scholarly journals Heavy Metal Contamination of Urban Mangrove Sediments and Their Environmental Significance in the Zhanjiang Bay

Author(s):  
Xun Zhou ◽  
Yao-Ping Wang ◽  
Yuan Gao ◽  
Jia Xia ◽  
Sibo Wang ◽  
...  

Abstract Urban mangroves can be used to measure the impact of human activities on the urban ecological environment because mangroves are sensitive to human activities. However, studies on the evaluation of heavy metal elements in urban mangroves are still limited. Consequently, this study selected the urban mangroves in a central commercial area of Zhanjiang Bay as a case study to investigate the content and distribution of the heavy metal elements in mangrove sediments. Combined with the results of elemental analysis, grain size analysis, risk level, influencing factors, and sources of heavy metal pollution in the surficial sediments of the mangroves in the study area were evaluated based on mathematical models and multivariate statistical analysis. The results show that (1) concentration of heavy metals: V> Pb> Cu> Ni> As> Co> Cd> Hg; (2) the content of the eight heavy metal elements has a significant positive correlation with total organic carbon (TOC) and total nitrogen (TN) values, likely as a result of adsorption, complexation, or precipitation of heavy metals by organic matter in the sediments; (3) the mangrove sediments in the study area are affected by heavy metal pollution, among which Cd pollution is the heaviest, followed by Hg pollution; (4) comprehensive analyses of multiple heavy metals using Potential Ecological Risk Index shows that the risk level of the study area is slight to very strong ecological risk; (5) the heavy metals in the study area are mainly derived from human activities such as urban domestic sewage, transportation, and ship pollution.

Author(s):  
Xiongfei Cai ◽  
Die Xu ◽  
Shijie Zhao ◽  
Li Lei ◽  
Ji Wang ◽  
...  

The thesis is aimed to provide a reference for the sustainable utilization of farmland soils along the Wuma River, an upstream tributary of the Chishui River in Guizhou Province. Geo accumulation index method, Nemero comprehensive pollution index method, and potential ecological hazard index method were used based on the experimental data for analyzing and evaluating the heavy metal pollution status of farmland soil along Wuma River. The results showed that: (1) The contents of heavy metals Ni, Cu, Zn, Pb and Hg in farmland soil exceeded the soil background values of 9.82%, 47.80%, 13.72% and 76.06% in Guizhou Province, respectively, but did not exceed the standard limit class II based on the environmental quality. (2). The pollutants of Pb and Zn in the research area mainly come from mineral exploitation, waste residue accumulation, and transportation. The enrichment of Cr and Cu may originate from the domestic garbage dumping and incinerated waste by residents along the coast and irrational agricultural activities. The main contents of Cd, As and Hg come from soil geochemistry. (3) The ranking of accumulations of eight heavy metals was IPb>IHg>ICu>INi>IZn>ICr>IAs>ICd, among which Pb was non-moderately polluted and the remaining heavy metals were at the clean level; Nemero comprehensive pollution index showed that As, Cr, Zn, and Ni were mildly polluted, while Pb, Hg, and Cu were moderately polluted. The ranking of potential ecological risk levels for the eight heavy metals was Hg, Pb, Cu, Ni, As, Cd, Cr, Zn. The overall ecological risk level is mild.


2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Dongping Liu ◽  
Jian Wang ◽  
Huibin Yu ◽  
Hongjie Gao ◽  
Weining Xu

