Heavy Metal Load Research Articles

Phytoremediation of Lebanese polluted waters: a review of current initiatives

Water pollution is presently considered as a serious apprehension in Lebanon. Heavy contamination load of nutrients, heavy metals and organic pollutants can be highly harmful for human health and detrimental to aquatic life and ecosystems. Phytoremediation in natural and constructed wetlands using aquatic macrophytes present a sustainable plant-based technology recognized as a very efficient option in water treatment. The employment of species such as Phragmites, Sparganium, Lemna sp and other aquatic macrophytes not only helps in pollution cleanup but also conserves aquatic communities. To date, two pilot constructed wetlands, Litani River and Bcharreh have been established in Lebanon. These promising initiatives have been, however, accompanied with very limited research studies to examine the role of utilized plants and their efficiency in the remediation process. This paper presents an overview of the status of these initiatives and phytoremediation potential in Lebanon.

The load of heavy metals leaching from grassland in central Ner River valley

Łódź is the largest Polish city in the zone of the main watershed of the country. The watershed zone offered a dense network of small streams, mostly belonging to the Ner River catchment. The use of the Ner River as a collector of industrial sewage caused the accumulation of high amounts of heavy metals in the river sediments and arable land, intensively fertilised with the waters of the Ner River for more than 40 years. Due to the continuation of irrigations in the river valley, water with a substantially lower degree of contamination with organic substance and biogens returns to Ner from the grassland complexes. The objective of the study is the determination whether improvement of water quality subject to circulation within the grassland complexes also concerns heavy metals. The study area covers grassland complexes in the middle section of the Ner River valley, between the weir in Charbice Górne and Jeżew. Due to the variability of acidic-alkaline and oxidation-reduction conditions caused by variable moisture of the soil containing high amounts of allochtonic (post-sewage) organic matter, the observed grassland complexes show liability in terms of retention and release of the analysed metals to Ner. In summer 2018 on the analysed grassland complexes, conditions favouring the emission of all studied metals occurred. This evidences what the discontinuation of irrigation of grassland complexes, previously irrigated with sewage from Łódź, can lead to. The comparison of sites located along the course of the Ner River also provides a complex image of changes in concentrations, with evident fluctuations of metal concentrations.

Reducing Heavy-Metal Load in Lithium-Ion Batteries

Reducing Heavy-Metal Load in Lithium-Ion Batteries

Heavy metal signatures in urban and peri-urban agricultural soils across the Mumbai Metropolitan Region, India

Millennium Development Goals recognized the contribution of urban and peri-urban agriculture (UPA) towards food security, income generation, and livelihood strategies. Given the scarcity of relevant data, the present study was conducted to assess heavy metal load of UPA soils (at 0.00–0.20, 0.20–0.60 and 0.60–1.00 m depth) in Mumbai Metropolitan Region, India by comparing the signatures from soil profiles of three railway gardens (RG1–3) and three farms (F1–3) over 2 years. Potential human health risks of consuming produce from these soils were assessed using the contamination factor, degree of contamination, pollution load index (PLI), enrichment factor, geoaccumulation index (Igeo), and total metal and element content in comparison with different safety standards. Semi-sequential extractions were performed to determine the concentration of available elements and heavy metals for plants. The total concentration of heavy metals (Cr, Ni, and Sr) exceeded the critical thresholds in all surface soils, while the contribution of water-soluble and exchangeable fractions of Cu, Fe, Co, and Cr was negligible across the selected gardens. At the same soil depth, the PLI was highest for RG3 (3.6) at 0.00–0.20 m depth and lowest in RG2 (1.2). The Igeo value for individual elements ranged from 0.08 to 0.12 (Ni), 0.06 to 0.12 (Cr), 0.07 to 0.10 (Zn), 0.10 to 0.18 (Cu), and 0.24 to 0.34 (Co), whereas the value for Mn was 0.01 similar in all gardens. The soil pollution assessments by these indices revealed moderate to considerable (chromium and strontium) heavy metal contamination and accumulation, however, the origin of these metals remain unclear.

