Heavy Metal Pollution In Water Research Articles

Using δ34S–SO4 and δ18O–SO4 to trace the sources of sulfate in different types of surface water from the Linhuan coal-mining subsidence area of Huaibei, China

Many studies have been carried out on the water environment in coal-mining subsidence area, which have mainly focused on the two aspects of nitrogen and phosphorus as well as heavy metal pollution in water. However, little attention has been paid to the problem of sulfate pollution. The surrounding conditions of subsidence area in Linhuan are complex, and there are a large number of coal gangue accumulation and coal mining activities. The sulfate pollution in water body is serious, while the specific sulfate source remains unclear. In the present study, the mining subsidence area in Linhuan, Huaibei was selected as the main study area, and 21 water samples were systematically collected from river water, subsidence area water and mine drainage. The conventional hydrochemical indexes were analyzed, and sulfur and oxygen isotopes were used to trace sources of sulfate in river water and subsidence area water. Our results showed that the total dissolved solid content was high in surface water, the hydrochemical type of Huihe River water was mainly Na+-Ca2+-HCO3-, and the hydrochemical type of subsidence area water was mainly Na+-Cl--SO42-. Before flowing through the mining area, sulfate in the main stream of Huihe River was mainly derived from two aspects: the dissolution of evaporative salt rocks in the upper reaches. The sulfate in the Baohe River tributaries was mainly derived from the combined effects of atmospheric precipitation. The two rivers converged and were discharged into the subsidence area, causing serious sulfate pollution and affecting the water quality in the subsidence area. The δ34SSO4 value and SO42− content showed a good correlation in river water, subsidence area water and mine drainage, indicating that the SO42− content in the subsidence area was mainly affected by double-ended sources. Besides the impact of the Huihe River, the discharge of local mining waste water was also an important sulfate source, reflecting the effect of coal-mining activities on the water environment.

Preparation of Carbon Aerogel Electrode for Electrosorption of Copper Ions in Aqueous Solution.

Carbon aerogel (CA) has a rich porous structure, in which micropores and mesopores provide a huge specific surface area to form electric double layers. This property can be applied to the application of capacitive deionization (CDI). The adsorption effect of CA electrode on Cu2+ in an aqueous solution was explored for solving heavy metal water pollution. The CAs were synthesized by a sol-gel process using an atmospheric drying method. The structure of CAs was characterized by scanning in an electron microscope (SEM) and nitrogen adsorption/desorption techniques. The adsorption system was built using Cu2+ solution as the simulation of heavy metal pollution solution. The control variate method was used to investigate the effect of the anion species in copper solution, the molar ratio of resorcinol to catalyst (R/C) of CA, and the applied voltage and concentration of copper ion on the adsorption results.

Distribution of mercury and methylmercury in surface water and surface sediment of river, irrigation canal, reservoir, and wetland in Taiwan.

In Taiwan, because of the co-use of some irrigation and drainage canals, a portion of industrial wastewater was directly discharged into irrigation canals or even flowed into rivers or wetlands, causing the heavy metal pollution in waters and sediments. Mercury (Hg) contamination in rivers, irrigation canals, and wetlands has been found in Taiwan, but a thorough investigation on the distribution of Hg and methylmercury (MeHg) in these waters and sediments, which may be present in a greater level with elevating total Hg (THg) concentration and markedly impact human health, is still lacking. In this study, surface waters and surface sediments were sampled from five major rivers, two irrigation canals, two reservoirs, and one wetland in Taiwan, and their THg and MeHg concentrations were quantified. Additionally, statistical analysis was carried out to understand the relationship between sediment properties and MeHg levels. The results showed that irrigation canal sediments were relatively more polluted by Hg and the THg concentrations of some sampling points exceeded the upper limit (i.e., 0.87mgkg-1) of sediment quality index (SQI) for THg promulgated by Taiwan Environmental Protection Administration, which may be attributed to the co-use of irrigation and drainage canals. Furthermore, the MeHg concentration in irrigation canal sediments was the highest; rivers came in second followed by wetlands. In addition, the Siangshan Wetland was analyzed to have the greatest THg and MeHg concentrations in its surface water. Linear regression analysis also indicated that total organic carbon and clay content substantially affected the MeHg production in sediments.

