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1.
Sci Total Environ ; 751: 141830, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-33182002

RESUMO

This systematic review presents the potential toxicity of heavy metals such as lead (Pb), mercury (Hg), cadmium (Cd), iron (Fe), nickel (Ni), aluminum (Al), and copper (Cu) in raw cow milk, focusing on their contamination sources and on the assessment of the related human health risk. Multiple keywords such as "raw cow milk, heavy metals, and human health" were used to search in related databases. A total of 60 original articles published since 2010 reporting the levels of these metals in raw cow's milk across the world were reviewed. Data showed that the highest levels of Ni (833 mg/L), Pb (60 mg/L), Cu (36 mg/L) were noticed in raw cow milk collected in area consists of granites and granite gneisses in India, while the highest level of Cd (12 mg/L) was reported in barite mining area in India. Fe values in raw cow milk samples were above the WHO maximum limit (0.37 mg/L) with highest values (37.02 mg/L) recorded in India. The highest Al level was (22.50 mg/L) reported for raw cow's milk collected close to food producing plants region in Turkey. The Target Hazard Quotients (THQ) values of Hg were below 1 suggesting that milk consumers are not at a non-carcinogenic risk except in Faisalabad province (Pakistan) where THQ values = 7.7. For the other heavy metals, the THQ values were >1 for Pb (10 regions out of 70), for Cd (6 regions out of 59), for Ni (3 out of 29), and for Cu (3 out of 54). Exposure to heavy metals is positively associated with diseases developments. Moreover, data actualization and continuous monitoring are necessary and recommended to evaluate heavy metals effects in future studies.


Assuntos
Metais Pesados , Leite , Animais , Bovinos , Monitoramento Ambiental , Feminino , Humanos , Índia , Metais Pesados/análise , Metais Pesados/toxicidade , Leite/química , Paquistão , Medição de Risco , Turquia
2.
Chemosphere ; 262: 128379, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182079

RESUMO

The co-existence of heavy metals and organics in industrial effluents is a prevalent problem. These pollutants usually have dissimilar compositions and properties, making their complete removal very tedious even with the use of conventional methods. In some cases, organics and heavy metals usually exist in a mixed matrix in industrial wastes. This poses harmful health risks to humans, aquatic lives and the entire ecosystem, because majority of these mixed pollutants amass in water in concentrations which are more than the permissible discharge limits in the environment. Therefore, it is necessary to remove these pollutants in order to prevent them from contaminating both the surface and ground water. Although, the removal of organic compounds and heavy metals (such as Hg, Pb, Cd, As and Cr) could be easily achieved individually, however, these pollutants exist together in many industrial effluents and even in surface waters. Hence the complete removal of these pollutants concurrently in a polluted system is the focus of this study. Several technologies have been used for the simultaneous removal of organics and heavy metal pollutants from water, which includes adsorption, ion exchange, photocatalysis, and coagulation. The success of these techniques depends on the water matrices and the choice of water treatment media such as adsorbents, resins, photocatalysts, and coagulants. The advantages and limitations of these technologies together with their respective mathematical modelling is critically examined in this review. Finally, the effect of joint existence of organic pollutants and heavy metals on the removal efficiency were examined in addition to the mathematical models that discusses the mechanisms of their combine elimination.


Assuntos
Resíduos Industriais , Metais Pesados/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Ecossistema , Indústrias , Águas Residuárias
3.
Chemosphere ; 262: 127940, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182111

RESUMO

Sodium hydroxide treated rice hulls were investigated to preconcentrate, remove, and recover metal ions including Be2+, Al3+, Cr3+, Co2+, Ni2+, Cu2+, Zn2+, Sr2+, Ag+, Cd2+, Ba2+, and Pb2+ in both batch mode and column mode. Sodium hydroxide treatment significantly improved the removal efficiency for all metal ions of interest compared to the untreated rice hull. The removal kinetics were extremely fast for Co, Ni, Cu, Zn, Sr, Cd, and Ba, which made the treated rice hull a promising economic green adsorbent to preconcentrate, remove, and recover low-level metal ions in column mode at relatively high throughput. The principal removal mechanism is believed to be the electrostatic attraction between the negatively charged rice hulls and the positively charged metal ions. pH had a drastic impact on the removal for different metal ions and a pH of 5 worked best for most of the metal ions of interest. Processed rice hulls provide an economic alternative to costly resins that are currently commercially available products designed for metal ion preconcentration for trace metal analysis, and more importantly, for toxic heavy metal removal and recovery from the environment.


