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1.
Huan Jing Ke Xue ; 43(1): 1-10, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989485

RESUMO

The rapid urbanization in China may lead to heavy metal pollution in urban soil, threatening the health of residents. By collecting literature data published in the last 15 years, the characteristics and risks of heavy metals in the urban soils of 52 cities in China were analyzed. The results showed that the average ω(Pb), ω(Cd), ω(Cu) and ω(Zn) in the urban soils of China were 58.5, 0.49, 42.1, and 156.3 mg·kg-1, respectively, and the average Igeo values were ordered as follows Cd(1.10) > Zn(0.36) > Pb(0.28) > Cu(0.13). The high concentrations of heavy metals in the urban soils were mainly found in cities located in coastal economically developed provinces (such as Jiangsu, Zhejiang, etc.) and resource-based provinces (such as Hunan, Henan, Inner Mongolia, etc.). The cities of Kaifeng, Yangzhou, Hohhot, Taiyuan, and Xiangtan had relatively high Igeo values for heavy metals in the soils. The concentrations of heavy metals in soils from industrial areas and roadsides were significantly higher than those from residential areas and parks, suggesting that heavy traffic and developed heavy industry were the main causes of heavy metal accumulation in the urban soils. No significant correlations between the average concentrations of heavy metals in urban soil and urban economic and environmental indicators[such as permanent population, GDP, ρ (PM10), ρ(PM2.5), and SO2 emissions] were found. The concentrations of heavy metals in urban soils showed large spatial heterogeneity, and hence the average concentrations may not reflect the overall accumulation level in a city. The non-carcinogenic risks for children posed by heavy metals in urban soils were generally low, and the main risk contributor was Pb. However, the exposure to heavy metals in soils in cities with developed smelting industries is worthy of attention.


Assuntos
Metais Pesados , Poluentes do Solo , Criança , China , Cidades , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise
2.
Huan Jing Ke Xue ; 43(1): 11-25, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989486

RESUMO

At present, plant growth regulators play an increasingly important role in global agricultural production. The average growth rate of global sales of plant growth regulators has been above 14% in the past decade. For many years, most plant growth regulators have been considered low-toxicity or slight-toxicity pesticides. However, recent studies have found that many plant growth regulators and their degradation products in the environment are potentially harmful to humans, animals, and plants. As the key factors to control the entering of plant growth regulators into the environment, the environmental behaviors of plant growth regulators in soil could make a significant influence on the risk of plant growth regulators to environmental safety. Therefore, it is critical to investigate the environmental behaviors of plant growth regulators in soil. This study systematically summarizes the environmental behaviors of plant growth regulators in soil from recent research, including the adsorption, desorption, hydrolysis, photolysis, and microbial degradation. Additionally, the factors affecting the environmental behaviors of plant growth regulators in the soil are discussed in detail. Moreover, the future research focus and direction to plant growth regulators are suggested.


Assuntos
Poluentes do Solo , Solo , Adsorção , Agricultura , Humanos , Reguladores de Crescimento de Plantas , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
3.
Huan Jing Ke Xue ; 43(1): 432-441, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989528

RESUMO

In order to ascertain the distribution characteristics of soil heavy metal pollution and main pollution sources in a small watershed in the southern mountainous area of Ningxia and to ensure the quality of the soil environment, the contents of heavy metals Pb, Ni, Zn, Mn, Cu, Cr, and Cd in 260 surface soil samples (0-20 cm) were collected and determined. Based on the soil background value in Ningxia, the soil heavy metal pollution status and potential ecological risk were evaluated through the single factor index, Nemera composite index, and potential ecological risk index, and the method of combining positive definite matrix factor analysis (PMF) and Kriging interpolation was used to analyze the soil heavy metal spatial distribution and source. The results showed that the average contents of ω(Pb), ω(Ni), ω(Zn), ω(Mn), ω(Cu), ω(Cr), and ω(Cd) were 31.42, 36.22, 62.89, 546.18, 22.26, 61.90, and 0.18 mg·kg-1, respectively. Except for Ni, the other elements were higher than the background value of Ningxia but lower than the background value of agricultural soil pollution risk selection criteria and green food environmental quality standards. The Nemera composite index showed that the proportions of mild, moderate, and severe heavy metal pollution were 71.92%, 19.23%, and 1.54%, respectively. The potential ecological risks were mainly minor risks, accounting for 98.85%. In addition, there were a very small number of samples with medium potential ecological risk levels, accounting for 1.15% of the total number of samples. Source analysis showed that the main sources of soil heavy metals in the small watershed in the mountainous area of southern Ningxia were mixed sources of fertilization and industrial emissions (12.6%), agricultural activity sources (23.5%), natural parent material sources (27.6%), mixed sources of pesticide use and mining development emissions (17.7%), and atmospheric deposition sources (18.6%).


