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1.
Molecules ; 26(22)2021 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-34834110

RESUMO

In-situ rehabilitation of fly ash at dumping sites has rarely been addressed for crop production due to growth-related constraints, largely of heavy metal (HM) contamination in soils and crops. Current communication deals with a novel approach to identify a suitable management option for rejuvenating the contaminated soils. In this background, a 60-days incubation experiment was conducted with different fly ash-soil mixtures (50 + 50%, A1; 75 + 25%, A2; 100 + 0%, A3) along with four ameliorants, namely, lime (T1), sodium sulphide (T2), di-ammonium phosphate (T3), and humic acid (T4) at 30 ± 2 °C to assess the ability of different fly ash-soil-ameliorant mixtures in reducing bio-availability of HMs. Diethylenetriaminepentaacetic acid (DTPA)-extractable bio-available HM contents for lead (Pb), cadmium (Cd), nickel (Ni), and chromium (Cr) and their respective ratios to total HM contents under the influence of different treatments were estimated at 0, 15, 30, 45, and 60 days of incubation. Further, the eco-toxicological impact of different treatments on soil microbial properties was studied after 60 days of experimentation. A1T1 significantly recorded the lowest bio-availability of HMs (~49-233% lower) followed by A2T1 (~35-133%) among the treatments. The principal component analysis also confirmed the superiority of A1T1 and A2T1 in this regard. Further, A1T1 achieved low contamination factor and ecological risk with substantial microbial biomass carbon load and dehydrogenase activity. Thus, liming to fly ash-soil mixture at 50:50 may be considered as the best management option for ameliorating metal toxicity. This technology may guide thermal power plants to provide the necessary package of practices for the stakeholders to revive their contaminated lands for better environmental sustainability.


Assuntos
Cinza de Carvão/metabolismo , Metais Pesados/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Biodegradação Ambiental
2.
Bull Environ Contam Toxicol ; 107(6): 1236-1242, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34164721

RESUMO

Cadmium accumulation in rice is a major source of Cd exposure in humans worldwide. A three-year field experiment was conducted to investigate the ecological safety and long-term stability of biochar combined with lime or silicon fertilizer for Cd immobilization in a polluted rice paddy. The results showed that the application of combined ameliorants could reduce the Cd content in brown rice to meet the Chinese maximum permissible limit for Cd content in food products (0.2 mg/kg). In addition, such amendments stimulated metabolic pathways in soil bacteria, including carbon metabolism, citrate cycle, pyruvate metabolism, biosynthesis of amino acids, and glycolysis/gluconeogenesis, revealing improvements in soil biological activity and soil health. Therefore, the results provide a practical strategy for the safe utilization of farmland with mild levels of heavy metal pollution.


Assuntos
Oryza , Poluentes do Solo , Cádmio/análise , Poluição Ambiental , Fertilizantes , Humanos , Solo , Poluentes do Solo/análise
3.
Ecotoxicol Environ Saf ; 142: 207-215, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28411516

RESUMO

This study was conducted to investigate the possibility of using a combined technology to synchronously reduce As and Cd accumulation in the edible parts of Brassica campestris. The results showed that a foliar application of selenite (Se) and silicon (Si) combined with soil ameliorants (including Ca-Mg-P fertilizer, sodium silicate and red mud) showed limited effects on the growth of B. campestris. The As concentration in the leaves of B. campestris in all treatments was below the Chinese safety standard. When sodium silicate and Ca-Mg-P fertilizer were added to the soil, the additional foliar application of Se and Si could in some cases help further reduce the concentrations of As and Cd in the leaves of B. campestris. However, when red mud was applied to the soil, the foliar application of Se and Si enhanced the Cd concentration in the leaves of B. campestris. In most cases, high levels of soil ameliorants plus foliar application of Se and Si significantly enhanced the As concentrations in both the soil solution and the roots of B. campestris but reduced the soil solution Cd concentration and the leaf As concentration. Most of the treatments reduced the thiobarbituric acid reactive substances (TBARS) concentration in the leaves of B. campestris, and the foliar application of Se and Si helped the soil ameliorants alleviate the oxidative stress resulting from As and Cd exposure. In this study, several treatments significantly increased the activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX). However, the enzymes peroxidase (POD) and catalase (CAT) were not induced by most treatments. In summary, the combined treatment of 1gkg-1 Ca-Mg-P fertilizer plus foliar spraying 2mmolL-1 sodium selenite was most effective in reducing the Cd concentration and a rather strong ability to reduce the As concentration and trigger the activities of SOD and APX in the leaves of B. campestris.


