Assessment of nutrients and heavy metals enrichment in surface sediments from Taihu Lake,a eutrophic shallow lake in China

Concentrations of the nutrients (TN and TP), phosphorus fractions and heavy metals (Co, Cr, Cu, Mn, Ni, Pb, Sr, Ti, V, Zn and Hg) in 40 surface sediment samples collected from Taihu Lake, a eutrophic shallow lake in China, were determined. The results showed that the northwest region of the lake possessed higher concentrations of TN and TP, as well as the similar spatial distribution trend in the water column. This should be related to excessive anthropogenic input from industrial effluents and domestic sewage in surrounding areas. Similarly, the concentrations of P fractions exhibited significant regularity. In addition, except for Sr showing low concentration, the rest of the heavy metals in the surface sediments had two- to four-folds of magnitude of the concentrations compared with the reference values in earth's crust. In the past decade, concentrations of heavy metals had undergone different levels of variations. Principal component analysis (PCA) and enrichment factors (EFs) of the compositional data aiming at heavy metals showed that Taihu Lake was slightly exposing to heavy metal contamination except Sr. High concentrations of heavy metals were ascribed to the discharge of untreated and partially treated industrial waste water via rivers. Co, Cr, Cu, Mn, Ni, Pb, V and Zn positively correlated with each other (R = 0.78–0.92), that indicated they had analogous sources and/or kindred geochemistry characteristics. Differing from nutrients, randomness in the space indicated that heavy metals had a complex distribution.     

太湖地区“禁磷”措施的效果及在富营养化控制中的作用

通过太湖地区采取“禁磷”措施前后城市生活污水、主要入湖河水和湖体水域中磷浓度与富营养化指数变化的分析 ,证实“禁磷”措施对降低居民生活污水中磷浓度的作用较为明显 ,降幅为 2 4 %左右 ,但对入湖河道和湖体水域中磷浓度与水体富营养化的影响则不明显。表明太湖富营养化的改善 ,除了实施“禁磷”措施外 ,尚需结合流域内其它污染治理措施 ,进行综合治理 ,才能取得较好的效果。     

Fractionation of heavy metals in surface sediments of Taihu Lake, East China

The BCR (European Communities Bureau of Reference) three-step sequential extraction procedure was applied to fractionate heavy metals in the sediment of Taihu Lake. For the determination of total metal concentration of the sediments, sample digestion was achieved by using HF/H2O2/HNO3 (2/1/1) acid mixture in a microwave-irradiated closed vessel system. The concentrations of Cd, Ni, Cr, Zn, Cu and Pb in various extracts solutions were analyzed by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The results obtained from the BCR three-step sequential extraction indicated relatively high mobility of Zn, Cu, Pb and Ni in the sediments while Cd and Cr were poorly mobile. Enrichment of heavy metals was found in the sediments collected in the northern parts of Taihu Lake. In the sediments collected in the southern and western sides of the Lake, heavy metal concentrations were relatively low. The relationship between total organic carbon (TOC) and heavy metals concentrations in the sediments is discussed.     

城市湖泊表层沉积物中的重金属污染现状及其风险评价——以武汉墨水湖为例

水体沉积物中的重金属会对生态系统构成直接和间接的威胁.为了研究工业化、城市化过程中城市湖泊沉积物重金属污染现状及其暴露风险，以武汉市墨水湖为研究对象，测定了5种重金属Zn、Cu、Ni、Pb及Cr在表层沉积物中的含量，分析了其污染程度、分布特征，并对其稳定度进行了分析.结果表明，墨水湖表层沉积物重金属污染程度较重，在所有采样点5种重金属含量均高于最低效应阈值（LEL），多数采样点甚至超过了严重效应阈值（SEL）.该湖泊沉积物中重金属分布具有比较明显的空间差异性：排污口区>湖中心水域>城区岸边带>林田岸边带；其稳定程度依次为：Zn < Cu < Ni < Pb < Cr，其中Zn交换态及碳酸盐结合态比例超过50%，稳定程度极低.而Pb、Cr稳定程度较高，其交换态及碳酸盐结合态比例小于10%.像墨水湖这样受纳高污染负荷市政污水、暴雨径流的城市湖泊，其潜在的重金属生物活性，必须引起足够的重视.     

