Impact of Toxic Elements on Water Quality and Treatment Methods

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
International Journal of Environmental Research and Public Health ijerph	-	7.3	2004	25.8 Days	CHF 2500
Water water	3.0	5.8	2009	17.5 Days	CHF 2600
Toxics toxics	3.9	4.5	2013	18.3 Days	CHF 2600

12 pages, 785 KiB

Open AccessArticle

Impact of Red Sludge Dumps, Originating from Industrial Activity, on the Soil and Underground Water

by Olimpia Smaranda Mintaș, Cristina Simeanu, Octavian Berchez, Daniela Camelia Marele, Adrian Gheorghe Osiceanu and Teodor Rusu

Water 2023, 15(5), 898; https://doi.org/10.3390/w15050898 - 26 Feb 2023

Cited by 5 | Viewed by 2870

Abstract

In the aluminum industry, one of the most sensitive economic and environmental problems is the management of resulting waste such as slag, ash and sludge, which become potential sources of pollution. Red sludge, which results from the aluminum industry, is a mixture made [...] Read more.

In the aluminum industry, one of the most sensitive economic and environmental problems is the management of resulting waste such as slag, ash and sludge, which become potential sources of pollution. Red sludge, which results from the aluminum industry, is a mixture made up of different forms of iron and aluminum oxides, sodium and aluminum silicates, various titanium compounds, constituted in the residue left after the alkaline solubilization of alumina. The Purpose of this research is to quantify the environmental aspects involved in the storage of sludge in a landfill that has an area of 381,189 square meters and is located in the hearth of a former ballast tank in the western industrial area of the town of Oradea, Romania. The objective of the research was to determine the impact of red sludge dumps, which originated from industrial activity, on the soil and groundwater. The degree of degradation of the soil cover was highlighted by analyzing a number of 12 soil samples (4 collection points, at 3 depths). A total of 14 samples (7 samples on 2 depths) were investigated to monitor the migration mode of the sludge in the structure of the dam. In order to monitor the quality of groundwater, samples from 3 observation boreholes were analyzed. Soil monitoring results did not indicate values of the analyzed parameters above the values imposed by the national legislation on soil quality. Since the dumps were not waterproofed, the quality parameters of the water from the observation boreholes were exceeded, and gravity caused the water to drain into the underground water network in the area. Based on the samples from the observation boreholes, several measurements exceeded allowable values: pH values of the water sample taken from upstream of the dump exceeded the value limits by about 7%, and both upstream and downstream, water samples indicate an excess of 13.60% in the aluminum indicator, 267% in the sulfate ion, and 417% in the sodium ion. This shows a risk of pollution which requires additional monitoring. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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15 pages, 2827 KiB

Open AccessArticle

Impact of Pressure on Arsenic Released from Pore Water in Clayey Sediment

by Cong Xiao, Yuzhu Chen, Teng Ma and Wen Xiong

Toxics 2022, 10(12), 738; https://doi.org/10.3390/toxics10120738 - 29 Nov 2022

Cited by 2 | Viewed by 1661

Abstract

Overpumping can cause arsenic to be released from the pore water in clayey aquitards into aquifers. The amount of water pumped during groundwater exploitation may change over time, leading to different soil-compaction rates or patterns. However, the impact of pressure on the release [...] Read more.

Overpumping can cause arsenic to be released from the pore water in clayey aquitards into aquifers. The amount of water pumped during groundwater exploitation may change over time, leading to different soil-compaction rates or patterns. However, the impact of pressure on the release of arsenic during the compaction of a clayey aquitard is poorly understood. We performed a laboratory-compaction experiment using clayey sediment to identify the effects of compaction rates and patterns on arsenic release by analyzing the chemical characteristics and arsenic species present in pore water samples collected at different stages of the compaction experiment. A rapid (PV increased linearly) and a slow (PV increased exponentially) water-release patterns were recognized according to the compaction rate. We observed that arsenic concentrations in the slow pattern (6.7 to 36.4 μg/L) were considerably higher than those in the rapid pattern (7.6 to 16.1 μg/L). Furthermore, concentrations were the highest in the accelerated compaction pattern (16.8 to 47.4 μg/L), followed by those in the constant and decelerated patterns (4.3 to 14.4 μg/L). Overall, compaction rate and pattern did not alter the arsenic-release mechanism; however, they did alter the moisture content of the sediment at each stage, which indirectly led to differences in the released arsenic concentrations. These results suggest that pumping rates and patterns must be considered to prevent arsenic contamination in groundwater-extraction scenarios. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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9 pages, 3089 KiB