Assuntos
Metais Pesados/análise , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Concentração de Íons de Hidrogênio , Íons , Cinética , Oryza , Hidróxido de Sódio , Água
4.
Chemosphere ; 262: 128365, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182124

RESUMO

The study of soil potentially toxic elements (PTE) contents and establishment of the geochemical characterization of areas which have never been studied is of great concern. In 2019, soil survey of the Armavir region (Armenia) was conducted in order to investigate the spatial pattern of PTE, reveal PTE geochemical associations and assess the origin-specific health risks. The application of compositional data analysis and geospatial mapping allowed to identify two clusters of samples. The first cluster was spatially located on volcanic rocks and was represented by Fe, Co, Mn, Ti, Zn, Ba, Pb suggesting a natural origin of PTE in these areas. The second cluster was allocated on the alluvial, deluvial, and proluvial sediments and represented by As, Cu, Cr, Ni. Such combination of elements in the same group indicates the anthropogenic introduction of some quantities of PTE. The latter is confirmed by the presence of outliers and extreme values for As, Cu and Ni, as well as by the spatial colocation of Fe, Mn, Co, Pb, Zn outliers and extreme contents. The health risk assessment showed that for children the multi-elemental non-carcinogenic risk was detected, while for the adults the non-carcinogenic risk and carcinogenic risk were below the allowable level. The detailed study of the risk levels showed that in first cluster comparatively higher risk were observed for Pb, V, Ba, Zn while in the second cluster: Fe, Co, Mn, As, Cr, Cu, Ni. The results indicated the necessity of additional in-depth studies with special focus on bioavailability of PTE.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Adulto , Armênia , Criança , Monitoramento Ambiental/métodos , Humanos , Medição de Risco , Solo/química
5.
Sci Total Environ ; 750: 141296, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182202

RESUMO

Marine mammals and the ecological functions they provide to coastal and pelagic ecosystems are increasingly threatened by the intensification of anthropogenic impacts. The Uruguayan coastline throughout the 20th century, like other coastal environments worldwide, has been the sink of a variety of trace metals derived from the rapid urbanization and industrialization of related land areas. This coastline is inhabited by two species of pinnipeds trophically and spatially segregated. Otaria byronia feeds in coastal environments while Arctocephalus australis preys mainly offshore. The present study aimed to analyze historic changes in concentrations of trace elements in teeth of both species from 1941 to the present day. We analyzed the dentin of 94 canine teeth using stable isotope analysis (δ13C) and ICP-MS to determine their feeding areas and the concentration of 10 trace elements (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) respectively. The concentration of Cr was significantly higher during '70-'80s, in both species coinciding with tannery industry development. Both species of pinnipeds have been differentially exposed to trace elements depending on their feeding area. A pelagic diet, possibly based on squid, increased the concentration of Cd in A. australis, while O. byronia has been more exposed to anthropogenic Pb and Cu associated to a costal and more benthic diet. Our results highlight dentin as a reliable matrix for historic studies on the exposure to trace elements. In light of our results, the O. byronia's declining population could be the result of the synergistic effects of trace elements together with other ecological pressures faced in their environment.


Assuntos
Caniformia , Metais Pesados , Oligoelementos , Poluentes Químicos da Água , Animais , Ecossistema , Monitoramento Ambiental , Hábitos , Metais Pesados/análise , Oligoelementos/análise , Poluentes Químicos da Água/análise
6.
Sci Total Environ ; 750: 141669, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33182204

