Vertical Profile of Acid Volatile Sulfide (AVS) and Risk Assessment of Sediments from Baihua Lake,China

Acid volatile sulfide (AVS), simultaneously extracted metals (SEMs), and total concentrations of trace elements (Cu, Cd, Pb, Zn, Ni, Hg, As, and Cr) were studied in sediment cores from Baihua Lake in southwest China. The molar ratios of SEMs to AVS for all samples were lower than 1.0 except for the 25- to 30-cm layer of the sample collected at location YPZ, indicating that the heavy metals were currently not significantly bioavailable as a whole to benthic organisms. Based on the sediment quality guidelines and the potential ecological risk assessment, Hg presented a high ecological risk for the water body.     

Metallic contaminant profiles in sediment cores from Lake Valencia,Venezuela

Total extractable concentrations of AI, Fe, Mn, Pb, Cu, Zn, Hg and organic carbon (C_org) were determined along four sediment cores from Lake Valencia. In one selected core, the percentage labile fractions were determined in order to establish anthropic enrichment factors, the depth reached by the contaminants and their mobilities. The distribution patterns of concentration versus depth reflect the original concentrations of the settling sediments. Only Mn seems to show diagenetic cycling. No enrichment of Fe and Mn occurs in the upper part of the cores, in spite of good water circulation and aeration of bottom lake waters during five months of the year. This immobility can be attributed to the high pH of water (7.6 – 8.9). Pb, Zn, Cu and Hg are enriched in the upper part of the cores, probably reflecting the input of contaminants. These elements show enrichment factors of up to 3.0. Background concentrations of the studied metals are reached below a depth of 30 cm.     

厦门西港沉积物中多环芳烃的垂直分布特征与污染追踪

采用气相色谱对厦门西港1号站和5号站柱状沉积物样中16种多环芳烃（PAHs）进行分离鉴定,结果显示,16种多环芳烃含量的垂直分布范围为158～337ng/g,半定量后的ΣPAHs分布为1.1～6.0μg/g。5号站（位于港湾内）较1号站（位于港口外围区）受PAHs沾污严重,但相比于世界上靠城市的近岸港口,污染则较轻微。厦门西港PAHs主要来源于油类污染及城市工业、生活污水的排放     

SUBSURFACE DISTRIBUTION OF NITRATES BELOW COMMERCIAL CATTLE FEEDLOTS,TEXAS HIGH PLAINS1

ABSTRACT. Samples for water-quality analyses were collected from beneath eighty commercial cattle feedlots in the Texas High Plains. Twenty-two feedlots were drilled and/or cored to establish vertical gradients of dissolved solids. Sample and gamma logs, size analyses and vertical permeability of cores were determined from samples beneath these lots. Relationships of groundwater saturated thickness, depth to watertable, and age of lots to specificion distribution were evaluated. The study includes lots ranging in age from 35 years to new installations. Runoff collection-systems on lots include playas, man-made ponds, and dammed and undammed stream channels. Infiltration of feedlot liquid waste to the watertable below feedyards is insignificant in most localities in the Texas High Plains. Infiltration of “collected” feedlot runoff and subsequent concentration of dissolved ions in groundwater in the High Plains are dependent upon, among other things, (1) surface and subsurface geology, (2) depth to water, (3) thickness of the groundwater zone, and to (4) differences in lateral and vertical permeabilities of the Ogallala Formation, the major aquifer. Certainly, no regional subsurface pollution problem exists today nor is one foreseen from cattle feedlot runoff in the Texas High Plains.     

Toxic marine diatoms of Hong Kong:A paleoecological study

To determine whether toxic diatoms in Hong Kong's Victoria Harbour have become more common during the last four decades,a gravity core was taken from the anaerobic sediments of Kowloon Bay in the harbour. Analysis of these sediments from a depth of 0-1cm,4-5cm and 9-10cm indicated that 6.4%,2.4% and 1.5% of the diatoms observed at each of these three respective depths belonged to the genus Pseudonitzschia. The abundance of Pseudonitzschia frustules in the surface sediments of Victoria Harbour was significantly higher(p<0.05)than it was in the harbour's deeper and older(ca.1965)sediments. The increase in potentially toxic diatom species over the last 30 years was attributed to a variety of factors including the addition of large amounts of nutrients to Hong Kong's coastal waters as a re- sult of man's activities.     

