Despite its often illegal nature, artisanal gold mining in Burkina Faso contributes to the economic and social development of the country. However, the rudimentary techniques used in gold panning have a significant im...Despite its often illegal nature, artisanal gold mining in Burkina Faso contributes to the economic and social development of the country. However, the rudimentary techniques used in gold panning have a significant impact on the environment due to inappropriate practices and the use of various chemical substances. This study aims to assess the impact of artisanal gold mining on the quality of water resources in a rural community at Méguet, Burkina Faso. To this end, surface and groundwater samples were collected and analyzed at the BUMIGEB laboratory. Field results show that the waters are slightly alkaline (6.97 < pH < 8.1), weakly mineralized and conductive (124 < EC < 543 μS/cm), with temperatures ranging from 24.6˚C to 31.6˚C. In addition, trace metals (TMEs) analyzed from surface and subsurface waters show very high levels, generally deviating from the levels recommended by WHO guidelines for Burkina Faso. Trace metals contamination of water resources in the commune of Méguet is mainly due to Fe (3.78 - 11.12 mg/kg), Hg (0.03 - 0.29 mg/kg), As (0.01- 6.31 mg/kg) and Pb (0.01 - 3.8 mg/kg). This study can serve as a basis for guiding national environmental policies to protect the water resources of the Méguet mine.展开更多
Sairme mineral water, one of the famous mineral waters in Georgia, is renowned for its exceptional healing properties. The distinctiveness and therapeutic benefits of the naturally sourced mineral water, known as “Sa...Sairme mineral water, one of the famous mineral waters in Georgia, is renowned for its exceptional healing properties. The distinctiveness and therapeutic benefits of the naturally sourced mineral water, known as “Sairme”, stem from its rich array of microelements, notably including iron and manganese. Since 1948, the bottling of Sairme mineral water has been a prominent activity. Named after the Sairme deposit, this mineral water is packaged in various formats to cater to diverse consumer preferences. The bottling process involves transporting the mineral water from wells to the bottling plant through pipelines. Prior to bottling, the mineral water undergoes meticulous processing stages in adherence to current Georgian and international regulations. This process ensures that the concentration of trace elements in the bottled water is minimized, maintaining its purity and quality. Given the importance of preserving the microelements present in bottled mineral water, our research is dedicated to optimizing the technological process. Our objective is to safeguard the valuable microelements while ensuring the highest standards of quality and safety in the final product.展开更多
Motivated by the fascinating merits of wide electrochemical stability window(ESW)and nonflammability,ionic liquids(ILs)have been utilized as advanced electrolytes in various emerging electrochemical energy storage tec...Motivated by the fascinating merits of wide electrochemical stability window(ESW)and nonflammability,ionic liquids(ILs)have been utilized as advanced electrolytes in various emerging electrochemical energy storage technologies.However,ILs are hygroscopic to the water in the air and the presence of trace water will narrow the ESW of ILs.In this article,we report that a localized solvation nanostructure(LSNS)is formed in ILs,which plays an important role in fully recovering the originally decreased ESW of[EMIM][TFSI]IL owing to the trace water.Such LSNS is consisted of Li^(+)ions with water molecules as the center,TFSI-anions as the secondary periphery and EMIM^(+)cations as the outermost layer after adding the proper amount of LiTFSI.This nanostructure can restrain the possibility of trace water to approach the electrode/electrolyte interfaces and adverse redox reactions,thereby recovering the ESW.Moreover,the effectiveness of this strategy in different kinds of ILs to fully recover ESW decreasing is verified.This article comes up with a feasible method to eliminate the trace water caused ESW drop for ILbased electrolytes and provides a new insight for understanding the molecular-level interaction between different ions in ILs with water molecules.展开更多
Environmental degradation and unethical human intervention in the natural system has increased the concern for the betterment of healthy living. The deterioration of aquatic system is commonplace in the developing wor...Environmental degradation and unethical human intervention in the natural system has increased the concern for the betterment of healthy living. The deterioration of aquatic system is commonplace in the developing world. The present paper shows the trace elements (Ni, Zn, Fe, Pb, Cd, Co, Cu and Mn) concentrations in the drinking water of Aligarh city and their possible effect on the health of the inhabitants. The higher concen- tration of some elements in the drinking water and the poor health of inhabitants are found correlated. The statistical analysis of the data shows positive correlation between some elements. The principal component analysis of the data gives four factors with significance level of 42%, 29%, 15% and 12% respectively.展开更多