A comparative approach to investigate heavy metals pollution in water and sediment of rivers (case study: Shahrud river)

سابقه و هدف: یکی از آلودگی­ های مهم منبع­ های آب سطحی، آلودگی ناشی از حضور فلز­های سنگین می باشد. فلز­های سنگین اجزای طبیعی تشکیل دهنده پوسته زمین هستند ولی فعالیت­ های انسان، سیکل ژئوشیمی و بیوشیمیایی تعادل این فلزها را برهم زده و سبب انتشار آن­ها در محیط زیست می شوند. در صورت ورود آلاینده­ ها به محیط آبی داخل رودخانه هر دو بخش آب و رسوب آن تحت تاثیر آلودگی قرار می­ گیرند، اما بخش رسوب ­ها بدلیل پویایی کمتر نسبت به محیط آب می ­تواند آلاینده­ های مختلف شیمیایی بویژه فلزهای سنگین را بیشتر در خود متمرکز سازند، بدین دلیل بررسی غلظت فلزهای سنگین در رسوب­ های بستر یک رودخانه، شدت آلودگی یا تاریخچه آن را بهتر از محیط آب آشکار می­سازد. این پژوهش برای بررسی غلظت فلزهای سنگین در آب و رسوب ­های رودخانه شاهرود با هدف تعیین وضعیت و شناسایی منبع ­های آلودگی فلزهای سنگین در منطقه مورد تحقیق انجام گرفت. مواد و روش­ ها: رودخانه شاهرود یکی از دو شاخة اصلی و عمده سفید رود می­باشد که از ارتفاع­ های البرز مرکزی سرچشمه می­ گیرد و تنها رودخانه دامنة جنوبی البرز است که به دریای خزر می­ ریزد. در تحقیق حاضر به بررسی غلظت فلزهای سنگین سرب، کادمیوم و آرسنیک در آب و رسوب­ های رودخانه شاهرود در محدوده شهر لوشان پرداخته شده است، همچنین ویژگی­ های فیزیکی و شیمیایی آب و رسوب­ها در مرحله اول نمونه برداری مورد بررسی قرار گرفتند، که با انتخاب 5 ایستگاه و انجام 4 مرحله نمونه برداری (فصل­ های پائیز و زمستان 95 – بهار و تابستان 96) انجام گرفت، در مجموع 40 نمونه آب و رسوب در طول رودخانه برداشت شد و پس از انتقال به آزمایشگاه غلظت پارامترهای مورد نظر اندازه گیری و مشخص شد. نتایج و بحث: نتایج به­ دست آمده بالا بودن پارامترهای BOD و COD را در نمونه ­های آب، بر اساس استاندارد­های تعیین شده در سازمان حفاظت از محیط زیست و EPA را نشان می­ دهد و بر اساس شاخص IRWQI(SC) در رده متوسط تا بد قرار گرفته ­اند. غلظت فلزهای سنگین در نمونه­ های آب، با رهنمودهای موسسه استاندارد ایران، سازمان حفاظت از محیط زیست ، WHOو EPA مقایسه شده و همچنین از نظر شاخص توصیفیIRWQI(ST) مورد رده بندی قرار گرفته ­اند که میانگین غلظت سرب و کادمیوم در آب بعضی ایستگاه ­های نمونه برداری بالاتر از میزان استاندارد تعیین شده بوده و از نظر شاخص توصیفی سرب در رده به ­نسبت خوب تا متوسط و کادمیوم در رده کمابیش خوب تا به ­نسبت بد قرار گرفته اند و غلظت آرسنیک در تمام ایستگاه­ ها پایین­تر از میزان استاندارد بوده و در رده خوب قرار گرفته است. غلظت سرب در رسوب ­های همه ایستگاه-ها پایین­ تر از میزان TEL، کادمیوم بالاتر از میزان PEL و آرسنیک پائین ­تر از میزان PEL در استانداردهای NOAA و CCME به ­دست آمد. برای ارزیابی کمی در رسوب­ ها، از شاخص­ های فاکتور آلودگی( Cf)، درجه آلودگی اصلاح شده (mCd)، شاخص زمین انباشت مولر(Igeo) و ارزیابی ریسک اکولوژیکی (Ri) استفاده شد که نتایج نشان دهنده آلودگی بالا و انسان زاد برای کادمیوم و ریسک اکولوژیکی زیاد و قابل توجه در رسوب­های منطقه مورد بررسی می­باشد. استفاده از کودهای شیمیایی فسفره در مزرعه­ ها و باغ ­ها و قرار گرفتن کارخانه سیمان در نزدیکی رودخانه را می­ توان از عامل­ های اصلی آلودگی کادمیوم در منطقه نام برد. همچنین بالا بودن BOD و COD در آب نشان از آلودگی بالای مواد آلی در منطقه بدلیل حضور مراکز صنعتی و سنتی فرآوری زیتون، کارخانه و کارگاه ­های روغن کشی زیتون و کشتارگاه ماکیان در منطقه می ­باشد. پنتیجه­ گیری: منطقه مورد مطالعه آلوده به فلزهای سنگین است و عامل اصلی در شکل گیری این آلودگی، غلظت بالای عنصر کادمیوم در رسوب­های رودخانه شاهرود می­ باشد و دارای اثرهای منفی و نامطلوب برای انسان، موجودات زنده و محیط زیست در محدوده شهر لوشان و منطقه­ های پایین دست رودخانه می­ باشد.

