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1.
Water Sci Technol ; 89(7): 1831-1845, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38619906

ABSTRACT

In this study, further treatment of coking wastewater treated in anoxic-oxic-membrane bioreactor (A2O-MBR) was investigated to meet the standards of the ministry by means of nanofiltration (NF) (with two different membranes and different pressures), microfiltration -powder activated carbon (MF-PAC) hybrid system and NF-PAC (with two different membranes and five different PAC concentrations) hybrid system. In addition to the parameters determined by the ministry, other parameters such as ammonium, thiocyanate (SCN-), hydrogen cyanide (HCN), dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), color were also examined to evaluate the flux performance and treatment efficiency of the hybrid processes. According to the results, chemical oxygen demand (COD) in the NF process, COD and total cyanide (T-CN) in the MF-PAC process could not meet the discharge standards. As for the NF-PAC hybrid system, XN45 membrane met the discharge standards in all parameters (COD = 96±1.88 mg/L, T-CN =<0,02 mg/L, phenol =<0.05 mg/L), with a recovery rate of 78% at 0.5 g/L PAC concentration.


Subject(s)
Coke , Water Purification , Wastewater , Charcoal , Powders , Water Purification/methods , Membranes, Artificial , Bioreactors , Waste Disposal, Fluid/methods
2.
Environ Monit Assess ; 196(5): 432, 2024 Apr 06.
Article in English | MEDLINE | ID: mdl-38581451

ABSTRACT

The East Kolkata Wetlands (EKWT), designated as a Ramsar Site for its crucial role in sewage water purification, agriculture and pisciculture, faces escalating environmental threats due to rapid urbanisation. Employing the pressure-state-response (PSR) framework and Environmental Risk Assessment (ERA), this study spans three decades to elucidate the evolving dynamics of EKWT. Using Landsat TM and OLI images from 1991, 2001, 2011 and 2021, the research identifies key parameters within the PSR framework. Principal component analysis generates environmental risk maps, revealing a 46% increase in urbanisation, leading to reduced vegetation cover and altered land surface conditions. The spatial analysis, utilizing Getis-Ord Gi* statistics, pinpoints risk hotspots and coldspots in the EKWT region. Correlation analysis underscores a robust relationship between urbanisation, climatic response and environmental risk. Decadal ERA exposes a noteworthy surge in high-risk areas, indicating a deteriorating trend. Quantitative assessments pinpoint environmental risk hotspots, emphasizing the imperative for targeted conservation measures. The study establishes a direct correlation between environmental risk and air quality, underscoring the broader implications of EKWT's degradation. While acknowledging the East Kolkata administration's efforts, the research recognises its limitations and advocates a holistic, multidisciplinary approach for future investigations. Recommendations encompass the establishment of effective institutions, real-time monitoring, public engagement and robust anti-pollution measures. In offering quantitative insights, this study provides an evidence-based foundation for conservation strategies and sustainable management practices essential to safeguard the East Kolkata Wetlands.


Subject(s)
Water Purification , Wetlands , Environmental Monitoring/methods , Agriculture , Sewage , Water Purification/methods
3.
J Hazard Mater ; 470: 134254, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38615644

ABSTRACT

The existence of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) has been a global public environment and health issue. Due to the different cell structures, gram-positive/negative ARB exhibit various inactivation mechanisms in water disinfection. In this study, a gram-negative ARB Escherichia coli DH5α (E. coli DH5α) was used as a horizontal gene transfer (HGT) donor, while a gram-positive ARB Bacillus as a recipient. To develop an efficient and engineering applicable method in water disinfection, ARB and ARGs removal efficiency of Fe(VI) coupled peroxydisulfate (PDS) or peroxymonosulfate (PMS) was compared, wherein hydroxylamine (HA) was added as a reducing agent. The results indicated that Fe(VI)/PMS/HA showed higher disinfection efficiency than Fe(VI)/PDS/HA. When the concentration of each Fe(VI), PMS, HA was 0.48 mM, 5.15 log E. coli DH5α and 3.57 log Bacillus lost cultivability, while the proportion of recovered cells was 0.0017 % and 0.0566 %, respectively, and HGT was blocked. Intracellular tetA was reduced by 2.49 log. Fe(IV) and/or Fe(V) were proved to be the decisive reactive species. Due to the superiority of low cost as well as high efficiency and practicality, Fe(VI)/PMS/HA has significant application potential in ARB, ARGs removal and HGT inhibition, offering a new insight for wastewater treatment.