Responses of propagule germination and sexual reproduction of submerged macrophytes exposed to cadmium

Submerged macrophytes are considered the main primary producers in shallow lakes. Recently, they have experienced a decline due to increasing environmental impacts, e.g., excessive heavy metal loads. Compared to extensive studies on vegetative growth, reports on effects of heavy metals on propagule germination and reproduction remain scarce. In this study, three experiments were conducted to investigate the effects of cadmium (Cd) on the propagule germination and sexual reproduction of submerged macrophytes. In Experiment I, six Cd concentrations were used (0, 0.05, 0.5, 1, 2.5, and 5 mg L−1), with seed germination found to be marginally affected by Cd treatment. In Experiment II, Cd exposure (5 d) at the six Cd concentrations was performed 15, 30, 60, 90, and 120 d prior to the designated germination date for turions/tubers. The Vallisneria spinulosa tubers did not germinate at ≥ 2.5 mg Cd L−1 when exposed to Cd 90 and 120 d prior to germination, whereas the Potamogeton crispus turions remained viable but with a low germination rate at ≥ 2.5 mg Cd L−1. In Experiment III, with an increase from 0 to 0.5 Cd mg L−1, the fruit weight of Ottelia alismoides and V. spinulosa decreased, whereas the fruit number increased for O. alismoides but not for V. spinulosa. Furthermore, the phenology of sexual reproduction for both species advanced under Cd exposure. In summary, Cd exposure affected the germination of asexual propagules and sexual reproduction of submerged macrophytes, with seeds found to be tolerant of Cd treatment up to 5 mg L−1.

Assessment of nutrient and heavy metal content and speciation in sewage sludge from different locations in Iran

More than 80% of sewage sludge (SS) produced in Iran is landfilled with high environmental impact. The chemical properties of SS produced from wastewater plants of cites of Arak, Isfahan, Kermanshah, Rasht, Saveh, Shiraz, Sanandaj, Tehran, Takestan, and Toyserkan were studied to assess the potential beneficial effects of their application to agricultural soil as sustainable SS management. The pH and EC values, total content and water-soluble concentration of nutrients and heavy metals, their water-extractable pools were determined, and their speciation was done through the NICA–Donnan model using the Visual MINTEQ software. Relatively high contents of N, P, and physiologically active cations indicated potential beneficial effects of SS for land application in the agro-ecosystems, whereas the heavy metal content depended on the SS production site, with higher levels found in the SS of the Arak and Saveh wastewater treatment plants. The pH value was the main factor controlling the metal speciation, with Cu and Pb having the highest affinity for the organic matter, and Zn and Mn being mainly present as free ions or inorganic species. Results showed that SS from different locations in Iran differed in their main chemical properties and elemental composition and that speciation analysis could be used to predict potential beneficial and harmful effects of SS, particularly upon the modeling of metal–organic complexes by the NICA–Donnan approach. Globally, our results confirmed that while the SS produced in Iran has potential suitable chemical properties for use in agriculture, their heavy metals load should not be ignored.

Simultaneous removal of heavy metals from synthetic storm water using sustainable urban drainage systems

ABSTRACTUtilization of filtration systems plays a significant role in removing contaminants from storm water runoff. In this study, pilot-scale experiments are conducted to investigate heavy metal removal capacity for ten substrate mixtures. Tested filter substrates contained 10−15 vol.-% compost. The experiments are conducted using synthetic storm water and heavy metal loads of 4–12 months based on a ratio 7:1 between connected drainage area and filter area. All filter substrates performed similarly in removing Cr, Cu, Pb and Zn, while the behaviour with Ni was somewhat different. The removal efficiency was more than 80% for Cr, Cu, Pb and Zn, compared to 53% to 88% for Ni. Regardless of substrate composition, the removal efficiency decreased in the following order: Pb ~ Zn > Cr > Cu > Ni. Measured effluent concentrations for Pb, Cr and Cu were very low and met the Austrian Groundwater Quality Ordinance requirements.