Assessment of Heavy Metal Pollution of Water, Sediments and Algae in River Benue at Jimeta-Yola, Adamawa State, Nigeria

Heavy metal pollution of water, sediments and Algae in the upper region of River Benue at Jimeta-Yola, Adamawa state, Nigeria was assessed. The concentrations of the heavy metals (Pb, Hg, Ni, Cu, Cr, Zn, Mn, Fe) in the samples were analyzed using Atomic Adsorption Spectrometer. Pollution parameters such as enrichment factor, contamination factor, pollution load index and geo-accumulation index were evaluated. The result of heavy metal analysis showed that, the concentration (ppm) of the metals in water samples ranged as follows: Pb(0.25-0.50), Hg(0.00-2.00), Ni(0.10-0.31), Cu(0.03-0.13), Cr(0.00-1.33), Zn(0.01-0.04), Mn(0.03-0.06) and Fe(105.15-118.75) respectively. This result when compared with the EPA maximum permissible limits for drinking water showed that, all the metals except Cu and Zn had values above the permissible limits. The evaluation of enrichment factor revealed that, Hg showed extremely high enrichment while Pb showed significant enrichment for Algae, water and sediment samples. The contamination factor showed low contamination for all metals except Hg which showed considerable contamination for sediments, water and Algae samples. The pollution load index for sediments, water and Algae indicated no pollution. The geo-accumulation index of the metals in sediments, water and Algae indicates no or minimal pollution. The samples were enriched with Hg and Pb. These metals are capable of causing various types of cancer, brain and kidney damage among other ailments.

Sources and Toxicological impacts of Surface Water Pollution on Fish in Egypt

Egypt has been listed as one of the most popular countries that are menaced by lack of water by the year 2025 due to overpopulation. The great deposition of highly polluted domestic and industrial effluents into its water ways, made a continuous and prompt damage to its surface and groundwater. The River Nile represents about 97% of Egypt's water resources; however winter rain and nonrenewable groundwater aquifers are also comprised. In Egypt, the main source of pollution is industrial wastes that are poured directly into the main water sources or through the municipal system. On the other hand, the pollution of the Mediterranean coast of Alexandria is mainly due to the discharge of wastes of industrial plants into the sea via Lake Marriott. The rural populations have little or even no access to sewer systems or wastewater treatment facilities and they depend only on the on-site disposal of wastewater. In the Delta region, drainage water is reused for irrigation after mixing with Nile water, while in Upper Egypt drainage water is disposed into the river Nile. Fertilizers and pesticides have been used on a wide range after the constructions of High Dam which resulted in weed flourishing which blocks the waterways, and provides habitats for Bilharzia snails. Egyptian fish aquaria exposed to toxicity due to water pollution from chemical plants and sewage pipes. The main sources of heavy metal pollution of water are industrial and agricultural discharges. Other sources also include: coal and oil combustion, phosphate fertilizers, plastics and pesticides. Recently, the consumption of contaminated fish has been the possible cause of heavy metal poisoning in human. The aim of this review is to disclose the main sources of water pollution in Egypt, and to elucidate the side effects of this pollution on fish.