不同营养湖泊沉积物中210Pbex和营养盐垂向分布特征及相关性分析

对比分析了两个不同营养湖泊抚仙湖和滇池湖中心部位沉积物柱芯放射性核素210Pbex和营养盐(TOC、TN和TP)的垂向分布特征,探讨了两个湖泊不同湖区沉积物柱芯中210Pbex与营养盐(TOC、TN和TP)之间的相关关系.结果表明,两个湖泊沉积物柱芯中210Pbex和营养盐各个指标的垂向分布存在差异,总体上滇池沉积物柱芯中210Pbex的波动变化幅度略高于抚仙湖.滇池表层沉积物中210Pbex较为紊乱的分布特征与人类活动影响下的沉积物中Pb的物理化学迁移有关.沉积物中营养盐各个指标的变化则与特定历史时期不同强度的自然演化和人类活动双重因素影响密切相关.放射性核素210Pbex和营养盐各个指标之间的相关关系与两个湖泊或同一湖泊不同湖区的营养水平高低有关,其变化关系为富营养化湖泊滇池>贫营养湖泊抚仙湖,抚仙湖北岸>南岸.就单个营养盐指标与210Pbex之间的相关关系而言,TOC最强,TP次之,TN最弱.     

珠江三角洲沉积物钻孔中多溴联苯醚的垂直变化规律研究

采用GC/MS分析方法测定了珠江三角洲水体5个钻孔(分别采自东江东莞段、珠江广州段、北江中段、西江入海口和顺德段)80个样品中10种多溴联苯醚(PBDEs,BDE209和∑9BDEs)的含量,对其沉积规律进行研究和探讨.∑9BDEs含量范围为1.54~94.8 ng·g-1,平均值为15.4 ng·g-1.BDE209含量范围为14.4~588 ng·g-1,平均值为136 ng·g-1,占总PBDEs含量的70%以上.钻孔中PBDEs含量从底部到表层呈现上升趋势,表明近年来珠江三角洲PBDEs环境排放仍在增加.5个钻孔中低溴代∑9BDEs从表层至底部逐渐增加,而高溴代∑9BDEs逐渐减少,意味着钻孔中可能存在脱溴降解行为.     

全氟化工厂土芯中全氟化合物的分布规律

本文对全氟化合物(PFASs)生产工厂厂内及周边土芯样品中的PFASs进行了研究.PFASs浓度范围为1.19—1495 ng·g-1dw(干重),其中全氟辛基磺酸盐(PFOS)浓度在3个主要单体(全氟己基磺酸盐(PFHxS)、PFOS及全氟辛酸(PFOA))中处于最高水平.整体上,土芯中PFASs浓度由上到下呈下降趋势,其浓度与TOC呈正相关.在一个已经停产10年左右的生产企业周围土芯中仍然发现了较高浓度的PFASs,说明其在环境中存在着较强的持久性.     

渤海湾天津段潮间带沉积物柱状样重金属污染特征

2003-11采集了渤海湾天津段北至大沽口,南到岐口海域潮间带3个沉积物柱状样,对沉积物的粒度、有机质、重金属含量进行分析,对渤海湾潮间带沉积物柱状样的地化性质、重金属污染概况以及重金属的空间、垂向分布特点进行了研究.渤海湾潮间带沉积物由北至南逐渐变细,大沽口和独流减河口海域的沉积物主要是极细砂-粉砂-细砂组成,岐口海域潮间带沉积物主要组分是粉砂和极细砂.3个柱状样的垂向粒度分布趋势表明渤海湾潮间带沉积物自下向上有“粗化”的趋势.Fe、Al、Mn3种元素的空间分布与沉积物的粒径呈显著的负相关性,即Fe、Al、Mn含量主要分布在粒度较细的沉积物中.渤海湾潮间带主要重金属污染元素是Pb、Zn、Cd 3种.通过归一化研究,这3类重金属元素在沉积物中有很明显的人为污染痕迹,含量远远高于其相应的环境背景值.     

关于建立工业园区统一规范碳核算方法体系的思考

工业园区是中国制造业发展的重要载体与做好碳达峰碳中和的关键支撑，建立统一规范的碳核算方法，是园区科学推进低碳发展的必要前提。本研究剖析了园区碳核算的复杂性，明确了园区“双碳”工作的核心要义，建立了“一芯四核”互馈式园区碳核算方法框架。该框架主要包括应用目标与范围定义、流分析与排放清单建立、碳排放计算、结果解释与决策支撑四个核心环节，四“核”间相互作用、迭代优化，根据园区发展实际进行具象化，并充分考虑向上与所在行政区域碳核算清单、向下与企业碳排放核算兼容，最终服务于准确把握低碳发展内涵、锻造新的产业竞争优势这一关键内“芯”。进一步地，研究阐述了“一芯四核”方法框架各主要步骤，分析了园区碳核算实践中面临的园区边界、核算范围、清单建立、数据质量等方面的难点，提出了基于检验清单的各环节工作原则、操作步骤及注意事项。研究为“千园千面”的工业园区提供了科学统一的碳核算理论框架，可为工业园区在低碳转型中锻造新的产业竞争优势提供决策支撑，为建立统一规范碳排放统计核算体系奠定方法基础。