Open AccessCommunication

Sensitivity of Hydra vulgaris to Nanosilver for Environmental Applications

by Arianna Bellingeri, Chiara Battocchio, Claudia Faleri, Giuseppe Protano, Iole Venditti and Ilaria Corsi

Toxics 2022, 10(11), 695; https://doi.org/10.3390/toxics10110695 - 17 Nov 2022

Cited by 2 | Viewed by 2808

Abstract

Nanosilver applications, including sensing and water treatment, have significantly increased in recent years, although safety for humans and the environment is still under debate. Here, we tested the environmental safety of a novel formulation of silver nanoparticles functionalized with citrate and L-cysteine (AgNPcitLcys) [...] Read more.

Nanosilver applications, including sensing and water treatment, have significantly increased in recent years, although safety for humans and the environment is still under debate. Here, we tested the environmental safety of a novel formulation of silver nanoparticles functionalized with citrate and L-cysteine (AgNPcitLcys) on freshwater cnidarian Hydra vulgaris as an emerging ecotoxicological model for the safety of engineered nanomaterials. AgNPcitLcys behavior was characterized by dynamic light scattering (DLS), while Ag release was measured by inductively coupled plasma mass spectrometry (ICP-MS). H. vulgaris (n = 12) subjects were evaluated for morphological aberration after 96 h of exposure and regeneration ability after 96 h and 7 days of exposure, after which the predatory ability was also assessed. The results show a low dissolution of AgNPcitLcys in Hydra medium (max 0.146% of nominal AgNPcitLcys concentration) and highlight a lack of ecotoxicological effects, both on morphology and regeneration, confirming the protective role of the double coating against AgNP biological effects. Predatory ability evaluation suggests a mild impairment of the entangling capacity or of the functionality of the tentacles, as the number of preys killed but not ingested was higher than the controls in all exposed animals. While their long-term sub-lethal effects still need to be further evaluated on H. vulgaris, AgNPcitLcys appears to be a promising tool for environmental applications, for instance, for water treatment and sensing. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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9 pages, 804 KiB

Open AccessCommunication

Does Biological Activated Carbon Filtration Make Chlor(am)inated Drinking Water Safer

by Jiazheng Pan, Feifei Wang, Lu Zhang, Yulin Hu and Chiquan He

Water 2022, 14(17), 2640; https://doi.org/10.3390/w14172640 - 27 Aug 2022

Viewed by 2154

Abstract

Biological activated carbon (BAC) filtration is an effective technology for the removal of natural organic matter. However, one potential drawback of BAC, especially old BAC, is that effluents can contain soluble microbial products released from the biofilm, which are recognized as more toxic [...] Read more.

Biological activated carbon (BAC) filtration is an effective technology for the removal of natural organic matter. However, one potential drawback of BAC, especially old BAC, is that effluents can contain soluble microbial products released from the biofilm, which are recognized as more toxic nitrogenous DBPs (N-DBPs) precursors. So far, limited studies reported the risk of DBP formation potentials (FPs) increase caused by the microbial leakage of BAC. This study compared removal differences of DBP FPs between two BAC filters operated for 1 year and 8 years in a drinking water plant. The results showed that the total summed haloacetic acid FPs and trihalomethane FPs decreased by 34.31% from chlorination, and 55.01% of the total summed halogen acetonitrile FPs from chloramination were removed by the new BAC. However, Chlorinated haloacetonitriles FPs increased by 2.33% after old BAC filtration. To sum up, BAC filtration decreased most DBP FPs, but a potential risk regarding more toxic N-DBP FPs from old BAC should receive more attention. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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18 pages, 5682 KiB

Open AccessArticle

Efficient and Fast Removal of Aqueous Tungstate by an Iron-Based LDH Delaminated in L-Asparagine

by Yaowu Cao, Qinghai Guo, Weihao Sun and Georgii A. Chelnokov

Int. J. Environ. Res. Public Health 2022, 19(12), 7280; https://doi.org/10.3390/ijerph19127280 - 14 Jun 2022

Cited by 3 | Viewed by 2210

Abstract

High concentrations of tungstate in aqueous systems pose a severe threat to the environment and human health. This study explored the potential of iron-based LDHs to remove tungstate from water. To improve its tungstate uptake capacity, environment-friendly L-asparagine was used to delaminate iron-based [...] Read more.