城市湖泊表层沉积物中的重金属污染现状及其稳定度分析——以武汉墨水湖为例

水体沉积物中的重金属会对生态系统构成直接和间接的威胁.为了研究工业化、城市化过程中城市湖泊沉积物重金属污染程度,以武汉市墨水湖为研究对象,测定了5种重金属Zn、Cu、Ni、Pb及Cr在表层沉积物中的含量,分析了其污染程度、分布特征,并对其稳定度进行了分析.结果表明,墨水湖表层沉积物重金属污染程度较重,在所有采样点5种重金属含量均高于最低效应阈值(LEL),多数采样点甚至超过了严重效应阈值(SEL);该湖泊沉积物中重金属分布具有比较明显的空间差异性:排污口区>湖中心水域>城区岸边带>林田岸边带;其稳定程度依次为:Zn相似文献   

Fractionation of Heavy Metals in Surface Sediments of Taihu Lake, East China

The BCR (European Communities Bureau of Reference) three-step sequential extraction procedure was applied to fractionate heavy metals in the sediment of Taihu Lake. For the determination of total metal concentration of the sediments, sample digestion was achieved by using HF/H₂O₂/HNO₃(2/1/1) acid mixture in a microwave-irradiated closed vessel system. The concentrations of Cd, Ni, Cr, Zn, Cu and Pb in various extracts solutions were analyzed by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The results obtained from the BCR three-step sequential extraction indicated relatively high mobility of Zn, Cu, Pb and Ni in the sediments while Cd and Cr were poorly mobile. Enrichment of heavy metals was found in the sediments collected in the northern parts of Taihu Lake. In the sediments collected in the southern and western sides of the Lake, heavy metal concentrations were relatively low. The relationship between total organic carbon (TOC) and heavy metals concentrations in the sediments is discussed.     

洞庭湖主要入湖口表层沉积物重金属分布特征与生态风险评价

尽管针对洞庭湖沉积物中重金属的研究工作较多,但缺乏针对其主要入湖口的研究。基于2014年12月和2015年6月对洞庭湖主要入湖口表层沉积物中重金属调查,分析了重金属含量的时空分布特征,并采用一致性沉积物质量基准法对其生态风险进行了评价。结果表明,Cd、Hg、As、Cu、Pb和Zn的平均含量分别为3.27、0.190、27.10、39.8、38.0和157.8 mg·kg-1,其大小顺序为ZnCuPbAsCdHg,Cd和As含量出现超过土壤环境质量三级标准的现象,是主要的重金属污染物。Cd、As、Pb和Zn等4种重金属含量的最高值均出现在湘江入湖口,Cu含量的最高值出现在资水入湖口,Hg含量以沅江入湖口最高,除Pb外,其他5种重金属在湘江和资水入湖口的含量均大于平均值,表明湘江和资水入湖口污染较为严重;汛期与非汛期6种重金属的含量均无显著性差异(P0.05)。6种重金属生态风险大小顺序为AsCdZnPbCuHg,各入湖口生态风险大小顺序为湘江入湖口资水入湖口沅江入湖口汨罗江入湖口澧水入湖口长江"三口"新墙河入湖口,其中湘江和资水入湖口为较高生态风险,其他入湖口为较低生态风险。入湖河流是洞庭湖湖体沉积物重金属污染的主要来源,在一定程度上,入湖河流沉积物中重金属的含量对洞庭湖湖体沉积物中重金属污染状况起着决定性作用,因此,洞庭湖流域重金属污染防控应以入湖河流为主,其中尤以湘江和资水为重点。     

Geochemical baselines of heavy metals in the sediments of two large freshwater lakes in China: implications for contamination character and history

