Heavy Metal Concentrations In Water Research Articles

Assessment of the status of selected heavy metals in water, sediments and a fish species (Oreochromis niloticus) of commercial value in Lake Nakuru with a focus on human health risks

AbstractThe present study presents selected water quality parameters and the levels of heavy metals in water, sediments and Nile tilapia (Oreochromis niloticus) of Lake Nakuru. Nine sediments and nine water samples, as well as 30 specimens of Nile tilapia, were collected from the northern part of the lake. Physical parameters were measured in situ using multiple probes and metres. Heavy metals were analysed using an atomic absorption spectrophotometer (AAS). The pH, dissolved oxygen concentration, temperature, salinity and electrical conductivity ranged from 9.52 to 9.72, 4.58 to 8.62 mg/L, 23.40°C to 25.7°C, 2.39‰ to 2.81‰ and 4470–5226 μs/cm, respectively. Heavy metal levels (mean ± SD) were generally low in the water samples. Chromium values ranged between 7.16 and 9.19 mg/kg dw in sediment samples, and between 3.7 and 13.06 mg/kg dw in fish samples. Lead values ranged between 12.5 and 31.04 mg/kg dw in sediment samples and 4.06 and 9.95 mg/kg dw in fish samples. Arsenic values ranged between 9.5 and 21.7 mg/kg dw in sediments and below detectable limit to 2.11 mg/kg dw in fish samples. Mercury values ranged between .14 and .31 mg/kg dw in sediment samples and .12 and .35 mg/kg dw in fish samples. Cadmium was the only heavy metal concentration that was below the detection limit in the three matrices. Significant differences were observed for some heavy metal concentrations in water, sediments and fish across sites (p < .05). The levels of lead and chromium in fish were above the East African Standard, World Health Organization and European Union limits. The results of the present study recommend a possible reclassification of the lake, an immediate ban on fish harvesting and consumption from Lake Nakuru and a policy intervention on the fishery and pollution management.

HEAVY METAL CONCENTRATION IN SEDIMENT AND WATER OF RIVER NYAMINDI, KIRINYAGA COUNTY, KENYA

Toxic heavy metals get into humans through absorption, inhalation and ingestion. All heavy metals are toxic to animals and plants when present in excessive amounts. The adverse effects of heavy metals in mammals may manifest in disorders such as growth retardation, decrease in longevity, changes in reproductive cycles, chronic diseases and formation of tumours. River Nyamindi flows from Mt. Kenya Forest passing through rocks, soil, agricultural land, residential areas and urban centres. Geological factors and human activities may have made heavy metals get into the river water. Since the water is used for domestic purposes and irrigation, it was necessary to determine if heavy metal concentration in river Nyamindi has reached alarming levels. Water and sediment samples were collected along river Nyamindi during wet and dry season. The samples were digested appropriately and the concentration of eight heavy metals determined using ICP-MS. The mean amount of Cd, Cr, Ni, Pb, Zn, As, Mn and Se in sediment were 0.0882, 41.1219, 91.7718, 10.7445, 54.3880, 2.4561, 1753.5587 and 5.7648 mg/kg respectively during wet season and 0.0590, 39.1176, 559.0917, 0.3781,76.3715, 3.0114, 1714.4195 and 6.5488 mg/kg respectively during dry season. The mean concentration of the same metals in water was 0.00005, 0.0167, 0.1943, 0.0223, below detection limit (BDL), 0.0002, 0.1379 and BDL ppm respectively during wet season and 0.0009, 0.0005, 0.0148, 0.0184, BDL, 0.00003, 0.0080 and 0.00003 ppm respectively during dry season. The mean amount of Cr, Ni and Mn in sediment were found to be above WHO and US EPA permissible limits during both seasons. The mean concentration of Cr and Mn in water were above WHO and KEBS/WASREB permissible limits during wet season. However, during dry season, all the eight heavy metal concentrations in water were below WHO, KEBS/WASREB permissible limits. Therefore, as far as the eight heavy metals are concerned, water from river Nyamindi was not be potable during rainy season but was potable during dry season. However, further investigations should be carried out to determine other water parameters to confirm it’s suitability as potable water.

