International Journal of Environmental Research and Public Health

Research

16 pages, 2050 KiB

Open AccessArticle

Treated Livestock Wastewater Irrigation Is Safe for Maize (Zea mays) and Soybean (Glycine max) Intercropping System Considering Heavy Metals Migration in Soil–Plant System

by Rakhwe Kama, Yuan Liu, Jibin Song, Abdoul Kader Mounkaila Hamani, Shouqiang Zhao, Siyi Li, Sekouna Diatta, Fengxia Yang and Zhongyang Li

Int. J. Environ. Res. Public Health 2023, 20(4), 3345; https://doi.org/10.3390/ijerph20043345 - 14 Feb 2023

Cited by 5 | Viewed by 1396

Abstract

Water deficit is a major problem affecting crop production worldwide. The use of treated wastewater in irrigation systems improves soil health and enhances crop growth and productivity. However, it has been characterized as a source of heavy metals. The unknown is how heavy [...] Read more.

Water deficit is a major problem affecting crop production worldwide. The use of treated wastewater in irrigation systems improves soil health and enhances crop growth and productivity. However, it has been characterized as a source of heavy metals. The unknown is how heavy metals’ movements would be impacted under an intercropping system when irrigated with treated wastewater. Understanding the dynamic of heavy metals in soil–plant systems is essential for environmental risk assessment and sustainable agriculture. A greenhouse pot experiment was conducted to explore the effects of treated wastewater irrigation on plant growth, soil chemical properties, and the movements of Zn, Cu, Pb, and Cd from soil to plants in monoculture and intercropping systems. Maize and soybean were selected as the test crops and groundwater and treated livestock wastewater as the water sources. This study found that treated wastewater irrigation and intercropping systems synergically increased the soil nutrient content and crop growth. The concentrations of Zn, Pb, and Cd were significantly higher in leaves compared to other plant parts contrastingly to Cu, which was higher in roots. In addition, treated wastewater irrigation increased grain nutrient content in mono- and intercropping systems while the concentration of heavy metals was in the acceptable range for human consumption. The enrichment degree of Cu and Pb due to treated livestock wastewater irrigation relative to groundwater irrigation was higher in uncultivated soil compared with cultivated soil. This study showed that the intercropping system facilitated heavy metals’ transfer from soil to plant except for Cd. These findings provide guidelines for a safe utilization of treated wastewater in agricultural systems and to reduce freshwater use pressure. Full article

(This article belongs to the Special Issue Agricultural Environmental Pollution in China)

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13 pages, 5036 KiB

Open AccessArticle

Efficient Removal of Heavy Metals from Contaminated Sunflower Straw by an Acid-Assisted Hydrothermal Process

by Huijuan Song, Jun Zhou, Shilong He, Qiao Ma, Liang Peng, Miaogen Yin, Hui Lin and Qingru Zeng

Int. J. Environ. Res. Public Health 2023, 20(2), 1311; https://doi.org/10.3390/ijerph20021311 - 11 Jan 2023

Cited by 5 | Viewed by 1679

Abstract

The removal of heavy metals is crucial to the utilization of contaminated biomass resources. In this study, we report an efficient process of hydrothermal conversion (HTC) of sunflower straw (Helianthus annuus L.) to remove heavy metals. The effect of different HTC temperatures [...] Read more.

The removal of heavy metals is crucial to the utilization of contaminated biomass resources. In this study, we report an efficient process of hydrothermal conversion (HTC) of sunflower straw (Helianthus annuus L.) to remove heavy metals. The effect of different HTC temperatures and concentrations of HCl additives on heavy metal removal efficiency was investigated. The results revealed that increasing the temperature or concentration of HCl promoted the transfer of heavy metals from hydrochar to liquid products during HTC. The heavy metals removed to the liquid products included up to 99% of Zn and Cd, 94% of Cu, and 87% of Pb after hydrothermal conversion with a temperature of 200 °C and HCl 2%. The species of heavy metals in hydrochars converted from unstable to stable with an increase in temperature from 160 °C to 280 °C. The stable fractions of heavy metals in the acidic condition decreased as the acid concentration increased. This aligns well with the high transfer efficiency of heavy metals from the solid phase to the liquid phase under acidic conditions. The FTIR indicated that the carboxy and hydroxy groups decreased significantly as the temperature increased and the concentration of HCl increased, which promoted the degradation of sunflower straw. A scan electron microscope showed that the deepening of the destruction of the initial microstructure promotes the transfer of heavy metals from hydrochars to liquid phase products. This acid-assisted hydrothermal process is an efficient method to treat biomass containing heavy metals. Full article