Copper Removal by Acid-Conditioned Zeolite, Part I: Equilibrium, and Numerical Simulations

Heavy metal water pollution is one of the most pressing environmental problems of the last decades. Wastewater from many industrial processes contain high concentrations of metals and have very acid pH. Thus, technologies to remove heavy metals from aqueous solutions are costly or suffer deterioration when in contact with substances with acid pH. Natural zeolites have demonstrated to be a low-cost heavy metal adsorbent. This study aimed to determine basic parameters for efficient copper removal by aluminosilicates. A Zeolite was conditioned with concentrated H 2 SO 4 to further develop the experiments to test 12 equilibrium isotherms (Freundlich, Redlich-Paterson, Sips, Halsey, Dubinin-Radushkevich, Flory-Huggins, Langmuir, Temkin, Elovich, Fowler-Guggenheim, Henry's and Kiselev) and pHpzc. Maximum removal was obtained with neutral pH values; the Freundlich model had the best performance. The removal efficiency increased as the initial concentration of the solution increased. The pH value at the point of zero charge was 2.9. Keywords: Isotherms; Aluminosilicates, Metals, Freundlich, Numerical Simulations DOI : 10.7176/JEES/9-3-03 Publication date :March 31 st 2019

Copper Removal by Acid-Conditioned Zeolite, Part Ii: Kinetics, and Thermodynamic Studies

Heavy metal water pollution is one of the most pressing environmental problems of the last decades. Wastewater from many industrial processes contain high concentrations of metals and have very acid pH. Thus, technologies to remove heavy metals from aqueous solutions are costly or suffer deterioration when in contact with substances with acid pH. Natural zeolites have demonstrated to be a low-cost heavy metal adsorbent. This study aimed to determine basic parameters for efficient copper removal by aluminosilicates. A Zeolite was conditioned with concentrated H 2 SO 4 to further develop the experiments to test 4 kinetics (Pseudo-first-order, Pseudo-second-order, Elovich and Webber-Morris) and to calculate thermodynamic parameters (ΔG°, ΔH°, ΔS° and Ea). Out of the studied kinetic models, the one that best correlated was the Pseudo-second order model. According to thermodynamic studies, the increase in temperature favors adsorption and the process is spontaneous. Keywords: Kinetics, Thermodynamic, Aluminosilicates, Metals, Pseudo-second-order. DOI : 10.7176/JEES/9-3-04 Publication date :March 31 st 2019

Assessment of heavy metal pollution in water and surface sediment and evaluation of ecological risks associated with sediment contamination in the Ganga River: a basin-scale study.

We investigated eight heavy metals (Cr, Cd, Cu, Ni, Pb, Zn, Mn, and Fe) in water and bed sediment at 9 study sites along with 2320km stretch of the Ganga River. Principal component analysis (PCA) and indices such as geo-accumulation index (Igeo), contamination factor (CF), enrichment factor (EF), pollution indices, and sediment quality guidelines were used to assess source apportionment and magnitude of contamination. Concentrations of Cr, Cd, Pb, Ni, Cu, and Fe in water have exceeded their respective standards in the middle and lower reaches of the river. Sediment Cr and Ni have reached probable effective concentration (PEC) at Kannauj, imposing likely threats to sediment dwellers. Highest Igeo values were recorded for Cr, Cd, and Pb at Kannauj, Rajghat, and Howrah. We further tested ecological risks (Er) and potential ecological risks (PERI) to assess individual and cumulative effects and found the Kannauj, Rajghat, and Howrah sites under the high-risk category. The modified pollution index (MPI) and the modified degree of contamination (mCd) also revealed the middle and lower river reaches under moderately to the heavily polluted category. Our study provides the first detailed watershed-scale database on heavy metal concentration in water and bed sediment, the magnitude of contamination, and likely ecological risks to aquatic organisms in the Ganga River. Given that the Ganga water is used for drinking and irrigation and the river harbors a diversity of habitats for fisheries, the study merits attention from a human health perspective as well.

