Pollution shapes the microbial communities in river water and sediments from the Olifants River catchment,South Africa

Archives of Microbiology - Human activities such as agriculture and mining are leading causes of water pollution worldwide. Individual contaminants are known to negatively affect microbial...     

Concentrations of zinc in Barbus marequensis from the lower Olifants River, Mpumalanga, South Africa

Zinc was detected in all the tissues examined, but in variable concentrations. The highest zinc concentrations were detected in the skin and ovaries. These zinc concentrations also differed significantly from the concentrations in the other tissues. The bioaccumulation pattern of zinc in the fish was determined as: skin >ovaries>liver>gills>vertebrae>testes>hindgut>foregut contents >kidney=foregut>hindgut contents>muscle>blood>fat>bile.Although significant differences (P<0.05) between localities were detected no clear trend as to where the highest bioaccumulation had occurred, could be established. Significant seasonal differences were detected, but it was not always the same tissue that indicates these seasonal differences. The zinc concentrations detected in the fish suggest no serious zinc pollution in the lower Olifants River. Zinc levels detected in some of the tissues might indicate chronic exposure, causing possible sub-lethal effects. However, this should be investigated before final conclusions can be made.     

Bioaccumulation of selected metals in the gill,liver and muscle tissue of rednose labeo Labeo rosae from two impoundments on the Olifants River,Limpopo river system,South Africa

Metal concentrations in the gill, muscle and liver tissues of Labeo rosae from two impoundments, Loskop and Flag Boshielo dams on the Olifants River, were evaluated in 2011 to detect patterns in metal associations between tissues and impoundments. Elevated concentrations of Ba, Zn, B, Al, Si and Fe, relative to a pristine site in the catchment, were found in the muscle, liver and gill tissues at both impoundments. Molybdenum concentrations were exceptionally high in all tissues at Loskop Dam and in liver at Flag Boshielo Dam. No definite pattern in the ratio metal concentrations within, or between, fish tissues was identified. The expected trend, liver > gills > muscle, was found at both impoundments, but was less prominent at Loskop Dam. Metal concentrations in muscle of Loskop Dam fish were significantly higher than in those at Flag Boshielo Dam. The inverse was true for liver. The long-term impact of elevated metal concentrations on fish health at both impoundments raises concern.     

广西锰矿恢复区食用农作物重金属污染评价

对广西平乐、荔浦两锰矿恢复区种植的食用农作物进行了调查和重金属含量分析.结果表明:两锰矿区农作物Zn、Pb、Cr、Cu和Cd的含量范围分别在1.18~20.46、0.52~16.16、0.33~6.62、0.01~6.24和0.01~2.76mg.kg-1之间.其中,豆类作物中的重金属含量最高,其次是薯类.单因子污染指数评价表明,农作物基本未受Zn、Cu污染,但受Pb、Cd和Cr污染严重,以Pb污染最重,受污染率达100%,Cr和Cd受污染率分别为96.9%和75.0%;从综合污染指数来看,农作物受污染率达100%,其中,重、中、轻污染分别占87.5%、9.4%和3.1%.表明在锰矿废弃地直接种植食用农作物存在较大风险,应重新考虑其恢复利用模式.     

Phytoplankton Distribution in the Coastal Area Subject to the Impact with the Tiber River Outfall

The taxonomic composition and geographical distribution of phytoplankton in the coastal zone surrounding the River Tiber mouth were investigated in twelve surveys from April 1978 to September 1979. Ninety phytoplankton species were identified from 168 samples. Diatoms were clearly the dominating species, accounting for more than 95 per cent of total phytoplankton.— Principal Component Analysis was utilized to analyse the total information obtained.—The direct impact on the coastal environment of River Tiber water and its considerable nutrient load were seen as providing a permanent potential for the development of less structured phytoplankton communities. Heterogeneity of local hydrological conditions and fluctuations in the river's impact, lead to a virtually constant instability in the neritic environment near the Tiber River outfall.     

Application of multivariate statistics and toxicity indices to evaluate the water quality suitability for fish of three rivers in the Kruger National Park,South Africa

The water quality of the Olifants, Letaba and Luvuvhu rivers within the Kruger National Park was assessed for their suitability to sustain fish populations. Since water quality assessments result in huge datasets, principal component analysis and an aquatic toxicity index (ATI) were employed to reduce these to more manageable indices. Water quality changed over time, with metal concentrations decreasing, and high flows resulted in increased concentrations of suspended metals. The ATI indicated that metals had no major effect on lowering index values in any of the rivers, and that these values were affected by turbidity in both the Olifants and Letaba rivers, whilst nutrients such as ammonium and orthophosphates negatively affected index scores in the Luvuvhu River. Water quality has improved from the 1990s to 2011.     