Assuntos
Metais Pesados , Poluentes do Solo , China , Monitoramento Ambiental , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise
4.
Huan Jing Ke Xue ; 43(1): 442-453, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989529

RESUMO

In order to ascertain the impact of pyrite mining on the surrounding farmland soil environment and human health, 42 surface soil samples (from 0-20 cm) were collected around the pyrite mining area in Longyou county. In this study, the concentrations of eight heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) and the pH in the topsoil were analyzed, and the concentration characteristics of heavy metals, source analysis, and human health risks assessment were studied using statistical analysis (SA), geo-accumulation index (Igeo), positive matrix factorization (PMF), and the health risk model. The average of ω(Cd), ω(Cu), ω(Pb), and ω(Zn) concentrations exceeded the background values of soils in Zhejiang province and China. According to the agricultural land pollution risk screening values (GB 15618-2018), Cd, Cu, Pb, and Zn were up to 82%, 49%, 42%, and 31%, respectively. The Igeo shows that the major pollutant element in the soils was Cd, followed by Cu, Pb, and Zn. The PMF analysis indicates that nature sources (As, Cr, and Ni), comprehensive pollution sources caused by high geological background and mining of ore-forming geological bodies (Cd, Cu, Pb, and Zn), and anthropogenic sources (Hg) were the three major sources of heavy metals in the study area, with contributions of 32%, 46%, and 22%, respectively. The results of the health risk assessment indicate that the major non-carcinogenic factor triggering risks was the ingestion of Pb; Cr exposure had carcinogenic risk for adults, and Cr and As exposure had carcinogenic risk for children.


Assuntos
Metais Pesados , Poluentes do Solo , Adulto , Criança , China , Monitoramento Ambiental , Fazendas , Humanos , Ferro , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Sulfetos
5.
Huan Jing Ke Xue ; 43(1): 454-462, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989530

RESUMO

Agricultural products are a primary pathway for humans to accumulate heavy metals (HMs) via the soil-crop system and should therefore should be included as a crucial part of the food security in our country. Given that previous studies on protection zoning for preventing farmland HM pollution rarely considered agricultural products as a basic element, this study attempted to establish a zoning system for farmland HM prevention, which was based on the perspective of agricultural product pollution. We subsequently took a representative peri-urban area in the black soil region, which was provided with a higher risk of being polluted, as an empirical case. The results indicated that:① the comprehensive quality index of agricultural products (IICQAP) was 1.09, illustrating only a mild HM pollution, with Pb and Ni having the highest accumulation levels; ② the human health risk index (QHI) was 0.61, showing no risk for human health; and ③ the designed zoning method revealed 89.45% of the farmlands to be risk-free at the moment and 10.55% of the farmlands to be under low risk of HM pollution in agricultural products. According to the zoning results, we suggested prioritized protection and an early-warning strategy, respectively, and further recommended prevention methods such as accumulation intervention, crop restructuring, and in-situ passivation. The results served to enrich the theoretical basis for preventing farmland HM pollution, to reinforce the management standards for agricultural products in the black soil region, and also to build a differentiated urban-rural farmland protection system.


Assuntos
Metais Pesados , Poluentes do Solo , China , Monitoramento Ambiental , Fazendas , Humanos , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise
6.
Huan Jing Ke Xue ; 43(1): 463-471, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989531

RESUMO

In order to explore the main controlling factors of Cd enrichment in rice under a geological high background in the Guangxi carbonate rock area, this study was based on rice grain-root soil samples from the carbonate rock areas in the southwest and north of Guangxi. Combined with diffusive gradients in thin films technology (DGT), the relationship between soil pH, organic matter, cation exchange capacity (CEC), DGT-Cd, and ω(rice-Cd)-BCF value in rice grains was analyzed and discussed. The main factors were determined by principal component analysis, and a quantitative model was established. The results showed that the average value of ω(soil-Cd) was 0.975 mg·kg-1, and the over-standard rate was 33.33%; the average value of ω(rice-Cd) was 0.020 mg·kg-1, and the average BCF value was 0.038, and the over-standard rate of Cd content in rice grains was 4.2%. The content of Cd in paddy soil was high, but bioavailability was low in the study area. The BCF value of rice grains in the study area was significantly negatively correlated with soil pH and cation exchange capacity at the level of 0.01, positively correlated with DGT-CD at the level of 0.01, and negatively correlated with organic matter at the level of 0.05. The results of principal component analysis showed that the total amount of Cd in the soil, pH, and DGT-Cd were the main factors affecting the accumulation of Cd in rice in the Guangxi carbonate rock area. Taking the total amount of Cd in the soil, pH, and DGT-Cd as variables, the fitting equation of BCF value of rice grains in the Guangxi carbonate rock region was established, and the determination coefficient of the model was 0.717, which could better predict the content of Cd in rice grains in this region.