(This article belongs to the Special Issue Agricultural Environmental Pollution in China)

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11 pages, 1138 KiB

Open AccessArticle

Mn Pretreatment Improves the Physiological Resistance and Root Exudation of Celosia argentea Linn. to Cadmium Stress

by Shaohong You, Zhenliang Deng, Mouyixing Chen, Yingyi Zheng, Jiu Liu and Pingping Jiang

Int. J. Environ. Res. Public Health 2023, 20(2), 1065; https://doi.org/10.3390/ijerph20021065 - 6 Jan 2023

Viewed by 1170

Abstract

Phytoextraction using Celosia argentea Linn. by Mn pretreatment can potentially decontaminate Cd-contaminated soils. However, the mechanism that accelerates the Cd bioaccumulation is still unknown. In order to study the effect and mechanism of Mn pretreatment on Cd bioaccumulation in C. argentea, the [...] Read more.

Phytoextraction using Celosia argentea Linn. by Mn pretreatment can potentially decontaminate Cd-contaminated soils. However, the mechanism that accelerates the Cd bioaccumulation is still unknown. In order to study the effect and mechanism of Mn pretreatment on Cd bioaccumulation in C. argentea, the hydroponic experiments were set to determine the chlorophyll content, antioxidant enzyme activity, malondialdehyde content, and root exudation of C. argentea. The results indicated that after seven days of Mn pretreatment, both the biomass and Cd concentrations in plants increased compared to the control group. One of the mechanisms for this was the improvement in the physiological resistance of C. argentea following pretreatment with Mn. Compared with Cd stress alone, Mn pretreatment increased photosynthesis and reduced membrane lipid peroxidation. Meanwhile, the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) were significantly reduced in leaves of C. argentea after Mn pretreatment through the reduction in the production of reactive oxygen species. In addition, Mn promoted the exudation of organic acids in the roots of C. argentea. The contents of citric and malic acids increased by 55.3% and 26.4%, respectively, which may be another important reason for Mn pretreatment increasing Cd bioaccumulation in C. argentea. Therefore, the present work shows that the pretreatment of seedlings with Mn can provide a meaningful strategy to improve the remediation efficiency of Cd-contaminated soils by C. argentea. Full article

(This article belongs to the Special Issue Agricultural Environmental Pollution in China)

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13 pages, 1743 KiB

Open AccessArticle

Analysis of Pollution Characteristics and Sources in Surface Water in Typical Crop-Producing Areas of Qinghai Province

by Pengtao Chen, Furong Fu, Jie Li, Jingui Wang, Yang Sun, Ruigang Wang, Lixia Zhao and Xiaojing Li

Int. J. Environ. Res. Public Health 2022, 19(24), 16392; https://doi.org/10.3390/ijerph192416392 - 7 Dec 2022

Cited by 1 | Viewed by 1279

Abstract

Currently used pesticides and organochlorine pesticides (OCPs), nitrogen and phosphorus were analyzed in surface water from 26 sampling sites of agricultural areas in Qinghai Province to elucidate their pollution characteristics and sources. The results showed that most of these currently used pesticides, with [...] Read more.

Currently used pesticides and organochlorine pesticides (OCPs), nitrogen and phosphorus were analyzed in surface water from 26 sampling sites of agricultural areas in Qinghai Province to elucidate their pollution characteristics and sources. The results showed that most of these currently used pesticides, with the exception of chlorpyrifos, were generally not detected. However, two OCPs were commonly detected in surface water from four typical crop-producing areas. The residual concentrations of hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) measured 0~1.68 ng/L and 0.41~2.41 ng/L, respectively, in the water from the four crop-producing areas. The residues of these two OCPs pesticides were much lower than the standard limit of surface water environmental quality. The main forms of HCHs and DDTs were β-HCH and pp’-DDE, respectively, indicating that the residues of HCHs and DDTs in the surface water of the four crop-producing areas in Qinghai were mainly derived from historical drugs that had degraded for a long time. The average concentrations of TN, NO₃⁻-N and NH₄⁺-N in the surface water of 26 sampling sites of four typical crop areas in Qinghai Province were 2.95, 1.71 and 0.17 mg/L, respectively. According to the national surface water environmental quality standards, TN concentrations in 57.7% of these sampling sites exceeded the Class V water standards. The average concentration of NO₃⁻-N was more than 70 times that of NH₄⁺-N. Nonetheless, there were no significant differences in the concentrations of TN, NO₃⁻-N and NH₄⁺-N in the four crop-producing areas. The concentrations of NO₃⁻-N and NO₃⁻-N in the surface water were positively correlated with the TN concentration (p < 0.05), indicating that the sources of nitrogen in the surface water were relatively consistent. The average value of TP concentrations in the surface water from these sampling sites was 0.034 mg/L, with no significant differences among different producing areas. The N/P values in surface water from the four crop-producing areas of Qinghai Province had a range of 9.2~302. Phosphorus was the limiting factor for the proliferation of plankton in water. Reducing the input of phosphorus in these areas may be the key to preventing the deterioration of water quality. Significant negative and positive correlations exist between HCHs and nitrate nitrogen, and total phosphorus, respectively, which may be attributed to the proliferation of degrading microorganisms caused by the eutrophication of water. The research results will help to identify the characteristics and sources of surface water pollution in the crop-producing areas of Qinghai Province, and provide data support for Qinghai Province to build an export area for green organic agricultural and livestock products. Full article