We tested for fourteen trace elements in samples collected from the Ordovician strata in Datun coal field.The vertical concentration variation of these trace elements is reported.The relationship of the variation to t...We tested for fourteen trace elements in samples collected from the Ordovician strata in Datun coal field.The vertical concentration variation of these trace elements is reported.The relationship of the variation to the water-bearing capacity of the Ordovician strata is discussed.The minimum concentration of eleven(of 14 total) trace elements appears in the lower Majiagou formation.The maximum concentrations mainly appear in the Badou and Jiawang formations:eight maxima are located in Badou and four more are in Jiawang.The study of karst development and the water-bearing capacity of Ordovician strata shows that karst is well developed in the Majiagou formation and there is a consequent high water-bearing capacity in this formation:Badou and Jiawang formations are contrary to this situation.The results illustrate that the minimum concentrations of most trace elements within certain Ordovician formations can be taken as strong evidence for the existence of a well developed karst and a high water-bearing capacity.展开更多
Mining subsidence pools are water bodies formed by soil subsidence near mines. We studied the impact the surrounding coal production activities and power plants have on these waters by measuring the concentrations of ...Mining subsidence pools are water bodies formed by soil subsidence near mines. We studied the impact the surrounding coal production activities and power plants have on these waters by measuring the concentrations of harmful trace elements in these waters. The concentration of the four elements F, Hg, Se and As increased by 0.92%, 0.78%, 0.70% and 0.81%, respectively, in the Datong mining subsidence pool from November 2004 to November 2006. The four elements increased by 1.58%, 1.23%, 1.08% and 0.92%, respectively, in the Xie’er mining subsidence pool and 1.16%, 1.06%, 1.02% and 1.01%, respectively, in the Pansan mining subsidence pool over the same time period. The absolute levels of F, Hg, Se and As in the pool are related to the background levels of the elements. A close relationship between nearby coal mines and power plants and increasing levels of the measured elements is noted.展开更多
Water contamination by chemical pollutants is increasingly associated with waterborne diseases worldwide. The objective of this study is to assess the chemical health risk associated with drinking water consumption in...Water contamination by chemical pollutants is increasingly associated with waterborne diseases worldwide. The objective of this study is to assess the chemical health risk associated with drinking water consumption in Dakar, Senegal. The methodology adopted in this study is based on the determination of trace metals (Cd, Pb, Fe, Cu and Mn) in human drinking water by flame atomic absorption spectrometry, the estimation of the exposure of populations of the study area on the basis of the quantity of water consumed daily and the determination of the hazard quotient which allows estimating the health risk. The results indicate unacceptable levels of Pb and Cd in the water according to World Health Organization (WHO) guidelines, while the concentrations of Fe, Cu and Mn are below the regulatory values. The hazard quotient (HQ) is in the majority of samples higher than 1 in children and infants for scenario 1 (based on WHO data), reflecting a high risk for this target. In scenario 2 based on consumption data from the populations studied, the HQ is greater than 1 only in heavy consumers. The drinking water consumed by Dakar population presents health risks related to Pb and Cd, particularly for infants, children and heavy consumers, hence the need to strengthen the water treatment system before home consumption.展开更多
This study was conducted during Dec2011-Nov2012 on three stations located in the south sector of Main Outfall Drain (MOD) River. Station 1 was near Al-Holandee Bridge which was the general carriage way in the center o...This study was conducted during Dec2011-Nov2012 on three stations located in the south sector of Main Outfall Drain (MOD) River. Station 1 was near Al-Holandee Bridge which was the general carriage way in the center of Al-Nassiriya city, station 2 was 20 km far from the first station, while station 3 was in the beginning of the new branch. This study reveals the Seasonal Variation of Total petroleum hydrocarbons (TPHs) in both surface waters, sediment and it is related with trace metals nickel and vanadium in water (dissolved, particulate) and sediment (residual and exchangeable) phases. Also, the study shows the relationships between the concentration of Ni and V with Total Organic Carbon (TOC%) in the sediment.展开更多