Assuntos
Oryza , Poluentes do Solo , Cádmio/análise , Carbonatos , China , Solo , Poluentes do Solo/análise
7.
Huan Jing Ke Xue ; 43(1): 472-480, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989532

RESUMO

The bioavailability of heavy metals in soil and the physiological activities of rice determine the accumulation of heavy metals in brown rice. In this study, a field experiment was conducted in a rice paddy in which the total amount of Cd in the soil did not exceed the national standard, whereas the Cd in rice grains was at risk of overreaching in the suburbs of Guangzhou city. The bioavailability of heavy metals in the soil and the physiological barrier of rice were taken as the starting point. The early and late rice yield, brown rice heavy metal content, Cd and Pb enrichment coefficient, total soil heavy metals, soil physical and chemical properties, and soil Cd and Pb species distribution were investigated under the Si-rich amendment (JD), Ca-Mg amendment (YY), Si-rich amendment+flooding irrigation (JD+YS), and Ca-Mg amendment+flooding irrigation (YY+YS) treatments. The results showed that:① the total ω(Cd) in the soil was only 0.13 mg·kg-1 in the CK treatment. However, the average ω(Cd) in the grain of early rice reached up to 0.19 mg·kg-1. The early rice varieties (hybrid rice) had a more vital ability to accumulate Cd and total As in brown rice than that in late rice varieties (conventional rice) but a lower capacity for Pb accumulation. ② JD and YY application alone had no noticeable inhibitory effect on the accumulation of Cd and Pb in brown rice; however, JD+YS and YY+YS treatments significantly inhibited the accumulation of Cd and Pb in brown rice in both early and late rice, especially in the JD+YS treatment, which decreased the Cd and Pb accumulation by 65.8% and 68% for early rice and by 71.43% and 49.15% for late rice, respectively. The primary mechanism of JD+YS was to increase soil pH and maintain a low redox potential to promote soil Cd and Pb to be transformed from acid-soluble to a reduced state and residue state, thus decreasing Cd and Pb to migrate from the soil to the rice. At the same time, it effectively suppressed the absorption and transportation of Cd and Pb by early and late rice via the physiological barrier effect of Si nutrition and the competition for transportation channels between calcium and magnesium ions and cadmium and inhibited the accumulation of Cd and Pb in the brown rice of early and late rice. These results provide a theoretical basis for the exploration and application of the control technologies in the brown rice Cd and Pb resistance and have important practical significance for guiding the safe production in the rice-growing area in South China.


Assuntos
Oryza , Poluentes do Solo , Cádmio/análise , Chumbo , Solo , Poluentes do Solo/análise , Água , Abastecimento de Água
8.
Huan Jing Ke Xue ; 43(1): 481-489, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989533

RESUMO

In recent years, dust pollution has occurred frequently in spring and haze or fog in autumn and winter. The inhalable particulate matters in the atmosphere, especially PM2.5, loaded in heavy metals such as cadmium, lead, and arsenic, are easily taken up by leafy vegetables and accumulate in the edible parts. It is not clear whether the accumulation of heavy metals in the edible parts of leafy vegetables in greenhouses is also affected by atmospheric deposition. Therefore, a field experiment was conducted to explore characteristics and health risk assessment of cadmium, lead, and arsenic accumulation in leafy vegetables planted in a greenhouse using six types of common leafy vegetables (spinach, leaf lettuce, lettuce, pakchoi, Chrysanthemum coronarium, and fennel) in the Beijing-Tianjin-Hebei region. The results showed that C. coronarium, pakchoi, and spinach are the leafy vegetables with a low accumulation of Cd, Pb, and As, respectively. Fennel is the leafy vegetable with a low accumulation of Cd and Pb. In the greenhouse, Pb concentrations in PM2.5 were 42.6 and 8.4 times of Cd and As, respectively. Moreover, PM2.5-Pb contributed on average 36.5% to the edible parts of six kinds of leafy vegetables, which indicated that the Cd, Pb, and As accumulated in leafy vegetables were mainly derived from the soil. Meanwhile, the concentrations of Cd, Pb, and As in the edible parts of vegetables did not exceed the safety limitations of three heavy metals (GB 2762-2017), and Pb accumulation in leafy vegetables does not pose a health risk to humans. However, Cd in the leafy vegetables could threaten the health of adults and children, except for the intake of fennel. Conversely, As in the C. coronarium could threaten the health of adults and children.