Assessment of Heavy Metal Pollution in Water and Sediment of River Thiba, Kirinyaga County, Kenya

Traceelementsfind their way into humans throughingestion, directabsorptionorinhalation. All tracemetals are toxic to animals and plants when present in excess amounts. The harmfuleffects of trace heavymetals in mammals may manifest asgrowth retardation, decrease in longevity, changes in reproductive cycles, chronic diseases and tumourformation. River Thibacatchment isMt. Kenya forestand thenflowsthrough rocks, soil, farmlands, residential areas and towncentres. Due to geological factors and human activities,traceheavy metals maybegettingin riverThibaand since the water is used for domestic purposes and irrigation, it was necessary to determine the heavy metal concentrationinthe river. Sedimentand watersamples were collected along river Thibaduring rainyand dry seasons. The samples were digested thenconcentrationsof eight heavy metals determined using ICP-MS. The mean amountsof Cd, Cr, Ni, Pb, Zn, As, Mn and Se in sedimentwere0.0908, 39.8969, 85.1085, 10.3918, 42.5555, 2.3679, 1678.3876and 5.4907mg/kg respectively during rainyseason and 0.0628, 42.6319, 396.4692, 3.2669,58.7585, 2.8139, 1766.4009 and 6.1059mg/kg respectively during dry season. The mean concentration of the same metals in water was 0.0002, 0.0916, 1.0066, 0.0434, BDL, 0.0025, 1.8484and0.0038ppm respectively during wet season and BDL,BDL, BDL,0.0068,BDL,0.00002, 0.0070 andBDL ppm respectively during dry season. The mean amount of Cr, Ni and Mn in sediment were found to be above WHO and US EPA permissible limitsduring both seasons.During rainy season, the mean concentration of Cr, Ni, Pband Mn in water were above WHO and KEBS/WASREB permissible limitsbut the concentrations of Cd, Zn, As and Se were below the limits. However, during dry season, all the eight heavy metal concentrations in water were below WHO, KEBS/WASREB permissible limits. As far as the eight heavy metals are concerned, water from river Thibamay not be potable during rainyseason but is potable during dry season. However, further investigations should be carried out to determine other water parameters.

Heavy metal concentrations in surface waters of Hurghada and environs, Red Sea Coast, Egypt, and their correlation with sediment distribution

This study investigates the properties and chemistry of surface water in Hurghada and its adjacent areas, with a focus on assessing the potential impact of human activities on water quality by measuring the concentrations of heavy metals in surface water samples. A total of fifty-nine surface water samples were collected and analyzed for various heavy metals, including manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg), and lead (Pb) using the AAS technique.The results indicate that at the Desert Rose Resort transect, the average total concentrations of heavy metals were within the following ranges: Fe (average of 26.96 μg/L), Cu (average of 0.61 μg/L), Zn (average of 6.31 μg/L), and Pb (average of 0.75 μg/L). Conversely, at the Abu-Shaar transect, Ni (0.87 μg/L) and Cd (average of 0.02 μg/L) were the dominant heavy metals, while Mn exhibited the highest mean value (1.80 μg/L) at the El-Samaka Village transect. Notably, Hg was not detected in any of the samples within the study areas.Comparative analysis of heavy metal concentrations in Hurghada's surface waters with data from the Red Sea coast and other global regions reveals that the study areas maintain heavy metal concentrations well below the maximum permissible values for the marine environment. These findings suggest that human activities have not significantly impacted heavy metal levels in the region's surface waters.Additionally, statistical assessments, such as correlation coefficients (r), were employed to explore the relationships between heavy metal concentrations in water and sediment. These relationships provide valuable insights into the dynamic balance of elements within the sediment and their potential direct or indirect transfer into the water.