In the present study, trace elements present in the river waters of Sarzhal and Akzhar region were measured using inductively coupled plasma mass spectrometry (ICP-MS). The reason for monitoring trace elements at thos...In the present study, trace elements present in the river waters of Sarzhal and Akzhar region were measured using inductively coupled plasma mass spectrometry (ICP-MS). The reason for monitoring trace elements at those two locations is to verify water quality. The village of Sarzhal is situated in an area that has been affected by weapon testing and continues to receive inputs of contaminants (including radionuclides). The concentrations of trace elements in the river water of Sarzhal and Akzhar villages were generally found to be within allowable levels. However, the concentrations of Na 251.56 mg/l, Cr 3.26 μg/l, P 64.56 μg/l and Se 18.162 μg/l in the river of Akzhar were found to be higher than the maximum allowable concentrations (MAC). In Sarzhal, the level of Al 6.66 mg/l, Cr 5.04 μg/l and P 13.44 μg/l exceeded the MAC values.展开更多
Faced with rapid population growth and fresh water scarcity, reuse of reclaimed water is growing worldwide and becoming an integral part of water resource management. Our objective was to determine the fate of nutrien...Faced with rapid population growth and fresh water scarcity, reuse of reclaimed water is growing worldwide and becoming an integral part of water resource management. Our objective was to determine the fate of nutrients, trace metals, bacteria, and legacy organic compounds (organochlorine pesticides) in the recycled water from five commercial nursery ponds in Florida. The pH of recycled water at all sites was 8.1 - 9.3, except one site (6.5), while the electrical conductivity (EC) was 0.31 - 0.36 dS/m. Concentrations of trace metals in recycled water were low: Fe (0.125 - 0.367 mg/L), Al (0.126 - 0.169 mg/L), B (0.104 - 0.153 mg/L), Zn (0.123 - 0.211 mg/L), and Mn (<0.111 mg/L). Total phosphorus (P) and total nitrogen (N) in the recycled water were 0.35 - 1.00 mg/L and 1.56 - 2.30 mg/L, respectively. Among organochlorine pesticides, endrin aldehyde was the only pesticide detected in all nursery recycled water ponds, with concentrations from 0.04 to 0.10 μg/L at four sites and 1.62 μg/L at one site. Other detected pesticides in recycled water were methoxychlor, endosulfan sulfate, dichlorodiphenyldichloroethylene (DDE) and α-chlorodane, with concentrations < 0.20 μg/L. Total coliforms and Escherichia coli (E. coli) in recycled water were 20 - 50 colony forming units (CFU)/100 mL. We conclude that the concentrations of various inorganic and organic compounds in recycled water are very low and do not appear to be problematic for irrigation purposes in Florida’s nursery recycled water ponds.展开更多
The indirect voltammetric determination of trace sulfate (2.0×10^(-6)~4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported....The indirect voltammetric determination of trace sulfate (2.0×10^(-6)~4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported.This method has been used for the analysis of natural waters with satisfactory results.展开更多
A novel and efficient technology for separating and recovering precious metals from waste water containing traces of Pd and Ag was studied by the combination of agglomeration and adsorption. The recovery process and t...A novel and efficient technology for separating and recovering precious metals from waste water containing traces of Pd and Ag was studied by the combination of agglomeration and adsorption. The recovery process and the impacts of operating conditions such as pH value of waste water, adsorption time, additive quantity of the flocculant and adsorbent on the recovery efficiency were studied experimentally. The results show that Freundlich isothermal equation is suitable for describing the behavior of the recovery process, and the apparent first-order adsorption rate constant k at 25 ℃ is about 0.233 4 h-1. The optimum technology conditions during the recovery process are that pH value is 8?9; the volume ratio of flocculant to waste water is about 1:(2 000-4 000); the mass ratio of adsorbent to waste water is 1:(30-40); and processing time is 2-4 h. Finally, the field tests were done at the optimum technology conditions, which show that the total concentration of Pd and Ag in the waste water below 11 mg/L can be reduced to be less than 1 mg/L.展开更多
Concentrations of nitrate and trace elements such as arsenic,cadmium,chromium,copper,manganese,nickel,lead,selenium,antimony and mercury in 18 different brands of bottled water were investigated.For comparison,samples...Concentrations of nitrate and trace elements such as arsenic,cadmium,chromium,copper,manganese,nickel,lead,selenium,antimony and mercury in 18 different brands of bottled water were investigated.For comparison,samples of tap and well water from three different places of Tehran were also analyzed.UV/VIS spectrophotometer and Graphite Furnace Atomic Absorption Spectrometer were used for the analysis of nitrate and trace elements,respectively.Results obtained were compared to Iranian,World Health Organization(WHO)and Environmental Protection Agency(EPA)guideline for drinking water.Nitrate concentration in bottled,tap and well water samples were in maximum safe nitrate concentration of Iranian and WHO standards.However,70%of bottled water samples and one sample of tap water were below the standard level proposed by EPA and probably remedial action should be taken.Concentration levels of all analyzed elements investigated in all examined water samples were below the maximum contaminant level prescribed by Iranian,WHO and EPA regulations.展开更多
