Analysis and speciation of heavy metals in the water, sediments, and drinking water plant sludge of a deep and sulfate-rich Algerian reservoir.

This study investigated the level of dissolved heavy metals in the water of Longhu Lake and focused on the speciation, mobility, and risks of heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, and Pb) in sediment. The levels of heavy metals in the water were found to be below the thresholds set by the Chinese safe drinking water standard. The highest average percentages of Cr, Ni, Zn, and As were bound with residual fractions, while Pb and Cu were bound with reducible fractions. Additionally, the highest percentage of Cd and Mn was bound to the acid-soluble fraction in the sediment. These findings suggest that Cd, Mn, Pb, and Cu likely originated from anthropogenic sources in the lake. There was a strong correlation between total organic carbon (TOC) and metal fractions in the sediment, indicating that TOC may play a role in transporting heavy metal fractions. Risk assessment code values for Cd and Mn indicated higher risks and mobility, while Ni, Cu, and Zn showed medium risks and mobility for aquatic biota. To mitigate heavy metal contamination, it is recommended to improve monitoring and regulation of urban runoff and inlet areas.

The concentrations of heavy metals (As, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were investigated in water, sediment and biota (aquatic plant, fish and shrimp) of Nansi Lake by an inductively coupled plasma-atomic emission spectrometry. The lower concentrations of heavy metals in lake water and the higher concentrations of heavy metals in sediment implied that there were low-level, persistent inputs of heavy metals in the Nansi Lake. The concentrations of Cr and Fe in aquatic plants exceeded their corresponding toxic concentrations. The correlations among the concentrations of heavy metals in water, sediment, aquatic plants and animals were lower. The factor analysis and the correlation analysis of different heavy metals in water, sediment and aquatic biota samples showed that most heavy metals had the same source except As. This finding implied that As was of different source compared to the other heavy metals in Nansi Lake. The comparison of heavy metals in different samples from upper lake and lower lake showed that the contamination of heavy metals in upper lake was more serious than that in lower lake. The intensive coal mining and more coal thermal plants were an important reason leading to contamination of heavy metals in Nansi Lake. The heavy metals in aquatic organisms were not accumulated along food web except As and Zn. There was a positive correlation between the accumulation of As and Zn and food web based on bioaccumulation factors value in Nansi Lake. Risk assessment of heavy metals in water, sediment and animals indicated that the water environment of Nansi Lake is safe at present. However, people should pay more attention to the intake of As and Zn.

Distribution and partitioning of heavy metals in water and sediments of a typical estuary (Modaomen, South China): The effect of water density stratification associated with salinity

BackgroundLimited information is available on heavy metal patterns in lakes under rapid watershed urbanization, especially considering a large spatial gradient with a long linear distance and great variations in topographic relief. To fill this gap, we studied concentrations of a series of heavy metals in both water and sediments from 20 lakes along a rural to urban gradient in central China, and we aimed to understand the effects of urban processes on heavy metal dynamics in lake ecosystems. Studied lakes were divided into five groups: A (rural reservoir group), B (rural commercial fishing group), C (urban park group), D (urban recreational fishing group), and E (urban commercial fishing group). An inductively coupled plasma optical emission spectrometer (ICP-OES) and an inductively coupled plasma-mass spectrometer (ICP-MS) were used to analyze the heavy metals in water and sediments.ResultsAn increasing trend of most heavy metals in water from rural to urban lakes was observed. Concentrations of cadmium (Cd), cobalt (Co), lead (Pb), chromium (Cr), arsenic (As), nickel (Ni), magnesium (Mn), iron (Fe), and aluminum (Al) in water were significantly lower in rural group A than those in other groups. Arsenic in sediments of rural group A was lower than those in other groups. No other heavy metal element in sediments was significantly different among groups. The enrichment factor analysis of selected heavy metals showed there were different degrees of enrichments of heavy metals in sediments. The potential ecological risk index showed a low level for heavy metals in sediments of all studied lakes.ConclusionsResults indicated that urban processes could have an impact on heavy metals in lake water. The sources of heavy metals in sediments were more likely from anthropogenic activities. These results could enhance our understanding of metal dynamics in lake ecosystems under urbanization and could help prevent heavy metal pollutions and promote sustainable management of urban ecosystems.