Determination of Some Heavy Metals Concentrations in Water and Irrigation Farms along Wulmi River in Pankshin Local Government, Plateau State, Nigeria

Levels of four heavy metals (Co, Cu, Pb and Cd) and three physico-chemical parameters (pH, temperature, total dissolved solids) were determined from Wulmi River at five sampling points (S1-S5) at an interval of 200m between points using atomic absorption spectrophotometer (AAS) and approved standard procedures respectively, and the control site located about 1000 meters away from the study area. Sampling was done monthly in wet season from May-December 2017. The weighted means of physico-chemical parameters determined at each sampling point in the river were in the range 6.53±0.21 - 6.85±0.17 for pH. 25.35±0.79 0C - 25.92±2.310C for temperature which is within the permissible limit of 300C (USEPA,2002), 9.43±3.90 mg/l - 26.71±2.75 mg/l for TDS which is also within the permissible limit of 1000 mg/l (USEPA,2002). The weighted mean of heavy metal concentrations in water at sampling points in the river ranged between 0.11±0.07 mg/l - 0.29 ± 0.19 mg/l for copper, 1.17±0.39 mg/l - 1.76± 0.31 mg/l for cadmium, 0.08 ± 0.05 mg/l - 0.91±0.03 mg/l for lead, 1.53± 0.39 mg/l - 6.48± 3.36 mg/l for cobalt. The soil samples from five irrigation farmlands (F1-F5) around the Wulmi River were also analysed for the heavy metals concentrations. The heavy metals concentrations in the soil ranged between 12.27 ± 3.46 μg/g - 28.05 ± 1.99 μg/g for copper, 5.49 ± 3.09 μg/g - 17.92 ± 2.18 μg/g for cadmium, 2.24 ± 0.02μg/g - 9.85 ± 1.43 μg/g for Lead, 13.48 ± 3.72 μg/g - 27.82 ± 2.65 μg/g for cobalt .Lead and cobalt concentrations in the soils are within the permissible limit set by USEPA (2002) and WHO [1] of 10μg/g and 50μg/g respectively. All the metals under investigation have geo-accumulation input in soils around Wulmi River, except in irrigation farms 2 and 4 which have geo-accumulation input of Pb to be 0.00. Analysis of variance indicates that there is significant difference in pH, concentrations of TDS, Cd, and Co from one sampling point to another throughout the periods of analyses. The data generated will be used to develop a computer based time series model, which can be used to predict the concentrations of the heavy metals in the near future at these sampling points in Wulmi River.

HEAVY METAL CONTENT IN WATER AND SEDIMENT OF SHRIMP FARMS OF SATKHIRA, BANGLADESH

Toxic contaminants moving along with runoff usually contaminates shrimp farms in most areas of Satkhira district, southwest Bangladesh. An investigation was carried out to assess the Physico-chemical properties and heavy metal concentration of sediments and water in shrimp farms from Satkhira district, southwest Bangladesh during December 2020 to March 2021. Twelve water and sediment samples were collected from six Ghers of two Upazilla e.g., Debhata and Assasuni of Satkhira. Physico-chemical attributes such as temperature, DO, BOD5, pH, TDS, EC, turbidity, salinity, HCO3-/CO3-, SO4-, NO3-, PO4- were estimated. The concentration attributes such as TDS (2280-5250 mg/l), EC (4380-9670 µs/cm), Turbidity (50.8-348 NTU), HCO3-/CO3- (219.6-445.3 mg/l), NO3- (0.3635-1.94 mg/l) were observed to be higher than the allowable standards recommended by WHO and FAO. Five trace metals such as chromium (Cr), cadmium (Cd) copper (Cu), lead (Pb) and Zinc (Zn), were measured in sediments and water by Atomic Absorption Spectrometer. The range of metal concentrations in sediment were as follows: Cr (1.95–3.43 mg/l), Zn (205.76-265.71 mg/kg), Cu (0.60–1.1mg/kg), Cd (3.8-4.1 mg/kg), and Pb (0.92-1.11mg/kg wet weight. The range of metal concentration in water were as follows: Cr (0.1-0.8 mg/l), Zn (0.003-0.34 mg/l), Cu (0.10-0.13 mg/l), Cd (0.07-0.08 mg/l), and Pb (0.23-0.34 mg/l). Higher concentrations of metal were recorded in most of the sediment and samples of water of the studied Ghers except Cr and Cu, those were below standard as prescribed by WHO and FAO. The concentration of Cu ranges from 0.602 to 1.113 mg/kg and 0.10 to 0.13 mg/l and range of Cr concentration were 1.95 to 3.43 mg/kg and 0.156 to 0.807 mg/l in sediment and water respectively. However, Cd, Zn and Pb were higher than the allowable standard as recommended by WHO and FAO. The higher heavy metal concentrations in water and sediment of shrimp Ghers suggest that shrimp could be contaminated by these heavy metals as well.