RESUMO

Abandoned mine sites are a cause of great environmental concern, being potential sources of toxic elements for adjacent aquatic ecosystems with intrinsic difficulties for their management (i.e. episodic nature of pollution, technical difficulties and high costs of monitoring, remoteness). Aquatic macrophytes can find effective application in these situations, providing cost-effective data for instream water quality assessment. In this study, native and transplanted specimens of the aquatic moss Platyhypnidium riparioides were used to evaluate metal(loid) contamination in a river receiving multiple acidic and metalliferous drainages from sulphide mineralized areas and derelict mines. Analysis of native P. riparioides thalli was used to identify, in the upland course of the river, the pattern of contamination (As, Cd, Cu, Pb and Zn) which was related to the geo-environmental features of the watershed and the nearby historical mining areas. Attenuation of metal(loid) availability in the lowland river, apparently due to eco-hydrological and physic-chemical processes, was also highlighted by spatial trends of concentrations data of native and transplanted moss. The latter, deployed for 21 days at specific stretches of the river and in a tributary hydrologically connected with a dismissed mine, supported the identification of point sources (i.e. mine effluents, metallurgical waste piles amassed on the banks of the river) and the reckoning of their quantitative impact on different segments of the watercourse. By exploring multi-elemental and native-to-transplant relationships, differences in metal(loid) accumulative capacities were recognized between sampled thalli and exposed moss bags in relation to the severity of the contamination. The observed discrepancy in the accumulation of As, Fe, Ni and Pb in highly contaminated areas between native and transplanted moss of P. riparioides raises questions on the possible competing mechanisms of element uptake and retention. These findings prompt studies to discern possible limitations of the transplanting moss technique under extreme stream-quality conditions.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental , Metais/análise , Metais Pesados/análise , Rios , Poluentes Químicos da Água/análise
7.
J Environ Sci (China) ; 99: 210-221, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183699

RESUMO

Assisted natural remediation (ANR) has been highlighted as a promising, less expensive, and environmentally friendly solution to remediate soil contaminated with heavy metals. We tested the effects of three amendments (10% compost, C; 5 or 15% phosphate sludge, PS5 and PS15; and 5 or 15% marble waste, MW5 and MW15) in combination with microorganism inoculation (rhizobacteria consortium alone, mycorrhizae alone, and the two in-combination) on alfalfa in contaminated soil. Plant concentrations of Zn, Cu, and Pb were measured, along with proline and malondialdehyde production. The microbiological and physicochemical properties of the mining soil were evaluated. Application of the amendments allowed germination and promoted growth. Inoculation with the rhizobacteria consortium and/or mycorrhizae stimulated plant growth. PS and MW stimulated the production of proline. Inoculation of alfalfa with the rhizobacteria-mycorrhizae mixture and the application of MW allowed the safe cultivation of the legume, as shown by the low concentrations of metals in plant shoots. Zn and Pb concentrations were below the limits recommended for animal grazing and accumulated essentially in roots. Soil analyses showed the positive effect of the amendments on the soil physicochemical properties. All treatments increased soil pH (around 7), total organic carbon, and assimilable phosphorus content. Notably, an important decrease in soluble heavy metals concentrations was observed. Overall, our findings revealed that the applied treatments reduced the risk of metal-polluted soils limiting plant growth. The ANR has great potential for success in the restoration of polymetallic and acidic mining soils using the interaction between alfalfa, microorganisms, and organo-mineral amendments.


Assuntos
Metais Pesados , Poluentes do Solo , Animais , Carbonato de Cálcio , Metais Pesados/análise , Fosfatos , Esgotos , Solo , Poluentes do Solo/análise
8.
J Environ Sci (China) ; 99: 267-273, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33183704

RESUMO

Generation of hydroxyl radicals (⋅OH) is the basis of advanced oxidation process (AOP). This study investigates the catalytic activity of microporous carbonaceous structure for in-situ generation of ⋅OH radicals. Biochar (BC) was selected as a representative of carbon materials with a graphitic structure. The work aims at assessing the impact of BC structure on the activation of H2O2, the reinforcement of the persistent free radicals (PFRs) in BC using heavy metal complexes, and the subsequent AOP. Accordingly, three different biochars (raw, chemically- and physiochemically-activated BCs) were used for adsorption of two metal ions (nickel and lead) and the degradation of phenol (100 mg/L) through AOP. The results demonstrated four outcomes: (1) The structure of carbon material, the identity and the quantity of the metal complexes in the structure play the key roles in the AOP process. (2) the quantity of PFRs on BC significantly increased (by 200%) with structural activation and metal loading. (3) Though the Pb-loaded BC contained a larger quantity of PFRs, Ni-loaded BC exhibited a higher catalytic activity. (4) The degradation efficiency values for phenol by modified biochar in the presence of H2O2 was 80.3%, while the removal efficiency was found to be 17% and 22% in the two control tests, with H2O2 (no BC) and with BC (no H2O2), respectively. Overall, the work proposes a new approach for dual applications of carbonaceous structures; adsorption of metal ions and treatment of organic contaminants through in-situ chemical oxidation (ISCO).