Assuntos
Antioxidantes/metabolismo , Arsenicais/análise , Brassica/metabolismo , Cádmio/análise , Fertilizantes/análise , Ácido Selenioso/farmacologia , Silicatos/farmacologia , Poluentes do Solo/análise , Arsenicais/metabolismo , Ascorbato Peroxidases/metabolismo , Brassica/química , Brassica/efeitos dos fármacos , Brassica/crescimento & desenvolvimento , Cádmio/metabolismo , Catalase/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Peroxidases/metabolismo , Folhas de Planta/química , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/química , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Solo/química , Solo/normas , Poluentes do Solo/metabolismo , Superóxido Dismutase/metabolismo
4.
Materials (Basel) ; 16(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37049089

RESUMO

The expansion of urban construction areas can reduce the infiltration rate of rainwater in permeable land, and a large amount of runoff rainwater cannot penetrate the soil. In extreme rainstorm weather, it is easy to cause serious urban waterlogging problems. To improve the infiltration and decontamination ability of green space soil, two types of inorganic ameliorants (i.e., sand and grain shell) and structural ameliorants (i.e., desulfurization gypsum and polyacrylamide) were utilized as amendments in the soil. The influence of the selected ameliorants on the infiltration and decontamination ability was analyzed through a soil infiltration test, soil pore distribution determination and a soil decontamination test. Three parameters including the soil infiltration rate, pore distribution characteristics and pollutant removal rate were proposed. The results showed that sand, grain shells and desulfurization gypsum (FGD gypsum) all enhanced the infiltration capacity of soil, while PAM decreased the infiltration capacity. Meanwhile, mixed sand and grain shell with the FGD gypsum and polyacrylamide can effectively improve the decontamination capacity of the soil. Comprehensive analysis showed that the better improvement combination is 10% sand + 20% grain hull + 0.5 g/kg FGD gypsum + 0.1 g/kg PAM.

5.
J Hazard Mater ; 454: 131443, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37094440

RESUMO

Although several approaches for reducing antibiotic resistance genes (ARGs) in soil have been proposed, the application of environmentally friendly approaches is now attracting much more attention. In the present study, two types of essential oils (EOs), namely lavender essential oil (LEO) and oregano essential oil (OEO), were selected to investigate their roles in regulating ARGs in soil. In a 28-day microcosm experiment, it was found that the different types and doses of EOs significantly changed the composition of microbial communities. The LEO treatments enriched more taxa belonging to Actinobacteria than the control, whereas the low dose of OEO reduced Actinobacteria enrichment. Besides, the control and the treatments with a high dose of LEO and OEO all significantly enriched the functional pathways related to Human Diseases, which were positively associated with ARGs. However, the low dose of these EOs helped to reduce the pathways. Because of inhibition of the functional pathways and ARG hosts, the low dose of OEO reduce the ARGs related to antibiotic efflux by 71.8% and the resistance genes to multidrug by 56.4%, but these roles did not occur in LEO treatments. These outcomes provide practical and theoretical support for the application of EOs in remediating ARG-contaminated soils.


Assuntos
Genes Bacterianos , Solo , Humanos , Microbiologia do Solo , Resistência Microbiana a Medicamentos/genética , Antibacterianos/farmacologia , Óleos
6.
Life (Basel) ; 13(2)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36836751

RESUMO

The article presents the results of the seven-year study on the state of arable lands and wastewaters in the districts of mining enterprises in Armenia. An assessment of the ecological and toxicological state of wastewaters and contaminated areas was carried out. Methods for their purification are proposed aimed at their further use and obtainment of environmentally safe agricultural products. An area of about 0.5 ha, next to the rural community of Syunik in southern Armenia, has been polluted for many years by mining sludges from the nearest mine watertight cofferdam of the Zangezur copper-molybdenum combine. Activities have been carried out to clean up the soil in this area. After plowing, soil improvers (zeolite, bentonite, and manure) were introduced into the soil. On-site treatments, soil tillage, and the introduction of soil improvers into the soil was implemented in late autumn. Soil and plant samples were taken to determine the content of heavy metals (Cu, Zn, Pb, Co, Mo, Ni). In the following spring, the area was planted with potatoes, eggplant, and peas. A rather high yield was obtained. Analysis of plant samples showed that the content of heavy metals does not exceed the permissible level of the international food safety standard. At the same time, soil studies were carried out in the adjacent areas of the Sotk mine, located to the southeast of Lake Sevan. It was revealed that due to the increase in the volume of the mining industry and the amount of rock dumps, the organoleptic and chemical indicators of the waters of the Sotk and Masrik rivers deteriorated. Compared to the previous decade, the amounts of suspended particles per 1 L of water have increased by 210…317.0%, in the waters of Sotk-by 32.1 mg/L, and in the waters of Masrik-by 13.2 mg/L. The same tendency is observed regarding the amounts of nitrates, sulfates, and hydrogen index, which is mainly due to the chemical composition of rocks. They contain a large amount of Ca, K, Na, Mg, etc. This trend is especially noticeable along the rivers, where intensive agriculture, primarily livestock farming is carried out. The material of the work solves a complex of environmental and economic problems. It is aimed at ensuring environmental safety, improving the ecological and resource properties of soils, increasing the productivity of cultural phytocenoses and the sanitary and hygienic quality of food products.

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