Trends and Health Risks of Dissolved Heavy Metal Pollution in Global River and Lake Water from 1970 to 2017.

Heavy metal pollution in surface water is a global environmental problem. This study analyzed the trends, health risks, and sources of eight dissolved heavy metal species in river and lake water across five continents (Africa, Asia, Europe, North America, and South America; Oceania was excluded owing to a lack of data) for the period 1970-2017. We wanted to assess the effects of various implemented countermeasures to pollution and to determine those that could be adopted worldwide. Collectively, the water system showed increasing trends for Cd, Cr, Cu, Ni, Mn, and Fe and decreasing trends for Pb and Zn. The mean dissolved concentrations of most heavy metals were highest in Asia and lowest in Europe. Most heavy metals had low non-carcinogenic risks over this period. The cancer risks associated with Pb were lower than the hazardous level on all five continents over the five decades, whereas the cancer risks related to Cr exceeded the hazardous level in the 1970s, 2000s, and 2010s, and in Africa, Asia, and North America over the entire period. Mining and manufacturing were consistently found to be critical sources of metal pollution from 1970 to 2017. However, the heavy metal sources differed significantly by continent, with waste discharge and rock weathering dominant in Africa; mining and manufacturing, along with rock weathering, are dominant in Asia and South America; fertilizer and pesticide use, along with rock weathering, are dominant in North America; and mining and manufacturing, waste discharge, and rock weathering are dominant in Europe. Global trends in the metal loadings in water and in relevant pollution-control measures suggest that countermeasures in Europe have successfully controlled heavy metal pollution. The successful measures include implementing rigorous standards for metal emissions, limiting the metal concentrations in products, and rigorously treating metal-contaminated waste. Therefore, the measures implemented in Europe should be extended worldwide to treat heavy metal pollution in water.

Novel 2D Nanosheets with Potential Applications in Heavy Metal Purification: A Review

AbstractOver the past decades, extensive studies have been carried out for the design of advanced materials for water purification. Heavy metal pollution in water is a serious global environmental problem due to their toxicity and carcinogenicity. With the discovery of graphene, novel 2D nanosheets, derived from the wide variety of traditional materials, have emerged as some of the most promising candidates for heavy metal purification. This review summarizes the recent progress on the novel 2D nanosheets with their applications in heavy metal purification. First, the authors introduce the unique advances on 2D nanomaterials, followed by the description of their composition and crystal structures. Some novel 2D nanosheets with great success in heavy metal purification field are then summarized, including insights on their advantages over traditional materials and limitations in practical applications, along with some advances in interfacial structure modifications for future work. The functional design of more and more novel 2D interfacial materials with unique properties is still demanding for future industrial applications.

Assessment of heavy metal pollution in water and sediments in the red river delta (Vietnam)

The paper studied the features of distribution of main heavy metals in the water-bottom sediments system in the Red River Delta (Vietnam). The tasks were to determine the flow of heavy metals, to study the adsorption processes of heavy metals in suspended matter and burial in bottom sediments. The studies were carried out during the main hydrological seasons of 2014 – 2016 years at 6 stations of main branches of the river for 8 basic heavy metals (Cu, Pb, Zn, Hg, Cd, As, Cr and Fe). Each year, the total flow of heavy metals entering the top of the delta was 98.8 thousand tons. The total flow of all heavy metals differed by hydrological seasons and by watercourses. In general, 1.76% - 16.25% of the flow of heavy metals accumulated throughout the year, the highest accumulation rates are for lead, iron and zinc. In the branches Ba Lat, Tra Ly, Ninh Co, due to the decrease in flow rates, an intensive process of the accumulation of suspended substances and sorbed heavy metals was observed.