Assuntos
Peróxido de Hidrogênio , Metais Pesados , Adsorção , Carbono , Carvão Vegetal , Oxirredução
9.
Sci Total Environ ; 752: 141827, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889271

RESUMO

Northwest China is abundant in iron ore reserves and has become one of the important iron ore mining bases in China. However, the contamination and microbial community structure of iron tailing ponds in Northwest China have not been extensively investigated. In the present study, we characterized the main physicochemical properties, the multiple heavy metal contamination, and the bacterial community structure of the soils surrounding an iron tailing pond in Linze County, Zhangye city, Gansu Province. The tailing-associated soils were barren, exhibiting alkaline pH and low organic matter (OM), total nitrogen (TN) and total potassium (TK) compared with the control areas. There was considerable multiple heavy metal pollution in the iron tailing pond, mainly including lead (Pb), manganese (Mn), arsenic (As), cadmium (Cd), zinc (Zn), iron (Fe) and copper (Cu). Among the 303 identified core operational taxonomic units (OTUs), Actinobacteria, Proteobacteria and Deinococcus-Thermus were predominant at the phylum level, and Blastococcus, Arthrobacter, Marmoricola, Kocuria, Truepera, and Sphingomonadaceae were prevalent at a finer taxonomic level. The bacterial richness and diversity of the tailing samples were significantly lower than those of the reference samples. RDA, VPA and Spearman correlation analyses showed that the soil pH, CEC, OM, TP, TK, Cd, Pb, Ni, Zn, As and Mn had significant effects on the bacterial community composition and distribution. This work profiles the basic features of the soil physicochemical properties, the multiple heavy metal contamination and the bacterial community structure in an iron tailing pond in Northwest China, thereby providing a foundation for the future ecological remediation of the iron tailing environment in the area.


Assuntos
Metais Pesados , Poluentes do Solo , China , Monitoramento Ambiental , Ferro , Metais Pesados/análise , Solo , Poluentes do Solo/análise
10.
Sci Total Environ ; 752: 141862, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32889281

RESUMO

Alternate wetting and drying (AWD) irrigation was reported to increase rice root activity and element bioavailability, which results in enhanced heavy metal (HM) absorption and this HM ends up in rice grains. HM uptake was also affected by the levels of phosphorus (P) fertilizer application. HMs enter food chain via consumption of rice grains and cause health problems. In this study, we compared the differences in grain yield, grain quality, water use efficiency (WUE), partial factor productivity of applied P (PFPp), HM contents in different tissues and transfer coefficient (TC) of HMs under a combination of treatments involving two irrigation regimes (continuous flooding (CF) and AWD irrigation) and three P fertilizer application levels (0.4 g P2O5/kg soil, HP; 0.2 g P2O5/kg soil, MP; 0 g P2O5/kg soil, LP). Compared to CF, AWD irrigation increased grain yield (without reducing grain quality), decreased irrigation water use and the number of irrigation events needed and improved WUE and PFPp at all three P fertilizer application levels, while the accumulation of HMs in grains increased when more P was applied. This accumulation of HMs in grains thus requires immediate attention to the level of P fertilizer application and its optimization in water-saving AWD irrigation to minimize grain HM content.


Assuntos
Metais Pesados , Oryza , Irrigação Agrícola , Grão Comestível , Fertilizantes , Fósforo , Solo , Água
11.
Sci Total Environ ; 752: 141894, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-32896791

RESUMO

The objective of this experiment was to valuate, after 14 years, the impact of annual compost applications on micronutrient and potentially toxic trace elements on nectarine tree uptake and soil fertility. The study was performed in the Po valley, Italy, on the variety Stark RedGold (grafted on GF677). Since orchard planting, the following treatments were applied, in a randomized complete block design, with four replicates: 1. unfertilized control; 2. mineral fertilization (N was supplied as NO3NH4 at 70-130 kg ha-1 year-1); 3. compost at 5 t DW ha-1 year-1; 4. compost at 10 t DW ha-1 year-1. The actual rate of application was 12.5 (LOW) and 25 (HIGH) t ha-1, since compost was concentrated in the tree row. Compost was made from domestic organic wastes mixed with pruning material from urban ornamental trees and garden management and stabilized for 3 months. The supply of compost HIGH induced an enrichment of soil total Cu, Zn and Cd, and a decrease of Fe and Co concentration; with values always below the European threshold limits for heavy metals in the soil. In addition, compost (at both rates) increased availability (DTPA-extractable) of Fe, Mn and Zn, Cd, Ni, and Pb in the top soil (0-0.15 m). Total micronutrient and trace element tree content was not affected by fertilization treatments; however, the recycled fraction returned to the soil at the end of the season through abscised leaves and pruned wood of Cu, Fe, Mn and Zn was increased by mineral fertilization; Fe and Zn also by compost HIGH. Our data show that the introduction of compost at both 12.5 and 25 t ha-1 year-1 in the row did not increase the risk of pollution related to potentially toxic trace elements and at the same time increased the bioavailability of Fe, Mn and Zn.


