微山湖养殖湖区水体中多环芳烃的分布及来源

采用HPLC定量分析微山湖养殖湖区水体中16种优先控制PAHs的总量浓度范围在5348.8～12970.8ng/L之间,平均值为8671.5ng/L,处于中等偏高污染水平;养殖湖区水体中的多环芳烃主要来源于养殖船只的石油泄露及煤炭、木材与石油的不完全燃烧,PAHs的组成以2～3环为主。     

大连城市大气中多环芳烃的污染特征和毒性评价

通过对大连市工业区、居民区和城市背景区3种类型区域连续7个月大气样品的采集,分析PAHs在大气中的污染特征,并对其毒性进行评价。结果显示,城市工业区大气中PAHs含量最高,其次是居民区,城市背景区最低。3种类型采样点大气中PAHs的组成相似,菲是含量最多的物质,其次是荧蒽、芴和芘。16种PAHs基于苯并[a]芘的总毒性当量浓度为:工业区5.1 ng/m^3;居民区3.6 ng/m^3;城市背景区4.6 ng/m^3。3种类型功能区大气中PAHs的TEQ值都高于我国的《空气质量标准》(GB 3095-2012)中规定的大气中苯并[a]芘的年平均浓度(1 ng/m^3)或24 h平均浓度(2.5 ng/m^3)。     

水环境多环芳烃污染溯源研究

基于正定矩阵因子分解（Positive Matrix Factorization,PMF）模型对石马河河口及滨岸带中多环芳烃（Polycyclic aromatic hydrocarbons,PAHs）污染来源及贡献率进行解析,分别于2021年4月（平水期）和7月（丰水期）采集地表水及表层沉积物水样进行研究分析。结果表明：该研究区内PAHs污染的来源主要包括原油泄漏、煤炭燃烧、交通运输及生物质燃烧等,其中,交通运输源对研究区沉积物中PAHs的贡献率超过60%;交通运输及煤炭燃烧源对地表水中PAHs的贡献率之和接近80%;原油泄漏与交通运输源对研究区悬浮颗粒中PAHs的贡献率之和接近70%。研究结果可为石马河地区水资源绿色开发与PAHs污染治理提供一定依据。     

广州土壤中短链氯化石蜡的含量水平和分布特征

短链氯化石蜡(SCCPs)是一类新的持久性有机污染物(POPs),目前我国相关研究较少。为了解SCCPs在土壤中的污染现状和分布特征,测定了24个广州土样(含3个剖面采样点)中SCCPs的含量,分析了其同族体分布模式。结果表明:广州表层土壤中SCCPs的含量变化范围为6.8～541.2ng/g,均值为79.6ng/g;剖面土壤中SCCPs的含量范围为7.5～115.8ng/g,均值为33.1ng/g。不同类型土壤中SCCPs各同系物组分的分布模式相似,以碳原子数为10和11的Cl6-SCCPs/Cl7-SCCPs为主。     

镇江东部地区土壤中多环芳烃的污染特征及来源解析

分析了镇江东部扬中地区土壤中16种优先控制的多环芳烃（PAHs）污染物的含量特征及污染水平。结果表明,该地区土壤的多环芳烃总量为2．4～49．9μg／Kg,其中荧蒽的含量最高,同我国其他地区相比,其污染水平比较低。5个采样点PAHs含量表明有两个点受工业企业影响,其他3个点具有类似的面源污染即地质成因来源。     

青藏湖区可鲁克湖氮形态空间分布研究

文章为评估青藏湖区湖泊氮赋存形态,于2013年8月对青藏湖区可鲁克湖共14个采样点进行了采样及分析,探讨了水体及表层沉积物中各形态氮的空间分布特征。结果表明,可鲁克湖上覆水中p(DTN)(溶解性总氮浓度)范围为0.46~1.14mg/L,平均值为0.72mg/L,全湖污染趋势从入湖到出湖,依次为人湖口处湖中心出湖口处;间隙水中p(DTN)范围为3.16~13.15mg/L,平均值为8.55mg/1,全湖入湖口处间隙水中各氮形态浓度值较低,全湖污染趋势依次为湖西北处出湖口处湖中心入湖口处;沉积物中w(TN)(总氮含量)为1 316.00~6 953.00mg/kg,平均值为3 816.21mg/kg,湖西北处、出湖口处湖泊沉积物污染最为严重。     