The aim of this study was to estimate the geochemical baseline concentrations of various heavy metals in the surface sediments of two large freshwater lakes in Taihu and Dianchi, China, and to assess the character and history of heavy metal contamination around the two lakes. Heavy metal concentrations in the sediments were obtained by field surveys and were supplemented with published data. The statistical methods of cumulative frequency and normalization were employed to obtain the baselines. The respective baseline concentrations for As, Sb, Hg, Co, Cr, Cu, Ni, Pb and Zn were 9.92, 1.67, 0.14, 22.62, 100.56, 31.63, 31.97, 33.05 and 97.01?mg/kg, respectively, in Taihu, and 24.60, 4.29, 0.25, 36.78, 135.68, 90.05, 50.76, 73.56 and 208.76?mg/kg, respectively, in Dianchi. The baseline concentrations of these heavy metals in Lake Taihu were equivalent to the pre-industrial concentrations determined from lakes in Sweden and Europe. Conversely, those in Lake Dianchi were much higher than the pre-industrial values. Li, Fe, Sc, Ti, V and Al were found to be the suitable reference elements for normalization, and one of these elements could be used to predict the baseline concentrations of heavy metals except Hg. Most of the heavy metals had one inflexion, and only Cu and Pb in Taihu, Sb, Pb and Zn in Dianchi, were found to have two inflexions in the cumulative curves, suggesting remarkable anthropogenic inputs of Cu and Pb in Taihu, Sb, Pb and Zn in Dianchi, which are generally consistent with the respective industrial structure around Taihu and Dianchi.     

Heavy metal pollution in various canals originating from river Yamuna in Haryana

Heavy metal pollution due to Fe, Ni, Pb, Cd, Co and Zn in the water of major canals originating from the river Yamuna in Haryana was studied. All these metals except Zn were found to be present in the Western Yamuna Canal (WYC) exceeding the maximum permissible limits. In the Sunder branch (SB), the heavy metal concentration was relatively more. Concentrations of the metals were, however, relatively less in the highly eutrophicated waters of Agra canal and Gurgaon canal as compared to that in WYC but Fe concentration were much higher. Except Zn and Ni the metal concentrations exceeded the standard permissible limits in these canals also.     

Human health ambient water quality criteria for 13 heavy metals and health risk assessment in Taihu Lake

• The concentrations of 13 heavy metals in Taihu Lake were analyzed. • Aquatic vegetables intake was first included in deriving human health AWQC. • The human health AWQC for 13 heavy metals in Taihu Lake were derived. • Human health risk assessment for 13 heavy metals were conducted in Taihu Lake. Heavy metals are widely concerning because of their toxicity, persistence, non-degradation and bioaccumulation ability. Human health ambient water quality criteria (AWQC) are specific levels of chemicals that can occur in water without harming human health. At present, most countries do not consider the effects of aquatic vegetables in deriving human health AWQC. Therefore, the intake of aquatic vegetables (Brasenia schreberi) was added to the derivation of human health AWQC and a health risk assessment for 13 heavy metals in Taihu Lake. The human health AWQC (consumption of water, fish and aquatic vegetables) values of 13 heavy metals ranged from 0.04 (Cd) to 710.87 μg/L (Sn), and the intake of B. schreberi had a very significant effect on the human health AWQC for Cu, with a more than 62-fold difference. The hazard quotients of As (2.8), Cd (1.6), Cr (1.4) and Cu (4.86) were higher than the safe level (HQ= 1), indicating that As, Cd, Cr and Cu in Taihu Lake posed a significant health risk. Sensitivity analysis showed that the contribution rate of B. schreberi intake to the human health risk from Cu was 91.6%, and all results indicated that the risk of Cu in B. schreberi to human health should be of particular concern. This study adds the consideration of aquatic vegetable consumption to the traditional method of human health AWQC derivation and risk assessments for the first time, and this approach can promote the development of risk assessments and water quality criteria.     