(This article belongs to the Special Issue Agricultural Environmental Pollution in China)

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19 pages, 3213 KiB

Open AccessArticle

Pollution Risk Assessment and Sources Analysis of Heavy Metal in Soil from Bamboo Shoots

by Zhihong Wang, Yingle Chen, Song Wang, Yujuan Yu, Wenyan Huang, Qiaolin Xu and Lei Zeng

Int. J. Environ. Res. Public Health 2022, 19(22), 14806; https://doi.org/10.3390/ijerph192214806 - 10 Nov 2022

Cited by 3 | Viewed by 1561

Abstract

In order to investigate the pollution situation and sources analysis of heavy metals in bamboo shoot soil in Guangdong Province, a total of 175 soil samples were collected at 46 sites. Atomic fluorescence spectrophotometer and inductively coupled plasma mass spectrometry were used to [...] Read more.

In order to investigate the pollution situation and sources analysis of heavy metals in bamboo shoot soil in Guangdong Province, a total of 175 soil samples were collected at 46 sites. Atomic fluorescence spectrophotometer and inductively coupled plasma mass spectrometry were used to determine the content of five heavy metals: lead (Pb), cadmium (Cd), arsenic (As), mercury (Hg), and chromium (Cr). In addition, the soil environmental quality was evaluated through different index methods, including single-factor pollution, Nemeiro comprehensive pollution, geoaccumulation, and potential ecological risk. Furthermore, the correlation coefficients were also discussed. The results showed that the soils collected were acidic or slight alkaline. The maximum content of Pb and As from some areas exceeded the standard limit value. The coefficient of variation value from six areas exceeded 100%. The index method mentioned above confirmed that the soil within study areas was divided into three pollution levels: no, slightly, and mild. Additionally, there was a very significant correlation between pH and Pb, Hg; the correlation between heavy metal As and Pb, Cr also reached a very significant level. The principal component analysis results show that PC1 accounts for 39.60% of the total variance, which includes Pb, Cd, and As. PC2 mainly includes Hg and Cr. Full article

(This article belongs to the Special Issue Agricultural Environmental Pollution in China)

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17 pages, 17319 KiB

Open AccessArticle

Response of Antibiotic Resistance Genes and Related Microorganisms to Arsenic during Vermicomposting of Cow Dung

by Zijun Li, Chen Chen, Keqiang Zhang, Zulin Zhang, Ran Zhao, Bingjun Han, Fengxia Yang and Yongzhen Ding

Int. J. Environ. Res. Public Health 2022, 19(21), 14475; https://doi.org/10.3390/ijerph192114475 - 4 Nov 2022

Cited by 2 | Viewed by 1566

Abstract

Antibiotic resistance pollution in livestock manure is a persistent issue that has drawn public attention. Vermicomposting is an ecofriendly biological process that can render livestock manure harmless and resourceful. However, little is known about the impact of vermicomposting on antibiotic resistance in livestock [...] Read more.

