊藻毒素还促进肿瘤的发生。简要介绍了近年来发展起来的几类微囊藻毒素监测技术 ,以期引起有关部门的重视     

城市地面沉降浅析

城市地面沉降是一种常见的地质现象,也是一种“慢性病”,它缓慢发生,且一直存在。只有同工程建设、生产和生活发展发生矛盾与冲突时,就会演变成灾害。只要找准其原因并及时采取恰当的措施,城市地面沉降是完全可以控制的。     

预处理＋超滤技术处理饮用水

在查阅了大量的国内外文献资料基础上,主要介绍了超滤技术及预处理应用于饮用水净化的研究。尽管超滤是一种去除病原微生物（病原菌、病毒和病原原生动物）有效的消毒工艺,但因它的截留分子量比较高,去除天然有机物相对无效。试验证明,适当的预处理可使超滤膜不仅能去除天然水中大量颗粒状物质,同时也可去除溶解性有机物及THMFP。     

生物接触氧化法处理稠油污水实验研究

将从稠油污水中筛选出的3株高效烃类降解菌株HD-1、HD-2和HD-3用于稠油污水处理,研究了单一菌株和混合菌株对原油和COD的去除率。实验结果表明,单一菌株对原油和COD具有很好的去除效果,混合菌株对原油和COD去除效果更加显著。室内模拟实验结果表明,在停留时间为6 h时,含油量和COD分别为30 mg/L和300 mg/L时,经过生物接触氧化处理,出水含油量和COD分别降至1 mg/L和50 mg/L以下,达到了反渗透膜组件预处理的要求,为稠油污水热采锅炉用水回用提供了理论基础。     

Depletion of chlortetracycline during composting of aged and spiked manures

Chlortetracycline (CTC) is one of the most important pharmaceuticals occurring in the environment. An increase of its application as feed supplement for livestock and poultry in the world leads to a substantial CTC contamination of manures, because most of the CTC is excreted to manure. The simulation experiment of aerobic composting was adopted to investigate CTC depletion in aged and spiked manure composting, and to address the extent of CTC depletion during composting. The results showed that the extractable CTC initial concentration was markedly different between the different manures, with 94.71mgkg(-1) in broiler manure and 879.6mgkg(-1) in hog manure. The concentration of extractable CTC decreased rapidly at the initial stage of composting, and subsequently declined slowly during aged and spiked manure composting. At the end of composting, more than 90% of CTC in the manure composting process (42 days) was depleted, except for hog manure composting with a removal of only 27%. The CTC half-lives were 11.0 days in broiler manure, 86.6 days in hog manure, 12.2 days in layer-hen manure (150.3mgkg(-1) CTC), 12.0 days in layer-hen manure (100.0mgkg(-1) CTC) and 4.39 days in layer-hen manure (53.10mgkg(-1) CTC), all according to the first order kinetics. The significance of experimental parameters in CTC depletion was assessed by the Pearson correlation approach. Microbial degradation of CTC was not effective from manure composting. CTC depletion was in good correlation with total organic carbon, total nitrogen, total phosphorus, C/N, N/P and total heavy metals.     

UASB+AF-生物接触氧化工艺处理皂素-酒精综合废水

采用水解酸化-UASB+AF-接触氧化工艺处理黄姜皂素-酒精综合废水,经调试启动和运行研究,结果表明:当进水COD在10 000~12 800 mg/L时,最终出水COD浓度可降低到200 mg/L以下;水解酸化、UASB+AF和接触氧化各阶段的COD去除率分别达到23%、75%和93.5%,系统总的COD去除率可达到98.4%,出水色度在30~50倍之间;同时该工艺具有运行稳定、耐冲击负荷能力强等特点。     

Recent atmospheric lead deposition recorded in an ombrotrophic peat bog of Great Hinggan Mountains, Northeast China, from Pb and Cs dating

Radioactive markers are useful in dating lead deposition patterns from industrialization in peat archive. Peat cores were collected in an ombrotrophic peat bog in the Great Hinggan Mountains in Northeast China in September 2008 and dated using ²¹⁰Pb and ¹³⁷Cs radiometric techniques. The mosses in both cores were examined systematically for dry bulk density, water and ash content. Lead also was measured using atomic emission spectroscopy with inductively coupled plasma (ICP-AES). Both patterned peat profiles were preserved well without evident anthropogenic disturbance. Unsupported ²¹⁰Pb and ¹³⁷Cs decreased with the depth in both of the two sample cores. The ²¹⁰Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the ¹³⁷Cs time marker. Recent atmospheric ²¹⁰Pb flux in Great Hinggan Mountains peat bog was estimated to be 337 Bq m⁻² y⁻¹, which is consistent with published data for the region. Lead deposition rate in this region was also derived from these two peat cores and ranged from 24.6 to 55.8 mg m⁻² y⁻¹ with a range of Pb concentration of 14-262 μg g⁻¹. The Pb deposition patterns were consistent with increasing industrialization over the last 135-170 y, with a peak of production and coal burning in the last 50 y in Northeast China. This work presents a first estimation of atmospheric Pb deposition rate in peatlands in China and suggests an increasing trend of environmental pollution due to anthropogenic contaminants in the atmosphere. More attention should be paid to current local pollution problems, and society should take actions to seek a balance between economic development and environmental protection.     

基于协同推进生态文明建设的“多评融合”路径初探

评估是一种权力。各类"评估"实际上都代表了其主管部门的权力和利益,甚至沦为各部门争夺话语权、攫取部门利益的一道关卡。多种评价"混战",不仅评价内容重复、程序烦琐、浪费人力和资源,同时评价背后代表其主管部门的利益和权力,评价的"混战"也成为各部门维护自身利益、争夺话语权的"混战"。本文在对现有评价制度、实施情况、存在问题的剖析的基础上,基于协同推进生态文明建设的要求,提出横向上协同相关部门、纵向上协同国家和地方、政府和市场、政策规划与项目等重大决策的多评融合实施路径,最后提出了多评融合的四项政策建议。