农田土壤中多环芳烃的高效液相色谱法测定

采用快速溶剂提取(ASE)—凝胶渗透色谱(GPC)—高效液相色谱法测定农田土壤中的多环芳烃(PAHs)。优化了ASE的提取溶剂和GPC的净化时间,方法具有良好的精密度和准确度,拥有良好的线性范围和检出限。对济南市某农田土壤样品进行了测定,共检出5种PAHs,总浓度为26.8μg/kg,参照Maliszewska-Kordybach土壤中PAHs污染分级方法,属于无污染水平,同时参考荷兰土壤质量标准中10种PAHs标准限值,均未超标。     

浙江台州典型电子废弃物无序拆解区土壤多环芳烃污染风险评估

电子废弃物的无序拆解会导致其中多环芳烃(polycyclic aromatic hydrocarbons, PAHs)的无规律释放,进而对周边生态环境和人体健康构成威胁。为了量化电子废弃物无序拆解区土壤中PAHs的含量及其对人体健康的风险,本研究从浙江省台州市路桥区某典型电子废弃物无序拆解区采集了3个作坊式电子废弃物拆解点、3个作坊式塑料或金属加工点和1个电子废弃物拆解尾渣倾倒点的土壤样品,以气相色谱-质谱联用法和美国环保署规定的暴露量化及风险表征方法为分析手段开展PAHs含量分析及其风险评估。结果发现:上述7个土壤样品PAHs的总量范围为32.62～1053.71μg/kg,平均为414.05μg/kg,其中一个作坊式电子废弃物拆解点的PAHs含量属于重污染级别,土壤存在强烈的环境风险,单体菲(Phe)、蒽(Ant)、荧蒽(Fla)和芘(Pyr)对环境风险的贡献率最大。此外,PAHs通过不同途径对人体造成的健康风险程度为呼吸途径﹥皮肤接触﹥经口途径。结果表明,电子废弃物无序拆解区土壤PAHs污染急需建立相关环境管理措施及污染控制标准,逐步规范电子废弃物无序拆解活动。     

低温捕集/热解吸气相色谱法分析废气中挥发性硫化物

采用低温捕集/热解吸/火焰光度检测填充柱气相色谱法可分析废气中挥发性硫化物。标准气浓度为2.80g/L～38.10g/L时,硫化氢、甲硫醇、乙硫醇、甲硫醚和二甲二硫的平均回收率及相对标准偏差分别为92.1%～106.8%及0.5%～6.0%,采样体积为1.0L时,上述挥发性硫化物的最低检出浓度为0.08ng/L～0.65ng/L。该分析测定了炼油厂某些污染源和催化燃烧脱硫中试装置废气中挥发性硫化物组成,验证了方法的适用性。     

大气降尘中多环芳烃的分布特征及源解析

为探讨大气降尘中多环芳烃的污染水平和来源的解析,于2008年冬、春、夏、秋四个季节采集了北京昌平地区大气降尘样品,采用超声抽提方法,使用GC/MS测定了样品中PAHs的含量。结果表明,冬、春、夏、秋四个季节样品中多环芳烃总量分别为18.6μg/g、17.3μg/g、15.1μg/g和11.0μg/g,单体化合物均值分别为1.04μg/g、0.96μg/g、0.84μg/g和0.61μg/g。与其他城市监测结果比较可知:昌平地区大气降尘中PAHs含量相对较低。使用多种方法对降尘中的PAHs来源进行解析,结果表明:化石燃料燃烧在不同季节中的贡献相对稳定,燃煤在冬季为多环芳烃主要来源之一,在其他季节贡献相对较低。     