Determination of some heavy metal concentrations in water and sediment of River Gidin Dorowa, at Gidin Dorowa, Taraba, North Eastern Nigeria

This study examined some heavy metal concentrations in water and sediment of River Gidin Dorowa, Taraba, North Eastern, Nigeria. It was examined with atomic absorption spectrophometer (AAS) buck scientific model 210 VGP. Mean concentrations of metals in water and sediment showed significant (p< 0.05) during the study period between September, 2022 to February, 2023. Samples were collected upstream and downstream at River Gidin Dorowa. Higher mean value (0.3087 mg/l) was reported for lead (Pb) in October compare to other metals with lower value (0.1647 mg/l) recorded in November. Zinc (Zn) recorded higher value (0.1334 mg/l) in September. Cadmium (Cd) recorded higher value (0.0170 mg/l) in September and lower value (0.0027 mg/l) in February. Heavy metals in sediment showed variation (p<0.05) between metal during the study. Cadmium recorded higher value (0.0154 mg/kg) in December and lower value (0.0087 mg/kg) in January. Lead (Pb) value (0.6380 mg/kg) was higher in January while lower value (0.3707 mg/kg) were observed in October and November. Zinc (Zn) recorded a higher mean value (1.6667 mg/kg) in October. Copper value showed higher variation (0.4000 mg/kg) in October and lower value (0.2667 mg/kg) in February. Monthly variation between water and sediment during the study period showed higher variation (0.3910 mg/kg) for Lead (Pb) in the sediment and water value (0.2880 mg/l) in September. Copper (Cu) value (0.1000 mg/l) in water was lower than values in the sediment. Mean Cadmium value for water (0.0027 mg/l) and value (0.0100mg/kg) in sediment showed variations (p<0.05) in February from other metals considered. The levels of Zn, Cu, and Cd in water and sediment at Gidin Dorowa for this study were generally low compared to safe limits recommended by WHO and USEPA except values of Lead (Pb) in water. Therefore, routine monitoring of the heavy metals’ concentrations in water and sediments of River Gidin Dorowa should be sustained.

Assessment of heavy metal concentrations in water and sediments at Motor Park and new bridge areas, lower River Benue, Ibi, Taraba, Nigeria

Heavy metals concentration in water and sediment was investigated at the Motor Park Area and New Bridge Site of lower River Benue, Ibi, Taraba State. The heavy metals levels were examined using atomic absorption spectrophotometer (AAS) Buck Scientific model 210 VGP using spectrophotometry techniques. The highest mean concentration of Zn recorded in the sediment at the Motor Park Area was 0.55 mg/kg while the lowest value of 0.004 mg/kg was recorded for Cr at the Motor Park Area. The highest mean concentration of Mn recorded in the water was 0.375 mg/l at New Bridge Site while the lowest value of 0.00 mg/l was recorded for Cu. Values for Cu, Cd, Cr. Cu were generally low throughout the study period. There was no significant difference (p>0.005) in Zn concentrations in sediment at the sampled locations (Motor Park Area and New Bridge Site) throughout the study periods. However, Cr, Cd and Pb show variations (p<0.005) at the sampled locations. The concentration of Mn (0.375 mg/l) was not significantly different (p>0.05) from Mn (0.325 mg/l) in water between the two location, Pb value (0.343 mg/l) of water in December at the New Bridge Site exceeded the WHO recommended safe limit. However, all other metals were within the WHO and FMENV safe limit for portable drinking water. Since Pb value (0.343 mg/l) exceeded the WHO and FMENV safe limit for December. It shows that there is need for continuous monitoring of Lower River Benue waters at Ibi, Taraba State.