Bacteria functionalized gold nanoparticle matrix based fiber-optic sensor for monitoring heavy metal pollution in water

In the present study, E.coli B40 bacteria were explored as possible receptors on localized surface plasmon resonance (LSPR) based biosensor for sensing heavy metal ions viz. mercury (Hg2+) and cadmium (Cd2+) in water. The E.coli B40 bacteria were immobilized on gold nanoparticles (AuNP) coated fiber-optic probes by depositing two bi-layers of oppositely charged polyelectrolytes. The E.coli immobilized sensor probes were subjected to different concentrations of Hg2+ and Cd2+ ions, ranging from 0.5 ppb to 2000 ppb. These metal ions interact with the thiols and other surface groups present on the bacterial cells, resulting in the change of refractive index around AuNP coated sensor probes, thereby modulating the sensor response. The detection was performed by spiking de-ionized (DI) water and tap water with metal ions and the limit of detection was found to be 0.5 ppb. The proposed sensor could detect heavy metal ions within 10 min from a small sample (<1 ml) and showed good selectivity towards heavy metal ions over other transition metal ions. Control studies performed using amino acids like cysteine as receptors were found to be less sensitive than the proposed scheme using bacterial cells.

A Case Study of Heavy Metal Pollution in Water of Bone River by Artisanal Small-Scale Gold Mine Activities in Eastern Part of Gorontalo, Indonesia

Bone River, which is located in the eastern part of Gorontalo, Indonesia, has an issue of contamination by heavy metals due to artisanal small-scale gold mine (ASGM) activities. This river is used as a source of water by inhabitants living along the river, due to the lack of another clean water supply. The purpose of this study is to investigate the concentration of As from the mining site alongside Bone River, and to reveal the As pollution source. Water and sediment samples were collected from ASGM and along Bone River to the delta. The concentrations of As, Hg, and Pb in water samples were identified by inductively coupled plasma mass spectroscopy (ICP–MS), while concentrations in sediment samples were determined by particle-induced X-ray emission (PIXE). Results showed that the concentrations of As, Hg, and Pb in water ranged from 66 to 82,500 µg/L, 17 to 2080 µg/L, and 11 to 1670 µg/L, respectively. These levels exceeded, by 1000 to 10,000 times, the safe limits of drinking water defined by the World Health Organization, which indicated that Bone River water is not safe for drinking or cooking purposes.

Descontaminación de arsénico, cadmio y plomo en agua por biosorción con Saccharomyces cerevisiae

La contaminación del agua con metales pesados es un problema potencial de salud pública, debido a su toxicidad. Los métodos tradicionales de descontaminación se enfocan principalmente a tratar efluentes industriales con altas concentraciones de metales pesados, pero con desventajas por los altos costos, grandes espacios de operación y en ocasiones, empleo o generación de otras sustancias tóxicas. Los metales pesados con mayor toxicidad presentes en el agua son arsénico, cadmio y plomo, cuya exposición crónica puede dañar diversos órganos y promover el desarrollo de cáncer. La eliminación de estos metales del agua de consumo con menores concentraciones que aún representen un riesgo a la salud, puede llevarse a cabo por el fenómeno de biosorción. Los materiales biosorbentes son molecularmente, diversos, económicos y pueden ser desde biopolímeros hasta biomasa microbiana. Se conoce que algunas cepas de levaduras han mostrado gran capacidad de remoción de metales pesados en soluciones acuosas, destacando las del género Saccharomyces, particularmente Saccharomyces cerevisiae. La biosorción con levaduras es una alternativa prometedora para la eliminación de bajas concentraciones de As3+, As5+, Cd2+ y Pb2+ en agua de consumo. Sin embargo, es necesario seguir estudiando las condiciones para su aplicación a gran escala, así como otras posibilidades que permitan su optimización.

POTENSI PENURUNAN KONSENTRASI LOGAM BERAT TEMBAGA (CU) DAN PERTUMBUHAN MIKROALGA SPIRULINA PLANTESIS PADA MEDIA KULTUR

ABSTRACT Water is an important environmental component for life. Heavy metal water pollution comes from many industries. Heavy Metals Copper (Cu) is one of several other heavy metals that are harmful to living things. One way to anticipate the increased pollution of heavy metals Copper (Cu) in waters is bioremediation using microalgae. This study aims to determine the ability of Spirulina plantesis in absorbing heavy metals Copper (Cu) and to determine the influence of heavy metal Copper (Cu) on the growth of Spirulina platensis. This study used an experimental method with Completely Randomized Design (RAL) consisting of four treatments and five replicates, namely A (S. platensis 0 ppm), B (S. platensis 1 ppm), C (S. platensis 3 ppm), D (S. Platensis 5 ppm). The results showed that Spirulina platensis was able to absorb heavy metal of Copper (Cu) so that it can be used as a heavy metal bioremediation agent. On treatment B (1 ppm) absorption of 87,719%, C (3 ppm) equal to 97,886% and D (5ppm) equal to 95,872 % Growth with the addition of Cu affects Spirulina platensis growthKeywords: Bioremediation, Spirulina platensis, Copper, Growth