High concentrations of tungstate in aqueous systems pose a severe threat to the environment and human health. This study explored the potential of iron-based LDHs to remove tungstate from water. To improve its tungstate uptake capacity, environment-friendly L-asparagine was used to delaminate iron-based LDH synthesized via a coprecipitation method. The successful delamination was proved by AFM, revealing that the thickness of the obtained nanoparticles was approximately 1–2 times that of a single LDH layer. XRD, TEM, and XPS analyses confirmed that the delaminated LDHs were amorphous and ultrathin and had surface defects within their nanosheets that acted as active sites, leading to a very fast tungstate sorption rate and superior tungstate uptake capacity. Notably, the original layered structure of the L-asparagine-treated LDH was recovered upon its reaction with tungstate-bearing solutions, and therefore, the high availability of aqueous tungstate to the interlayer regions during the structural restoration of the delaminated iron-based LDH contributed to its excellent capability of tungstate removal as well. In addition, the tungstate uptake by the delaminated iron-based LDH was not affected substantially by the presence of coexisting anions, implying that the strong inner-sphere complexation between the tungstate and LDH layers with defects (i.e., Fe-O bonds) was the primary mechanism responsible for the tungstate removal. The delamination process described in this paper was validated to be an effective way to enhance the immobilization of tungstate by iron-based LDHs without inducing secondary pollutions, and delaminated iron-based LDHs are promising to be used extensively in the practice of treating tungstate-rich waters. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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11 pages, 15059 KiB

Open AccessReview

Associations between Polyfluoroalkyl Substances Exposure and Breast Cancer: A Meta-Analysis

by Haihong Jiang, Huan Liu, Ge Liu, Jing Yu, Nana Liu, Yunqin Jin, Yongyi Bi and Hong Wang

Toxics 2022, 10(6), 318; https://doi.org/10.3390/toxics10060318 - 11 Jun 2022

Cited by 17 | Viewed by 4380

Abstract

Polyfluoroalkyl substances (PFASs) are persistent pollutants that may cause breast cancer. However, associations between exposure to PFASs and the risk of breast cancer are controversial. We retrieved studies on the association between PFASs—perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and [...] Read more.

Polyfluoroalkyl substances (PFASs) are persistent pollutants that may cause breast cancer. However, associations between exposure to PFASs and the risk of breast cancer are controversial. We retrieved studies on the association between PFASs—perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS)—and breast cancer risk in women from PubMed, Embase, and the Web of Science. The pooled odds ratios (ORs) or relative risks (RRs) and their 95% confidence intervals (CIs) were extracted or calculated from provided data. Moreover, subgroup and metaregression analyses were performed to distinguish the potential sources of heterogeneity between studies. Lastly, eight original studies were included in the meta-analysis. PFOA and PFHxS were positively correlated with breast cancer risk, and the pooled ORs (and 95% CIs) were 1.32 (1.19 and 1.46) and 1.79 (1.51 and 2.11), respectively. PFNA was negatively correlated with breast cancer risk and the pooled OR (and 95% CIs) was 0.76 (0.6 and 0.96), and PFOS was shown to have no correlation with breast cancer risk and the pooled OR (and 95% CIs) was 1.01 (0.87 and 1.17). All results were merged in a random-effects model with significant heterogeneities (I² > 90%, p < 0.001). The results demonstrated that PFASs might be potential risk factors for breast cancer, and the compounds in low exposure levels could have a more harmful impact on human health. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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12 pages, 1835 KiB

Open AccessArticle

Feasibility of Remediation of Heavy-Metal-Contaminated Marine Dredged Sediments by Active Capping with Enteromorpha Biochar

by Zhaowei Wang, Shuang Song, Huan Wang, Wenchao Yang, Jianbo Han and Hong Chen

Int. J. Environ. Res. Public Health 2022, 19(9), 4944; https://doi.org/10.3390/ijerph19094944 - 19 Apr 2022

Cited by 5 | Viewed by 2324

Abstract

Enteromorpha biochar (BC) has been proposed as a potential absorbent in the marine environments. This study attempts to understand the process of active capping using Enteromorpha BC to prevent the release of heavy metals (Pb and Cd) from contaminated marine dredged sediments. The [...] Read more.