Assessment of Physico-Chemical Characteristics and Heavy Metal Content of Mangrove Water and Sediment from Selected Sites, Gulf of Khambhat, Gujarat, India

Due to their function in averting catastrophic weather occurrences like tsunamis and cyclones, mangrove forests are of paramount importance. The current study sought to determine the heavy metal content in water and sediment as well as the physico-chemical quality of mangrove water and sediment. Physico-chemical parameters and edaphic characteristics were studied for different sites i.e. Vadgam, Tada Talav and Kantiajal of the Gulf of Khambhat having mangrove vegetation. Physico-chemical parameters and heavy metals were higher at Kantiajal which is situated in Hansot tehsil of Bharuch district. This might be because it is adjacent to the industrial area of Ankleshwar and Panoli. Some of the physico-chemical parameters studied were turbidity, salinity, dissolved oxygen, COD, sulphate, phosphate, ammonical nitrogen, Iron (Fe), Manganese (Mn), Zinc (Zn), Copper (Cu), Cobalt (Co) and Lead (Pb) were the metal selected for the study. In order to develop conservation and management plans, a thorough research of the mangrove species in the Gulf of Khambhat, Gujarat, is required. The current study gives the baseline data for these species.

Evaluation of metal pollution related to human health risk in freshwater snail Viviparus contectus (Millet, 1813) as a potential bioindicator species in Lake Habitat (Turkey).

Freshwater mollusks are employed as bioindicators for the assessment of water quality in biomonitoring studies since the water quality of natural resources is crucial for humans. The freshwater snail species known as Viviparus contectus (Viviparidae: Gastropoda) is one that people eat. Here, the levels of heavy metals (Cd, Cr, Pb, As, Zn, and Cu) in water and V. contectus samples were determined. An Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES, Spectro Arcos, vertical plasma) was used for the analysing the heavy metal concentrations in water and freshwater snail samples. The results of the current investigation demonstrated that freshwater snails accumulated metals in their water and soft tissues in the following orders: Pb > Cr = Zn = Cu = Cd = As and Zn > Cu > Pb > Cd > As = Cr. Autumn was the time of year when higher amounts of heavy metals (As, Cr, Cu, Zn, and Hg) were found. Pb content in the freshwater snail samples was strongly impacted by seasonal fluctuations (P 0.05). For adults, the EDI (estimated daily intake) values were lower than the TDI (tolerable daily intake) values, and the HI (hazard index) values were below 1. Freshwater snail samples had Zn and Pb levels that were over the FAO/WHO, Turkish Food Codex, JECFA, and EC limit values. Except for Pb, the water study shows mean metal concentrations below the USEPA, Turkish Pollution Control Regulation, and World Health Organisation maximum allowed levels. Aquatic ecosystems were negatively impacted by anthropogenic activities overall, and this study can provide a helpful data set for investigations on metallic contamination in water bodies and biomonitoring in freshwater ecosystems.

Heavy Metal Contamination Status of Water, Agricultural Soil, and Plant in the Semiarid Region of Kandahar, Afghanistan

Agricultural irrigation using wastewater containing heavy metals (HM) might impose risks in bioaccumulation in foods. The current study was performed to assess the status of HM in terms of water-soil–plant systems in Kandahar, Afghanistan, where industrial and domestic wastewater was partially reused for irrigation. Water, soil, and plant samples were collected from wastewater sites in Haji-Arab (HA), Bala-Karz (BKZ), and Mahal-e-Nejat (MN) in comparison with those from a freshwater-irrigated site in Char-Bagh (CB). The HM levels in unfiltered water samples remained lower than the World Health Organization (WHO) and Food and Agriculture Organization (FAO) permissible values, but the HM concentrations in soil and crops were higher at the HA, BKZ, and MN (wastewater-irrigated sites) than those at the CB site (freshwater-irrigated site). Lead (Pb) levels were high in soils (43–83 mg/kg) and crops (18–36 mg/kg) and extremely exceeded the safe limits even for those crop samples cultivated in the freshwater-irrigated site. Continuous wastewater irrigation increased the HM concentration in water, soil, and plants, but the Pb pollution was found to be ascribed to the minerals in that area since the underground water was showing high Pb levels. The bioaccumulation of HM in the studied sites was related to the cultivated crops and correlated with the land use in the watershed area. This study is important in understanding the risks associated with HM and exercising prudence when applying various irrigation resources in Afghanistan.