Subject(s)
Gene Transfer, Horizontal , Iron , Peroxides , Peroxides/chemistry , Iron/chemistry , Water Purification/methods , Escherichia coli/drug effects , Escherichia coli/genetics , Drug Resistance, Bacterial/genetics , Disinfection/methods , Sulfates/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Bacillus/genetics , Bacillus/drug effects , Bacillus/metabolism
4.
J Hazard Mater ; 470: 134286, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38615649

ABSTRACT

Microplastic hetero-aggregates are stable forms of microplastics in the aqueous environment. However, when disinfecting water containing microplastic hetero-aggregates, the response of them in water to different oxidizing agents and the effect on water quality have not been reported. Our results showed that Ca(ClO)2, K2S2O8, and sodium percarbonate (SPC) treatment could lead to the disaggregation of microplastic hetero-aggregates as well as a rise in cell membrane permeability, which caused a large amount of organic matter to be released. When the amount of oxidant dosing is insufficient, the oxidant cannot completely degrade the released organic matter, resulting in DOC, DTN, DTP and other indicators being higher than before oxidation, thus causing secondary pollution of the water body. In comparison, K2FeO4 can purify the water body stably without destroying the microplastic hetero-aggregates, but it only weakly inhibits the toxic cyanobacteria Microcystis and Pseudanabaena, which may cause cyanobacterial bloom as well as algal toxin and odorant contamination in practical application. Compared with the other oxidizers, K2S2O8 provides better inhibition of toxic cyanobacteria and has better ecological safety. Therefore, when treating microplastic-containing water bodies, we should consider both water purification and ecological safety, and select appropriate oxidant types and dosages to optimize the water treatment.


Subject(s)
Microplastics , Oxidants , Water Pollutants, Chemical , Oxidants/chemistry , Microplastics/toxicity , Microplastics/chemistry , Water Pollutants, Chemical/chemistry , Water Pollutants, Chemical/toxicity , Carbonates/chemistry , Water Purification/methods
5.
J Hazard Mater ; 470: 134281, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38626680

ABSTRACT

Eutrophication has led to the widespread occurrence of cyanobacterial blooms. Toxic cyanobacterial blooms with high concentrations of microcystins (MCs) have been identified in the Lalla Takerkoust reservoir in Morocco. The objective of this study was to evaluate the efficiency of the Multi-Soil-Layering (MSL) ecotechnology in removing natural cyanobacterial blooms from the lake. Two MSL pilots were used in rectangular glass tanks (60 × 10 × 70 cm). They consisted of permeable layers (PLs) made of pozzolan and a soil mixture layer (SML) containing local soil, ferrous metal, charcoal and sawdust. The main difference between the two systems was the type of local soil used: sandy soil for MSL1 and clayey soil for MSL2. Both MSL pilots effectively reduced cyanobacterial cell concentrations in the treated water to very low levels (0.09 and 0.001 cells/mL). MSL1 showed a gradual improvement in MC removal from 52 % to 99 %, while MSL2 started higher at 90 % but dropped to 54% before reaching 86%. Both MSL systems significantly reduced organic matter levels (97.2 % for MSL1 and 95.8 % for MSL2). Both MSLs were shown to be effective in removing cyanobacteria, MCs, and organic matter with comparable performance.


Subject(s)
Cyanobacteria , Eutrophication , Lakes , Microcystins , Soil , Lakes/microbiology , Cyanobacteria/growth & development , Microcystins/analysis , Soil/chemistry , Water Purification/methods , Environmental Restoration and Remediation/methods , Morocco
6.
Sci Total Environ ; 927: 172155, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38575028

ABSTRACT

As of 2022, China's rural sewage treatment rate is only approximately 31 %. Rapid rural development has led to higher demand. However, China's rural areas are complex and face many problems, such as uneven economic development, population distribution, and water availability. Long-lasting and low-cost wastewater treatment measures are needed for application in rural areas. The quantity and quality of rural domestic wastewater in China were characterized first. Next, the hot topic of domestic wastewater in Chinese villages was confirmed via bibliometric analysis using CiteSpace, and the treatment technologies for rural domestic wastewater were compared. Specifically, the technical status and challenges of the most common technology in rural domestic wastewater treatment, constructed wetlands, were summarized.