Enteromorpha biochar (BC) has been proposed as a potential absorbent in the marine environments. This study attempts to understand the process of active capping using Enteromorpha BC to prevent the release of heavy metals (Pb and Cd) from contaminated marine dredged sediments. The capping efficiency was assessed with a series of lab-scale column experiments. Results showed that the Enteromorpha BC exhibits rough pore structure and higher specific surface area, as well as more surface organic functional groups, which is favorable for its adsorption capacity and selectivity towards heavy metals. The capping thickness of 2 cm for Enteromorpha BC was sufficient to prevent the release of heavy metals from sediments, with the capping efficiency of 47% for Pb and 62% for Cd. Kinetic studies showed that heavy metals released into the overlying water can be described by a three-parameter sigmoidal kinetic model. Importantly, the fractions of heavy metals in the dredged sediments below the capping layer were analyzed to reveal the capping remediation mechanism. The outcomes of the present study indicate that capping with Enteromorpha BC is a promising method to regulate the water environment by preventing the release of heavy metals from the contaminated dredged sediments. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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12 pages, 1840 KiB

Open AccessArticle

Experimental Study on the Detection of Hazardous Chemicals Using Alternative Sensors in the Water Environment

by Su-Han Nam, Tae-Geom Ku, Ye-Lim Park, Jae-Hyun Kwon, Do-Sung Huh and Young-Do Kim

Toxics 2022, 10(5), 200; https://doi.org/10.3390/toxics10050200 - 19 Apr 2022

Cited by 3 | Viewed by 3019

Abstract

Chemical accidents in rivers may be triggered by natural or anthropogenic causes and refer to the flow of large quantities of hazardous chemicals into rivers. In South Korea, domestic water is sourced from large rivers, such as the Nakdong River. However, owing to [...] Read more.

Chemical accidents in rivers may be triggered by natural or anthropogenic causes and refer to the flow of large quantities of hazardous chemicals into rivers. In South Korea, domestic water is sourced from large rivers, such as the Nakdong River. However, owing to rapid industrialization, industrial facilities have become heavily concentrated in the middle and upper reaches of the Nakdong River. Therefore, severe problems could arise if harmful chemicals are leaked from industrial facilities into the river, and this contaminated river water is supplied to cities. Quantitative evaluation based on instrumental analysis during chemical accidents and prediction research based on modeling is actively being conducted however, research on the initial response is insufficient. Therefore, in this study, the variations in pH and EC were analyzed according to their chemical concentrations for seven chemicals. These seven chemicals are designated accident-preparedness substances that frequently cause chemical spills in South Korea. Additionally, we evaluated the possibility of identifying unknown substances by comparing the variations in pH and EC and statistics while diluting unknown substances. Thus, the potential of pH and EC as alternative indicators for detecting and identifying chemicals was evaluated in this study. NaF, NH₄HF₂, NaCN, and NH₄OH were classified by comparing their spatial distributions in a pH-EC relation curve. However, H₂SO₄, HCl, and SOCl₂ showed similar spatial distributions in the pH-EC curves and were difficult to identify. The results of this study provide information for chemical detection and identification using alternative sensors that permit easy and rapid field measurements in the event of a chemical spill and could be used as preliminary data for rapidly responding to accidents. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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12 pages, 677 KiB

Open AccessArticle

Removal of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli, ST98, in Water for Human Consumption by Black Ceramic Water Filters in Low-Income Ecuadorian Highlands

by Carlos Bastidas-Caldes, Juan Ochoa, Laura Guerrero-Latorre, Carlos Moyota-Tello, Wilson Tapia, Joaquín María Rey-Pérez and Maria Isabel Baroja

Int. J. Environ. Res. Public Health 2022, 19(8), 4736; https://doi.org/10.3390/ijerph19084736 - 14 Apr 2022

Cited by 6 | Viewed by 3173

Abstract

Fecal contamination in natural water sources is a common problem in low-income countries. Several health risks are associated with unprotected water sources, such as gastrointestinal infections caused by parasites, viruses, and bacteria. Moreover, antibiotic-resistant bacteria in water sources have become an increasing problem [...] Read more.