Fractionation,mobility and multivariate statistical evaluation of metals in marine sediments of Cape Town Harbour,South Africa

Abstract

Distribution of possible chemical forms of Al, Si, Sn, Pb, Zn, Fe, Hg, Cd and Cu in marine sediments of Cape Town harbour was investigated using a modified Tessier’s sequential extraction procedure and ICP-MS and ICP-AES for heavy metals determination. The mean fractions for all metals at all locations were: 1.5–7196 mg kg^-1 for Si, 7.79–7266 mg kg^-1 for Al, 161-639 mg kg^-1 for Cu, 19–41978 mg kg^-1 for Fe, 2.83–5864 mg kg^-1 for Zn, 1.45–13.26 mg kg^-1for Cd, 9.87–223 mg kg^-1 for Sn, 11.98-979 mg kg^-1 for Pb and 0.13–5.93 mg kg^-1 for Hg. Si, Al and Zn were mostly associated with Fe–Mn oxides, whereas Sn and Hg were mainly bound to residual and organic matter. Pb existed mainly in the residual and iron/manganese oxide phases while Cd was evenly distributed in all the five phases. The loading plots of heavy metals bound to the various chemical forms, as well as Pearson correlation coefficients, enabled the determination binding relationship. Pb, Sn and Hg exhibited similar binding behaviour which indicated an anthropogenic point source from wastes from the ship maintenance workshop, and the presence of Sn in the organic phase can be identified with the use of anti-fouling paints at the harbour, whereas Al, Fe, Si, Cu and Zn would probably be of natural origin. Lastly Cd probably came from a diffuse pollution sources in the harbour due to its unique binding characteristic. The mobility of heavy metals varied depending on location and the heavy metal type. The mobility of metals followed the order: Si > Zn > Fe > Cu> Al> Cd> Pb > Sn > Hg. The high percentage of Cd and Pb in the bioavailable forms suggested the need to keep close surveillance on these metals because of their high toxicity.     

Metal contamination and human health risk associated with the consumption of Labeo rosae from the Olifants River system,South Africa

The Olifants River, a tributary of the Limpopo River system, is one of the most polluted rivers in South Africa. In May 2011 the concentrations of metals in fish muscle tissue from two impoundments, Loskop and Flag Boshielo dams, on the Olifants River were measured and a human health risk assessment conducted to investigate whether it was safe to consume Labeo rosae from these impoundments. Labeo rosae is one of the most common pan fish in these impoundments and is readily available to rural communities. Metals are accumulating in the muscle tissue of L. rosae even although the fish populations appear to be healthy. At Loskop Dam all L. rosae analysed exceeded the recommended hazard quotient (HQ) of 1 for antimony, and less than 50% exceeded that for lead. At Flag Boshielo Dam, the recommended HQ was exceeded for lead in less than 50% of L. rosae analysed, and more than 50% exceeded that for antimony. The weekly consumption of 150?g of L. rosae muscle tissue from these impoundments may pose an unacceptable health risk to rural communities.     