Subject(s)
Waste Disposal, Fluid , Wastewater , China , Waste Disposal, Fluid/methods , Wetlands , Rural Population , Water Purification/methods , East Asian People
7.
Sci Total Environ ; 927: 172141, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38580119

ABSTRACT

Microalgal-bacterial (MB) consortia create an excellent eco-system for simultaneous COD/BOD and nutrients (N and P) removals in a single step with significant reduction in or complete elimination of aeration and carbonation in the biological wastewater treatment processes. The integration of membrane separation technology with the MB processes has created a new paradigm for research and development. This paper focuses on a comprehensive and critical literature review of recent advances in these emerging processes. Novel membrane process configurations and process conditions affecting the biological performance of these novel systems have been systematically reviewed and discussed. Membrane fouling issues and control of MB biofilm formation and thickness associated with these emerging suspended growth or immobilized biofilm processes are addressed and discussed. The research gaps, challenges, outlooks of these emerging processes are identified and discussed in-depth. The findings from the literature suggest that the membrane-based MB processes are advanced biotechnologies with a significant reduction in energy consumption and process simplification and high process efficiency that are not achievable with current technologies in wastewater treatment. There are endless opportunities for research and development of these novel and emerging membrane-based MB processes.


Subject(s)
Membranes, Artificial , Microalgae , Waste Disposal, Fluid , Wastewater , Microalgae/physiology , Waste Disposal, Fluid/methods , Wastewater/microbiology , Biofilms , Bacteria , Bioreactors , Water Purification/methods
8.
J Hazard Mater ; 470: 134210, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38581876

ABSTRACT

Modern metallurgical and smelting activities discharge the lead-containing wastewater, causing serious threats to human health. Bacteria and urease applied to microbial-induced carbonate precipitation (MICP) and enzyme-induced carbonate precipitation (EICP) are denatured under high Pb2+ concentration. The nano-hydroxyapatite (nHAP)-assisted biomineralization technology was applied in this study for Pb immobilization. Results showed that the extracellular polymers and cell membranes failed to secure the urease activity when subjected to 60 mM Pb2+. The immobilization efficiency dropped to below 50% under MICP, whereas it due to a lack of extracellular polymers and cell membranes dropped to below 30% under EICP. nHAP prevented the attachment of Pb2+ either through competing with bacteria and urease or promoting Ca2+/Pb2+ ion exchange. Furthermore, CO32- from ureolysis replaced the hydroxyl (-OH) in hydroxylpyromorphite to encourage the formation of carbonate-bearing hydroxylpyromorphite of higher stability (Pb10(PO4)6CO3). Moreover, nHAP application overcame an inability to provide nucleation sites by urease. As a result, the immobilization efficiency, when subjected to 60 mM Pb2+, elevated to above 80% under MICP-nHAP and to some 70% under EICP-nHAP. The findings highlight the potential of applying the nHAP-assisted biomineralization technology to Pb-containing water bodies remediation.


Subject(s)
Biomineralization , Durapatite , Lead , Urease , Water Pollutants, Chemical , Durapatite/chemistry , Lead/chemistry , Urease/metabolism , Urease/chemistry , Water Pollutants, Chemical/chemistry , Water Purification/methods , Carbonates/chemistry , Environmental Restoration and Remediation/methods
9.
Sci Total Environ ; 927: 172227, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38582104

ABSTRACT

The sensory quality of drinking water, and particularly its taste and odor (T&O) is a key determinant of consumer acceptability, as consumers evaluate water by their senses. Some of the conventional treatment processes to control compounds which impart unpleasant T&O have limitations because of their low efficiency and/or high costs. Therefore, there is a great need to develop an effective process for removing T&O compounds without secondary concerns. The primary objective of this study was to assess for the first time the effectiveness of spirulina-based carbon materials in removing geosmin (GSM) and 2-methylisoborneol (2-MIB) from water, two commonly occurring natural T&O compounds. The efficiency of the materials to remove environmentally relevant concentrations of GSM and 2-MIB (ng L-1) from ultrapure and raw water was investigated using a sensitive headspace solid-phase microextraction coupled with gas chromatography mass spectrometry (HS-SPME-GC/MS) method. Moreover, the genotoxic and cytotoxic effects of the spirulina-based materials were assessed for the first time to evaluate their safety and their potential in the treatment of water for human consumption. Based on the results, spirulina-based materials were found to be promising for drinking water treatment applications, as they did not exert geno-cytotoxic effects on human cells, while presenting high efficiency in removing GSM and 2-MIB from water.


