Dynamics of the lakes in the middle and lower reaches of the Yangtze River basin, China, since late nineteenth century

The middle and lower reaches of the Yangtze River basin have the most representative and largest concentration of freshwater lakes in China. However, the size and number of these lakes have changed considerably over the past century due to the natural and anthropogenic impact. The lakes, larger than 10 km² in size, were chosen from relief maps and remotely sensed images in 1875, 1950, 1970, 1990, 2000, and 2008 to study the dynamics of lakes in the middle and lower reaches of the Yangtze River basin and to examine the causes and consequences of these changes. Results indicated that there was a dramatic reduction in lake areas, which decreased by 7,841.2 km² (42.64 %) during the study period (1875–2008), and the number of lakes in this region changed moderately. Meanwhile, a large number of lakes in the middle and lower reaches of the Yangtze River basin were directly converted into paddy fields, ponds, building lands, or other land-use types over the study period. Therefore, all kinds of lake reclamation should be identified as the major driving factors for the loss of lake in this region. Furthermore, flooding, soil erosion, and sedimentation were also the main factors which triggered lake changes in different periods. Some wetland conservation and restoration projects have been implemented since the 1970s, but they have not reversed the lake degradation. These findings were of great importance to managers involved in making policy for the conservation of lake ecosystems and the utilization of lake resources.     

青岛市区春夏季大气能见度与颗粒物的关系

利用青岛市灰霾综合观测站2012年3月2日-2012年6月7日期间的监测数据,分析了青岛市区大气能见度与不同粒径颗粒物质量浓度的日变化特征,比较了各级别大气能见度下不同粒径颗粒物质量浓度及所占比例的相关性,研究了相对湿度对大气能见度和颗粒物质量浓度相关性的影响.结果表明,监测时段大气能见度与颗粒物质量浓度呈现较好的负相关,每天大气能见度最低值出现在早晨07:00--09:00;剔除相对湿度高于90％的前提下,PM2.5是影响大气能见度的主要因子,随着其在PM1o中所占比例上升,大气能见度级别不断下降,相关系数为-0.84;不同相对湿度区间下,PM2.5对大气能见度的影响最明显,其中,相对湿度为60％ ～ 70％,大气能见度与颗粒物质量浓度之间的相关性最好.     

华东森林及高山背景区域SO2、NOx、CO本底特征

国家大气背景监测福建武夷山站是中国华东区域背景站点之一,可代表华东森林及高山区域背景状况。为了解该区域的大气背景状况,评估区域污染现状以及污染物输送在区域污染中的作用,选取福建武夷山背景站2011年3月至2012年2月主要气体污染物（SO₂、NO_x、CO）为期1年的监测数据,研究各污染物在不同时间尺度的浓度变化特征和相关关系,以及与气象因子的相关关系,并利用后向轨迹模式探讨区域输送对华东森林及高山背景区域各气体污染物质量浓度的影响。结果表明,武夷山背景点监测期间SO₂、NO_x、CO的平均质量浓度分别为3.9、5.1、409.8 μg/m³,且具有明显的季节变化特征,春、冬季明显高于夏、秋季;三者日变化幅度均很小,呈现出单谷型分布型态,说明武夷山背景点受人为活动的影响很小,主要受气象条件影响;相关性分析结果显示,SO₂与NO_x浓度相关性较好,与湿度有较好的负相关,与风速在冬季具有一定的正相关,NO_x与CO浓度在秋季和冬季的相关性较好,且二者与温度的负相关性较好。后向轨迹分析结果表明,SO₂全年最大浓度峰值主要来自北方采暖季燃煤排放的远距离输送影响,NO_x、CO全年最大值则源于生物质燃烧的远距离输送影响。     

“MMA”技术路线在太湖蓝藻水华监测中的应用

通过对3S技术整合,提出"MMA"技术路线应用于蓝藻水华监测,包括监测、测绘、分析等关键步骤。对太湖蓝藻水华研究结果表明,总体规律一致,但又有所差异。一方面,太湖蓝藻密度(CBD)、叶绿素a(Chl-a)及水华频率分布图结果均呈现"西高东低"的空间分布规律;另一方面,太湖湖心区CBD和Chl-a浓度亦较高,而遥感监测后的水华频率图显示为无水华或频率小于1%。故应参照"MMA"技术路线,综合应用3S技术,并核验比对,弥补单项技术存在的不足,全面真实反映藻类水华情况。"MMA"技术路线既适用于水华监测,亦可推广至其他环境监测工作。     

射阳湖浮游动物群落结构特征及其与环境因子相关性研究

2016—2017年对射阳湖开展浮游动物群落结构和水质指标逐月监测。结果表明,射阳湖共鉴定出浮游动物61种,其中原生动物、轮虫、枝角类和桡足类分别为25种、24种、7种和5种。浮游动物种类数呈现春夏季多于秋冬季的变化趋势。浮游动物优势种数量较多、分布广,群落结构相对复杂且稳定。运用Shannon-Wiener指数、均匀度指数和B/T指数对射阳湖水质作评价,结果表明,该湖处于轻度—中度污染状态,生物学指标评价法与常规水质评价结果一致。浮游动物群落结构与水质指标相关性分析表明,水温、透明度、Chl-a和DO是影响射阳湖浮游动物群落结构的主要水质指标。     