贵阳花溪区石灰土林地土壤重金属含量特征及其污染评价

选取贵阳市花溪区典型石灰土林地土壤作为研究对象,分析了林地石灰岩和土壤中7种重金属(Cu、Zn、Mn、Cd、Ni、Pb、Co)的含量特征,以贵州省土壤背景值和全国石灰(岩)土类背景值为评价标准进行林地土壤重金属污染评价和潜在生态风险评价.结果表明:林地石灰岩以Pb的平均含量(40.21mg·kg-1)最高,Zn的(5.78 mg·kg-1)最低,7种重金属平均含量高低顺序为:Pb＞Ni＞Mn＞Co＞Cu＞Cd＞Zn;林地土壤中以Mn的平均含量(451.16 mg·kg-1以上)最高,Cd的(2.87mg·kg-1以下)最低,7种重金属含量的变异系数在8.57%～63.10%之间,Zn的平均含量明显低于贵州省土壤背景值和全国石灰(岩)土类背景值,Cu、Mn、Cd、Pb、Ni、Co的平均含量高于或接近于贵州省土壤背景值和全国石灰(岩)土类背景值.Cu、Zn、Mn、Ni、Co,Ni与Pb,Cd与Pb,Cd与Co来源相同的可能性较大,而Cd与Cu、Ni,Pb与Mn、Cu、Co的来源不同;石灰土偏碱性,富含Ca、Mg元素,有利于重金属Cd、Pb的累积.单因子污染指数和多因子综合指数(内梅罗指数法)与Hakanson潜在生态危害指数的评价结果一致,林地土壤重金属综合污染指数在3.67以上,达到重污染程度,以Cd的污染指数(4.94以上)最高,污染程度最为严重,其次是Pb(1.82以上),Zn、Mn污染程度最低,林地土壤重金属潜在生态危害指数(RI)为173.75以上,为中度生态危害程度,产生最大生态危害的是Cd,其次是Pb、Ni、Co、Cu,危害程度最小的是Mn、Zn,在相同的成土母岩和人为活动影响下,无林地土壤重金属的综合污染指数和潜在生态危害指数均明显高于有林地.     

Bioremediation of metal contamination in the Plankenburg River,Western Cape,South Africa

Three bioreactors (two laboratory-scale and one on-site) were evaluated for their efficiency to reduce metal concentrations in water collected from the Plankenburg River, South Africa. Water (bioreactors one, two and on-site) and bioballs (bioreactors two and on-site) collected throughout the study periods were digested and analysed using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Aluminium (Al), nickel (Ni), and zinc (Zn) concentrations decreased from 0.41 mg l^?1 to 0.06 mg l^?1 (85%), 0.2 mg l^?1 to 0.07 mg l^?1 (65%) and 75 mg l^?1 to 0.02 mg l^?1 (97%), respectively (bioreactor one). Aluminium [(1.55–0.38 mg l^?1 (75%)], copper (Cu) [57% (from 0.33 mg l^?1 to 0.14 mg l^?1)], iron (Fe) [71.99–40.4 mg l^?1 (44%)] and manganese (Mn) [57% (0.07–0.03 mg l^?1)] concentrations also decreased in the water samples from bioreactor two. In the on-site, six-tank bioreactor system, concentrations for Fe, Cu, Mn and Ni decreased, while Zn and Al concentrations increased. The concentrations recorded in biofilm samples were higher than the corresponding water samples. The bioballs employed in the bioreactor were thus shown to be efficient attachment surfaces for biofilm development and subsequent metal accumulation. Potentially metal-tolerant organisms (Pseudomonas sp., Sphingomonas sp., and Bacillus sp.) were also identified using phylogeny.     

Traffic-Related Heavy Metal Accumulation in Soils and Plants in Northwest China

Pollution caused by traffic activities is increasingly becoming a great threat to urban environmental quality and human health in many municipalities in Northwest China. The Sophora japonica L., a native tree species occurring widely in many regions of Northwest China, was used as a case study to assess the potential effects of traffic pollution on heavy metal accumulation in leaves of S. japonica trees and associated soils. Fifty-four leaf samples and 41 relevant soil samples (0–10 cm) were collected systematically along main trunk roads and at parks distant from main trunk roads in the city of Lanzhou, Northwest China, respectively. Traffic pollution has resulted in significant accumulation of heavy metals in both the roadside leaves and soils, but the pattern and level of accumulation varied remarkably between elements. The nine elements examined can be classified into three groups relating to their responses to traffic pollution. The first group, including Zn, Cd, Hg, Pb and Cr, showed greater accumulation in both roadside soils and leaves. The second group, including Co, Ni and As, indicated greater accumulation in the roadside leaves only. The third group included only Cu and demonstrated a greater accumulation in the roadside soils only. Overall, Zn, Cd, Hg, Pb, Cu and Cr concentrations in the roadside soils were higher (8–72%) than those in the park soils, as well as much higher (32–300%) than the background values of the respective elements set for local soils (Lanzhou). Zn, Cd, As, Hg, Pb, Cr, Ni and Co concentrations in the roadside leaves were higher (27–111%) than those in the park leaves. The differences found among elements in the levels of accumulation suggest that the relative importance of the individual elements contributing to urban environmental deterioration will vary considerably.     