西溪湿地底泥质量现状与生态风险初步评价

为了解西溪湿地底泥质量现状,2012年9月采集保护区内不同干扰类型的底泥样本,测试了底泥中重金属和POPs中PCBs、OCPs和PAHs的含量,并对湿地底泥污染进行了生态风险初步评价。结果表明,底泥中未检出PCBs和OCPs,但检测出14种EPA优控PAHs,总PAHs的浓度范围为115.9～217.8 ng·g^-1,低于潜在生态风险的效应区间低值ERL,其中列入中国＂水中优先控制污染黑名单＂的7种PAHs均有检出并且其总量占∑PAHs 1/2左右（平均为50.08%）;底泥中8种重金属含量平均值低于《土壤环境质量标准》（GB 15618—1995）的二级标准,但Hg、Zn、Pb、Ni含量在多个位点已超过一级标准;分别采用土壤背景值和国家一级标准为参比值对湿地底泥中重金属进行单因子污染风险指数评价,发现分别有7种和4种元素的污染指数大于1;综合分析不同干扰类型的底泥质量,发现底泥疏浚能有效降低有机质含量、全氮和PAHs含量,但对全磷、重金属含量则无明显效果,封闭水体的干塘措施能显著减少污泥量和有机物含量。研究结果表明,西溪湿地底泥中高环PAHs和重金属污染水平可能对西溪湿地生物具有潜在的生物毒性作用及不利的生态影响效应,其疏浚底泥农用则无生态风险。     

A critical appraisal of PAH indices as indicators of PAH source and composition in Elelenwo Creek,southern Nigeria

The survey of polycyclic aromatic hydrocarbons (PAHs) and their relation to potential pollution sources were investigated in suspended particulate matter (SPM), surface waters, and sediments from Elelenwo Creek, southern Nigeria. Total PAH concentrations varied from 2,021.35 to 3,926.84 μg/kg dry weights in SPM and from 4,238.00 to 5,490.84 μg/kg dry weights in sediments. Furthermore, concentration levels of PAHs varied from 720.46 to 857.65 μg/l in the surface waters, which indicates that the aquatic ecosystem is polluted by PAHs. The 2, 3-ring PAHs were not dominant in SPM (34.73%), surface water (40.09%), and sediments (22.43%). While anthracene was more abundant, of the 2, 3-ring PAHs in SPM, the most abundant in the surface waters and sediments were fluorene and acenaphthylene. Four origin indices or concentration ratios of PAH isomer pairs were used to evaluate the suitability of these compounds as tracers to distinguish between the contamination arising from different sources. A critical appraisal of the PAH indices, therefore, suggested that biomass combustion is the major PAH source in the environmental matrices. Relative PAH patterns in the environmental matrices were also evaluated using principal component analysis, and were found to correlate with the PAH patterns of the different potential contamination sources.     

Fractionation of selected metals in the sediments of Cochin estuary and Periyar River, southwest coast of India

Cochin estuary is one of the highly polluted aquatic systems of the southwest coast of India. The present study focuses on the assessment of heavy metals (Zn, Cd, Pb, and Cu) present in the sediments of Cochin estuary and the adjoining Periyar River. The sediments were analyzed for total metal content and various chemically bound fractions such as exchangeable, carbonate bound, easily reducible, organic, and residual. Total metal content of sediment was found higher than the average values reported from other Indian rivers. The mean concentration of Zn, Cd, Pb, and Cu in the sediments was 1,249.44, 9.5, 221.37, and 166.14???g/g, respectively. The results of sequential extraction showed that the concentration of Cd was high in the first two weakly bound fractions (exchangeable and carbonate bound) than the other metals, which are high in residual and organic bound fractions. Risk-assessment code analysis and environmental indices (enrichment factor and pollution load index) suggest that the sediments are highly polluted with metals, especially Cd.     