Fecal contamination in natural water sources is a common problem in low-income countries. Several health risks are associated with unprotected water sources, such as gastrointestinal infections caused by parasites, viruses, and bacteria. Moreover, antibiotic-resistant bacteria in water sources have become an increasing problem worldwide. This study aimed to evaluate the bacterial pathogens present in water within a rural context in Ecuador, along with the efficiency of black ceramic water filters (BCWFs) as a sustainable household water treatment. We monitored five natural water sources that were used for human consumption in the highlands of Ecuador and analyzed the total coliforms and E. coli before and after BCWF installation. The results indicated a variable bacterial contamination (29–300 colony-forming units/100mL) in all unfiltered samples, and they were considered as high risk for human consumption, but after filtration, no bacteria were present. Moreover, extended-spectrum beta-lactamase-producing E. coli with bla_TEM, bla_CTX-M9, and bla_CTX-M1 genes, and two E. coli classified in the clonal complex ST10 (ST98) were detected in two of the locations sampled; these strains can severely impact public health. The clonal complex ST10, found in the E. coli isolates, possesses the potential to spread bacteria-resistant genes to humans and animals. The results of the use of BCWFs, however, argue for the filters’ potential impact within those contexts, as the BCWFs completely removed even antibiotic-resistant contaminants from the water. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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11 pages, 1958 KiB

Open AccessArticle

Effect of TOC Concentration of Humic Substances as an Electron Shuttle on Redox Functional Groups Stimulating Microbial Cr(VI) Reduction

by Yi Zhou, Jingtao Duan, Jie Jiang and Zhen Yang

Int. J. Environ. Res. Public Health 2022, 19(5), 2600; https://doi.org/10.3390/ijerph19052600 - 24 Feb 2022

Cited by 7 | Viewed by 2397

Abstract

Humic substances as an electron shuttle play an essential role in the biogeochemistry processes. However, the influence of total organic carbon (TOC) concentrations of humic substances on microbial Cr(VI) reduction remains unclear. In this study, the rates and extents of Cr(VI) reduction by [...] Read more.

Humic substances as an electron shuttle play an essential role in the biogeochemistry processes. However, the influence of total organic carbon (TOC) concentrations of humic substances on microbial Cr(VI) reduction remains unclear. In this study, the rates and extents of Cr(VI) reduction by Shewanella oneidensis MR-1 in the presence of Leonardite humic acids (LHA) and Pahokee peat humic acids (PPHA) with different TOC concentrations were evaluated. We found that the enhanced reduction in Cr(VI) was associated with TOC concentrations of 2.5–50 mg C/L of HA samples. The result shows that HA as an electron shuttle impacted both rates and extents of microbial Cr (VI) reduction, which delivered differently in terms of low TOC concentration range of 2.5 to 15 mg C/L and high concentration range of 15–50 mg C/L. The rates of Cr(VI) reduction significantly enhanced in the low TOC concentration range of HA compared to a high concentration range. The highest acceleration rate of Cr(VI) reduction was achieved at 15 mg C/L of HA. The quinone-like fluorophore was responsible for the main redox-active functional groups of HA by the three-dimensional excitation-emission spectroscopy. The fluorescence intensity of quinone-like fluorophore of HA in the low TOC concentration range was positively correlated with its acceleration coefficient, corresponding to the highest microbial Cr(VI) reduction rate obtained in 15 mg C/L of HA. These findings highlighted the effect of the TOC concentration of HA on microbial Cr(VI) reduction processes. It emphasized that the low TOC concentration of HA contributed to the high rates of Cr(VI) reduction, which is critical for better understanding the fate of Cr(VI) and evaluating the effectiveness of Cr(VI) restoration strategies in the future. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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11 pages, 1269 KiB

Open AccessArticle

Phytoextraction and Antioxidant Defense of Mangrove Seedling (Kandelia obovata) to Inorganic Arsenate Exposure

by Guirong Wu, Kang Mei, Caimei He, Sujuan Wang and Liling Jiang

Water 2022, 14(4), 643; https://doi.org/10.3390/w14040643 - 18 Feb 2022

Cited by 1 | Viewed by 2387

Abstract

Increasing arsenic (As) pollution is posing potential endangerment to mangrove wetland ecosystems. Mangrove phytoextraction, translocation, and responses to As exposure must be urgently addressed. In this study, the growth and physiological response of Kandelia obovata seedlings were examined after addition of 25−200 mg [...] Read more.