Hooded Vulture Necrosyrtes monachus and African White-backed Vulture Gyps africanus nesting at the Olifants River Private Nature Reserve,Limpopo province,South Africa

Basic ecological information is still lacking for many species of African vultures. The Hooded Vulture Necrosyrtes monachus is known as a rare breeding resident in north-eastern South Africa. This study set out to monitor the nests of Hooded Vultures and, secondarily, White-backed Vultures Gyps africanus in the Olifants River Private Nature Reserve over two breeding seasons in 2013 and 2014. A total of 12 Hooded Vulture nests, placed mostly in the tree Diospyros mespiliformis, were found along the Olifants River, with an average inter- nest distance of 0.76 km. Nest success was estimated to be between 0.44–0.89 offspring pair?1 y?1 in 2013 and 0.50–0.67 offspring pair?1 y?1 in 2014, which are the first estimates for Hooded Vultures in South Africa. It is thought that nests of this species have been under-reported due to the fact that they are placed within or below the canopy of densely leafed trees and hence difficult to view from aerial surveys. African White-backed Vultures also bred along the Olifants River, with nests placed in clusters of up to six. Nesting density of this species ranged from about 1.0 to 1.2 nests km?1 and nests were predominantly placed in Ficus sycomorus trees.     

Heavy metal contamination of water and fish in peri-urban dams around Bulawayo,Zimbabwe

Urban effluents are significant sources of heavy metal pollution in fresh water. Metal contamination in dams around the city of Bulawayo, Zimbabwe, were monitored during October 2014 to assess ecological and public health risks. Heavy metals were measured in water, sediment and fish in dams located downstream of effluent discharge zones in Bulawayo and were compared to those in a pristine upstream dam. Water conductivity indicated pollution of downstream dams. Levels of lead (0.13–0.28 ppm) and cadmium (0.02–0.06 ppm) in water from downstream dams exceeded WHO safe limits for drinking water. Cadmium levels in polluted dams also exceeded the safe limit for agricultural use. Sediments of effluent-polluted dams had metal contamination factors ranging from 8.8 to 31.2 relative to the control, and fish from the dams had higher metal content and were unfit for human consumption. Metal levels were also measured along an urban stream to establish the sources of metals. The city’s industrial zone had the highest levels of metals, suggesting that industrial effluents were major sources of contamination. The environmental consequences and human health risks of the pollution of peri-urban water bodies from urban effluents are discussed.     

Contrasting genetic patterns and population histories in three threatened redfin species (Cyprinidae) from the Olifants River system, western South Africa

Differentiation occurred in different areas of the same river system in Pseudobarbus phlegethon and two sister species of the serrated redfin lineage ( Barbus calidus and Barbus erubescens ) of the Western Cape region of South Africa. In an analysis of 27 allozyme loci a deep divergence was found within P. phlegethon between the Olifants and Doring catchments (seven fixed allelic differences; 0·338 <  D  < 0·366; F _ST = 0·925). In contrast, speciation in the serrated redfin lineage occurred within the Doring catchment between B. calidus and B. erubescens (one fixed allelic difference; 0·008 <  D  < 0·052; F _ST = 0·760). Different niche preferences, behaviour and morphology probably played an important role in the formation of these contrasting patterns of genetic structure and suggest that B. calidus may have been better able to disperse between the Olifants and Doring catchments (no fixed allelic differences; 0 <  D  < 0·040; F _ST = 0·281) than P. phlegethon .     

山东省部分水岸带土壤重金属含量及污染评价

为了解山东省水岸带土壤重金属的含量特征和污染状况,于2010年9月—10月采集了39个水岸带土壤样品,分析了土壤中Cr、Co、Ni、Cu、Zn、Cd、Pb和Hg的含量以及土壤的pH值、粒度和有机质,采用单因子指数法、综合指数法和潜在生态危害指数法对水岸带土壤重金属污染进行了评价,并利用相关分析和聚类分析对其来源进行了初步的解析。结果表明：水岸带土壤的pH值为5.67—8.66,主要呈碱性;有机质的平均含量为9.39 g/kg,土壤粒度主要以砂粒和粉粒为主,其平均体积百分比分别为50.33%和38.48%,平均粒径为89.69 μm;Cr、Co、Ni、Cu、Zn、Cd、Pb和Hg的平均含量为53.03 mg/kg、10.33 mg/kg、24.96 mg/kg、18.38 mg/kg、56.13 mg/kg、0.142 mg/kg、22.48 mg/kg和0.020 mg/kg。各水岸带土壤重金属的含量均符合《土壤环境质量标准》（GB15618-1995）二级标准。以山东省土壤元素背景值为评价标准,水岸带土壤重金属总体表现为轻度污染和轻微生态风险,其中Cd和Hg是主要的污染因子,其对潜在生态危害指数的平均贡献率分别为46.8% 和33.6%。洙赵新河、廖河、门楼水库和东平湖水岸带土壤重金属污染及潜在生态危害明显高于其他水源地。源解析的结果表明：水岸带土壤重金属的含量受自然源和人为源的双重影响,人为源主要包括地表径流、工业废气、垃圾和交通运输等。     