环境监测实验室方法确认过程中常见问题探讨

根据实验室资质认定对于方法确认的要求,结合环境监测实验室的特点,提出了新项目方法确认的具体步骤,并分析了其中存在的常见问题。指出在方法确认过程中,应严格按照标准方法和监测技术规范进行全过程试验,尤其不能忽视采样现场实验、空白实验和检出限的测定。建议在精密度与准确度检验过程中,使用高、中、低不同浓度的有证标准样品,实际样品加标回收,比对试验（方法比对、人员比对、实验室间比对）,增加分析次数等多种手段,确保新项目开展的可靠性。     

SPE-HPLC法测定水中硝基苯酚类化合物

建立了以固相萃取为前处理条件,用液相色谱法测定水中10种硝基苯酚类化合物的分析方法。实验使用HLB(6 L/150 g)固相萃取柱富集水样中的目标化合物,二氯甲烷与乙酸乙酯体积比1:2的混合溶剂洗脱,采用Phenyl柱(4.6 mm×250 mm,5 μm)分离目标化合物,以乙腈(1%甲酸)/水(1%甲酸)为流动相进行梯度洗脱,二极管阵列检测器检测。10种硝基苯酚类物质在0.02~10 mg/L范围内呈现良好的线性。方法检出限为0.1~0.3 μg/L,水样加标相对标准偏差为5.19%~18.2%,平均加标回收率为49.8%~124%。该方法适用于水中10种硝基苯酚类化合物的测定。     

Risk assessment of heavy metals in road and soil dusts within PM2.5, PM10 and PM100 fractions in Dongying city, Shandong Province, China

15 road and 14 soil dust samples were collected from an oilfield city, Dongying, from 11/2009-4/2010 and analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS) for V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb within PM(2.5), PM(10) and PM(100) fractions synchronously. Metal concentrations, sources and human health risk were studied. Results showed that both soil and road dust exhibited higher values for Mn and Zn and lower values for Co and Cd for the three fractions. Mass concentration ratios of PM(2.5)/PM(10) and PM(10)/PM(100) for metals in road and soil dust indicate that most of the heavy metals tend to concentrate in fine particles. Geoaccumulation index and enrichment factors analysis showed that Cu, Zn and Cd exhibited moderate or heavy contamination and significant enrichment, indicating the influence of anthropogenic sources. Vanadium, Cr, Mn and Co were mostly not enriched and were mainly influenced by crustal sources. For Ni, As and Pb, they ranged from not enriched to moderately enriched and were influenced by both crustal materials and anthropogenic sources. The conclusions were confirmed by multivariate analysis methods. Principle component analysis revealed that the major sources were vehicle emission, industrial activities, coal combustion, agricultural activities and crustal materials. The risk assessment results indicated that metal ingestion appeared to be the main exposure route followed by dermal contact. The most likely cause for cancer and other health risks are both the fine particles of soil and road dusts.     

Enantioselective aquatic toxicity of current chiral pesticides

Chiral pesticides are ubiquitous in the aquatic environment, and their enantioselectivities in aquatic toxicity are known to be complicated. The difference in enantioselective effects between enantiomers may sometimes differ by approximately 100-fold or more, which makes it important to incorporate enantioselective effects into the risk assessment of chiral pesticides. In this paper, we reviewed relevant work on the aquatic toxicity of chiral pesticides with an emphasis on the enantioselective aquatic toxicity under both chronic and acute exposure conditions. We provided a personal account of the importance of studies on molecular mechanisms of developmental toxicity and specific endpoints such as vitellogenin, yolk sac edema and pericardial edema in future research. Given the widespread use of chiral pesticides, we suggest that a more comprehensive understanding of the significance of enantioselective aquatic toxicity will be very helpful in improving risk assessment and regulation of chiral pesticides.     

Heavy metal concentration and speciation of seven representative municipal sludges from wastewater treatment plants in Northeast China

The analysis of heavy metals is very important for assessing the feasibility of the agricultural utilization for the municipal sludge. In this paper, a four-step sequential extraction method was applied to extract heavy metals (Cu, Zn, Mn, Cr, and Ni) in municipal sludges from seven individual wastewater treatment plants located in Jilin and Heilongjiang Province, China, for estimating the mobility and bioavailability of the metal ions in the agricultural application. The total concentrations of heavy metals and their chemical fractions after the sequential extraction were determined. Principal component analysis (PCA) was applied to analyze the relations of heavy metals fractions in the municipal sludges. Experimental results indicated that the total concentrations of Cu, Zn, Cr, and Ni in all sludge samples were below the threshold values set out by the Chinese legislation (GB18918-2002). Specially, Zn had a high bioavailability and mobility, Cu and Cr had potential bioavailability, while Mn mainly existed in the residual fraction of municipal sludge. On the other hand, Ni had different mobility in different municipal sludge. PCA results were confirmed by the environmental behavior of heavy metals.