Increasing arsenic (As) pollution is posing potential endangerment to mangrove wetland ecosystems. Mangrove phytoextraction, translocation, and responses to As exposure must be urgently addressed. In this study, the growth and physiological response of Kandelia obovata seedlings were examined after addition of 25−200 mg kg⁻¹ As under sediment culture conditions. Results showed that the seedling morphological variations were not significant below 100 mg kg⁻¹ compared to the control group, indicating superoxide dismutase, peroxidase, and catalase synergetic interaction to resist the As exposure. High As concentrations (150–200 mg kg⁻¹) inhibited the seedling growth accompanied by a significant increase in malondialdehyde content and decrease in activities of antioxidant enzymes. Toxicity symptoms and mortality appeared in 200 mg kg⁻¹ As, presumably because the plant reached the limit of As tolerance. Besides, As accumulated mainly in roots, accounting for 87.04–97.85% of the total As, and the bioaccumulation factor (BCF) was >100%. However, the BCF and translocation factor (TF) in stems and leaves were below unity, illustrating a weak capacity of transferring As to aerial parts of the seedlings. Overall, K. obovata is a potential remediated species in polluted coastal wetlands due to high phytoextraction capacity and high tolerance to As exposure. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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14 pages, 2846 KiB

Open AccessArticle

Adsorption Performance of Cd(II) by Chitosan-Fe₃O₄-Modified Fish Bone Char

by Wenhao Yang, Wenwen Luo, Tong Sun, Yingming Xu and Yuebing Sun

Int. J. Environ. Res. Public Health 2022, 19(3), 1260; https://doi.org/10.3390/ijerph19031260 - 23 Jan 2022

Cited by 14 | Viewed by 3063

Abstract

In order to develop a low-cost, fast, and efficient adsorbent, the fish bone charcoal B₆₀₀ prepared at 600 °C was modified by chitosan (Cs) and Fe₃O₄ to produce the material Cs-Fe₃O₄-B₆₀₀. Results showed [...] Read more.

In order to develop a low-cost, fast, and efficient adsorbent, the fish bone charcoal B₆₀₀ prepared at 600 °C was modified by chitosan (Cs) and Fe₃O₄ to produce the material Cs-Fe₃O₄-B₆₀₀. Results showed that Cs-Fe₃O₄-B₆₀₀ had magnetic responsiveness and can achieve solid–liquid separation, macropores disappeared, pore volume and specific surface area are increased, and amino functional groups appear on the surface. The adsorption process of Cd(II) by Cs-Fe₃O₄-B₆₀₀ conformed best to the pseudo-second order kinetics model and the Langmuir model, respectively. The behavior over a whole range of adsorption was consistent with chemical adsorption being the rate-controlling step, which is a very fast adsorption process, and the isothermal adsorption is mainly monolayer adsorption, which belongs to favorable adsorption. In addition, the saturated adsorption capacity obtained for the Cs-Fe₃O₄-B₆₀₀ to Cd(II) was 64.31 mg·g⁻¹, which was 1.7 times than B₆₀₀. The structure and morphology of Cs-Fe₃O₄-B₆₀₀ were characterized through SEM-EDS, TEM, FTIR, and XRD, indicating that the main mechanism of Cs-Fe₃O₄-B₆₀₀ and Cd(II) is mainly the complexation of amino groups, and it also includes part of the ion exchange between Cd(II) and Fe₃O₄. Therefore, Cs-Fe₃O₄-B₆₀₀ can be employed as an effective agent for remediation of Cd contaminated water. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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15 pages, 5805 KiB

Open AccessArticle

Assessment of Risk and Social Impact on Groundwater Pollution by Nitrates. Implementation in the Gallocanta Groundwater Body (NE Spain)

by José María Orellana-Macías and María Jesús Perles Roselló

Water 2022, 14(2), 202; https://doi.org/10.3390/w14020202 - 11 Jan 2022

Cited by 9 | Viewed by 3151

Abstract

Groundwater is an essential resource for humans concerning freshwater supply; therefore, preserving and protecting its quality is necessary. Risk assessment, based on hazard, intrinsic vulnerability information and mapping, may be considered as a key aspect of sustainable groundwater management. An approach has been [...] Read more.

