大连湾表层沉积物中汞的赋存形态与生物可利用性研究

为了解大连湾沉积物中汞的赋存形态和生物可利用性,对大连湾表层沉积物中总汞(THg)和甲基汞(Me Hg)的含量进行了分析,并采用选择连续提取法对表层沉积物中汞的赋存形态进行了研究,探讨了沉积物中汞的赋存形态与甲基汞的关系。结果表明:大连湾表层沉积物中总汞和甲基汞的平均含量分别为95.1、0.71 ng/g,甲基汞占总汞的比例(甲基化率)为0.76%,与自然背景值相比,沉积物中总汞含量明显受到了人类活动的影响;大连湾表层沉积物中各赋存形态汞比例的平均值由小至大依次为水溶态汞(Hg-w)(3%)<胃酸溶解态汞(Hg-h)(10%)<硫化物结合态汞(Hg-s)(24%)<有机结合态汞(Hg-o)(31%)<强络合态汞(Hg-e)(32%),Hg-e、Hg-o和Hg-s为主要存在形态;沉积物中Hg-w、Hg-h和Hg-o与甲基化率呈正相关,显示Hg-w、Hg-h和Hg-o具有较高的生物可利用性。研究表明,采用选择连续提取法进行沉积物中汞赋存形态的研究,对了解沉积物中汞的生物可利用性具有较好的指示意义。     

张家山矿区矿体赋存特征及可利用性评价分析

结合张家山煤矿的自然地理、地质构造、地层岩性、水文等因素对该矿体进行了圈定,进一步查明该矿体的赋存特征,通过对煤炭的物理性质、煤层特征、化学性能及工艺性能等方面进行分析,对各个煤层的工业用途及其可利用性进行了评价,为以后该煤矿开采提供了地质依据。     

污泥堆肥化对重金属生物可利用性的影响

通过重金属形态分析及在模拟雨水、酸雨淋溶条件下重金属迁移实验和理论分析，研究了堆肥化处理对污泥中重金属生物可利用性的影响。结果表明：堆肥化处理使重金属的不稳定形态含量降低，原污泥在酸雨淋溶下重金属已经迁移到约16厘米深的土柱中，而经过处理后的污泥淋出液中的重金属含量很低，仅有少量污泥中含量较高的元素向土柱深层迁移。迁移量及深度明显低于未处理的原污泥。实验及理论分析均证明了堆肥化处理可以降低污泥中重金属在土壤中的迁移性，使重金属的生物可利用性降低。     

再生混凝土的可利用性

随着城市改造步法的加快,对许多在用的或使用期满的建筑物,开始采用先进的爆破法迅速解体,加上自然灾害的破坏和混凝土加工厂积累的剩余物等,使对大量废旧混凝土处置的课题,已经摆在我们的面前。与此同时,对天然集料的需求量日益增多,而可提供的资源却日趋减少。因此,对旧混凝土的再循环利用的研究,已成当务之急。一些先进国家,早已开设回收利用废旧混凝土的工厂,成立废料再利用委员会,     

钢渣中MgO赋存形态及制品体积安定性的研究分析

对钢渣进行科学、高效的资源化利用具有重要意义。为探索钢渣中MgO的赋存形态对掺有钢渣的混凝土与水泥制品体积安定性的影响及检测方法,本文介绍了钢渣中MgO的三种赋存形态（化合态、游离态以及固溶态）,阐述了游离态MgO引起混凝土与水泥制品体积安定性不良的原因,归纳了钢渣中游离态MgO含量的测定方法以及MgO混凝土体积安定性的检测方法,为检测掺有钢渣的混凝土体积安定性提供参考。     

间歇生物反应器中氮的赋存状态与转化规律研究

目前废水生物脱氮技术着重于对氨氮的去除,很难达到去除总氮的目的。为了更好的去除氨氮及总氮,实验研究了不同进水pH、溶解氧浓度、进水C/N比及不同温度条件下间歇生物反应器中氮的存在状态及其转化规律。结果表明：在生物反应器运行初期氨氮、总氮浓度均有明显的下降;进水氨氮浓度在30～70 mg/L的污水,优化处理操作参数为pH值8.0±0.5,溶解氧（4.2±0.5）mg/L,温度20～26℃,C/N为6,曝气时间6 h,沉淀2 h,氨氮去除率可达到90％,总氮去除率接近60％。     