Assessment of physico-chemical properties and metal contents of water and sediments of Bodo Creek,Niger Delta,Nigeria

Some physico-chemical properties and the concentrations of the metals Fe, Mn, Ni, Cd, Cr, Co, Cu, Pb, and Zn in water and sediments were examined from September 2011 to January 2012 in Bodo Creek, where oil spills have been recurrent. Temperature, pH, total dissolved solid, conductivity, salinity, dissolved oxygen, biological oxygen demand (BOD), chemical oxygen demand (COD), total hardness, sulfate, nitrate, and phosphate were determined in surface water. Particle size, total organic matter (TOM), and pH were also determined in the sediments. The parameters were within permissible limits except the mean values of BOD, COD, total hardness, and sulfate that exceeded levels permissible for domestic use. The sediments consisted mainly of sand, with TOM ranging from 0.2% to 5.5%. With the exception of cadmium that was below detection limit, metal levels (mg kg^?1) in the sediments were 12 (Mn), 1070 (Fe), 10 (Cu), 10 (Zn), 5.3 (Cr), 1.1 (Pb), 1.0 (Ni), and 0.5 (Co) while in water they were 24, 98, 21, 6.9, 4.0, 0.6, 0.18, and 0.16, respectively. The latter were higher than World Health Organization recommended permissible levels for both surface and drinking water.     

太湖典型河网区地表水与沉积物氮、磷和重金属含量空间分异

将无锡城乡交错区河网分为城镇生活区水巷、工业区主河道、农业区主河道、农业区支流和鱼塘5种类型区.通过秋季(旱季)和夏季(雨季)2次采样,研究氮、磷和Cu、Zn、Pb、Cr、Cd在地表水和沉积物中的含量及其空间变化.结果表明:(1)城乡交错区地表水氮、磷来源于生活污染和工业污染的比例大于农田,同时具有来源分散、污染面广的特征.(2)由于城镇地表径流和工业活动影响,各类型区地表水重金属含量均有不同程度提高.但地表水重金属主要沿主河道迁移,旱季和雨季主河道重金属含量均大于农业区支流,而且随着与城镇距离增加,主河道沉积物重金属含量迅速降低,重金属污染影响范围较小.(3)与重金属相比,地表水氮、磷污染仍是太湖水网区主要的环境问题.但城镇及其周围河流沉积物中富集的重金属含量很高,其潜在环境风险不容忽视.     

Quantitative characterization of Cu binding potential of dissolved organic matter （DOM） in sediment from Taihu Lake using multiple techniques

Dissolved organic matter （DOM） plays an important role in heavy metal speciation and distribution in the aquatic environment especially for eutrophic lakes which have higher DOM concentration. Taihu Lake is the third largest freshwater and a high eutrophic lake in the downstream of the Yangtze River, China. In the lake, frequent breakout of algae blooms greatly increased the concentration of different organic matters in the lake sediment. In this study, sediment samples were collected from various part of Taihu Lake to explore the spatial difference in the binding potential of DOM with Cu. The titration experiment was adopted to quantitatively characterize the interaction between Cu（II） and DOM extracted from Taihu Lake sediments using ion selective electrode （ISE） and fluorescence quenching technology. The ISE results showed that the exogenous DOM had higher binding ability than endogenous DOM, and DOM derived from aquatic macrophytes had a higher binding ability than that derived from algae. The fluorescence quenching results indicated that humic substances played a key role in the complexation between DOM and Cu（II） in the lake. However, because of the frequent breakout of algae blooms, protein-like matters are also main component like hnmic matters in Taihu Lake. Therefore, the metals bound by protein-like substances should be caused concern as protein-like substances in DOM were unstable and they will release bound metal when decomposed.     

Organophosphate esters in sediment from Taihu Lake,China: Bridging the gap between riverine sources and lake sinks