Bioaccumulation of Heavy Metals in the Water, Sediment, and Organisms from The Sea Ranching Areas of Haizhou Bay in China

Heavy metals (HMs) have the characteristics of high toxicity, long residual time, and difficult degradation, which pose a potential threat to aquatic ecosystems. The distribution and migration of HMs in different media can reflect their potential impact on aquatic ecosystem health. In this study, we analyzed the distribution characteristics of seven HMs (Zn, Cu, Cr, Ni, Hg, As, and Pb) in the water and sediment and five groups of organisms (fish, Crustacean, cephalopod, bivalvia, and gastropoda) in the sea ranching area of Haizhou Bay and explored the regularity of HM accumulation from water and sediments to organisms. The results showed that in the water, Zn and Hg had the smallest concentrations in the nearshore area, Cr had the lowest concentrations in the offshore area, and As, Cu, Pb, and Ni had the lowest concentrations in the central area. In the sediment, Hg had the smallest concentrations in the nearshore area and As, Pb, Cr, Cu, Ni, and Zn had the lowest concentrations in the offshore area; the average contents of seven heavy metals all meet the Class I standard of sediments in China. The concentrations of Cu and Zn in crustaceans were significantly higher than those in fishes (p < 0.05), and As showed a higher enrichment effect in cephalopods. Under the influence of feeding habits and habitat environment, the BAF value of benthic crustaceans and bivalvia accumulated HMs from sediments is high, and the BAF value of fish accumulated HMs from water and sediments is low. Overall, the concentration of HMs in water is high, and HMs in sediments are in good condition, crustaceans and bivalviaa have a strong ability to accumulate HMs from water and sediments, while fish are weak. Therefore, in order to ensure the safety of biological quality, it is necessary to focus on the discharge of heavy metal pollutants near the coast in the future.

Determination of heavy metal content in water, sediment and some macrophyte species, iron reeds, Bitlis-Türkiye case study

Determination of heavy metal content in water, sediment and some macrophyte species, iron reeds, Bitlis-Türkiye case study

Seasonal variation of physicochemical parameters and heavy metal concentration in water and bottom sediment at harboring areas of Digha coast, West Bengal, India

This investigation attempts to reveal the seasonal variations in physicochemical parameters and heavy metal concentrations in winter and summer at harboring zones in the Digha coastal region of west Bengal. The area showed higher pH, electrical conductivity (EC), total dissolved solids (TDS), biochemical oxygen demand (BOD), sodium, potassium, organic carbon (OC) in summer and higher dissolved oxygen (DO), total alkalinity (TA), total hardness (TH) in winter. The concentration of heavy metals viz., cadmium, zinc, manganese, and chromium exceeded the permissible limit in summer, while copper, lead, nickel, and arsenic exceeded the limit in winter. Principal component analysis (PCA) results revealed that the metals responded positively and negatively among various harboring sampling sites The present study establishes the grave concern about heavy metal concentrations in the Digha coastal ecosystem and human health which are closely associated and dependent on it.

Multiple evaluations, risk assessment, and source identification of heavy metals in surface water and sediment of the Golmud River, northeastern Qinghai-Tibet Plateau, China

The water quality of the Golmud River is essential for environmental preservation and economic growth of Golmud city and Qarhan Salt Lake in China. Thirty-four samples of surface water and sediment from seventeen places in the Golmud River and thirty-two dustfall samples in the Qaidam Basin were collected. The concentrations of heavy metals (HMs) were measured; water quality, risk assessment, and multiple source analysis were applied. Concentrations of HMs in water were Zn > Cu > Ni > As > Pb > Cd > Hg, and in sediment were Ni > Zn > Pb > As > Cu > Cd > Hg. In water, the Nemerow pollution index (NP) values indicated that most of the sampling points seemly were seriously polluted; other water quality assessment results suggested no pollution. In sediment, the concentrations of 27% HMs exceeded the background values of soil in Qinghai; 48% exceeded the Earth crust background values, which were As, Hg, and Cd. The single factor index method (Pi), geological accumulation index (Igeo), and contamination factor (CF) revealed that As pollution is serious, followed by Hg and Cd; the pollution load index (PLI) and modified pollution index (mCd) values indicated that 64% and 57% of samples were polluted. NP values are shown serious pollution. The ecological risk results demonstrated a low risk in water and a medium risk in sediment. The average total hazard quotient values in sediment and water for adults and children revealed low non-carcinogenic risks. Carcinogenic risk indicated Ni in water and sediment, and As in sediment may be involved in cancer risk. Multivariate statistics showed that the HMs mainly came from nature, and human activities will also impact them. The upper continental crust values indicated that As and Hg have high background values. The saline dust storm was one of the essential sources of HMs, especially Hg. Various provenances constituted the material cycling of HMs in the surface environment.