土壤污染物生物可给性对健康风险评估的重要性及应用

土壤污染问题已逐渐成为了一个世界范围的环境问题,而土壤污染物的健康风险评估是土壤污染研究中一个关键的组成部分,因此需要找到一个科学有效的实验研究方法。由于经口直接摄入土壤污染物为土壤污染物的主要的暴露途径,土壤污染物生物有效性的研究的重要作用日益体现。本文介绍了生物可给性及生物有效性的概念,综合比较了国外现有生物可给性实验方法,介绍了生物可给性实验在国外的应用实例,并进一步分析了应用中所存在及需要解决的问题,以更充分推广生物可给性研究,推进科学有效的土壤污染物健康风险评估。     

旧沥青及矿料性能评价及可利用性的研究

通过RAP料的级配分析、RAP结团状况分析、RAP料中旧集料级配及残余性能分析以及RAP料中旧沥青三大指标试验,对旧沥青及矿料的性能评价及可利用性进行了分析探讨,为了提高新沥青胶浆的高温性能,建议乳化沥青冷再生混合料掺加一定量的矿粉,调节混合料级配;为了满足级配要求,冷再生混合料有时需要掺加新集料调节级配。     

城市高层建筑形态优化与风能利用的融合研究

从整体布局优化、细部造型优化两个层面对高层建筑的形态优化进行了重点探究,深入分析了高层建筑的风能利用的重点环节,研究结果可为城市环境的规划设计提供重要理论参考。     

Heavy metal pollution status in surface sediments of the coastal Bohai Bay

Bohai Bay, the second largest bay of Bohai Sea, largely due to the huge amount of pollutants discharged into it annually and its geohydrologic condition, is considered to be one of the most polluted marine areas in China. To slow down, halt and finally reverse the environmental deterioration of Bohai Sea, some researchers have proposed to connect it with Jiaozhou Bay in the western coast of Southern Yellow Sea by digging an interbasin canal through Shandong Peninsula. In order to assess the heavy metal pollution and provide background information for such a large geoengineering scheme, surface sediments from 42 stations covering both riverine and marine regions of the northwestern coast of Bohai Bay were analyzed for heavy metal content and fractionation (Cd, Cr, Cu, Ni, Pb and Zn). Three empirically derived sediment quality guidelines were used to assess the pollution extent of these metals. The studied metals had low mobility except for Cd at all stations and Zn at some riverine stations. Although a high mobility of Cd was observed, it could hardly cause a bad effect on the environment owing to its low total concentrations. Anthropogenic influence on the accumulation of studied heavy metals in sediments of Bohai Bay was obvious, but their contents were relatively lower to date comparing with some other marine coastal areas that receive important anthropogenic inputs. Taking as a whole, surface sediments of northwestern Bohai Bay had a 21% probability of toxicity based on the mean effects range-median quotient.     

Distributions of total mercury and methylmercury in surface sediments and fishes in Lake Shihwa, Korea

The concentrations of total mercury (THg) and methylmercury (MeHg) in the sediments of Lake Shihwa, an artificial salt lake in Korea located near two large industrial complexes, were determined to investigate the state of Hg contamination in the lake sediments and the effect of local Hg source. THg and MeHg concentrations in the sediments, monitored for 2 years, ranged from 0.02 to 0.28 µg g^− 1 and ≤ 0.026 to 0.67 ng g^− 1, respectively. The overall distribution of Hg in lake sediments showed higher values near industrial complexes and in the central part of the lake. However, the correlations between Hg and environmental factors, such as organic material (OM) content, and acid volatile sulfide (AVS), were weak and did not clearly explain the variation in Hg distribution. The spatial distribution of sediment Hg and monthly precipitation data during the sampling period showed that the amount of runoff following rain events and water gate operation may be additional important factors regulating Hg level and distribution in lake sediments. The levels of THg in fish species in this lake ranged from 9.8 to 35 ng g^− 1, suggesting that the bioavailability of sediment Hg in the lake may be low. Although the THg concentrations in Lake Shihwa sediment were lower than those in other foreign study sites, they were higher than in neighboring coastal regions, and are constantly increasing. This result indicates that the nearby industrial complexes may be the major source of Hg found in the sediments of Lake Shihwa.     