• Eleven OPEs were detected in river sediment and lake sediment in Taihu Lake. • TnBP dominated in river sediment, while TBEP dominated in lake sediment. • A strong correlation existed between logK_oc and logK_ow of OPEs. • Vertical profiles of OPEs in sediment cores varied according to sampling location. Surface sediment samples from Taihu Lake in China and its inflow rivers, along with two lake sediment core samples, were collected and analyzed for organophosphate esters (OPEs). The concentrations of total OPEs varied from 28.60 ng/g to 158.72 ng/g (median: 54.25 ng/g) in river surface sediment and from 62.57 ng/g to 326.84 ng/g (median: 86.37 ng/g) in lake sediment. Tributyl phosphate (TnBP) was the predominant compound in river surface sediment, and tris(2-butoxyethyl) phosphate was predominant in lake sediment. High contamination occurred in the north-west region, which was related to the high level of urbanization and high usage of OPEs. The sediment–water partition coefficients of OPEs (logK_oc) were calculated, showing a significant correlation with logK_ow (p<0.05). The concentration and composition of OPEs in two sediment cores varied due to the different sampling locations, with more OPE species found in the northern region than in the southern one. Principal component analysis and positive matrix factorization indicated that sewage discharges, vehicle emissions, and atmospheric deposition were the possible sources of OPEs in Taihu Lake sediments. Tris(1-chloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, and TnBP were the main OPEs causing ecological risks.     

人为活动对城市湖泊沉积物重金属污染的影响——以武汉墨水湖为例

人类活动使得大量的重金属向水环境中排放,导致了城市湖泊严重的重金属污染.为了研究中国的工业化、城市化发展对城市水体重金属污染的影响,以武汉墨水湖为例,测定了沉积物中几种常见痕量重金属Zn、Pb、Ni、Cu、Cr的含量和富集系数,并运用主成分分析对重金属的污染来源进行了初步探讨.结果表明,墨水湖表层沉积物重金属污染程度较重,主要受人为输入的影响;5种重金属在全湖区域上具有比较高的富集系数,尤以排污口为甚,排污口是重金属富集的主要区域.主成分分析表明,Pb可能主要来自于暴雨径流面源,而Cr可能主要来自于工矿企业的点源排放,其他3种金属则有着大小相当的点、面源输入贡献。以上结果表明,城市化和工业化进程已经给城市湖泊带来了很高的重金属污染负荷.     

太湖水华蓝藻中元素的组成及其环境意义

利用电感耦合等离子质谱仪对2008年7、9和10月采自太湖南泉水域的水华蓝藻样本中19种元素(Na、Mg、K、Ca、Zn、Mn、Fe、Al、Cu、Cr、Co、Ni、As、Se、Mo、Ag、Tl、Cd和Pb)的质量含量(w)及组成变化进行研究。结果表明,在藻华中w较高(1 000μg.g-1,以干质量计)的常量元素或有益元素为Ca、K、Na、Mg、Al、Fe。其中,w(Ca)和w(K)较高(4 000μg.g-1),w(Ca)随月份变化不大,而w(K)、w(Mg)、w(Na)则逐月升高。w(Al)、w(Fe)变化较大,7月最高(1 000μg.g-1),之后迅速降低(400μg.g-1);藻华中w在10~100μg.g-1之间变化的元素为Mn、Zn、Ni、Cu,其中,7月这4种元素w均最高,9~10月则降低。藻华中还检出痕量元素Co、Mo和Se,Tl未检出。藻华中积累的有毒元素中w(As)较高(5~15μg.g-1),而w(Cr)、w(Cd)、w(Pb)、w(Ag)均较低(5μg.g-1)。有毒元素w最高值均出现在7月。基于上述结果,推算出2007—2009年采取物理方法除藻从太湖中移除的元素量约为:K595.89 t、Ca 544.03 t、Mg 181.18 t、Al 83.06 t、Na 63.97 t、Fe 55.45 t、Mn 2.99t、Zn 2.26 t、Ni 1.67 t、Cu 1.11 t、As 0.76 t、Cr 94.5 kg、Cd 82.70 kg、Se 45.01 kg、Pb 37.64 kg、Co 32.27 kg、Mo5.41 kg和Ag 2.46 kg。该研究不仅可为进一步寻找关键元素在蓝藻水华爆发过程中的限制作用及其机制提供基础数据,同时也可为评价利用物理除藻方法去除太湖中有毒元素和降低有可能促进藻华发展的营养元素的负荷量的有效性,从而保护和修复渔业环境提供理论依据。     