Subject(s)
Drinking Water , Odorants , Spirulina , Taste , Water Pollutants, Chemical , Water Purification , Drinking Water/chemistry , Odorants/analysis , Water Pollutants, Chemical/analysis , Water Purification/methods , Naphthols , Humans , Camphanes , Adsorption , Solid Phase Microextraction/methods , Carbon , Gas Chromatography-Mass Spectrometry
10.
Water Sci Technol ; 89(6): 1454-1465, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38557711

ABSTRACT

We used bench-scale tests and mathematical modeling to explore chemical oxygen demand (COD) removal rates in a moving-bed biofilm reactor (MBBR) for winery wastewater treatment, using either urea or nitrate as a nitrogen source. With urea addition, the COD removal fluxes ranged from 34 to 45 gCOD/m2-d. However, when nitrate was added, fluxes increased up to 65 gCOD/m2-d, twice the amount reported for aerobic biofilms for winery wastewater treatment. A one-dimensional biofilm model, calibrated with data from respirometric tests, accurately captured the experimental results. Both experimental and modelling results suggest that nitrate significantly increased MBBR capacity by stimulating COD oxidation in the deeper, oxygen-limited regions of the biofilm. Our research suggests that the addition of nitrate, or other energetic and broadly used electron acceptors, may provide a cost-effective means of covering peak COD loads in biofilm processes for winery or another industrial wastewater treatment.


Subject(s)
Waste Disposal, Fluid , Water Purification , Waste Disposal, Fluid/methods , Nitrates , Biofilms , Bioreactors , Organic Chemicals , Water Purification/methods , Nitrogen , Urea , Denitrification
11.
Water Sci Technol ; 89(6): 1570-1582, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38557719

ABSTRACT

Despite the high adsorption capacity of polyaluminum chloride and anionic polyacrylamide water treatment residuals (PAC-APAM WTRs) for Pb2+, Cd2+, Cu2+, and Zn2+, their influence on the adsorption behavior of heavy metals in traditional bioretention soil media remains unclear. This study investigated the impact of PAC-APAM WTRs at a 20% weight ratio on the adsorption removal of Pb2+, Cd2+, Cu2+, and Zn2+ in three types of soils. The results demonstrated improved heavy metal adsorption in the presence of PAC-APAM WTRs, with enhanced removal observed at higher pH levels and temperatures. The addition of PAC-APAM WTRs augmented the maximum adsorption capacity for Pb2+ (from 0.98 to 3.98%), Cd2+ (from 0.52 to 10.99%), Cu2+ (from 3.69 to 36.79%), and Zn2+ (from 2.63 to 13.46%). The Langmuir model better described the data in soils with and without PAC-APAM WTRs. The pseudo-second-order model more accurately described the adsorption process, revealing an irreversible chemical process, although qe demonstrated improvement with the addition of PAC-APAM WTRs. This study affirms the potential of PAC-APAM WTRs as an amendment for mitigating heavy metal pollution in stormwater bioretention systems. Further exploration of the engineering application of PAC-APAM WTRs, particularly in field conditions for the removal of dissolved heavy metals, is recommended.


Subject(s)
Acrylic Resins , Aluminum Hydroxide , Metals, Heavy , Water Purification , Cadmium , Soil , Adsorption , Lead , Metals, Heavy/analysis , Water Purification/methods
12.
Chemosphere ; 355: 141834, 2024 May.
Article in English | MEDLINE | ID: mdl-38565376

ABSTRACT

Membrane fouling caused by the organics-coated particles was the main obstacle for the highly efficient shale gas produced water (SGPW) treatment and recycling. In this study, a novel hybrid electrocoagulation (EC) and E-peroxone process coupled with UF (ECP-UF) process was proposed to examine the efficacy and elucidate the mechanism for UF fouling mitigation in assisting SGPW reuse. Compared to the TMP (transmembrane pressure) increase of -15 kPa in the EC-UF process, TMP in ECP-UF system marginally increased to -1.4 kPa for 3 filtration cycles under the current density of 15 mA/cm2. Both the total fouling index and hydraulically irreversible fouling index of the ECP-UF process were significantly lower than those of EC-UF process. According to the extended Derjaguin-Landau-Verwey-Overbeek theory, the potential barriers was the highest for ECP-UF processes due to the substantial increase of the acid-base interaction energy in ECP-UF process, which was well consistent with the TMP and SEM results. Turbidity and TOC of ECP-UF process were 63.6% and 45.8% lower than those of EC-UF process, respectively. According to the MW distribution, the variations of compounds and their relative contents were probably due to the oxidation and decomposing products of the macromolecular organics. The number of aromatic compound decreased, while the number of open-chain compounds (i.e., alkenes, alkanes and alcohols) increased in the permeate of ECP-UF process. Notably, the substantial decrease in the relative abundance of di-phthalate compounds was attributed to the high reactivity of these compounds with ·OH. Mechanism study indicated that ECP could realize the simultaneous coagulation, H2O2 generation and activation by O3, facilitating the enhancement of ·OH and Alb production and therefore beneficial for the improved water quality and UF fouling mitigation. Therefore, the ECP-UF process emerges as a high-efficient and space-saving approach, yielding a synergistic effect in mitigating UF fouling for SGPW recycling.