Abstract Background Heavy metal pollution of aquatic systems is a global issue that has received considerable attention. Canonical correlation analysis (CCA), principal component analysis (PCA), and potential ecological risk index (PERI) have been applied to heavy metal data to trace potential factors, identify regional differences, and evaluate ecological risks. Sediment cores of 200 cm in depth were taken using a drilling platform at 10 sampling sites along the Xihe River, an urban river located in western Shenyang City, China. Then they were divided into 10 layers (20 cm each layer). The concentrations of the As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were measured for each layer. Eight heavy metals, namely Pb, Zn, As, Cd, Cr, Cu, Ni, and Hg, were measured for each layer in this study. Results The average concentrations of the As, Cd, Cu, Hg, and Zn were significantly higher than their background values in soils in the region, and mainly gathered at 0–120 cm in depth in the upstream, 0–60 cm in the midstream, and 0–20 cm downstream. This indicated that these heavy metals were derived from the upstream areas where a large quantity of effluents from the wastewater treatment plants enter the river. Ni, Pb, and Cr were close or slightly higher than their background values. The decreasing order of the average concentration of Cd was upstream > midstream > downstream, so were Cr, Cu, Ni and Zn. The highest concentration of As was midstream, followed by upstream and then downstream, which was different to Cd. The potential factors of heavy metal pollution were Cd, Cu, Hg, Zn, and As, especially Cd and Hg with the high ecological risks. The ecological risk levels of all heavy metals were much higher in the upstream than the midstream and downstream. Conclusions Industrial discharge was the dominant source for eight heavy metals in the surveyed area, and rural domestic sewage has a stronger influence on the Hg pollution than industrial pollutants. These findings indicate that effective management strategies for sewage discharge should be developed to protect the environmental quality of urban rivers.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1801
Author(s):  
Valentina Andreea Calmuc ◽  
Madalina Calmuc ◽  
Maxim Arseni ◽  
Catalina Maria Topa ◽  
Mihaela Timofti ◽  
...  

It is a well–known fact that heavy metal pollution in sediments causes serious problems not only in the Danube basin, but also in the large and small adjacent river streams. A suitable method for assessing the level of heavy metals and their toxicity in sediments is the calculation of pollution indices. The present research aims to assess heavy metal pollution in the Lower Danube surface sediments collected along the Danube course (between 180 and 60 km) up to the point where the Danube River flows into the Danube Delta Biosphere Reserve (a United Nations Educational, Scientific and Cultural Organization – UNESCO, protected area). In addition, this monitored area is one of the largest European hydrographic basins. Five heavy metals (Cd, Ni, Zn, Pb, Cu) were analyzed in two different seasons, i.e., the autumn of 2018 and the spring of 2019, using the Inductively Coupled Plasma Mass Spectrometry (ICP– MS) technique. Our assessment of heavy metal pollution revealed two correlated aspects: 1. a determination of the potential risks of heavy metals in sediments by calculating the Potential Ecological Risk Index (RI), and 2. an evaluation of the influence of anthropogenic activities on the level of heavy metal contamination in the surface sediments, using three specific pollution indices, namely, the Geo–Accumulation Index (Igeo), the Contamination Factor (CF), and the Pollution Load Index (PLI). The results of this pioneering research activity in the region highlighted the presence of moderate metal (Ni and Cd) pollution and a low potential ecological risk for the aquatic environment.


2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Xia Sun ◽  
Bao-Shi Li ◽  
Xuan-Li Liu ◽  
Cheng-Xuan Li

Coastal waters are polluted by heavy metals to varying degrees, posing potential risks to marine ecology and human health. In May 2006, the pollution levels, sources, and ecological risks of heavy metals (Cu, Pb, Zn, Cd, Hg, and As) in seawater, surface sediments, and living organisms were studied in Jiuzhen Bay in Fujian, China. This study identified Hg (0.26–0.72 µg/L) and As (20.3–31.5 µg/L) pollution in the seawater of Jiuzhen Bay. In sediments, heavy Pb pollution (946 µg/g dw) was only detected at one station at a level posing very serious potential risk, while Hg pollution (0.052–0.087 µg/g dw) was observed at three stations at a level posing serious potential risk. No heavy metal pollution was detected in sediments at other stations. The concentrations of five heavy metals (Cu, Zn, As, Cd, and Pb) exceeded the corresponding National Quality Standards for oysters, indicating heavy pollution, based on an ecological risk assessment. In clams, two heavy metals (Pb and As) exceeded the standards, indicating light pollution, based on an ecological risk assessment. No heavy metal pollution was found in fish or shrimps. The heavy metals in the seawater and sediments of Jiuzhen Bay are mainly derived from the river discharges of Luxi and Wujiang Rivers although sewage discharge along the coast of Jiuzhen Bay is another source of heavy metal pollution at some stations. Given the pollution of Pb, Hg, and As in seawater and sediments at some stations within the bay, the potential risks of Pb, Hg, and As in living organisms to both the marine ecology and human health deserve increased attention.