The concentration of heavy metals (Cr, Cd, Pb, Cu, Zn, Co, Ni and Tl) in water and surface sediment were investigated in the Pearl River Estuary, China. The concentrations of heavy metals in sediment were 1000-100,000 times higher than those in water. Correlation analysis and principal component analysis found that heavy metals (Zn, Cr, Pb and Co) in water may originate from anthropogenic activities, but the heavy metals in sediment indicate that Pb was dominated by nature and Zn, Cr, Co, Cd, Cu, Tl and Ni were mostly influenced by anthropogenic pollution. Enrichment factor and accumulation index of sediment heavy metal concentrations showed that S5, S6 and S7 presented a relatively serious pollution.

Jakarta Bay is a crowded area with many activities so that a gathering place for pollutants from the land that is transported through the 13 rivers that flow in Jakarta. The purpose of this research is to explain the process and sources of heavy metal with to compare distribution profile heavy metal in water and sediment in Transitional Season I and Transitional Season II in the Jakarta Bay. The research heavy metal in water and sediment in Jakarta Bay was conducted in September 2014. Analysis of heavy metal in water and sediment use procedure (APHA 2012). The results showed hydro-oceanographic condition in the Jakarta Bay for current velocity range from 0.002-0.028 m/s to wards west and southwest, the wind speed range 4-17 knot blowing to the southwest and tidal tipe of single of riding the tide of 0,84 m. The temperature range 28.9-30.2 °C, salinity range 29.5-30.6 psu, acidity (pH) range 7.80-8.17 and suspended solid (TSS) range 25-68 mg/l. Heavy metals in water for Pb range 0.006-0.016 ppm, Cd range 0.001-0.003 ppm, Cu range from 0.001-0.005 ppm, Ni range 0.001-0.016 ppm and Zn range 0.003-0.097 ppm. Heavy metal in sediment for Pb range 24.86-59.32 ppm, Cd range 0.32-3.49 ppm, Cu range 11.42-67 ppm, Ni range 19.80-39.85 ppm and Zn range 26.14 to 241.01 ppm. Distribution of heavy metal in water and sediment to indicated the sources of heavy metal in the Jakarta Bay largely derived input material from the terrestrial.