Assuntos
Arsênio , Metais Pesados , Poluentes do Solo , Adulto , Cádmio/análise , Criança , Humanos , Chumbo , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Verduras
9.
Huan Jing Ke Xue ; 43(1): 490-499, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989534

RESUMO

To study the characteristics of polychlorinated biphenyls (PCBs) in waste residue-soil-vegetable in an e-waste dismantling area and the potential health risks to humans, three samples of e-waste residue were collected, and 10 and 18 samples were taken from farmland soil and vegetables (six lettuce, six green bean, and six cabbage samples), respectively, next to the waste residue. High-resolution gas chromatography-mass spectrometry was used to detect the content of PCBs in waste residue, soil, and vegetables. The results showed that the total PCBs levels were as follows:waste residue (11938 ng·g-1, dw) > soil (45.54 ng·g-1, dw) > vegetables (11.51 ng·g-1, dw). The bio-sediment/soil enrichment factor values were as follows:lettuce samples (0.18) > green bean samples (0.05) > cabbage samples (0.01). There were 37 PCB identical homologues detected in the waste residue and soil, and 33 types were detected in vegetables, all of which were within the homologues detected in the waste residue and soil. Some homologues in the soil were correlated with cabbages (P<0.05). The column chart of PCB chlorination number in waste residues, soil, and vegetables showed that low-chlorinated biphenyls from trichlorobiphenyl to pentachlorobiphenyl mass fraction accounted for the largest proportion, accounting for 77.92%, 59.73%, and 73.96%, respectively. The proportion in the soil was relatively low, with the overall proportion showing a downward trend with increasing rate of chlorine generation. The results of the health risk assessment showed that the total HQ of PCBs in the soil and vegetables exposed to adults (male/female) and children was less than 1, which was at an acceptable level. The total CR of PCBs in the soil and vegetables exposed to adults (male/female) and children all exceeded 1×10-6, which is at an unacceptable level, and the values for adults (male/female) were higher than those for children.


Assuntos
Resíduo Eletrônico , Bifenilos Policlorados , Poluentes do Solo , Adulto , Criança , Monitoramento Ambiental , Humanos , Bifenilos Policlorados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Verduras
10.
Huan Jing Ke Xue ; 43(1): 500-509, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989535

RESUMO

The residual content of organochlorine pesticides (OCPs) in soil and crops of typical agricultural land in the southern Leizhou peninsula were determined using gas chromatography-mass spectrometry (GC-MS). Additionally, the bioconcentration factors of organochlorine pesticides in eight crops were investigated, and the human health risk was evaluated. The results indicated that 10 types of OCPs were detected to varying degrees; HCHs and heptachlor were the main OCPs in the study area, with the residual contents of 23.83-111.51 ng·g-1 and 11.01-25.97 ng·g-1 in soil and 7.54-61.28 ng·g-1 and 3.96-30.97 ng·g-1 in crops, respectively. A small number of soil and crop samples were found to exceed the standard. The ratio of α-HCH/γ-HCH was less than 1 in 87.50% of the soil samples, and ß-HCH/α-HCH was larger than 1. This indicates that the HCHs were probably derived from the recent use of lindane and historical residual pollution, whereas the heptachlor was mainly derived from underground insect pests and the application of termite control agents. The enrichment ability of OCPs was significantly different among different crops. The bioaccumulation capacity of vegetables was higher than that of fruit. Furthermore, bulb vegetables (leeks) were significantly stronger than other vegetables. A human health risk assessment of OCPs showed that OCP-combined pollution would not cause significant health risks to the population in the study area. However, the maximum value of HI in some crop samples was greater than 1, indicating that there were still potential risks, which should not be ignored.