Water ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 180
Author(s):  
Arup Acharjee ◽  
Zia Ahmed ◽  
Pankaj Kumar ◽  
Rafiul Alam ◽  
M. Safiur Rahman ◽  
...  

River sediment can be used to measure the pollution level in natural water, as it serves as one of the vital environmental indicators. This study aims to assess heavy metal pollution namely Copper (Cu), Iron (Fe), Manganese (Mn), Zinc (Zn), Nickel (Ni), Lead (Pb), and Cadmium (Cd) in Surma River. Further, it compares potential ecological risk index values using Hakanson Risk Index (RI) and Monte Carlo Simulation (MCS) approach to evaluate the environmental risks caused by these heavy metals. in the study area. With obtained results, enrichment of individual heavy metals in the study area was found in the order of Ni > Pb > Cd > Mn > Cu > Zn. Also, variance in MCS index contributed by studied metals was in the order of Cd > Pb > Ni > Zn > Cu. None of the heavy metals, except Ni, showed moderate contamination of the sediment. Risk index values from RI and MCS provide valuable insights in the contamination profile of the river, indicating the studied river is currently under low ecological risk for the studied heavy metals. This study can be utilized to assess the susceptibility of the river sediment to heavy metal pollution near an urban core, and to have a better understanding of the contamination profile of a river.


2017 ◽  
Vol 14 (3-4) ◽  
Author(s):  
Nusreta Djonlagic

In this study the results of a 15-year long monitoring survey on heavy metals in water at Lake Modrac were assessed using pollution indices of heavy metals, such as Heavy metal pollution index HPI, Heavy metal evaluation index HEI and the Degree of contamination CD. The results of the survey on heavy metal pollution of sediment conducted in 2015 were used as input data for the following pollution indices: Concentration factor , Pollution load index PLI, Enrichment factor EF, Index of geo-accumulation Igeo, Ecological risk factor , Potential ecological risk index to the water-body, RI. The results showed a good correlation and the lake sediment was characterized as polluted. Enrichment factors and indices of geo-accumulation of heavy metals were indicated as very high enriched in the sediment, and have been identified as an anthropogenic source of pollution. Cumulative presence in the sediment is assessed through the pollution index, RI, and has been assessed as moderate ecological risk to the lake water-body. The application of pollution indices presents a valuable tool in assessing the long-term pollution status of Lake Modrac.


Author(s):  
Xiuling Li ◽  
Henglun Shen ◽  
Yongjun Zhao ◽  
Weixing Cao ◽  
Changwei Hu ◽  
...  

The Yi River, the second longest river in Shandong Province, China, flows through Linyi City and is fed by three tributary rivers, Beng River, Liuqing River, and Su River in the northeastern part of the city. In this study, we determined the concentrations of five heavy metals (Cr, Ni, Cu, Zn, and Pb) in water, sediment, and aquatic macrophyte samples collected from the junction of the four rivers and evaluated the potential ecological risk of heavy metal pollution. Most of the heavy metals in water were in low concentrations with the water quality index (WQI) below 1, suggesting low metal pollution. The sediments showed low heavy metal concentrations, suggesting a low ecological risk based on the potential ecological risk index (RI) and the geo-accumulation index (Igeo). The aquatic plant species Potamogeton crispus accumulated considerable amounts of heavy metals, which were closely related to the metal concentrations of the sediment. The plant species Salvinia natans also showed an excellent metal accumulation capability. Based on our results, the junction of the four rivers is only slightly polluted in terms of heavy metals, and the plant species P. crispus is a suitable bioindicator for sediment heavy metal pollution.