On-line refueling for the Advanced High Temperature Reactor (AHTR)

Abstract Several academic and commercial organizations around the world are developing the Fluoride salt-cooled High-temperature Reactor (FHR) technology, due to its safety features and potential to generate high temperature energy for electricity and process heat applications. The Advanced High Temperature Reactor (AHTR) being considered in this study is a FHR design developed at Oak Ridge National Laboratory (ORNL). It is based on the use of graphite as moderator, FLiBe as coolant, and hexagonal fuel elements with fuel plates (or “planks”) composed of TRISO particles embedded in a carbonaceous matrix. The AHTR reference design is based on traditional batch refueling approach, which requires to shut down the reactor and replace/reshuffle a certain amount of fuel assemblies in the core at a specific frequency. Several options have been evaluated in the design process, in order to maximize the cycle length and optimize the use of fuel. However, the relatively short cycle and poor fuel utilization are intrinsic features of this family of reactors, due to the low heavy metal loading in the core and insufficient moderation, which are competing aspects in terms of core volume fraction. Since the fuel is expected to be more expensive than the fuel of light water reactors (LWR), this issue might challenge the economic viability of the AHTR. In order to eliminate or ameliorate this issue, a novel approach to refueling has been developed and proposed, consisting of continuous on-power refueling, or on-line refueling, in which the refueling procedure is performed at full power or partially reduced power (the reactor is not shut down) and a single assembly is removed for each refueling operation. A systematic neutronic and thermal-hydraulic analysis approach has been developed and performed to assess the viability and safety of the refueling operations, followed by the evaluation of the core design requirements and a quantification of the economic advantages resulting from the implementation of this procedure.

Technological Review of Permeable Pavement Systems for Applications in Small Island Developing States

This paper presents a technological review of permeable pavement systems (PPS) for applications in urban areas of small island developing states (SIDS). This review includes a literature survey of PPS, challenges and opportunities of climate change and urban development in SIDS, and key aspects worth considering for widespread acceptance and use of PPS in SIDS. SIDS is comprised of several nations located across the Atlantic, Pacific, and Indian Oceans, as well as the Caribbean, Mediterranean, and South China seas. They are particularly susceptible to the effects of climate change and increasing urbanization. Urban stormwater management and flooding are often serious challenges faced by authorities in most SIDS. PPS are resilient infrastructure which can assist in mitigating flooding by reducing runoff and peak flows and improving the landscape perviousness. PPS can further improve stormwater runoff quality to receiving natural waters by reducing pollutant loadings of suspended solids, heavy metals, and hydrocarbons. Unlike most territorial states, the geographical and geologically confined nature of most SIDS present unique parameters for consideration when designing permeable pavements for SIDS. This literature survey found that some of the most important parameters include traffic loads, cost, construction aggregate choice, and availability, permeability of existing soil at the intended location, depth of water table, potential for groundwater contamination, slope of the pavement, stormwater reuse option, clogging, maintenance, and support from policy makers. Continued practical research into the use of permeable pavements for urban runoff management in SIDS is on‐going with the expectation of PPS being utilized in many SIDS.

Prediction of long-term heavy metal leaching from dredged marine sediment applied inland as a construction material.

Column leaching studies have been suggested as a reference for site-specific prediction of the long-term leaching characteristics of trace constituents in granular materials used as construction materials. In this study, the concept of the long-term leaching prediction using column studies is applied for dredged marine sediment impacted by heavy metals. The column studies show tailing of the liquid to solid ratio-dependent heavy metal leaching for sediment after heavy metal treatment by acid washing. A dual-mode first-order decay model, applied for the first time in this study for column leaching studies, is able to reproduce the leaching characteristics observed. A procedure for long-term leaching prediction using the dual-mode model is developed and applied to a virtual field scenario for which the sediment is beneficially used as a construction material. The prediction results show that by more accurately reproducing the column study results, the dual-mode model generally predicts greater long-term heavy metal loading to the underlying soil layer and longer duration of leaching than the single-mode model. The heavy metal leaching observed in the columns does not show any correlation with the sequential extraction procedure and toxicity characteristic leaching procedure (TCLP) results, suggesting that the column leaching test should be considered to be independent of such batch test procedures.