Impact of urbanization on Bellandur Lake, Bangalore--a case study

Lake and river water is the prime source for drinking, irrigation and other domestic purposes. Bellandur Lake is one of the major Lakes of Bangalore city. The addition of effluents from urbanized Bangalore city has changed the characteristics of the Lake from being a natural ecologically healthy Lake to an artificial reservoir of domestic sewage and industrial effluents. The DO of the Bellandur Lake water ranged from 3.8-6.3 mg/l. The Bellandur lake water BOD ranged from 89-99 mg/l due to absorption of pollutants by aquatic flora in lake system. If the present state of affairs continues for long, the Bellandur Lake may soon become an ecologically inactive Lake.     

淀山湖上覆水与沉积物孔隙水中重金属的分布特征

研究了淀山湖上覆水和沉积物孔隙水中Pb ,Cd,Cr,Cu ,Fe和Mn的浓度及Eh 分布 ,分析了孔隙水中重金属的扩散通量 .结果表明 ,淀山湖中重金属的浓度由高到低依次为 :Mn >Fe >Cr,Cu ,Pb >Cd ;Fe和Mn在孔隙水中的浓度远远大于它们在上覆水中的浓度 ,表层沉积物孔隙水中Pb ,Cd ,Cr,Cu的浓度稍大于它们在上覆水中的浓度 ;沉积物中的重金属可能按照浓度梯度经孔隙水从沉积物向上覆水中扩散而最终影响上覆水的水质     

Metal accumulation in sediment,water, and freshwater fish in a Dam Lake

Metal concentrations were determined in water, sediment, and freshwater fish samples (Squalus cephalus, Barbus esocinus, and Barbus xanthopterus) collected from Karakaya Dam Lake, Turkey, to estimate the risk of human consumption and pollution. Metal concentrations differed between the species (p??Zn?=?Cu in water and Fe?>?Zn?>?Mn?>?Ni?>?Cu in sediment. In general, the accumulation order of elements in the tissues all of the species sampled were found as Fe?>?Zn?>?Se?>?Mn?>?Cu?>?Ni?>?Cd in muscle, Zn?>?Fe?>?Mn?>?Se?>?Cu?>?Ni?>?Cd in gills, Fe?>?Zn?>?Se?>?Mn?>?Cu?>?Ni?>?Cd in liver and gonad, and Zn?>?Fe?>?Cu?>?Mn?>?Se?>?Ni?>?Cd in kidney. It was concluded that the fish from the dam lake are not heavily burdened with metals, but they should be controlled periodically to avoid excessive intake of trace metals by humans, and to monitoring the pollution of aquatic environment.     

Spatial distribution and ecological risk assessment of heavy metals in surface sediments from a typical plateau lake wetland, China

Surface sediment (0-15 cm) samples were collected from 31 different grid points throughout the Yilong Lake in April 2004. Samples were subjected to a total digestion technique and analyzed for As, Cd, Cr, Pb, Ni, Cu, and Zn in order to study spatial distribution characteristics based on Kriging method and assess their ecological risks posed by these heavy metals. Results showed that the mean concentrations of these heavy metals were lower than potential effect levels. Patches of higher heavy metal concentrations occurred in the inflow area of the Cheng River and northeast area nearby the road and railway. The higher concentrations of As and Cr also appeared in the east area (lake outlet), while the patches of lower concentrations were uniformly distributed at the southwest corner between Luosewan and Xiaoguoxi. The heavy metal loads such as As, Cd and Pb might come from the common sources due to industrial sewage and traffic pollution, while higher concentrations of Ni, Cr, and Zn in these sediments were dominated by parent rocks. However, Cu originated from both sources. Sediments with respect to As, Cd and Cu were grouped below the effect range low (ERL) at all sites, and with respect to Cr and Pb were grouped into the range from ERL to the effect range median (ERM) at more than 50% of sampling sites. The mean heavy metal toxic units in the Yilong Lake decreased following the order Pb > Cr > As > Ni > Zn > Cd > Cu, with higher contributions to the sum of toxic units of Pb, Cr and As.