The study investigates the occurrence and bioaccumulationof heavy metals in water, sediment,fish, and prawn from the Ojo River with a view to identify the source of origin and the associated ecological and human health risks. The result shows that heavy metal concentrations in water [As = 0.010, Cd = 0.001, Cr = 0.041, Cu = 0.019, Co = 0.050, Fe = 0.099, Pb = 0.006, Ni = 0.003, and Zn = 0.452(mg/L)]were within theacceptable limits. The heavy metals in the sediment [As = 0.050, Cd = 0.287, Cr = 0.509, Cu = 0.207, Co = 0.086, Fe = 33.093, Pb = 0.548, Ni = 0.153 and Zn = 4.249 (mg/kg)]were within their respective background levels orearth's crust and theTEL and PEL standardlimits. The bioaccumulation ofheavy metals in fish and prawntissues are in this hierarchical form: Fe > Zn > Cu > Cr > Ni > Co > Pb > Ar > Cd and Fe > Zn > Cu > Cr > Pb > Ar > Ni > Co > Cd, respectively. The bioaccumulation factors of heavy metals in fishranged from 0.893 - 16.611 and 1.056 - 49.204 in prawn, which were higher than the biota-sedimentation factors (BSAF) values, inferring that the fish and prawns of this study ingested heavy metals highly from watercolumn. The aggregated BSAF scores (fish = 5.584 and prawn = 9.137) showed that these organisms are good concentrators of heavy metals in sediments. The water quality index and other pollution indices (Singlepollutionindex, Heavymetal assessment index, and Heavy metalpollutionindex) demonstrates slightlycleanwater, with a moderate level of contamination. The HI values of heavy metals in water, fish, and prawn were lower than 1, implying non-carcinogenic risk in children or adults. The ADD and EDI values of the metals were within their respective oral reference doses (RfD). The TCR values showed that exposure to water, either by ingestion or dermal absorption and the consumption of P. obscura and M. vollenhovenii from the Ojo River would not induce cancer risks in people, though As, Cr, Cd, and Pb showed carcinogenic potentials. The sediment contamination indices such as CF, mCd, EF, and Igeo showed a moderate level of pollution. The ecological risk values (NMPI, mCd = 0.068, PLI = 0.016, and R.I = 86.651) of heavy metals implies "no-moderate risk" except for Cd, which showed high risk. The ecotoxicologicalparameters, m-PEL-Q (0.024) and m-ERM-Q (0.016) denotes low contamination and no probability of acute toxicity. The CV analysis showed high dispersions and variabilities in the distributions of the heavy metals in water. Other source analyses (Pearson's correlation matrix, PCA, and HCA) showed that both natural processes and anthropogenic activities are responsible for the occurrence of heavy metals in water and sediment from the Ojo River.

Mangroves are often converted into gei wai ponds for aquaculture, but how such conversion affects the accumulation and behavior of heavy metals in sediments is not clear. The present study aims to quantify the concentration and speciation of heavy metals in sediments in different habitats, including gei wai pond, mangrove marsh dominated by Avicennia marina and bare mudflat, in a mangrove nature reserve in South China. The results showed that gei wai pond acidified the sediment and reduced its electronic conductivity and total organic carbon (TOC) when compared to A. marina marsh and mudflat. The concentrations of Cd, Cu, Zn and Pb at all sediment depths in gei wai pond were lower than the other habitats, indicating gei wai pond reduced the fertility and the ability to retain heavy metals in sediment. Gei wai pond sediment also had a lower heavy metal pollution problem according to multiple evaluation methods, including potential ecological risk coefficient, potential ecological risk index, geo-accumulation index, mean PEL quotients, pollution load index, mean ERM quotients and total toxic unit. Heavy metal speciation analysis showed that gei wai pond increased the transfer of the immobilized fraction of Cd and Cr to the mobilized one. According to the acid-volatile sulfide (AVS) and simultaneously extracted metals (SEM) analysis, the conversion of mangroves into gei wai pond reduced values of ([SEM] - [AVS])/foc, and the role of TOC in alleviating heavy metal toxicity in sediment. This study demonstrated the conversion of mangrove marsh into gei wai pond not only reduced the ecological purification capacity on heavy metal contamination, but also enhanced the transfer of heavy metals from gei wai pond sediment to nearby habitats.

The study aimed to determine eight hazardous heavy metals in surface water and sediment samples collected from the Naf River, Shah Porir Dwip (estuary), and mostly around Saint Martin's Island in the Bay of Bengal. The results of heavy metals in water samples were ranged as Pb 14.7-313.0, Cd 33.0-70.0, Cr < 11.0-37.0, Cu 38.0-57.0, Zn 26.8-69.2, Ni 102.0-285.0, and Hg 0.3-1.6μgL-1. The concentrations of metals in sediment samples were ranged as Pb < 10.0-37.5, Cd 0.2-1.0, Cr < 5.0-30.1, Cu < 3.0-30.9, Zn 24.1-88.0, Ni < 4.0-48.3, As 0.1-7.3, and Hg < 0.01-0.08mgkg-1 dw. Ni and Cr were strongly correlated, suggesting that this pair of metals might diffuse from a common origin. The contamination factor (Cif) demonstrated that sediment samples were mostly contaminated by Cd and slightly contaminated by Pb and Zn. The geoaccumulation index (Igeo) revealed considerable values for Cd on Saint Martin's Island. Cd as a single regulator posed moderate to considerable risk frequently among the sampling stations. Pollution load index (PLI) values remained below 1 (< 1), which indicated a decrease from baseline pollution value among all stations. However, potential ecological risk (PER) was graded for two stations (St1 and St13) with a moderate-risk zone due to the Cd contribution. However, shipping emission and lithogenic sources were the most predominant for heavy metals in the sediment, which were determined by applying the principal component analysis-absolute principal component score (PCA-APCS). Graphical abstract.