Assuntos
Hidrocarbonetos Clorados , Praguicidas , Poluentes do Solo , China , Monitoramento Ambiental , Humanos , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Medição de Risco , Solo , Poluentes do Solo/análise
11.
Huan Jing Ke Xue ; 43(1): 510-520, 2022 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-34989536

RESUMO

As an important part of the soil microbial system, fungi can clearly indicate changes in the soil environment.Human activities in the city can easily affect the soil condition, so the phenomenon of artificial heavy metal enrichment often appears in urban soil. The objective of this study was to analyze the fungal community structure in different urban functional areas and to determine the effect of heavy metal content in different urban functional areas on the soil fungal community structure. This study provides theoretical basis for protecting and repairing the urban soil ecosystem and transforming and improving urban environmental quality. Soil samples from eight sampling sites in five functional areas of Beibei District in Chongqing were taken as the research objects. The diversity and community structure of fungi in soil were studied using high-throughput sequencing technology. The content of Cd and Hg in the soil of different functional areas in Beibei District exceeded the environmental background value of Chongqing. The 20-40 cm and 40-60 cm soil layers of JD were slightly polluted. The 20-40 cm soil layer and 0-20 cm soil layer of JLD and ZYY, respectively, were in the alerting state of heavy metal pollution. The Sobs index, Chao 1 index, and Ace index of most sampling points decreased with the increase in soil depth. The NMDS analysis showed that the composition of fungal communities between the 0-20 cm and 20-40 cm soil depths in both JD and ZYY were quite different. From the perspective of community composition, Ascomycota was the most abundant phylum in the soil, followed by unclassified _k _Fungi and Basidiomycota. At the genus level, unclassified_k_Fungi, unclassified_p_Ascomycota, unclassified_o_Sordariales, Scopuloides, Robillarda, and Dactylonectria had higher abundances. The redundancy analysis (RDA) showed that Pb and Zn had the greatest effect on the samples, and the effect on the fungal community structure was significantly different. This study has deepened the understanding of the relationship between the content of heavy metals in different urban functional areas and the structure of fungal communities and has provided a scientific basis for the rational use and planning of urban soil.


Assuntos
Metais Pesados , Micobioma , Poluentes do Solo , China , Ecossistema , Humanos , Metais Pesados/análise , Solo , Microbiologia do Solo , Poluentes do Solo/análise
12.
J Environ Manage ; 304: 114321, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-35021593

RESUMO

BACKGROUND: Mining activity in the Touissit district of Eastern Morocco has led to an unprecedented accumulation of heavy metals, mainly lead and zinc, in the tailing ponds of the open-air mines. This poses a real danger to both the environment and local population. OBJECTIVES: The goal of this work was to characterize the Plant Growth Promoting Rhizobacteria (PGPR) isolated from the rhizosphere soil of R. pseudoacacia plants grown wild in the abandoned Pb- and Zn-contaminated tailing ponds in the mining district of Touissit, in Eastern Morocco. MAIN RESULTS: One hundred bacterial strains were isolated from the rhizosphere of black locust (Robinia pseudoacacia L.) plants growing naturally in the Touissit mine tailings. Quantitative determination of indole-acetic and siderophores production, inorganic phosphate solubilization, hydrolysis of 1-aminocyclopropane-1-carboxylic acid (ACC deaminase activity), and ability to act as a biocontrol agent allowed selection of the 3 strains, 7MBT, 17MBT and 84MBT with improved PGP properties. The three strains grew well in the presence of high concentration of Pb-acetate and ZnCl2; and the addition of Pb or Zn to the culture medium differently affected the PGP properties analyzed. NOVELTY STATEMENT: Inoculation of black locust grown with the 3 selected strains, in the presence 1000 µg ml-1 of Pb-acetate, produced varying effects on the plant dry weight. The strain 84MBT alone or in combination with strains 7MBT and 17MBT increased significantly the dry weight of the plants by 91, 62, and 85% respectively. The 16S rRNA gene sequence analysis of each strain showed that the strains 7MBT 17MBT and 84MBT had 99.34, 100, and had 99.72% similarity with Priestia endophytica (formerly B. endophyticus), B. pumilus NBRC 12092T, and B. halotolerans NBRC 15718T, respectively.