Study of Heavy Metals in the Soils of Two Localities in Dolj County

AbstractThe study was conducted in two neighboring localities located in the northern county of Dolj, namely Murgasi and Bulzesti. The purpose of the study was twofold: namely, the study of heavy metal loading in order to identify possible pollution areas and to know the soil content of these localities in heavy metals in order to be able to give the verdict on the use of sludge from Craiova wastewater treatment plant as fertilizer on these soils. In order to determine the suitability of sewage sludge from the Craiova wastewater treatment plant as a fertilizer, physical and chemical properties and heavy metal content of the soils in these areas were analysed, as well as the chemical composition of sludge, according to Order 344/2004 of the Ministry of Environment and Water Management of Romania, respectively 13 physical and chemical parameters of the soils in these localities and the chemical composition of the sludge and respectively the quantity of heavy metals to be introduced annually into the soil by using it.

Heavy metal contribution by runoff in a high-altitude megacity: a method based on the road-deposited sediment characterization

El objetivo de este artículo es presentar el desarrollo y aplicación de un método para determinar la contribución de metales pesados (MP) derivados del lavado ejercido por la escorrentía sobre sedimentos viales (SV) en una megaciudad de elevada altitud (Bogotá, Colombia). El método está basado en una ecuación que considera dos procesos: transporte y lixiviación de MP. La contribución de MP por escorrentía varía entre un 24.7-50.3%, con respecto a la masa total por unidad de área de MP asociados con SV de tiempo seco (Mn, Cd, As, Zn, Cu, Ba, Pb y Fe). Los MP que presentan una mayor contribución son Cd, Zn y Mn. La fracción inferior a 250 μm de los SV contribuye en promedio con un 81.6% de la carga total de MP. Los hallazgos sugieren que la fracción inferior a 250 μm es referente para el diseño de sistemas de control de contaminación en Bogotá.

Distribution and leaching characteristics of heavy metals in a hazardous waste incinerator

In this study, distribution and leaching characteristics of heavy metals (As, Cd, Cr, Cu, Pb, Se, Zn, and Hg) along flue gas cleaning systems were investigated in a hazardous waste incinerator located in Zhejiang, China. The particle size distribution, heavy metal loading, and morphological and mineralogical characteristics of solid incineration residues were assessed before and after acetic acid extraction. Results showed that Hg, Cd, As, Pb, and Zn were transmitted into the fly ash mainly by evaporation, condensation, and adsorption, while Se and Cr were mainly by entrainment. High chlorine availability in the industry hazardous waste favored the evaporation of Cu, Pb and Zn. Due to the mass ratio of the bottom slag in the incineration residues being more than 52%, most of Cu, Cr, As, and Zn remained in the bottom slag. Scarcely any Hg and less than 9.6% of Cd were found in the bottom slag. Cd was mainly retained in the fly ash and the absorbent solution of the wet flue gas desulfurization (WFGD) system while most of Pb was found in the fly ash. WFGD system had a high Hg removal efficiency and more than 74.7% of Hg was retained in the absorbent solution of WFGD system. The distinction in the distribution and migration characteristics of heavy metals between two continuous operating conditions was mainly due to the different physicochemical properties of wastes. The studied heavy metals in the bottom slag, with the exception of Zn, showed low leachability, with a leaching ratio below 2%. Cd and Zn presented the highest leachability, and over 56.2% of Cd and more than 39.5% of Zn in the fly ash were transferred into the leachate. For the each studied heavy metal, the leaching ratio in the bag filter ash was the highest.

Studies on Reactivity Coefficients of Thorium-Based Fuel (Th-233U)O2 with Molten Salt (Flibe) Cooled Pebble

A combination of the neutronics features of gas-cooled high-temperature reactors by using the fuel in the form of ceramic-coated particles, called tristructural-isotropic, and the heat removal feature of molten salt reactors by using molten salt as a coolant is an attractive option in designing a reactor with a high-power density operation without compromising the safety aspects. Neutronics feasibility of such a combination of the molten salt (LiF-BeF2) as a coolant and thorium-based fuel, in particular (Th-233U)O2, in a graphite-moderated system is investigated. This technical note presents the influence of the heavy metal (HM) loading on neutronics features of a pebble lattice cell, that is, infinite multiplication factor (K-inf), temperature coefficients of reactivity (TCR), the void reactivity coefficient, etc. In addition, enriched uranium fuel has also been studied just to make a comparison with thorium-based fuel. Furthermore, the minimum HM loading of fuel per pebble that is needed to achieve negative coolant-temperature reactivity coefficients and void reactivity coefficients has been estimated for molten salt coolant.The analyses show that Th2/U3 fuel gives a less negative fuel temperature reactivity coefficient as compared with that of uranium-based fuel. This study also shows that all the TCR of both fuel types improve, becoming less positive or more negative, by increasing HM loading per pebble. Further, the burnup dependence of K-inf and the reactivity coefficients are studied for limiting HM loadings, e.g., 30 g per pebble. The change in the spectrum and the four-factor formula are used to explain the behavior of the reactivity coefficients as a function of HM loading and burnup.