The some trace elements in the Antarctic and Arctic snow, ice, water were studied using the methodology and theory of water vapor chemistry. The concentrations of ions Zn 2+ , Cd 2+ , Pb 2+ , Cu 2+ , S...The some trace elements in the Antarctic and Arctic snow, ice, water were studied using the methodology and theory of water vapor chemistry. The concentrations of ions Zn 2+ , Cd 2+ , Pb 2+ , Cu 2+ , Sn 4+ , Bi 3+ in Antarctic and Arctic snow a significant spatial similarity; they are also close to those defined elsewhere on the basic of studies of water vapor chemistry: on average Zn 2+ 5.0 μg/L, Cd 2+ 0.080 μg/L, Pb 2+ 0.030 μg/L, Cu 2+ 0.70 μg/L, Sn 4+ 0.99 μg/L, Bi 3+ 0.18 μg/L. Apparently, the ion concentration in the Antarctic and Arctic region represent natural baseline values and are controlled by natural water cycles.展开更多
Fishponds waters intended to satisfy the nutritional needs of the populations in terms of supply of fish resources are strongly and unfortunately exposed to the mobility and dispersion of metallic trace elements (TMEs...Fishponds waters intended to satisfy the nutritional needs of the populations in terms of supply of fish resources are strongly and unfortunately exposed to the mobility and dispersion of metallic trace elements (TMEs) or to the persistence in the environment and in the form of pesticide residues from human activities. The objective of this work is to evaluate, on the one hand, the levels of identified pesticide residues and, on the other hand, those of researched TMEs (lead, cadmium, mercury and arsenic) in the waters of ponds used for fish farming in Zépréguhé, a locality located 9 km from the town of Daloa in the centre-west of Côte d’Ivoire. The dosage of the samples carried out by means of a gas chromatograph coupled to a mass spectrometer (GC/MS) made it possible to detect nine (9) pesticide molecules, including eight (8) organochlorines and a single molecule from the pyrethroid family, obtained from the detection limit of 0.006 μg/L and the quantification limit of 0.018 μg/L. The maximum average concentration was obtained with α-endosulfan for a content reaching 0.8038 μg/L and well above the maximum admissible concentration of 0.1 μg/L. The TMEs were quantified using an atomic absorption spectrophotometer (AAS). Arsenic is the most abundant metal with an average concentration of 9.497 μg/L. With the exception of lead, these measured levels are above the acceptable limit values for freshwater. This study showed that human activities such as the use of fertilisers and plant protection products in plantations, sand extraction and road traffic have a negative impact on the quality of the water in ponds used for fish breeding.展开更多
Household desalinated drinking water samples collected from outdoor points and from indoor consumption points at 99 locations representing more than 95% of the residential areas in Kuwait were analyzed for 25 trace el...Household desalinated drinking water samples collected from outdoor points and from indoor consumption points at 99 locations representing more than 95% of the residential areas in Kuwait were analyzed for 25 trace elements and water quality parameters. Only Al, Cr, Co, Cu, Fe, Pb, Ni, and Zn were found to be over-represented at the consumption point compared with the outdoor point, with wide variations among the sampling locations and elements. The highest increases were observed for Fe (135%) and Zn (123%), followed by Pb (69%), Co (58%), Cu (42%), Cr (31%), and Al (30%), and the lowest increase was observed for Ni (19%). In most cases, the increases in Cu, Fe, and Zn were inversely proportional to the conductivity and directly proportional to the Cl– concentration. In the outdoor samples, only Fe exceeded the US-EPA guideline (in 3% of the outdoor samples taken), whereas Fe, Pb, and Ni exceeded the US-EPA and WHO guidelines in 8.5%, 0.3%, and 1% of the indoor consumption point samples, respectively. Thus, leaching from household utilities may cause health concerns for consumers of drinking water in Kuwait. The increases in Fe were the highest in the summer (240%), and in this regard, Fe exhibited the greatest difference between summer and winter (the increase was 139% higher in the summer). The results of the present study may be useful for water production authorities and consumers in Kuwait and suggest the use of alternative new pipes with more resistant internal coatings and connecting techniques.展开更多