Assuntos
Robinia , Poluentes do Solo , Bactérias/genética , Biodegradação Ambiental , Marrocos , RNA Ribossômico 16S/genética , Rizosfera , Solo , Microbiologia do Solo , Poluentes do Solo/análise
13.
Environ Monit Assess ; 194(2): 85, 2022 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-35018529

RESUMO

Increasing mining and industrial discharge of untreated wastewater, as well as excessive use of fertilizers for agricultural purposes, and heavy metal contamination in soil have become one of the serious environmental problems worldwide. In the present study, pot experiments were conducted to evaluate the influence of arsenic contamination and other factors on the growth and development of local forage grasses like Purple guinea and Ruzi grasses under controlled conditions. Influence of arsenic concentration, soil properties, and fertilizers on biosorption and withstanding potential of grasses was studied using model soil and real-time arsenic-contaminated mine soil. High arsenic contents in soil significantly affected the growth as well as biomass production of grasses and declined the overall biomass production concerning exposure durations. Purple guinea and Ruzi grasses showed growth tolerance in arsenic-contaminated soils with concentrations of 100 and 150 mg/kg respectively. Grass species, soil compositions, and properties, fertilizers, growth duration, etc. potentially influenced arsenic accumulation in grasses. Both local forage grasses showed <1 bio-accumulation factor (BAF) and bio-concentration factor (BCF) after 45 days that indicates the minimum harvesting time of 45 days, and biosorption rate was found significant to the exposure duration. Maximum translocation factor (TF) values observed in Purple guinea and Ruzi grasses were 0.65 and 0.95, respectively which are < 1, therefore, these local forage grasses could be labeled as arsenic-metallophytes and ability to tolerate high levels of heavy metals without much biosorption. The results confirmed that local forage grasses have much growth tolerance potential against arsenic in real-time mine soil with desired fertilizers and these species could be used for sustainable management of ecological health of the Thung Kum gold mine area in Thailand.


Assuntos
Arsênio , Poluentes do Solo , Arsênio/análise , Biodegradação Ambiental , Monitoramento Ambiental , Guiné , Poaceae , Solo , Poluentes do Solo/análise
14.
Anal Chim Acta ; 1189: 339214, 2022 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-34815040

RESUMO

Bioaccessibility (the amount of a contaminant extracted by the gastrointestinal fluids during digestion) is often incorporated in the assessment of contaminated soils and foods. Current methods, including those published by the United States Environmental Protection Agency (US EPA) and United States Pharmacopoeia (USP), use a batch method of analysis which requires hours of extraction prior to instrumental analysis with inductively coupled plasma mass spectrometry (ICPMS). The continuous on-line leaching method (COLM) uses a more direct method of analysis as extracts are sent directly to the ICPMS instrument, which can reduce extraction time and give real-time elution kinetics. For this study, four reference soils (NIST 2710, NIST 2710a, NIST 2711a, and BGS 102) that are typically used with bioaccessibility methods were extracted using the COLM and US EPA and USP gastrointestinal fluids. With the transient time-resolved data from the COLM, differential elution indicating multiple Pb sources was observed in NIST 2710a, NIST 2711a, and BGS 102. Two methods for calculating the Pb isotope ratios to identify these sources included a point-by-point ratio average method and a more precise regression slope method. There was no statistically significant difference between the ratios obtained by these methods of calculation. Furthermore, NIST 2710a and NIST 2711a did not have any statistically significant difference between the Pb isotope ratios of two observed sources. BGS 102 had a significantly different secondary source of Pb, which was identified to be from Pb historically added to gasoline. Investigation into the regions these soil reference materials were sourced from supported this finding as BGS 102 comes from a more densely populated, industrialized area where soil contamination with Pb from gasoline is likely to be more prevalent. This type of bioaccessibility investigation is only possible with the COLM as it gives real time elution information. Incorporation of the COLM into future bioaccessibility studies (and inclusion of other elements for isotopic analysis, like Sr) will lead to more thorough and comprehensive bioaccessibility studies in the future.


Assuntos
Poluentes do Solo , Solo , Chumbo , Espectrometria de Massas , Poluentes do Solo/análise , Análise Espectral
15.
J Environ Manage ; 302(Pt B): 114087, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34773780