Assessment of Surficial Loads of Heavy Metals in sediment of Ipo Stream and Sombriero River, Rivers State, Nigeria

The concentrations of Cd, Ni, Cu, Pb and Fe were determined in sediments and water samples of two aquatic systems after mineralization with HNO3, HCl and HClO4 and analyzed using Atomic Absorption Spectrophotometer model 507KL. The mean concentration obtained in sediments of Ipo stream were as follows Cd (1.2 – 1.7) mg/Kg, Ni (3.0 – 3.5) mg/Kg, Cu (14.62 – 25.22) mg/Kg, Pb (20.05 – 24.6) mg/Kg, Fe (18.20 – 24.82), while in water, in mg/L was Cd (1.09 – 1.65), Ni (3.09 – 3.72), Cu (14.14 – 24.10), Pb (20.00 – 24.20), and Fe (711 – 907). In Sombreior sediment, the following concentration in mg/Kg were obtained Cd (0.10 – 0.12), Ni (102 – 70.34), Cu (34.02 – 84.20) Pb (18.22 – 23.05), and Fe (11780 – 15642.2). However, in water the heavy metals occurred in the range Cd (<0.001 – 0.02), Ni (64.21 – 82.01), Cu (30.41 – 3961), Pb (8.02 – 16.38), and Fe (712 – 872.0) mg/L. The results showed that Ipo stream contained more heavy metals than Sombriero river and significant difference occurred in the mean concentration of heavy metals in Ipo stream and Sombreior river at p<0.05. The results showed that the major source of pollution of the study area is anthropogenic activities.

Preliminary assessment of heavy metals in water, sediment and macrophyte (Lemna minor) collected from Anchar Lake, Kashmir, India

Water samples, sediments and free floating macrophytic plant, Lemna minor specimens were collected from five designated sites in Anchar lake (Srinagar, J&K, India) to assess its heavy metal (Cu, Cr, Zn, Ni, Cd, Pb) load and changes on seasonal basis. The concentration of heavy metals was determined using atomic absorption spectroscopy. Most of the samples were found within limits of maximum permissible concentrations as recommended by WHO (Guidelines for drinking water quality, pp 491–493, 2006). During all the seasons, highest concentration of all heavy metals (Cu, Cr, Zn, Ni, Cd, Pb) was recorded at highly polluted sites of the lake viz. near agricultural fields (S1), near settlements (S3) and SKIMS (S4). These sites received huge agrochemical run-off from the surrounding agricultural fields, solid and liquid wastes from the nearby catchment areas and effluents from Sher-e-Kashmir Institute of Medical Sciences (SKIMS) compared to control site lake centre (S5). Furthermore, most of the metals in water and sediment were found with highest concentration during autumn (Viz., Cu-1.5 ppm; Zn-0.38 ppm; Ni-1.89 ppm; Pb-0.84 ppm in water and Cu-26.9 ppm; Zn-13.6 ppm; Pb-4.33 ppm in sediment) and summer (Viz., Cr-0.68 ppm in water and Ni-4.8 ppm; Cd-2.6 ppm; Cr-8.01 ppm in sediment) seasons. Also in Lemna minor plant highest concentration was observed during summer season (Cu-29.09 ppm; Zn-19.11 ppm; Ni-5.7 ppm; Cd-1.34 ppm; Cr-9.18 ppm and Pb-9.77 ppm). From these observations, it was found that the sources of heavy metals in Anchar lake were both natural and anthropogenic ones. This study recommended that continuous monitoring of heavy metals (Viz; Cu, Cr, Zn, Ni, Cd and Pb) in water, sediment and other aquatic biota of Anchar lake should be directed to protection of ecological status of the lake and its surrounding area.