The vertical distributions of trace metals and physicochemical parameters in water columns in Kigoma Bay and Kungwe Bay in eastern Lake Tanganyika, Tanzania, were studied. The Al, Ba, Ca, Co,K, Mg, Mn, Mo, Na, Sn, Sr,...The vertical distributions of trace metals and physicochemical parameters in water columns in Kigoma Bay and Kungwe Bay in eastern Lake Tanganyika, Tanzania, were studied. The Al, Ba, Ca, Co,K, Mg, Mn, Mo, Na, Sn, Sr, and V concentrations were low and varied very little with depth. The toxic heavy metal(As, Cr, Cu, Ni, Pb, and Zn) concentrations were relatively high in the surface water, and the Cu, Ni, Pb, and Zn concentrations decreased with depth. Principal component and cluster analyses indicated that the metals in the lake had three main sources. Al, Ba, Ca, Co, Cu, Cr, Mn, Sr, Sn, and V were found to be geogenic; As, Cr, Cu, Mo, Ni, Pb, Sn and Zn anthropogenic; and As, Ca, Co, Mg, and Na biogenic.Human health risk assessments were performed, and it was found that trace metals in the water at most of the sampling sites would cause no potential adverse ef fects or non-carcinogenic health risks through dermal contact or ingestion. However, trace metals in surface water in Kungwe Bay could have certain adverse ef fects on human health through the ingestion pathway(the total hazard quotient for ingestion(ΣHQi ng)was 1.75(a value >1 was de?ned as possibly indicating adverse ef fects). The Pb HQi ng for surface water in Kungwe Bay was 1.50 and contributed >80% of the ΣHQ_(ing_, implying that Pb pollution is a water quality and safety problem that needs to be carefully monitored and the potential sources identi?ed.展开更多
文摘Despite its often illegal nature, artisanal gold mining in Burkina Faso contributes to the economic and social development of the country. However, the rudimentary techniques used in gold panning have a significant impact on the environment due to inappropriate practices and the use of various chemical substances. This study aims to assess the impact of artisanal gold mining on the quality of water resources in a rural community at Méguet, Burkina Faso. To this end, surface and groundwater samples were collected and analyzed at the BUMIGEB laboratory. Field results show that the waters are slightly alkaline (6.97 < pH < 8.1), weakly mineralized and conductive (124 < EC < 543 μS/cm), with temperatures ranging from 24.6˚C to 31.6˚C. In addition, trace metals (TMEs) analyzed from surface and subsurface waters show very high levels, generally deviating from the levels recommended by WHO guidelines for Burkina Faso. Trace metals contamination of water resources in the commune of Méguet is mainly due to Fe (3.78 - 11.12 mg/kg), Hg (0.03 - 0.29 mg/kg), As (0.01- 6.31 mg/kg) and Pb (0.01 - 3.8 mg/kg). This study can serve as a basis for guiding national environmental policies to protect the water resources of the Méguet mine.
文摘Sairme mineral water, one of the famous mineral waters in Georgia, is renowned for its exceptional healing properties. The distinctiveness and therapeutic benefits of the naturally sourced mineral water, known as “Sairme”, stem from its rich array of microelements, notably including iron and manganese. Since 1948, the bottling of Sairme mineral water has been a prominent activity. Named after the Sairme deposit, this mineral water is packaged in various formats to cater to diverse consumer preferences. The bottling process involves transporting the mineral water from wells to the bottling plant through pipelines. Prior to bottling, the mineral water undergoes meticulous processing stages in adherence to current Georgian and international regulations. This process ensures that the concentration of trace elements in the bottled water is minimized, maintaining its purity and quality. Given the importance of preserving the microelements present in bottled mineral water, our research is dedicated to optimizing the technological process. Our objective is to safeguard the valuable microelements while ensuring the highest standards of quality and safety in the final product.
基金supported by the Zhaoqing Municipal Science and Technology Bureau(2019K038)the Research Start-up Funds from Sun Yat-sen University。
文摘Motivated by the fascinating merits of wide electrochemical stability window(ESW)and nonflammability,ionic liquids(ILs)have been utilized as advanced electrolytes in various emerging electrochemical energy storage technologies.However,ILs are hygroscopic to the water in the air and the presence of trace water will narrow the ESW of ILs.In this article,we report that a localized solvation nanostructure(LSNS)is formed in ILs,which plays an important role in fully recovering the originally decreased ESW of[EMIM][TFSI]IL owing to the trace water.Such LSNS is consisted of Li^(+)ions with water molecules as the center,TFSI-anions as the secondary periphery and EMIM^(+)cations as the outermost layer after adding the proper amount of LiTFSI.This nanostructure can restrain the possibility of trace water to approach the electrode/electrolyte interfaces and adverse redox reactions,thereby recovering the ESW.Moreover,the effectiveness of this strategy in different kinds of ILs to fully recover ESW decreasing is verified.This article comes up with a feasible method to eliminate the trace water caused ESW drop for ILbased electrolytes and provides a new insight for understanding the molecular-level interaction between different ions in ILs with water molecules.