RESUMO

Polymer materials have become one of the potential materials for remediation of heavy metal (HM) contamination in water and soil. However, the specific advantages of polymers are rarely studied. Water-soluble thiourea formaldehyde resin (WTF) is one of the effective polymer amendments. Through leaching experiments, WTF can stabilize 93.0% of Cd2+ and 99.7% of Cu2+. The results of HM morphology analysis show that after adding WTF, most of the HMs have been transformed into a relatively stable state. For example, in the process of remediation of 6 mg/kg Cd contaminated soil, the proportion of acid-soluble Cd decreased from 56.5% to 12.8%, and the residual state increased from 13.5% to 45.4%. Compared with the resin-free structure, the three-dimensional structure of the resin plays an important role, but the efficiency of precipitation with HMs is doubled. According to the simulation of the adsorption process by Materials Studio, the characterization of the scanning electron microscope-energy dispersive instrument and the results of the adsorption experiment, in the solution, the precipitate formed by WTF and Cd2+ has multilayer adsorption of HMs, and can further adsorb HM by -OH. Soil enzyme activity experiments proved that the risk of secondary pollution by adding WTF is rare, and even WTF can achieve the effect of slow-release nitrogen fertilizer. In the WTF remediation process, the biological toxicity reduction of HMs is result from, on the one hand, the complexation of functional group of WTF; on the other hand, the resin structure of WTF; in addition, multi-layer adsorption and adsorption of end groups in the precipitation formed by WTF and HM. This work provides a theoretical basis for the potential capabilities of water-soluble resins and is beneficial to the design and development of subsequent amendments.


Assuntos
Metais Pesados , Poluentes do Solo , Adsorção , Cádmio/análise , Metais Pesados/análise , Polímeros , Solo , Poluentes do Solo/análise , Água
16.
J Environ Radioact ; 241: 106773, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34781090

RESUMO

With the extensive exploitation of nuclear energy and uranium, the problem of uranium-contaminated soil is becoming increasingly prominent. In recent years, various technologies for remediation of uranium-contaminated soil have emerged, such as bioremediation, physical remediation and chemical remediation. Bioremediation technology has the widespread attention because of its environmental friendliness, low cost and high economic benefits. This paper mainly reviews the evaluation index of uranium-contaminated soil, soil remediation technology and its advantages and disadvantages, introduces especially the research status of soil bioremediation technology in detail, and puts forward some suggestions and prospects for bioremediation of uranium-contaminated soil.


Assuntos
Recuperação e Remediação Ambiental , Monitoramento de Radiação , Poluentes do Solo , Urânio , Biodegradação Ambiental , Solo , Tecnologia , Urânio/análise
17.
J Environ Manage ; 302(Pt B): 114102, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34800766

RESUMO

We assessed the effect of three organic amendments and two organo-clays on sorption, persistence, and phytotoxicity of scopoletin, an allelochemical compound with potential as bioherbicide, in a Mediterranean alkaline soil. The aim was to elucidate whether the phytotoxicity of scopoletin could be expressed better in amended than unamended soil. The three organic amendments were fresh solid olive-mill waste (OMW), composted solid olive-mill waste (OMWc), and biochar (BC) prepared from OMWc. The two organo-clays were a commercial organo-montmorillonite (Cloi10) and lab-synthesized oleate-modified hydrotalcite (HT-OLE). The amendments enhanced sorption of scopoletin by the soil consistently with their individual affinities for the allelochemical: Cloi10 ≫ OMW > BC > OMWc > HT-OLE. The soil persistence of scopoletin increased significantly because of the addition of Cloi10, OMW, and BC. This increase was attributed to a combination of sorption, which protected the allelochemical from rapid biodegradation, and microbial activity changes. Although the inhibitory effect produced by the amendments themselves obscured the phytotoxicity of scopoletin to Lactuca sativa L. in soil treated with OMW and Cloi10, applying scopoletin to BC-amended soil led to a marked reduction in root length and aerial biomass of the emerged seedlings even though BC alone did not negatively affect these parameters. This inhibitory effect of scopoletin in BC-amended soil was in contrast to the negligible effect exerted by the allelochemical when applied to unamended soil. The results show that soils treated with suitable amendments, such as BC, might provide a scenario in which the herbicidal properties of 7-hydroxycoumarins could be better expressed.


Assuntos
Poluentes do Solo , Solo , Argila , Feromônios , Escopoletina , Poluentes do Solo/análise
18.
J Environ Manage ; 302(Pt B): 114105, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34801866