Application And Prospect Of Talc As Heavy Metal Passivation Agent

Heavy metal pollution in water and soil has been widely concerned by all sides. Heavy Metal passivation agents can change the presence of heavy metals in water and soil, thus reducing mobility, toxicity and bioavailability. In this paper, the application, effect and prospect of using talc to repair heavy metal pollution are introduced, and some problems and prospects of remediation method of heavy metal pollution are prospected.

Metal Nanoparticle Carbon Gel Composites in Environmental Water Sensing Applications.

The synthesis of organic-inorganic nanocomposites that can interact with different environmental pollutants and can be mass-produced are very promising materials for the fabrication of chemical sensor devices. Among them, metal (or metal oxide) nanoparticles doped conductive porous carbon composites can be readily applied to the production of electrochemical sensors and show enhanced sensitivity for the measurement of water pollutants, thanks to the abundant accessible and functional sites provided by the interconnected porosity and the metallic nanoparticles, respectively. In this personal account, an overview of several synthesis routes of porous carbon composites containing metallic nanoparticles is given, paying special attention to those based on sol-gel techniques. These are very powerful to synthesize hybrid porous materials that can be easily processed into powders and thin films, so that they can be implemented in electrode fabrication processes based on screen-printing and lithography techniques, respectively. We emphasize the sol-gel routes developed in our group for the synthesis of bismuth or gold nanoparticle doped porous carbon composites applied to fabricate electrochemical sensors that can be scaled down to produce miniaturized on-chip sensing devices for the sensitive detection of heavy metal pollutants in water. The trend towards the miniaturization of electrochemical sensors to be readily employed as analytical tools in environmental monitoring follow the market requirements of rapid and accurate on-site analysis, small sample consumption and waste production, as well as potential for continuous or semi-continuous in-situ determination of a wide variety of target analytes.

Capture of Pb2+ and Cu2+ Metal Cations by Neisseria meningitidis-type Capsular Polysaccharides.

Heavy metal pollution of water is a significant environmental and public health concern. Current biological strategies for heavy metal removal from water are performed using microbial biopolymers, including polysaccharides, that are already fully formed. This creates limitations in adapting polysaccharides to increase binding affinity for specific metals. We propose that altering the specificity of polysaccharide-producing enzymes could be beneficial to improving metal capture by modified polysaccharides. We assess binding of Cu2+ and Pb2+ metal cations to Neisseria meningitidis-type polysaccharides. All concentrations of metal cations tested were able to completely bind to colominic acid. This polymer is equivalent to the capsular polysaccharide of N. meningitidis serogroup B comprised of a homopolymer of negatively charged sialic acid. There was slightly less binding observed with N. meningitidis serogroup W, which contains repeating units of the neutral sugar galactose and sialic acid. Our work represents the first assessment of the metal-binding properties of these capsular polysaccharides. Future work will seek to optimize metal-binding with Neisseria meningitidis serogroup W polysaccharide.

Pollution Assessment of Surface and Drainage Water by Heavy Elements in Al Ahrar District, Wasit Governorate, Iraq

The study area lies in Wasit governorate south west Kut city, where Al Ahdeb oil field is located to the south of Al Ahrar district. The present study deals with assessment of heavy metals pollution in water by collecting eleven water samples (five samples from drainage and six samples from surface water) in 5th of December 2016. The water samples analysis of heavy elements in the study area shown that water is polluted with high concentration of (Pb, Cd) elements, while the concentration of (Cu, Fe, Zn) in water samples are within the permissible limits of both World Health Organization, and Iraqi standards and there are no hazard effects from these elements. The study detected some diseases that injured the people living in the vicinity of the oil field complex such as scabies, vitiligo, eczema and contact dermatitis, as a result of increasing of (Pb) ion in water samples.