文摘Environmental degradation and unethical human intervention in the natural system has increased the concern for the betterment of healthy living. The deterioration of aquatic system is commonplace in the developing world. The present paper shows the trace elements (Ni, Zn, Fe, Pb, Cd, Co, Cu and Mn) concentrations in the drinking water of Aligarh city and their possible effect on the health of the inhabitants. The higher concen- tration of some elements in the drinking water and the poor health of inhabitants are found correlated. The statistical analysis of the data shows positive correlation between some elements. The principal component analysis of the data gives four factors with significance level of 42%, 29%, 15% and 12% respectively.
文摘We tested for fourteen trace elements in samples collected from the Ordovician strata in Datun coal field.The vertical concentration variation of these trace elements is reported.The relationship of the variation to the water-bearing capacity of the Ordovician strata is discussed.The minimum concentration of eleven(of 14 total) trace elements appears in the lower Majiagou formation.The maximum concentrations mainly appear in the Badou and Jiawang formations:eight maxima are located in Badou and four more are in Jiawang.The study of karst development and the water-bearing capacity of Ordovician strata shows that karst is well developed in the Majiagou formation and there is a consequent high water-bearing capacity in this formation:Badou and Jiawang formations are contrary to this situation.The results illustrate that the minimum concentrations of most trace elements within certain Ordovician formations can be taken as strong evidence for the existence of a well developed karst and a high water-bearing capacity.
基金Projects 070414168 supported by the Provincial University National Natural Science Foundation of Anhui2006KJ009A by the Key National Science Foundation of Anhui Province
文摘Mining subsidence pools are water bodies formed by soil subsidence near mines. We studied the impact the surrounding coal production activities and power plants have on these waters by measuring the concentrations of harmful trace elements in these waters. The concentration of the four elements F, Hg, Se and As increased by 0.92%, 0.78%, 0.70% and 0.81%, respectively, in the Datong mining subsidence pool from November 2004 to November 2006. The four elements increased by 1.58%, 1.23%, 1.08% and 0.92%, respectively, in the Xie’er mining subsidence pool and 1.16%, 1.06%, 1.02% and 1.01%, respectively, in the Pansan mining subsidence pool over the same time period. The absolute levels of F, Hg, Se and As in the pool are related to the background levels of the elements. A close relationship between nearby coal mines and power plants and increasing levels of the measured elements is noted.
文摘Water contamination by chemical pollutants is increasingly associated with waterborne diseases worldwide. The objective of this study is to assess the chemical health risk associated with drinking water consumption in Dakar, Senegal. The methodology adopted in this study is based on the determination of trace metals (Cd, Pb, Fe, Cu and Mn) in human drinking water by flame atomic absorption spectrometry, the estimation of the exposure of populations of the study area on the basis of the quantity of water consumed daily and the determination of the hazard quotient which allows estimating the health risk. The results indicate unacceptable levels of Pb and Cd in the water according to World Health Organization (WHO) guidelines, while the concentrations of Fe, Cu and Mn are below the regulatory values. The hazard quotient (HQ) is in the majority of samples higher than 1 in children and infants for scenario 1 (based on WHO data), reflecting a high risk for this target. In scenario 2 based on consumption data from the populations studied, the HQ is greater than 1 only in heavy consumers. The drinking water consumed by Dakar population presents health risks related to Pb and Cd, particularly for infants, children and heavy consumers, hence the need to strengthen the water treatment system before home consumption.
文摘This study was conducted during Dec2011-Nov2012 on three stations located in the south sector of Main Outfall Drain (MOD) River. Station 1 was near Al-Holandee Bridge which was the general carriage way in the center of Al-Nassiriya city, station 2 was 20 km far from the first station, while station 3 was in the beginning of the new branch. This study reveals the Seasonal Variation of Total petroleum hydrocarbons (TPHs) in both surface waters, sediment and it is related with trace metals nickel and vanadium in water (dissolved, particulate) and sediment (residual and exchangeable) phases. Also, the study shows the relationships between the concentration of Ni and V with Total Organic Carbon (TOC%) in the sediment.
文摘In the present study, trace elements present in the river waters of Sarzhal and Akzhar region were measured using inductively coupled plasma mass spectrometry (ICP-MS). The reason for monitoring trace elements at those two locations is to verify water quality. The village of Sarzhal is situated in an area that has been affected by weapon testing and continues to receive inputs of contaminants (including radionuclides). The concentrations of trace elements in the river water of Sarzhal and Akzhar villages were generally found to be within allowable levels. However, the concentrations of Na 251.56 mg/l, Cr 3.26 μg/l, P 64.56 μg/l and Se 18.162 μg/l in the river of Akzhar were found to be higher than the maximum allowable concentrations (MAC). In Sarzhal, the level of Al 6.66 mg/l, Cr 5.04 μg/l and P 13.44 μg/l exceeded the MAC values.