Assuntos
Compostagem , Metais Pesados , Poluentes do Solo , Oligoelementos , Itália , Solo , Poluentes do Solo/análise , Oligoelementos/análise
12.
Chemosphere ; 262: 127835, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32763581

RESUMO

This study evaluates the bioaccessibility and health risks related to heavy metals (Cd, Cr, Co, Cu, Mn, Ni, Pb, Zn and metalloid As) in airborne dust samples (TSP and PM2.5) in Zabol, Iran during the summer dust period, when peak concentration levels of PM are typically observed. High bioaccessibilities of carcinogenic metals in PM2.5 (i.e. 53.3%, 48.6% and 47.6% for Ni, Cr and As, respectively) were calculated. The carcinogenic and non-carcinogenic health risks were assessed for three exposure pathways (inhalation, ingestion and dermal contact), separately for children and adults. Non-carcinogenic inhalation risks were very high (Hazard Index: HI > 1) both for children and adults, while the carcinogenic risks were above the upper acceptable threshold of 10-4 for adults and marginally close (5.0-8.4 × 10-5) for children. High carcinogenic risks (>10-4) were found for the ingestion pathway both for children and adults, while HI values > 1 (8.2) were estimated for children. Carcinogenic and non-carcinogenic risk estimates for dermal contact were also above the limits considered acceptable, except for the carcinogenic risk for children (7.6 × 10-5). Higher non-carcinogenic and carcinogenic risks (integrated for all elements) were associated with the inhalation pathway in adults and children with the exception of carcinogenic risk for children, where the ingestion route remains the most important, while As was linked with the highest risks for nearly all exposure pathways. A comparative evaluation shows that health risks related with toxic elements in airborne particles in Sistan are among the highest reported in the world.


Assuntos
Poluição do Ar/estatística & dados numéricos , Poeira/análise , Exposição Ambiental/estatística & dados numéricos , Substâncias Perigosas/análise , Adulto , Carcinógenos/análise , Criança , Monitoramento Ambiental , Humanos , Irã (Geográfico) , Metais Pesados/análise , Medição de Risco , Estações do Ano
13.
Chemosphere ; 262: 127838, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32768756

RESUMO

Nitrogen and heavy metals can co-occur in various industrial wastewaters such as coke-oven wastewater. Removal of these contaminants is important, but cost-efficient removal technology is limited. In this study, we examined the usefulness of nitrate-dependent ferrous iron oxidation (NDFO) for the simultaneous removal of nitrate and heavy metals (iron and zinc), by using an NDFO strain Pseudogulbenkiania sp. NH8B. Based on the batch culture assays, nitrate, Fe, and Zn were successfully removed from a basal medium as well as coke-oven wastewater containing 5 mM nitrate, 10 mM Fe(II), and 10 mg/L Zn. Zinc in the water was most likely co-precipitated with Fe(III) oxides produced during the NDFO reaction. Simultaneous removal of nitrate, Fe, and Zn was also achieved in a continuous-flow reactor fed with a basal medium containing 10 mM nitrate, 5 mM Fe(II), 4 mM acetate, and 10 mg/L Zn. However, when the reactor is fed with coke-oven wastewater supplemented with 10 mM nitrate, 5 mM Fe(II), 4 mM acetate, and 10 mg/L ZnCl2, the reactor performance significantly decreased, most likely due to the inhibition of bacterial growth by thiocyanate or organic contaminants present in the coke-oven wastewater. Use of mixed culture of NDFO bacteria and thiocyanate/organic-degrading denitrifiers should help improve the reactor performance.