Total mercury and methyl mercury levels in British estuarine and marine sediments

Total mercury and methyl mercury levels in some British estuarine and marine sediments are presented. Results are compared for estuaries of the Rivers Clyde and Mersey. These, together with data from Irish Sea sediments, are discussed in comparison with other literature values. The use of the methyl mercury to total mercury ratio is examined.     

Speciation, bioavailability, and systemic distribution of chromium from Whetlerite dust

Exploratory studies were conducted to determine if chromium from Whetlerite dust is bioavailable when administered intratracheally to rats, and if so, to determine its speciation. These studies indicated that chromium in this form and by this route of administration was bioavailable and was found in the trivalent state only. Less than 25% of the administered dose was recovered after 4 h, suggesting that most of the chromium was rapidly absorbed, distributed, and eliminated. Most of the chromium was found in the lungs and kidneys. The time course in the kidney suggests that this organ may be involved in the metabolism and elimination of trivalent chromium. Unexpected mortality in the experimental group of rats may have been due to the copper content of the Whetlerite, which exceeded the LD50 in the dose administered.     

Speciation of phosphorus fractionation in river sediments by explanatory data analysis

This article investigates the controls on sediment phosphorus (P) speciation dynamics as a function of its fractionation into chemically defined operational pools along a river continuum. A total of 27 variables were analyzed in bed sediment samples collected for one year from six sampling points, along a 75km river continuum (Louros River, NW Greece). Multivariate explanatory analysis of the complex experimental data matrix was performed in order to unravel the spatial pattern of P speciation. Non-parametric examinations were also applied in order to elucidate the temporal variations encountered in the speciation of P. The results suggest that inorganic P species control P bioavailability in space and time. Organic P was found to be very reactive among the various fractions thus changing its bioavailability but exhibited no temporal variation. The utility of the proposed approach in the differentiation of natural and anthropogenic P inputs and their classification to point and non-point sources is demonstrated presenting a significant improvement compared to mere fractionation analysis.     

Total mercury distribution in sediment cores from Kuwait Bay

Five sediment cores from Kuwait Bay were taken in order to study the present distribution of total mercury (THg) in the vicinity of the Salt and Chlorine Plant (SCP) operated in the 1963–1985 period. The THg concentration profiles were also determined in four sediment cores from the northern part of Kuwait Bay. Additionally, average THg contents were measured in the surface layer (40 cm) of five sediment samples in the entrance of Kuwait Bay, in order to compare the present Hg levels in other parts of this reservoir. The cores were dated by ²¹⁰Pb method. The observed contents of mercury were in the range of 35 to 2000 µg/kg dry weight (ppb). Thus, the bottom sediments in these three areas of Kuwait Bay are still contaminated by Hg. In a few cases, the depth concentration profiles of THg were disturbed as an effect of partial mixing of the sediment layers, especially in the shallow, northern part of Kuwait Bay. This suggestion was supported by the results of additional measurements of the anthropogenic ¹³⁷Cs profiles in the same cores.     