Remediation of Some Heavy Metals, Radionuclides and Bacterial Load of Medically Acclaimed Edible Kaolin

Remediation of Some Heavy Metals, Radionuclides and Bacterial Load of Medically Acclaimed Edible Kaolin

Emission of heavy metals from an urban catchment into receiving water and possibility of its limitation on the example of Lodz city

Heavy metals are among the priority pollutants which may have toxic effects on receiving water bodies. They are detected in most of samples of stormwater runoff, but the concentrations are very variable. This paper presents results of study on the amount of heavy metals discharged from urban catchment in Lodz (Poland) in 2011–2013. The research was carried out to identify the most important sources of their emission and to assess the threats to receiving water quality and opportunities of their limitation. The city is equipped with a combined sewerage in the center with 18 combined sewer overflows and with separate system in other parts. Stormwater and wastewater from both systems are discharged into 18 small urban rivers. There is a need of restoration of water bodies in the city. Research results indicate that the main issue is high emission of heavy metals, especially zinc and copper, contained in stormwater. Annual mass loads (g/ha/year) from separate system were 1629 for Zn and 305 for Cu. It was estimated that about 48% of the annual load of Zn, 38% of Cu, 61% of Pb, and 40% of Cd discharged into receiving water came from separate system, respectively 4% of Zn and Cu, 10% of Pb and 11% of Cd from CSOs, and the remaining part from wastewater treatment plant. Effective reduction of heavy metals loads discharged into receiving water requires knowledge of sources and emissions for each catchment. Obtained data may indicate the need to apply centralized solution or decentralized by source control.

Groundwater chemistry and human health risk assessment in the mining region of East Singhbhum, Jharkhand, India

Groundwater chemistry of mining region of East Singhbhum district having complex contaminant sources were investigated based on heavy metals loads and other hydrochemical constituents. This study aimed to identify the degree of heavy metals exposure and their potential health risk to local population. The results of hydrochemical analysis showed that Na+, K+, and Ca2+ ions are the dominant cations in the groundwater, while HCO3−, F− and Cl− ions dominate the anionic part of the groundwater. The weathering process was considered the dominant factor to determine the major ionic composition in the study area. Compositional analysis for heavy metal has identified that groundwater of the study area is contaminated by Cd, Pb and Cr elements. Source of these metals have been identified as an anthropogenic inputs from mining activities and mineral processing units. Health risk analysis of individual heavy metal for chronic daily intake (CDI) and hazard quotient (HQ) was found in the order of Cr > As > Cd > Pb which is indicating high health risk for the population. In addition, Hazard Index (HI) analysis for heavy metals was found significantly high (>1) which is considered as a threat for human population because they have the tendency to accumulate in the body and cause variety of diseases like kidney problem, dysfunction of liver and renal cortex as well as cancer.

Heavy metal enrichment and ecological risk assessment of surface sediments in Khorramabad River, West Iran.

The ecological health of rivers has often been threatened in urbanized catchments due to the expansion of industrial activities and the population growth. Khorramabad River which flows through Khorramabad city, west of Iran, is an example of such settings. The river water is used for agricultural purposes downstream. In this study, the effect of Khorramabad city on heavy metal and metalloid (Cu, Pb, Zn, Ni, Cr, and As) loads in Khorramabad River sediments was investigated. To evaluate sediment pollution and potential adverse biological effects, surface sediment samples were collected at selected locations along the river and were characterized for their geochemical properties. Contamination factor (CF), pollution load index (PLI), and ecological risk assessment (RI) were calculated. Also, sediment quality guidelines (SQGs) were used to screen contaminants of concern in the study area. The results showed that sediments were moderately polluted, with stations located in more densely populated areas showing higher pollution indicators. Copper, Zn, and Pb sources could be attributed to urban wastewater, whereas Ni, Cr, and As had both natural and anthropogenic sources. Moreover, ecological risk assessments showed that sediments could be classified in the category of low risk. The results of the present study showed the effect of anthropogenic activities on heavy metal loads of the river sediments and these findings can be used to mitigate potential impacts on the environment and human health.