Assuntos
Reatores Biológicos , Metais Pesados/química , Nitratos/química , Eliminação de Resíduos Líquidos/métodos , Betaproteobacteria , Coque , Desnitrificação , Compostos Ferrosos , Ferro , Nitrogênio , Óxidos de Nitrogênio , Oxirredução , Águas Residuárias , Zinco
14.
Chemosphere ; 262: 127768, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32777611

RESUMO

Heavy metals and antimicrobial resistant bacteria in livestock and poultry environments can cause declines in production and significant economic losses, leading to potential environmental and public health issues. In this study, the heavy metal pollution status of livestock breeding water bodies in the Dawen river basin of Shandong Province in China was evaluated, and a total of 10 heavy metals were measured. In addition, antimicrobial susceptibility tests were conducted for Escherichia coli strains isolated from the water samples. The results showed that among all the metals, copper, zinc, and iron were detected at each sampling point, followed by nickel (detection rate of 95.74%), arsenic (detection rate of 89.36%), selenium (detection rate of 68.09%), lead (detection rate of 27.66%), and mercury (detection rate of 12.77%). Cadmium and hexavalent chromium were not detected. The contents of nine heavy metals were below the existing water standard values in China, whereas the iron pollution index in the water body in the study area was large and may pose a potential risk. A total of 17 E. coli isolates showed different resistance to ß-lactams, aminoglycosides, tetracyclines, quinolone antibiotics and chloramphenicol, but were mainly resistant to ß-lactams and tetracyclines. The detection rate of the tetA resistance gene was relatively high, indicating the overuse of cephalosporins and tetracyclines. The results of the present study might provide evidence of metal pollution and theoretical basis on the treatment of colibacillosis in the livestock industries.


Assuntos
Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Monitoramento Ambiental/métodos , Escherichia coli/isolamento & purificação , Metais Pesados/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Antibacterianos/farmacologia , China , Indústria de Laticínios , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Fazendas , Rios/química , Rios/microbiologia , Águas Residuárias/microbiologia
15.
Chemosphere ; 262: 127772, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32799140

RESUMO

This study utilized the freshwater amphipod (Hyalella azteca) for the indication of contamination risk levels of sediment-associated contaminants in the Erren (ER1∼ER10) and Sanye Rivers (SY1∼SY5) which were contaminated by metal scrap and smelting industries for decades. Toxicity identification evaluations involving the manipulation of pore water and whole-sediment samples were conducted to identify causative pollutants. Impacts on the aquatic environment were then evaluated in order to explore how industrial development led to contaminant accumulation in sediments and resulted in biological effects. A whole-sediment TIE indicated that the major toxicant at sampling sites ER8 and SY5 was ammonia and that its toxicity was significantly reduced by the addition of zeolite. Toxicity at sampling sites ER4 and ER9 was induced by ammonia and heavy metals (Zn, Cd, Cr, As), whereas Cr was at toxic levels at ER6. ∑PAHs was another major class of contaminants at site ER2. Metals (Zn, Ni, Pb, Cd, Cr, and As) were identified as major toxic contaminants at three sites (ER3, SY1, and SY3). The application of TIEs confirmed that a causative toxicant can be identified and that its measured toxicity correlated with its concentration. In conclusion, a TIE approach was successful in demarcating most effective contaminant groups (ammonia, heavy metals, and non-polar organic compounds) in whole-sediment cores, their porewaters and potential toxicities from a highly polluted river after remediation in southern Taiwan to an invertebrate animal model H. azteca.


Assuntos
Anfípodes/efeitos dos fármacos , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Rios/química , Poluentes Químicos da Água/toxicidade , Amônia/análise , Amônia/toxicidade , Animais , Água Doce/química , Metais Pesados/análise , Metais Pesados/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Taiwan , Clima Tropical , Poluentes Químicos da Água/análise , Zeolitas/química
16.
Chemosphere ; 262: 127749, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32805655