Pollution arising from uncontrollable combustion processes, including artisanal refineries are common in communities through which Kolo Creek traverses. Previous studies have centered on the effect of oil and gas production on Kolo Creek at shell flow station at Imiringi. Therefore, the aim of this study is to investigate the risk and distribution of heavy metals (Zn, Ni, Cr, Cu, Pb, Co, and Cd) in water and sediments along Ibelebiri axis of Kolo creek in Ogbia L.G.A., Niger Delta region of Nigeria. Water and sediment samples were collected at locations upstream, within and downstream at Ibelebiri community, and also from a control site. Generally, heavy metal concentrations showed a decreasing trend of Cu˃Zn˃Pb˃Cr˃Cd˃Co˃Ni for water samples. The mean concentration of these metals: Ni, Cr, Zn and Cu recorded in this study was below international recommended limits. But, Pb, Cd levels in locations LC1, LC3 and LC4 are above the international recommended limits. The heavy metals in the sediments showed a decreasing trend of Zn˃Pb˃Cu˃Co˃Cr˃Ni˃Cd. The concentrations of these metals Cd, Pb, Ni, Cr, Cu and Zn are below the permissible limit set by Department of Petroleum Resources (DPR). However, Co values at locations LC3 and LC4 are slightly above the DPR target value of 20 mg/kg for sediments. Using the geoaccumulation index (Igeo) classification, the sediments across the four locations are uncontaminated with Cd, Cr, Cu, Zn, Co and Ni. But, the sediments in locations LC1, LC3 and LC4 are moderately contaminated with Pb. Similarly, the contamination factor (CF) classification, revealed low contamination of Cd, Cr, Cu, Zn, Ni and Co across the four locations; moderate contamination of Pb in the four locations. Finally, principal component analysis (PCA) identified two major factors.

This paper combines environmental science, inorganic chemistry, water quality monitoring and other disciplines to analyze and assess the heavy metals in the water bodies and sediments of the Fenghe River Basin (FRB) in Shaanxi Province, and reveal their sources. The Water Quality Index (WQI), Nemero Index (Pn), Geological Accumulation Index (I-geo) and Potential Ecological Risk Index (RI) are used to assess heavy metals in water and sediments. Pearson correlation analysis (CA), hierarchical cluster analysis (HCA), principal component analysis (PCA) and positive matrix factorization (PMF) models are used to study the relationship and source of heavy metals. The results show that most of the residual heavy metals in the water are below the corresponding environmental quality standards for surface water. Most of the heavy metals in the sediment exceed the background value of the soil. The factors or sources of heavy metals in water and sediment are revealed in detail through PMF models. The main sources of pollution in the region are urban construction and transportation, the electronics industry, machinery manufacturing and tourism. In water, the average contribution rates of these four sources to heavy metals were 36.8%, 11.7%, 9.4% and 42.0%, and in sediments were 8.0%, 29.2%, 23.9% and 38.9%. Therefore, these sectors should be given sufficient attention.