PERSISTING SEDIMENT YIELDS AND SEDIMENT DELWERY CHANGES1

ABSTRACT: The Buffalo River is a tributary to the Mississippi River in west-central Wisconsin that drains a watershed dominated by agricultural land uses. Since 1935, backwater from Lock and Dam 4 on the Mississippi River has inundated the mouth of the Buffalo's valley. Resurveys of a transect first surveyed across the lake in 1935 and cesium-137 dating of backwater sediments reveal that sedimentation rates at the Buffalo's mouth have remained unchanged since the mid-1940s. Study results indicate that sediment yields from the watershed have persisted at relatively high levels over a period of several decades despite pronounced trends toward less cultivated land and major efforts to control soil erosion from agricultural land. The maintenance of sediment yields is probably due to increased channel conveyance capacities resulting from incision along some tributary streams since the early 1950s. Post-1950 incision extended the network of historical incised tributary channels, enhancing the efficient delivery of sediment from upland sources to downstream sites.     

滇池沉积物重金属污染状况评估

本文通过多年滇池底泥的采样监测数据,采用地积累指数法和对数衰减模型评估滇池的底泥质量状况,希望摸清底泥中重金属污染状况,并分析评价其对水生生物的风险,为底泥疏浚、截污护岸的滇池治理工程提供一定的科学依据。研究表明:以地积累指数法评价,(1)滇池监测断面底泥质量呈现轻度污染,镉出现一定程度富集,汞在个别监测断面也出现富集情况;(2)6种重金属污染排序为镉>汞>铅>铜>铬>砷;(3)从监测断面来看,海口西污染程度较重,滇池南底泥质量较好。采用对数衰减模型评价,(1)滇池监测断面沉积物重金属污染存在潜在生物风险,应引起重视;(2)从产生可以观察到毒性效果的可能性大小看,6种重金属潜在危害可能性排序为砷>铅>铜>铬>镉>汞;(3)从监测断面来看,白鱼口和观音山中潜在危害可能性大。从富集污染程度分析,海口西监测断面的底泥污染最重,可考虑在海口西监测断面附近进行一定的底泥疏浚工程。从而达到治标治本的目的。滇池监测断面沉积物重金属污染存在潜在生物风险,应引起重视,但在可控范围。     

九寨沟白水河污染特征研究

通过对2012年4月～2013年3月九寨沟白水河不同断面水样分析,研究了《地表水环境质量标准》（GB3838—2002）中表1“地表水环境质量标准基本项目”的含量变化,并对铬、镉、硒、铜、汞、锌、铅、砷、氨氮、高锰酸盐指数进行污染状况评价。结果显示：镉、铜、汞、锌、铅均未检出;对铬、砷、硒、氨氮、高锰酸盐指数等有检出项目进行单项污染指数和内梅罗综合污染指数评价,水样中铬、砷、硒、氨氮、高锰酸盐指数全年监测平均浓度分别为0．294μg／L、0．024μg／L、0．084μg／L、0．187mg／L、0．695mg／L,用国家水质环境标准的一级标准,所有监测点位（PN〈1）未超标。从单因子污染指数来看,高锰酸盐指数在4月、7月、10月P,〉1,属于轻度污染,初步推断人为活动所致。通过本文的研究发现九寨沟水质依然较好,未受到污染。     

MERCURY IN WATER AND SEDIMENT OF STEAMBOAT CREEK,NEVADA: IMPLICATIONS FOR STREAM RESTORATION1

ABSTRACT: The objective of this study was to characterize the sources, concentrations, and distribution of total and methylmer‐cury in water, and channel and bank sediments of Steamboat Creek, Nevada. This information was needed to begin to assess the potential impacts of stream restoration on mercury pollution in this tributary to the Truckee River. The Truckee River flows into Pyramid Lake, a terminal water body home to one endangered and one threatened fish species, where stable pollutants will accumulate over time. Mercury in Steamboat Creek was originally derived from its headwaters, Washoe Lake, where several gold and silver mills that utilized mercury were located. In the 100 plus years since ore processing occurred, mercury‐laden alluvium has been deposited in the stream channel and on streambanks where it is available for remobilization. Total mercury concentrations measured in unfiltered water from the creek ranged from 82 to 419 ng/L, with greater than 90 percent of this mercury being particle‐bound (> 0.45 (m). Mercury in sediments ranged from 0.26 to 10.2 μg/g. Methylmercury concentrations in sediments of Steamboat Creek were highest in wetlands, lower in the stream channel, and still lower in streambank settings. Methylmercury concentrations in water were 0.63 to 1.4 ng/L. A streambank restoration plan, which includes alterations to channel geometry and wetland creation or expansion, has been initiated for the creek. Data developed indicate that streambank stabilization could reduce the mercury loading to the Creek and that wetland construction could exacerbate methylmercury production.     