Antibiotic resistance pollution in livestock manure is a persistent issue that has drawn public attention. Vermicomposting is an ecofriendly biological process that can render livestock manure harmless and resourceful. However, little is known about the impact of vermicomposting on antibiotic resistance in livestock manure under stress caused by potentially toxic arsenic levels. Herein, lab-scale vermicomposting was performed to comprehensively evaluate the shift in antibiotic resistance genes (ARGs) and related microorganisms in fresh earthworm casts as well as vermicompost product health (i.e., nutrient availability and enzyme activity) when they were fed on arsenic-contaminated cow manure. The results showed that the earthworms’ interaction with cow dung led to a significant reduction in ARG concentrations, especially for tetracycline ARGs (tet-ARGs), β-lactam ARGs (bla-ARGs), and quinolone ARGs (qnr-ARGs). However, arsenic significantly enhanced ARG accumulation in earthworm casts in a dose-dependent manner. Moreover, vermicomposting increased the percentage of Bacteroidota in the converted products. Furthermore, arsenic exposure at low concentrations promoted the proliferation of Proteobacteria, whereas high concentrations had little effect on Proteobacteria. Our study provides valuable insight into the changes in the antibiotic resistome and related microorganisms during vermicomposting of arsenic-amended cow manure, and it is crucial to explain the environmental impact of earthworms and improve our understanding of the reciprocal benefits of soil invertebrates. Full article

(This article belongs to the Special Issue Agricultural Environmental Pollution in China)

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11 pages, 2382 KiB

Open AccessArticle

Distribution Pattern and Influencing Factors of Heavy Metal Resistance Genes in the Yellow River Sediments of Henan Section

by Kai Zhang, Kuangjia Li, Minghui Tong, Yangchun Xia, Yongxin Cui, Ziyi Liu, Qi Chen, Qidi Li, Feiyue Hu and Fengxia Yang

Int. J. Environ. Res. Public Health 2022, 19(17), 10724; https://doi.org/10.3390/ijerph191710724 - 28 Aug 2022

Cited by 9 | Viewed by 1846

Abstract

The transformation of heavy metal resistance genes (MRGs) in the environment has attracted increasing attention in recent years. However, few studies have reported the MRG content in the Yellow River, one of the main irrigation water sources in the North China Plain. In [...] Read more.

The transformation of heavy metal resistance genes (MRGs) in the environment has attracted increasing attention in recent years. However, few studies have reported the MRG content in the Yellow River, one of the main irrigation water sources in the North China Plain. In this study, we quantified MRG abundance by a metagenomic approach, and assessed the influence on MRGs of both bioavailable and total heavy metal (HM) content. The results indicate that Cu-resistant genes are the most common genes, and the prevalence of arsM needs more attention. Comamonadaceae is the dominant family in the Yellow River, and the presence of organic pollutants may contribute to the prevalence of Vicinamibacteraceae, Nocardioidaceae, and Flavobacteriacea. The results of the Mantel test and Spearman analysis indicate that both the bioavailable fractions and total content of HMs could have little influence on MRGs. Network analysis results indicate that some dominant bacteria could be the potential hosts of some prevalent MRGs, which may exert an adverse impact on human health. Full article

(This article belongs to the Special Issue Agricultural Environmental Pollution in China)

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21 pages, 1920 KiB

Open AccessArticle

Evaluating China Food’s Fertilizer Reduction and Efficiency Initiative Using a Double Stochastic Meta-Frontier Method

by Xi Chen, Mingzhe Pu and Yu Zhong

Int. J. Environ. Res. Public Health 2022, 19(12), 7342; https://doi.org/10.3390/ijerph19127342 - 15 Jun 2022

Cited by 2 | Viewed by 1808

Abstract

Improving the efficiency of fertilizer usage is important to achieve sustainable agricultural production. As a major agricultural producer, China formally proposed a national fertilizer reduction and efficiency initiative in 2015. Using the double stochastic meta-frontier method to measure the fertilizer use efficiency of [...] Read more.

Improving the efficiency of fertilizer usage is important to achieve sustainable agricultural production. As a major agricultural producer, China formally proposed a national fertilizer reduction and efficiency initiative in 2015. Using the double stochastic meta-frontier method to measure the fertilizer use efficiency of 31 provinces in mainland China from 2005 to 2019, this study evaluates the effectiveness of the said initiative on grain production. The results show that China’s initiative has achieved some success, with the average value of fertilizer use efficiency in national grain production increasing by 2.53 percentage points. However, the changes in fertilizer use efficiency show regional heterogeneity. Specifically, the fertilizer use efficiency of the main grain-producing and marketing regions has increased significantly, while that of grain-producing-and-marketing-balanced regions has declined. Further investigation shows that this phenomenon may be related to the importance attached by local governments to the initiative and the uneven distribution of related resources. Full article

(This article belongs to the Special Issue Agricultural Environmental Pollution in China)

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