Development and application of a new sensitivity analysis model for the remote sensing retrieval of heavy metals in water

This work proposes a new sensitivity analysis model, referred to as the D-δ(ε) model, for the remote sensing retrieval of heavy metals in bodies of water. By defining the reflectance ratio function (δ(ε)), we deduce the mathematical relationships between the heavy metal concentration sequences (Di) that can be effectively used for remote sensing retrievals and the radiometric resolution (ε) of the remote sensing instrument. Then, as a function of wavelength, we obtain the curve of the lower limit of the heavy metal concentrations in water that can be retrieved by remote sensing. To demonstrate the advantages of this model, we take two compounds, copper sulphate (CuSO4) and cadmium sulphide (CdS), as examples to discuss the remote sensing sensitivity of different wavelengths when retrievals are performed using the Chinese HJ-1A's hyperspectral imager (HSI). The results showed that the lowest detectable concentration of CuSO4 in the wavelength range of 460.04–496 nm (corresponding to bands 1–17 of the HSI image) can be below 0.15 mg/L, while the concentration of CdS can be lower than 0.001 mg/L in the separate ranges of 460.04–493.59 nm (bands 1–16) and 526.885–594.79 nm (bands 29–51). This model clearly demonstrates the mathematical relationship obeyed by "D-ε". Additionally, this model can not only calculate the retrieval concentration sequences at any observation wavelength but also intuitively provide the curve of the lower concentration limit for heavy metal retrievals. This work provides a theoretical basis for the selection of the most sensitive bands for remote sensing retrieval using hyperspectral images in the future.

Determination of heavy metals and essential minerals in water, soil and edible plant samples from the vicinity of ankpa coal mine, kogi state

This research work determined the physicochemical properties (pH, temperature, electrical conductivity, total dissolved solids and total suspended solids) of water, heavy metals (Cr, Cd, Cu, Pb and Zn) and essential minerals ( P, Ca, K, Mg and Na) in water, plant and soil samples collected from the vicinity of Ankpa Coal mine, Kogi State. The heavy metals were analyzed using a Flame Atomic Absorption Spectrophotometer machine and the essential minerals analyzed using Microwave Plasma Atomic Emission Spectrophotometer machine. Results obtained for physical parameters of water are within the ranges; pH (4.51-6.91), temperature (19.8-26.5˚C), electrical conductivity (110-210 µs/cm), TDS (7.0-13 mg/l) and TSS (0-1.5 mg/l). The heavy metals concentration in water are as follows; Cd (ND), Pb (0.001-0.077 mg/l), Cr (0.028-3.459 mg/l), Cu (0.09-0.057 mg/l) and Zn (0.050-0.161 mg/l). In plants, Cd (ND), Pb (0.043-0.096 mg/kg), Cr (0.138-0.325 mg/kg), Cu (0.139-0.153 mg/kg) and Zn (0.150-0.510 mg/kg). In soils, Cd (ND), Pb (0.127-0.664 mg/kg), Cr (1.206-4.718 mg/kg), Cu (0.155-0.934 mg/kg) and Zn (0.00-0.400 mg/kg). Results obtained for essential minerals ranged as follows; In water, P (0.19-43.31 mg/l), Ca (5.75-158.63 mg/l), K (5.04-32.28 mg/l), Mg (1.98-11.34 mg/l) and Na (10.70-28.29 mg/l). In plants, P (15.12-23.90 mg/kg), Ca (30.13-144.44 mg/kg), K (64.10-119.06 mg/kg), Mg (10.38-25.69 mg/kg) and Na (0.94-3.55 mg/kg). In soil, P (180.01-1879.51 mg/kg), Ca (11.61-85.18 mg/kg), K (3.02-114.98 mg/kg), Mg (2.59-14.05 mg/kg) and Na (8.24-15.03 mg/kg). The results were compared with the maximum permissible limit (MPL) set by World Health Organization (WHO), Food and Agricultural Organization (FAO) and recommended dietary intake set by Food and Nutrition Board (FNB). The physicochemical parameters were all within WHO maximum permissible limit for drinking water. Lead and Cr exceeded the MPL set for drinking water, all heavy metals were within set limit for plants. Lead, Cu and Chromium exceeded the MPL set for soil. The essential minerals in all samples were compared to recommended dietary intake (RDI). Correlation analysis was done using Pearson’s correlation coefficient. In plants Zn correlated positively with Ca (0.9298), K (0.7860) and Mg (0.9967) and in soil samples Cu correlated positively with P (0.8212), K (0.8191) and Na (0.8658), Cr correlated positively with P (0.9911), K (0.9915) and Na (0.8363) and Lead correlated positively with P (0.9734), K (0.9905) and Na (0.7948). It can be inferred from this result that Ankpa coal mine has negatively impacted its vicinity.