2020 ◽  
Author(s):  
Dongping Liu ◽  
Huibin Yu ◽  
Hongjie Gao ◽  
Weining Xu

Abstract Background Heavy metal pollution of aquatic systems is a global issue that has received considerable attention. Canonical correlation analysis (CCA), principal component analysis (PCA), and potential ecological risk index (PERI) have been applied to heavy metal data to trace potential factors, identify regional differences, and evaluate ecological risks. Sediment cores of 200 cm in length were taken using a drilling platform at 10 sampling sites along the Xihe River, an urban river located in western Shenyang City, China, divided into 10 layers (20 cm each). The concentrations of the As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were measured for each layer. Eight heavy metals, namely Pb, Zn, Ag, Cd, Cr, Cu, Ni, and Hg, were measured for each layer in this study. Results The average concentrations of the As, Cd, Cu, Hg, and Zn were significantly higher than their background values in soils in the region, and mainly gathered at 0–120 cm in depth in the upstream, 0–60 cm in the midstream, and 0–20 cm downstream. This indicated that these heavy metals were derived from the upstream areas where a large quantity of effluents from the wastewater treatment plants enter the river. Ni, Pb, and Cr were close or slightly higher than their background values. The decreasing order of the average concentration of the Cd was upstream > midstream > downstream, so were the Cr, Cu, Ni and Zn. The trend of the average concentration of the As was different to the Cd; being highest midstream, followed by upstream and then downstream. The potential factors of heavy metal pollution were Cd, Cu, Hg, Zn, and As concentrations, especially Cd and Hg, whose ecological risks were much higher than those of Ni, Cr, and Pb. The ecological risk levels of all heavy metals were much higher upstream than midstream and downstream. Conclusions Industrial discharge was the dominate source for eight heavy metals in the surveyed area, and rural domestic sewage has a stronger influence on the Hg pollution than industrial pollutants. These findings indicate that effective management strategies should be developed to protect the environmental quality of urban rivers.


2019 ◽  
Vol 252 ◽  
pp. 09011
Author(s):  
Justyna Kujawska ◽  
Wojciech Cel

Owing to their toxicity, heavy metals constitute a serious threat to the environment. In the pages that follow, we will report the results of evaluation of the potential ecological risk and trend of soil heavy metal pollution surrounding the drilling waste deposition site in western Poland. The concentrations of heavy metals: Cd, Cr, Cu, Pb were determined by inductively coupled plasma optical emission spectrometry. The procedure used for potential ecological risk assessment was as proposed by Hakanson (1980). The calculated potential ecological risk factors come in the following order EiR(Cd)>EiR(Pb)>EiR(Cu)>EiR(Cr), which shows that Cd is the most important factor leading to risk. The uniform model was employed to determine the time in which Cd concentration will exceed the permissible concentration level, as regulated by Polish Law. The Pearson correlation coefficient was employed along with the correspondence analysis in order to determine the relationships between heavy metal concentrations.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jun Yi ◽  
Linus Shing Him Lo ◽  
Hongbin Liu ◽  
Pei-Yuan Qian ◽  
Jinping Cheng

Estuarine sediments are increasingly contaminated by heavy metals as a result of urbanization and human activities. Continuous multi-heavy metal accumulation in the ecosystem can provoke new effects on top of the complex environmental interactions already present in estuarine ecosystems. It is important to study their integrated influence on imperative microbial communities to reflect on the environmental and ecological risks they may impose. Inductively coupled plasma optical emission spectroscopy analysis for five metals Cd, Cr, Cu, Pb, and Zn showed that Cr and Cu concentrations in intertidal sediments of the urbanized Yangtze River estuary in China have consistently exceeded respective threshold effect concentration (TEC) levels. The geo-accumulation and potential ecological risk index results of the five metals showed that all sampling sites were weakly to moderately polluted, and at considerable to high ecological risk, respectively. Redundancy and correlation analyses showed that Zn followed by Cr in the ecosystem were explanatory of the shifts in recorded microbial community structures. However, the spatial variation in metal concentrations did not correspond to the selection of metal resistance genes (MRGs). Unlike many other dominant bacterial taxa, most of the sulfate-reducing bacteria (SRB) and associated sulfate respiration as the dominant microbially contributed ecological function were found to negatively correlate with Zn and total heavy metal pollution. Zn concentration was proposed to be a potent indicator for heavy metal pollution-associated microbial community compositional shifts under urbanized estuarine conditions. The associations between heavy metals and estuarine microbial communities in this study demonstrate the influence of heavy metals on microbial community structure and adaptations that is often overshadowed by environmental factors (i.e., salinity and nutrients).


Sign in / Sign up

Export Citation Format

Share Document