文摘Faced with rapid population growth and fresh water scarcity, reuse of reclaimed water is growing worldwide and becoming an integral part of water resource management. Our objective was to determine the fate of nutrients, trace metals, bacteria, and legacy organic compounds (organochlorine pesticides) in the recycled water from five commercial nursery ponds in Florida. The pH of recycled water at all sites was 8.1 - 9.3, except one site (6.5), while the electrical conductivity (EC) was 0.31 - 0.36 dS/m. Concentrations of trace metals in recycled water were low: Fe (0.125 - 0.367 mg/L), Al (0.126 - 0.169 mg/L), B (0.104 - 0.153 mg/L), Zn (0.123 - 0.211 mg/L), and Mn (<0.111 mg/L). Total phosphorus (P) and total nitrogen (N) in the recycled water were 0.35 - 1.00 mg/L and 1.56 - 2.30 mg/L, respectively. Among organochlorine pesticides, endrin aldehyde was the only pesticide detected in all nursery recycled water ponds, with concentrations from 0.04 to 0.10 μg/L at four sites and 1.62 μg/L at one site. Other detected pesticides in recycled water were methoxychlor, endosulfan sulfate, dichlorodiphenyldichloroethylene (DDE) and α-chlorodane, with concentrations < 0.20 μg/L. Total coliforms and Escherichia coli (E. coli) in recycled water were 20 - 50 colony forming units (CFU)/100 mL. We conclude that the concentrations of various inorganic and organic compounds in recycled water are very low and do not appear to be problematic for irrigation purposes in Florida’s nursery recycled water ponds.
文摘The indirect voltammetric determination of trace sulfate (2.0×10^(-6)~4.0×10^(-5) mol/L ) with the adsorptive complex wave of lead(Ⅱ)-tetrakis (4-trimethylammonium phenyl) porphyrin (PbTTMAPP) is reported.This method has been used for the analysis of natural waters with satisfactory results.
文摘A novel and efficient technology for separating and recovering precious metals from waste water containing traces of Pd and Ag was studied by the combination of agglomeration and adsorption. The recovery process and the impacts of operating conditions such as pH value of waste water, adsorption time, additive quantity of the flocculant and adsorbent on the recovery efficiency were studied experimentally. The results show that Freundlich isothermal equation is suitable for describing the behavior of the recovery process, and the apparent first-order adsorption rate constant k at 25 ℃ is about 0.233 4 h-1. The optimum technology conditions during the recovery process are that pH value is 8?9; the volume ratio of flocculant to waste water is about 1:(2 000-4 000); the mass ratio of adsorbent to waste water is 1:(30-40); and processing time is 2-4 h. Finally, the field tests were done at the optimum technology conditions, which show that the total concentration of Pd and Ag in the waste water below 11 mg/L can be reduced to be less than 1 mg/L.
文摘Concentrations of nitrate and trace elements such as arsenic,cadmium,chromium,copper,manganese,nickel,lead,selenium,antimony and mercury in 18 different brands of bottled water were investigated.For comparison,samples of tap and well water from three different places of Tehran were also analyzed.UV/VIS spectrophotometer and Graphite Furnace Atomic Absorption Spectrometer were used for the analysis of nitrate and trace elements,respectively.Results obtained were compared to Iranian,World Health Organization(WHO)and Environmental Protection Agency(EPA)guideline for drinking water.Nitrate concentration in bottled,tap and well water samples were in maximum safe nitrate concentration of Iranian and WHO standards.However,70%of bottled water samples and one sample of tap water were below the standard level proposed by EPA and probably remedial action should be taken.Concentration levels of all analyzed elements investigated in all examined water samples were below the maximum contaminant level prescribed by Iranian,WHO and EPA regulations.
文摘The some trace elements in the Antarctic and Arctic snow, ice, water were studied using the methodology and theory of water vapor chemistry. The concentrations of ions Zn 2+ , Cd 2+ , Pb 2+ , Cu 2+ , Sn 4+ , Bi 3+ in Antarctic and Arctic snow a significant spatial similarity; they are also close to those defined elsewhere on the basic of studies of water vapor chemistry: on average Zn 2+ 5.0 μg/L, Cd 2+ 0.080 μg/L, Pb 2+ 0.030 μg/L, Cu 2+ 0.70 μg/L, Sn 4+ 0.99 μg/L, Bi 3+ 0.18 μg/L. Apparently, the ion concentration in the Antarctic and Arctic region represent natural baseline values and are controlled by natural water cycles.