RESUMO

Beans of cacao (Theobroma cacaoL.) are used to produce a variety of chocolate products. Bioaccumulation of metals at toxic levels through the consumption of contaminated products has been identified as a health concern in humans. Both metal diversity and concentration as well as their interactions in the soil influence essential and non-essential metal uptake in plants; but the effects of these on bioaccumulation of metals in cacao is not understood across diverse soil types. In this study eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were investigated in 12 soil subgroups belonging to four soil orders across 15 locations in Trinidad, with the aim to investigate the effect of soil metal diversity and concentration on metal bioaccumulation in cacao. Soil metals were extracted using five methods (aqua regia, DTPA, Mehlich 3, nitric acid, and water). Cacao leaf metal concentrations were determined using the USEPA 3052 method. Metal extraction efficiency ranged between methods with aqua regia ≥ nitric acid > Mehlich 3 ≥ DTPA ≥ water across all metals. The soil extraction method that best predicted cacao leaf metal concentrations varied with the metal - Mehlich 3 or DTPA for Cd, Ni, Zn; aqua regia, Mehlich 3, or nitric acid for Pb, and water for Mn. A stepwise regression analysis showed that plant metal concentration can be predicted using soil physicochemical characteristics as well as the concentration of metals in the soil. The importance of soil type on cacao leaf metal bioaccumulation is discussed.


Assuntos
Bioacumulação , Cacau/química , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Disponibilidade Biológica , Cacau/efeitos dos fármacos , Cacau/crescimento & desenvolvimento , Humanos , Metais Pesados/metabolismo , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Poluentes do Solo/metabolismo , Trinidad e Tobago
17.
Chemosphere ; 262: 128013, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182094

RESUMO

The main aim of this work is to assess the extent of soil contamination, potential ecological and health risks associated with the disposal of municipal solid waste (MSW) near a Ramsar site in Assam, India. Soil samples were collected and analysed for three heavy metals (HMs), namely, chromium (Cr), manganese (Mn) and zinc (Zn). The sources of HMs and their pollution levels were evaluated using different indices. The results demonstrated that Cr contamination was high near the metal scrap segregations unit within the dumping site, otherwise, the ecological risks associated with Zn and Mn were found to be low. The speciation of Cr and Zn were associated with the Fe-Mn oxide bound (F4) fraction, accounting 44.23% and 30.68%, respectively, whereas Mn (52.55%) was associated with the exchangeable fraction (F2). The fate and origin of HMs were assessed using mobility and enrichment factors and 16 out of the 20 sampling sites fell under the category of heavily polluted category for Cr, while others which were nearby the metal segregation units fell under the strongly to extremely polluted category. In few sites, significant enrichment was observed for Zn and minimal to moderate enrichment for Mn, respectively. Health risk assessment results indicated that Cr posed higher threat to human health through ingestion.


Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Humanos , Índia , Medição de Risco
18.
Chemosphere ; 262: 128305, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182158

RESUMO

The fine particulate matter (PM2.5) was collected at academic campus of Indian Institute of Technology, Delhi, India from January-December 2017. The PM2.5 samples were analysed for carcinogenic (Cd, Cr, As, Ni, and Pb) and non-carcinogenic (V, Cu, Zn, Fe) trace metals and their elicited effects on carcinoma epithelial cell line A549. Toxicological testing was done with ELISA kit. Same analyses were repeated for standard reference material (NIST-1648a) represents urban particulate matter. The student-t test and spearman correlation were used for data analysis. The seasonality in PM2.5 mass concentration and chemical composition showed effect on biological outcomes. The PM2.5 in post-monsoon and winter had higher amount of trace metals compared to mass collected in pre-monsoon and monsoon. Following the trend in PM mass concentration significantly (p < 0.5) lower cell viability was observed in post-monsoon and winter compared to other two seasons. NIST UPM 1648(a) samples always had higher cytotoxicity compared to ambient PM2.5 Delhi sample. Strong association of Chromium, Nickel, Cadmium, and Zinc was observed with cell viability and reactive oxygen species (ROS) production. In winter IL-6, IL-8 production were 2.8 and 3 times higher than values observed in post-monsoon and 53 and 9 times higher than control. In winter season trace metals As, Cu, Fe, in pre-monsoon Cr, Ni, As, Pb, V, and Fe, in post-monsoon Cd and V strongly correlated with ROS generation. ROS production in winter and pre-monsoon seasons found to be 2.6 and 1.3 times higher than extremely polluted post-monsoon season which had 2 to 3 times higher PM2.5 concentration compared to winter and pre-monsoon. The result clearly indicated that the presence of Fe in winter and pre-monsoon seasons catalysed the ROS production, probably OH˙ radical caused high cytokines production which influenced the cell viability reduction, while in post-monsoon PM majorly composed of Pb, As, Fe and Cu and affected by photochemical smog formation showed significant association between ROS production with cell viability. Overall, in Delhi most toxic seasons for respiratory system are winter and post-monsoon and safest season is monsoon.