Study on Analysis of Lead (Pb) Heavy Metal in White Shrimp (P. merguiensis) on the Muara Badak Estuary was conducted in May until July 2016. This aims to determine how much the concentration of lead (Pb) heavy metals in water, sediment and white shrimp (P. merguiensis) in the Muara Badak estuary. The method is using purposive sampling at 3 stations namely, near the pier and the residents, the transportation lines near of fishermen and the transit of oil tankers. During the research the temperatures ranging between 29.705 ° C 30.025 ° C shows the range was quite good for the aquatic biota growth, pH ranged from 7.135 to 7.425 which included in the category of normal pH, salinity ranged from 3.64 to 22.415 ‰ which showed freshwater, TDS ranged 13300-2320 mg/L which included in the range of high and exceed the quality standards set, and DO range from 7.16 to 7.61 which included in the category of normal. Levels of lead (Pb) heavy metals were measured using Atomic Absorption Spectrophotometry (AAS). The mean levels of lead (Pb) heavy metals in the water from Station 1 to Station 3 are 0.515, 0.273 and 0.216 mg/L which exceeds the quality standards specified by KMNLH no. 51 2004 was 0.008 mg/L, the average concentration of lead (Pb) heavy metals in sediment was 0.844, 0.758 and 0.835 mg/kg which is still safe because it is below the quality standard is 36 mg/kg and the average concentration of lead (Pb) heavy metals on white shrimp (P. merguiensis) is 0.534, 1.079 and 0.921 mg / kg which exceeded the quality standards set by BPOM RI in 2009 at 0.5 mg / kg.

Contamination, ecological risk and source apportionment of heavy metals in sediments and water of a contaminated river in Taiwan

To estimate the ecological risk of toxic organic pollutant (formaldehyde) and heavy metals (mercury (Hg), arsenic (As), cadmium (Cd), and chromium (Cr)) in water and sediment from a landscape Lake in Tianjin City, an ecological risk assessment was performed. The risk quotient (RQ) method and the AQUATOX model were used to assess the ecological risk of formaldehyde in landscape water. Meanwhile, the RQ method and the potential ecological risk index method were used to assess the ecological risk of four heavy metals in water and sediment from the studied landscape lake, respectively. The results revealed that the maximum concentration of formaldehyde in landscape water was lower than the environmental quality standards of surface water in China. The maximum simulated concentrations of formaldehyde in phytoplankton and invertebrates were 3.15 and 22.91μg/L, respectively, which were far less than its toxicity data values (1000 and 510μg/L, respectively), suggesting that formaldehyde in landscape water was at a safe level for aquatic organisms. The RQ model indicated that the risks of phytoplankton and invertebrates were higher than that of fish posed by Hg and Cd in landscape water, and the risks from As and Cr were acceptable for all test organisms. Cd is the most important pollution factor among all heavy metals in sediment from studied landscape lake, and the pollution factor sequence of heavy metals was Hg > As > Cr > Cd. The values of risk index (RI) for four heavy metals in samples a and b were 43.48 and 72.66, which were much lower than the threshold value (150), suggesting that the ecological risk posed by heavy metals in sediment was negligible.

The conclusion about the effect of macrophytes rhizosphere and mollusks bioturbation on morphology and mobility of heavy metals in the sediments is not entirely consistent. It is necessary to study further on influence mechanism of macrophytes growth and macrobenthos bioturbation on speciation and release of heavy metals in natural water body. This study intends to explore the influence mechanism of Bellamya aeruginosa (Bel) bioturbation and Pontederia cordata (Pon) growth on the speciation and release kinetics of Cu in sediment through construction of an aquatic organism-water-sediment system by indoor potted experiment. The results show that the particulate Cu in water of the control group and Pon treatment always maintain in lower level and the particulate Cu concentration in water of Bel treatment and Pon+Bel treatment appeared to a certain level of fluctuations at latter period. There was a significant positive correlation between the content of particulate Cu in water and the water turbidity. Bellamya aeruginosa bioturbation has not significantly affected the different speciation of heavy metals in surface sediments and the concentration of reducible Cu and Zn in the rhizosphere sediment was significantly lower than that in the control group.