文摘Fishponds waters intended to satisfy the nutritional needs of the populations in terms of supply of fish resources are strongly and unfortunately exposed to the mobility and dispersion of metallic trace elements (TMEs) or to the persistence in the environment and in the form of pesticide residues from human activities. The objective of this work is to evaluate, on the one hand, the levels of identified pesticide residues and, on the other hand, those of researched TMEs (lead, cadmium, mercury and arsenic) in the waters of ponds used for fish farming in Zépréguhé, a locality located 9 km from the town of Daloa in the centre-west of Côte d’Ivoire. The dosage of the samples carried out by means of a gas chromatograph coupled to a mass spectrometer (GC/MS) made it possible to detect nine (9) pesticide molecules, including eight (8) organochlorines and a single molecule from the pyrethroid family, obtained from the detection limit of 0.006 μg/L and the quantification limit of 0.018 μg/L. The maximum average concentration was obtained with α-endosulfan for a content reaching 0.8038 μg/L and well above the maximum admissible concentration of 0.1 μg/L. The TMEs were quantified using an atomic absorption spectrophotometer (AAS). Arsenic is the most abundant metal with an average concentration of 9.497 μg/L. With the exception of lead, these measured levels are above the acceptable limit values for freshwater. This study showed that human activities such as the use of fertilisers and plant protection products in plantations, sand extraction and road traffic have a negative impact on the quality of the water in ponds used for fish breeding.
文摘Household desalinated drinking water samples collected from outdoor points and from indoor consumption points at 99 locations representing more than 95% of the residential areas in Kuwait were analyzed for 25 trace elements and water quality parameters. Only Al, Cr, Co, Cu, Fe, Pb, Ni, and Zn were found to be over-represented at the consumption point compared with the outdoor point, with wide variations among the sampling locations and elements. The highest increases were observed for Fe (135%) and Zn (123%), followed by Pb (69%), Co (58%), Cu (42%), Cr (31%), and Al (30%), and the lowest increase was observed for Ni (19%). In most cases, the increases in Cu, Fe, and Zn were inversely proportional to the conductivity and directly proportional to the Cl– concentration. In the outdoor samples, only Fe exceeded the US-EPA guideline (in 3% of the outdoor samples taken), whereas Fe, Pb, and Ni exceeded the US-EPA and WHO guidelines in 8.5%, 0.3%, and 1% of the indoor consumption point samples, respectively. Thus, leaching from household utilities may cause health concerns for consumers of drinking water in Kuwait. The increases in Fe were the highest in the summer (240%), and in this regard, Fe exhibited the greatest difference between summer and winter (the increase was 139% higher in the summer). The results of the present study may be useful for water production authorities and consumers in Kuwait and suggest the use of alternative new pipes with more resistant internal coatings and connecting techniques.
基金Supported by the Construction Plan for Overseas Scientific Education Base of the Chinese Academy of Sciences(No.SAJC201609)the National Natural Science Foundation of China(No.51409241)the National Key Research and Development Program of China(No.2016YFE0123300)
文摘The vertical distributions of trace metals and physicochemical parameters in water columns in Kigoma Bay and Kungwe Bay in eastern Lake Tanganyika, Tanzania, were studied. The Al, Ba, Ca, Co,K, Mg, Mn, Mo, Na, Sn, Sr, and V concentrations were low and varied very little with depth. The toxic heavy metal(As, Cr, Cu, Ni, Pb, and Zn) concentrations were relatively high in the surface water, and the Cu, Ni, Pb, and Zn concentrations decreased with depth. Principal component and cluster analyses indicated that the metals in the lake had three main sources. Al, Ba, Ca, Co, Cu, Cr, Mn, Sr, Sn, and V were found to be geogenic; As, Cr, Cu, Mo, Ni, Pb, Sn and Zn anthropogenic; and As, Ca, Co, Mg, and Na biogenic.Human health risk assessments were performed, and it was found that trace metals in the water at most of the sampling sites would cause no potential adverse ef fects or non-carcinogenic health risks through dermal contact or ingestion. However, trace metals in surface water in Kungwe Bay could have certain adverse ef fects on human health through the ingestion pathway(the total hazard quotient for ingestion(ΣHQi ng)was 1.75(a value >1 was de?ned as possibly indicating adverse ef fects). The Pb HQi ng for surface water in Kungwe Bay was 1.50 and contributed >80% of the ΣHQ_(ing_, implying that Pb pollution is a water quality and safety problem that needs to be carefully monitored and the potential sources identi?ed.