Groundwater is an essential resource for humans concerning freshwater supply; therefore, preserving and protecting its quality is necessary. Risk assessment, based on hazard, intrinsic vulnerability information and mapping, may be considered as a key aspect of sustainable groundwater management. An approach has been made by combining the Nitrogen Input Hazard Index and the hydrogeological parameters considered in a modified DRASTIC method. A three-level classification has been used to determine the degree of risk, and the thresholds have been established following measurable criteria related to the potential nitrate concentration in groundwater. The second part of the study focused on estimating the socioeconomic impact of groundwater pollution by relating the degree of risk and social vulnerability to groundwater pollution. The method has been tested in the Gallocanta Groundwater Body (Spain). As a result, a risk map and an impact map are provided. The risk map shows that 67% of the study area can be classified as moderate and high-risk areas, corresponding to high hazard sources located in moderate and high vulnerability zones, whereas the impact of groundwater pollution is classified as moderate in the whole groundwater body. The proposed analysis allows comparison between aquifers in different areas and the results required by water authorities to implement control and mitigation measures. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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14 pages, 3276 KiB

Open AccessArticle

Spatiotemporal Evaluation of Water Quality and Hazardous Substances in Small Coastal Streams According to Watershed Characteristics

by Han-Saem Lee, Su-Jin Lim, Byung-Ran Lim, Hong-Seok Kim, Heung-Soo Lee, Tae-Ung Ahn and Hyun-Sang Shin

Int. J. Environ. Res. Public Health 2022, 19(2), 634; https://doi.org/10.3390/ijerph19020634 - 6 Jan 2022

Cited by 2 | Viewed by 2048

Abstract

In this study, spatial and temporal changes of eight water quality indicators and 30 types of hazardous substances including volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), pesticides, and inorganic matters for the small coastal streams along the West Coast of South Korea [...] Read more.

In this study, spatial and temporal changes of eight water quality indicators and 30 types of hazardous substances including volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), pesticides, and inorganic matters for the small coastal streams along the West Coast of South Korea were investigated. In coastal streams with clear seasonal changes in water quality, larger watershed areas led to greater contamination by particulate matter (i.e., suspended solids, r = 0.89), and smaller watershed areas led to greater contamination by organic matter (i.e., BOD, r = −0.78). The concentration of VOCs and pesticides was higher in agricultural areas, and those of SVOCs and metals were often higher in urban areas. According to the principal component analysis (PCA), during the wet season, the fluctuation in the water quality of coastal streams was higher in urban areas than in agricultural areas. Furthermore, coastal streams in residential areas exhibited higher levels of SVOCs, and those in industrial areas exhibited higher levels of metallic substances. Based on these results, the spatial and temporal trends of water quality and hazardous substances were obtained according to watershed characteristics, thereby clarifying the pollution characteristics of small-scale coastal streams and the major influencing factors. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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16 pages, 13654 KiB

Open AccessArticle

The Impact of Extreme Weather Events on Bacterial Communities and Opportunistic Pathogens in a Drinking Water Treatment Plant

by Wei Tang, Yunsi Liu, Qiuyan Li, Ling Chen, Qi Li, Pan Li and Shengji Xia

Water 2022, 14(1), 54; https://doi.org/10.3390/w14010054 - 28 Dec 2021

Cited by 5 | Viewed by 4061

Abstract

Drinking water treatment processes are highly effective at improving water quality, but pathogens can still persist in treated water, especially after extreme weather events. To identify how extreme weather events affected bacterial populations in source and treated water, water samples were collected from [...] Read more.

Drinking water treatment processes are highly effective at improving water quality, but pathogens can still persist in treated water, especially after extreme weather events. To identify how extreme weather events affected bacterial populations in source and treated water, water samples were collected from the Yangtze River Delta area and a local full-scale drinking water treatment plant. Bacterial community structure and the occurrence of pathogens were investigated in samples using 16S rRNA sequencing and qPCR techniques. In this study, the results show that intense rainfall can significantly increase levels of bacteria and opportunistic pathogens in river and drinking water treatment processes (p < 0.05); in particular, the relative abundance of Cyanobacteria increased after a super typhoon event (p < 0.05). The biological activated carbon (BAC) tank was identified as a potential pathogen reservoir and was responsible for 52 ± 6% of the bacteria released downstream, according to Bayesian-based SourceTracker analysis. Our results provide an insight into the challenges faced by maintaining finished water quality under changing weather conditions. Full article

(This article belongs to the Topic Impact of Toxic Elements on Water Quality and Treatment Methods)

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Impact of Toxic Elements on Water Quality and Treatment Methods

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Published Papers (15 papers)

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