Biomonitoring of mercury in the Kastela Bay using transplanted mussels

Kastela Bay, located on the central part of east Adriatic coast, is heavily contaminated by mercury. The main source of contamination was a chlor-alkali plant, which was operating for 40 years since 1949. Previous studies showed that mercury concentrated in the sediment close to the plant is being dispersed throughout the bay by remobilization processes. Subsequent remobilization of mercury buried in the sediment may be harmful to various marine organisms. In order to assess the availability of remobilised mercury to marine organisms and to assess the health risk of consumption of shellfish species from the bay, a monitoring programme was initiated in September 1997. One thousand six hundred specimens of mussels (Mytilus galloprotincialis) of the same size and age, collected in a very clean area, were transferred to four stations in the bay 1.5 m above the sea bottom. Every month during the summer period and every second month in the winter period, 50 mussels were taken from each station for the analysis of mercury and monomethylmercury (MeHg) content. The results obtained during 1 year of biomonitoring suggest that the equilibrium concentration in transplanted mussels was established in a relative short period of time. The digestive gland is preferential organ for the accumulation of total mercury. Seasonal variation of mercury content both in the whole soft tissue, and organs (gills and digestive gland) was observed at all stations. However, methyl mercury is more concentrated in soft tissues than in digestive gland and gills, despite the fact that it is absorbed through these organs. The mercury levels in tissues were below accepted limits for human consumption. Obtained results showed that the implantation of mussels in an area containing sediment contaminated by mercury may be a good monitoring tool for the assessment of the availability of remobilised mercury to marine organisms.     

大连市皮口海域口虾蛄群体繁殖生物学特征初步研究

为了解大连市皮口海域口虾蛄Oratosquilla oratoria群体的繁殖生物学特征,于2014年5月—2015年4月,每月中旬对皮口海域口虾蛄群体进行随机取样,采用组织学和电镜技术对其性腺发育规律和生殖细胞发生过程进行了初步研究。结果表明:除7月份以外,其他月份的雌、雄口虾蛄比例与期望值1∶1之间均无显著性差异(χ2=0.500,P>0.05);口虾蛄雌、雄性比为0.79~1.34,全年雌、雄性比平均为1.04±0.05,雌、雄性腺周年发育变化趋势类似,雄性发育略快,性成熟高峰期均有2个,雌性在5月和11月达性成熟高峰期,而雄性在4月和11月达性成熟高峰期;口虾蛄卵子发生过程分为卵原细胞、初级卵母细胞、次级卵母细胞、卵黄形成前期细胞、卵黄形成期细胞、早期成熟期卵细胞和成熟期卵细胞,卵巢发育分为未发育时期、卵母细胞期、生长前期、生长中期、生长后期、成熟前期、成熟期和恢复期;精子的发生过程分为精原细胞、精母细胞和精子,精巢发育分为精原细胞期、精母细胞期、早期精子期和精子期。本研究结果可为口虾蛄繁殖生物学的深入研究奠定理论基础,并为早日实现口虾蛄栖息地养护及人工增养殖提供参考。     

Spatial variations of mercury in sediment of Minamata Bay, Japan

Mercury-contaminated effluent was discharged into Minamata Bay from a chemical plant over a period of approximately 40 years until 1968. In October 1977, the Minamata Bay Pollution Prevention Project was initiated to dispose of sedimentary sludge containing mercury concentrations higher than 25 mg kg(-1). In March 1990, the project was completed. In an effort to estimate current contamination in the bay, the vertical and horizontal distributions of mercury in sediment were investigated. Sediment core samples were collected on June 26, 2002 at 16 locations in Minamata Bay and Fukuro Bay located in the southern part of Minamata Bay. The sediment in Fukuro Bay had not been dredged. The total mercury concentration in surface sediment was 1.4-4.3 mg kg(-1) (2.9+/-0.9 mg kg(-1), n=9) for the dredged area of Minamata Bay and 0.3-4.8 mg kg(-1) (3.6+/-1.6 mg kg(-1), n=4) for Fukuro Bay. In the lower layers of long cores taken from both areas, the total mercury concentration decreased with depth and finally showed relatively uniform low values. These values can be considered to represent the background concentration absent of anthropogenic influence, which was estimated for the study area to be 0.068+/-0.012 mg kg(-1) (n=10). From the surface, the total mercury concentration in Fukuro Bay increased with depth and reached a maximum at 8-14 cm. In Minamata Bay, several centimeters from the surface the total mercury concentration did not change significantly having considerably higher values than the background level. At six stations, the methylmercury concentration was determined. Although the vertical variations were similar to those for total mercury, Fukuro Bay sediment showed a higher concentration of methylmercury than Minamata Bay sediment.