The impact of urbanization on tropical mangroves (Fortaleza,Brazil): Evidence from PAH distribution in sediments

This investigation represents the first environmental diagnosis of the distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments from a tropical mangrove in Fortaleza, northeastern Brazil. Sediment cores from six sampling stations in the Cocó and Ceará Rivers were retrieved in June-July 2006 to determine 17 priority PAHs. The total PAH concentrations (Σ_PAHs) ranged from 3.04 to 2234.76 μg kg^?1(Cocó River) and from 3.34 to 1859.21 μg kg^?1 (Ceará River). These levels are higher than those of other cities with more industrial development. PAH concentrations did not reach probable effect levels (PELs). However, from 4.5 to 87.5% of individual PAH concentrations can occasionally cause adverse biological effects for aquatic organisms. The PAH molecular ratios indicate that the PAHs in the sediment core were derived mainly from petroleum, wood, and charcoal combustion (pyrogenic source), and that atmospheric deposition and urban runoff may serve as important pathways for PAH input to the sediment. Clearly, the Σ_PAHs in sediments collected in the Cocó and Ceará Rivers indicate that ongoing pollution is more severe than past pollution.     

Temporal and spatial distributions of sediment total organic carbon in an estuary river

Understanding temporal and spatial distributions of naturally occurring total organic carbon (TOC) in sediments is critical because TOC is an important feature of surface water quality. This study investigated temporal and spatial distributions of sediment TOC and its relationships to sediment contaminants in the Cedar and Ortega Rivers, Florida, USA, using three-dimensional kriging analysis and field measurement. Analysis of field data showed that large temporal changes in sediment TOC concentrations occurred in the rivers, which reflected changes in the characteristics and magnitude of inputs into the rivers during approximately the last 100 yr. The average concentration of TOC in sediments from the Cedar and Ortega Rivers was 12.7% with a maximum of 22.6% and a minimum of 2.3%. In general, more TOC accumulated at the upper 1.0 m of the sediment in the southern part of the Ortega River although the TOC sedimentation varied with locations and depths. In contrast, high concentrations of sediment contaminants, that is, total polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), were found in sediments from the Cedar River. There was no correlation between TOC and PAHs or PCBs in these river sediments. This finding is in contradiction to some other studies which reported that the sorption of hydrocarbons is highly related to the organic matter content of sediments. This discrepancy occurred because of the differences in TOC and hydrocarbon source input locations. It was found that more TOC loaded into the southern part of the Ortega River, while almost all of the hydrocarbons entered into the Cedar River. This study suggested that the locations of their input sources as well as the land use patterns should also be considered when relating hydrocarbons to sediment TOC.     

Precise and Economical Dredging Model of Sediments and Its Field Application: Case Study of a River Heavily Polluted by Organic Matter,Nitrogen, and Phosphorus

Environmental dredging is an efficient means to counteract the eutrophication of water bodies caused by endogenous release of nitrogen and/or phosphorus from polluted sediments. The huge operational cost and subsequent disposal cost of the dredged polluted sediments, as well as the adverse effect on the benthic environment caused by excessive dredging, make the currently adopted dredging methods unfavorable. Precise dredging, i.e., determining the dredging depth based on the pollution level, not only significantly decreases the costs but also leaves a uniform favorable environment for benthos. However, there is still no feasible process to make this promising method executable. Taking a river heavily polluted by organic compounds as an example, we proposed an executable precise dredging process, including sediment survey, model establishment, data interpolation, and calculation of dredging amount. Compared with the traditional dredging method, the precise one would save 16 to 45 % of cost according to different pollutant removal demands. This precise dredging method was adopted by the National Water Project of China to treat the endogenous pollution of Nanfei River in 2010. This research provides a universal scientific and engineering basis for sediment dredging projects.