Assuntos
Poluentes Atmosféricos/toxicidade , Monitoramento Ambiental/métodos , Células Epiteliais/efeitos dos fármacos , Metais Pesados/toxicidade , Material Particulado/toxicidade , Espécies Reativas de Oxigênio/análise , Células A549 , Poluentes Atmosféricos/análise , Sobrevivência Celular/efeitos dos fármacos , Citocinas/análise , Células Epiteliais/imunologia , Células Epiteliais/patologia , Humanos , Índia , Metais Pesados/análise , Material Particulado/análise , Estações do Ano
19.
Chemosphere ; 262: 128031, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182077

RESUMO

In this research, raw jujube seeds (RJS) treated with sulphuric acid followed by ultrasonic treatment such as ultrasonic assisted jujube seeds (UAJS) based biochar have been experimented as a viable material for treating Zn(II) and Pb(II) contaminated water. The adsorption ability of UAJS was compared with RJS through Langmuir adsorption capacity. The produced adsorbents were analysed by using BET surface area and thermogravimetric analyses. The removal kinetics, isotherms and thermodynamic behaviours of metal ions adsorption by UAJS were studied. Adsorption equilibrium data were analysed using various equilibrium models and Freundlich isotherm was appropriate towards explain the adsorption characteristics. UAJS Langmuir capacity of 221.1 mg/g and 119.8 mg/g were obtained for Zn(II) ions and Pb(II) ions, respectively. The results observed that UAJS holds higher capacity as compared with RJS. The pseudo-first order model was relevant to address adsorption behaviour. The mechanism on the separation of metal ions by UAJS was tested using diffusion and Boyd models. The mechanism outcomes observed that the internal and external diffusion controlled the separation process. The thermodynamic results explain the separation process was viable, exothermic and natural. The electroplating industrial wastewater was also treated with UAJS biochar to remove the metal ions such as copper, nickel, chromium and zinc ions from wastewater. Desorption process showed that 0.1 N HCl provide the good results as compared with other desorbing agents. The adsorbent property is not lost till the maximum of 5 adsorption/desorption cycles. The produced UAJS can be a better adsorbent for treating the heavy metal polluted wastewater.


Assuntos
Carvão Vegetal/química , Galvanoplastia , Metais Pesados/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Adsorção , Difusão , Íons , Cinética , Sementes/química , Termodinâmica , Ziziphus/química
20.
J Environ Manage ; 277: 111500, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33069155

RESUMO

There are thousands of disused and abandoned mining sites around the world with substantial accumulations of exposed mine spoil materials that pose a direct threat to their surrounding environment. Management of such sites, and neutralisation of the environmental threats they pose, is therefore extremely important and is an issue of global significance. Low cost management and remediation strategies need to be developed because many abandoned mine sites are in remote and/or economically challenged areas. One promising option is the incorporation of biochar into spoil materials, which has the potential to immobilise leachable toxic constituents and facilitate revegetation and thereby stabilisation of spoil heaps. This study investigated the capacity of readily available biochar materials made from wheat and rice waste products to immobilise and retain key metallic contaminants Pb and Zn from solution, and also investigated the utility of biochar application for remediating mine spoil heaps from different mine types in terms of facilitating establishment of vegetation coverage and minimising porewater element mobility within spoil heaps. The results demonstrated the high sorption capacity of the biochars (typically >97% of Pb or Zn in solution) and their ability to retain the metals despite an active desorption procedure (>93% of sorbed Pb retained and >75% of sorbed Zn). The remediation trial revealed that biochar application increased plant yield and decreased plant assimilation of many potentially toxic elements and also decreased spoil porewater concentrations of Al, Cd, Pb and Zn in most cases. In some spoil types investigated biochar addition also significantly decreased porewater concentrations of As (e.g. from ~30 mg/L to ~5 mg/L), demonstrating its potential utility for low cost environmental remediation across a range of mine spoil types.


Assuntos
Recuperação e Remediação Ambiental , Metais Pesados , Poluentes do Solo , Carvão Vegetal , Metais Pesados/análise , Mineração , Solo , Poluentes do Solo/análise
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