RESUMO

Food is the major route of arsenic (As) intake for humans, and rice is the staple food for more than half of the world's population. Unfortunately, rice bioaccumulates large amounts of As from the paddy field, and the toxicity of this element in the kernel is closely linked to its chemical form. Therefore, it is of the utmost importance to have access to an integrated set of analytical methods, capable of measuring the concentration of As in its various chemical forms in soil and rice. Hence, the principal aim of this study was to assess and validate a group of inductively coupled plasma - mass spectrometry (ICP-MS) and IC-ICP-MS (IC, Ionic Chromatography) methods designed to measure the amount of the total or extracted As and its main chemical species (As(III), As(V), monomethylarsonic acid, MMA, and dimethylarsinic acid, DMA) in flours of rice grain and in soils. Great attention has been given to the assessment and the optimization of extraction methods of As species from these matrices. No appreciable interconversion among As species has been observed using an aqueous solution 1 mol dm-3 of phosphoric acid and 0.5 mol dm-3 of L (+)-ascorbic acid for the extraction from soils, and an aqueous solution 0.2% (w/v) of nitric acid for the extraction from rice flour. Validation has been successfully accomplished in terms of limit of detection, limit of quantification, linearity and accuracy. In addition to many certified reference materials, these methods have been tested on real samples of soils and rice grains of the Aleramo genotype obtained through traditional or intermittent irrigation methods. Data obtained revealed the critical role of the intermittent irrigation methods in determining the nature and the amount of the As chemical species in rice grains as well as in soils. As(V) is the only species found in soil irrigated by sprinkling, while the most toxic As(III) dominates in soil irrigated by continuous flooding. On the other hand, the most abundant species found in continuously flooded Aleramo rice grains are As(III) and - mostly - DMA, whereas As(V), less toxic than As(III), represents 60% of the total inorganic compounds measured in sprinkler-irrigated rice. Lastly, the total amount of As measured in this rice is 3.8% of that measured in rice irrigated by continuous flooding.


Assuntos
Arsênio , Oryza , Poluentes do Solo , Arsênio/análise , Cromatografia Líquida de Alta Pressão , Grão Comestível , Humanos , Solo , Poluentes do Solo/análise
19.
Chemosphere ; 286(Pt 1): 131595, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34293572

RESUMO

Because of the high hydrophobicity, low volatility, and high sorption capacity of PAHs, their remediation in contaminated soil is challenging. Electrokinetic (EK) enhanced chemical remediation is an emerging dual technology employed in this study, using a new oxidant peroxymonosulfate (PMS) to remediate PAHs contaminated soil. Here, PMS migration under electric field and the remediation efficiency for the PAHs polluted soil were assessed. We observed that the PMS removal efficiencies (59.7%-82.8%) were higher than those with persulfate (PS) (53.9%-78.5%), indicating PMS's superior oxidation capacity for PAHs. Although oxidant PMS can decontaminate PAHs in polluted soils, its removal of PAHs was only 11.0% without the enhanced methods. The enhancements increased the removal efficiency for PAHs from 0.33 to 2.10 times. At fixed catholyte pH of 4, the highest removal efficiency (34.1%) was achieved because it enhanced PMS migration from cathode to anode. These findings suggested that PMS was a potential oxidant for EK remediation, and some enhancements must be applied in EK combined PMS remediation PAHs polluted soil.


Assuntos
Recuperação e Remediação Ambiental , Poluentes do Solo , Peróxidos , Solo , Poluentes do Solo/análise
20.
Chemosphere ; 286(Pt 1): 131638, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34303908

RESUMO

Soil samples were collected from a representative arsenic (As) contaminated region under phytoremediation of hyperaccumulation plants. Relative abundance and diversity of microbial communities in the soil samples were characterized via 16S rRNA genes sequencing. At the phylum level, Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Gemmatimonadetes and Firmicutes shows the highest abundance, accounting for more than 90 % of the classified sequences in the soil samples. Physicochemical parameters including pH, total organic carbon (TOC), cation exchange capacity (CEC), and electrical conductivity (EC), and heavy metal concentrations including total and bioaccessible contents in the soil samples were determined to investigate potential relationships between the microbial communities and the environmental factors. Principal component analysis (PCA) based on the operational taxonomic units (OTUs) matrix revealed distinct separation among the samples. The soil pH was confirmed as the dominant force to discriminate the soil samples with similar land use type and heavy metal contamination. There was little relevance between the total concentrations of heavy metals and the microbial communities. However, the bioaccessible concentrations of heavy metals were associated with the physicochemical parameters and relative abundances of bacterial genera according to correlation analyses. Although the soil samples were considerably contaminated by As, the abundances of bacterial phyla linked with As were lower than 1.0 % in most of the soil samples. The results indicated that the abundances of microbial communities in the soils were the consequence of concerted effects from all the environmental factors.


Assuntos
Metais Pesados , Microbiota , Poluentes do Solo , Arsenicais , Metais Pesados/análise , RNA Ribossômico 16S/genética , Solo , Microbiologia do Solo , Poluentes do Solo/análise , Sulfetos
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