Ecotoxicological Assessment of Heavy Metal and Its Biochemical Effect in Fishes.

Level of toxic heavy metal concentration like lead (Pb), chromium (Cr), cadmium (Cd), iron (Fe), copper (Cu), zinc (Zn), and nickel (Ni) in thirty-six soft and hard organs and their impact on lipid profile of Hypophthalmichthys molitrix and Catla catla fish species inhibiting in Tanda Dam reservoir were investigated. The heavy metal concentrations in water, sediment, and fish of the different regions in the reservoir were determined with atomic absorption spectrophotometer. Lipid profile was carried out by AOAC official methods. The results showed that Pb was dominant among all the heavy metals in six organs, and its maximum concentration of Pb (22.5 mg kg-1 and 32.9 mg kg-1) was observed in scales in Hypophthalmichthys molitrix and tail of Catla catla, respectively. The maximum concentrations of Cd were observed in the head, scales, fins, and gills of Catla catla. The bioaccumulation of heavy metals was significantly different at (p ≤ 0.01) within the organs and between the fish species. The lipid concentration was minimum in those organs where the concentrations of heavy metals were maximum. It is clear from the findings that heavy metal accumulation reduces the lipid content of fish. It is inevitable to monitor the Tanda Dam reservoir to safeguard human health.

Heavy Metal Removal Efficiency of Tulsi (Ocimum Sanctum) from Water – A Review

Presence of heavy metal concentration in water is generally resulting from industrial pollution. Certain amount of some metals in water is good for human health but their elevated concentration in water is toxic for us as it causes irreversible damage to the organs. Therefore it is essential to monitor concentration of metals in water and to adopt proper mitigation measures to remove their excess concentration. Adsorption is one of the economic and environmental friendly methods to remove metal contamination from water and many bioadsorbents are used for the purpose. This review will focus on ability of a medicinal plant Tulsi (Ocimum Sanctum) to remove heavy metals (Pb, Cd, Cr, Fe, Cu, Zn) from water.

Occurrence and distribution of heavy metals in water and soil sediments of Vellore District, Tamil Nadu, India.

The occurrence of heavy metals (HMs) in water and soil sediments represents a serious environmental concern. This study revealed the presence and distribution of HMs in water and soil sediments of various places in Vellore District, Tamil Nadu, India. Twenty-one sites were selected along the study area, and inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to analyze the concentration of the heavy metals. The dominance of various HMs in the soil sediment sample follows the order strontium (Sr) > Manganese (Mn) > Barium (Ba) > Zinc (Zn) > Nickel (Ni) and Sr > Mn > Zn > Boron (B) > , respectively. It was found that the concentration of HMs in water and soil sediments in Ambur market and Mottukollai area was significantly higher than the recommended limits. Thus, the results showed that the presence of HMs in water and soil sediments could be threatened pollution factors unsafe for irrigation, drinking, and other human activities.