Occurrence,distribution and possible sources of organochlorine pesticides in peri-urban vegetable soils of Changchun,Northeast China

The characterizations of residue levels and sources of organochlorine pesticides (OCPs) in soils are necessary to evaluate the potential pollution and risks of OCPs to the ecosystems and human health. A total of 51 surface soil samples were collected from peri-urban vegetable fields of Changchun and 13 OCPs were analyzed to learn the composition, spatial distribution and sources. The concentrations were in the ranges of 0.94–107.8 ng g^?1 for DDTs, 0.89–98.3 ng g^?1 for HCHs, 0.22–18.20 ng g^?1 for Chlordanes, nd–4.49 ng g^?1 for aldrin and nd–9.66 ng g^?1 for dieldrin, respectively. The total OCPs concentrations ranged from 2.44 to 177.1 ng g^?1 and the higher residues were mainly distributed in northeast and southwest sites, as well as sites along the Yitong River. According to the concentrations and detection frequencies, DDTs and HCHs were the most dominant compounds. Compositional analysis and principal component analysis suggested that DDT, HCH and chlordane in most soil samples derived from historical application except the slight fresh introduction at some locations. There exist a variety of OCPs residues in peri-urban vegetable soils of Changchun, but it is still safe and suitable for agricultural production for the most part, and some specific locations with high OCPs residues ought to be a cause for concern.     

浑河水系着生藻类的群落结构与生物完整性

以辽宁省浑河水系为研究范例,调查了全流域范围内62个样点的着生藻类群落和水环境理化特征,并应用着生藻类生物完整性评价指数(P-IBI),结合栖息地环境质量评价指数(QHEI),对浑河流域水生态系统进行健康评价.结果表明:浑河水系着生藻类群落结构具有明显的空间异质性,浑河水系的采样点可划分为4组(Group),不同组间的着生藻类群落结构、物种多度、密度和香农多样性指数均存在明显差异.典范对应分析(CCA)结果显示,驱动浑河着生藻类群落结构形成的水环境因子为铵氮( NH4+-N)和活性磷(PO43--P).P-IBI和QHEI在浑河水系某些河段上的评价结果有较大出入,但从全流域尺度上看,P-IBI和QHEI的评价结果基本一致,表现为浑河上游的苏子河健康状况较好,而上游的浑河以及中下游的浑河干流健康状况较差.     

漓江水陆交错带土壤理化性质及其分布特征

水陆交错带是水生生态系统与陆地生态系统之间的过渡带,是一种典型的生态交错区,承载着能量流动、物质循环和信息交换的重要作用。土壤作为水陆交错带系统的重要组成部分,是水陆交错带功能实现的基础之一。鉴于此,以桂林漓江水陆交错带纵向梯度(上游、中游、下游)不同植被覆盖条件下的土壤为研究对象,采用野外取样调查、实验分析与统计检验相结合,系统的分析了土壤理化性质及其分布特征,旨在为该区域退化生态系统恢复与重建提供依据。结果表明:11个土壤理化性质,其中5个指标(土壤含水量、全氮、全磷、速效氮和速效钾)在上游、中游和下游均差异性显著。不同梯度下的土壤理化性质的相关性及相关性大小也不尽相同,但在总体上存在一些较相似的变化规律,如上游、中游和下游的土壤容重和孔隙度均呈现显著负相关,土壤全磷和有机质与多数土壤化学性质呈显著正相关;土壤含水量在下游与多数土壤化学性质均显著相关,但在上游仅与土壤全磷显著负相关。PCA主成分分析表明,土壤容重、土壤孔隙度和土壤全磷含量的贡献均大于其他环境因子的平均贡献率,体现了它们是影响漓江水陆交错带土壤理化性质的重要环境因子。