Subject(s)
Ultrafiltration , Water Purification , Natural Gas , Hydrogen Peroxide , Membranes, Artificial , Water Purification/methods , Electrocoagulation
13.
Chemosphere ; 355: 141884, 2024 May.
Article in English | MEDLINE | ID: mdl-38575083

ABSTRACT

Global water demand and environmental concerns related to climate change require industries to develop high-efficiency wastewater treatment methods to remove pollutants. Likewise, toxic pollutants present in wastewater negatively affect the environment and human health, requiring effective treatment. Although conventional treatment processes remove carbon and nutrients, they are insufficient to remove pharmaceuticals, pesticides, and plasticizers. Electrochemical processes effectively remove pollutants from wastewater through the mineralization of non-biodegradable pollutants with consequent conversion into biodegradable compounds. Its advantages include easy operation, versatility, and short reaction time. In this way, this review initially provides a global water scenario with a view to the future. It comprises global demand, treatment methods, and pollution of water resources, addressing various contaminants such as heavy metals, nutrients, organic compounds, and emerging contaminants. Subsequently, the fundamentals of electrochemical treatments are presented as well as electrochemical treatments, highlighting the latest studies involving electrocoagulation, electroflocculation, electroflotation, capacitive deionization and its derivatives, eletrodeionization, and electrochemical advanced oxidation process. Finally, the challenges and perspectives were discussed. In this context, electrochemical processes have proven promising and effective for the treatment of water and wastewater, allowing safe reuse practices and purification with high contaminant removal.


Subject(s)
Environmental Pollutants , Metals, Heavy , Water Pollutants, Chemical , Water Purification , Humans , Wastewater , Water Pollutants, Chemical/analysis , Water Purification/methods , Water
14.
Environ Monit Assess ; 196(5): 476, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38662019

ABSTRACT

The ingestion of Ti-containing nanoparticles from drinking water has emerged as a concern in recent years. This study therefore aimed to characterize Ti-containing nanoparticles in water samples collected from four water treatment plants in Taiwan and to explore the challenges associated with measuring them at low levels using single particle-inductively coupled plasma mass spectrometry. Additionally, the study sought to identify the most effective processes for the removal of Ti-containing nanoparticles. For each water treatment plant, two water samples were collected from raw water, sedimentation effluent, filtration effluent, and finished water, respectively. Results revealed that Ti-containing nanoparticles in raw water, with levels at 8.69 µg/L and 296.8 × 103 particles/L, were removed by approximately 35% and 98%, respectively, in terms of mass concentration and particle number concentration, primarily through flocculation and sedimentation processes. The largest most frequent nanoparticle size in raw water (112.0 ± 2.8 nm) was effectively reduced to 62.0 ± 0.7 nm in finished water, while nanoparticles in the size range of 50-70 nm showed limited changes. Anthracite was identified as a necessary component in the filter beds to further improve removal efficiency at the filtration unit. Moreover, the most frequent sizes of Ti-containing nanoparticles were found to be influenced by salinity. Insights into the challenges associated with measuring low-level Ti-containing nanoparticles in aqueous samples provide valuable information for future research and management of water treatment processes, thereby safeguarding human health.


Subject(s)
Titanium , Water Pollutants, Chemical , Water Purification , Taiwan , Water Purification/methods , Water Pollutants, Chemical/analysis , Environmental Monitoring , Metal Nanoparticles , Filtration , Drinking Water/chemistry
15.
Environ Monit Assess ; 196(5): 475, 2024 Apr 25.
Article in English | MEDLINE | ID: mdl-38662271

ABSTRACT

The potentially harmful effects of consuming potentially toxic elements (PTEs) and microplastics (MPs) regularly via drinking water are a significant cause for worry. This study investigated PTEs (Cd, Cu, Cr, Ni, Pd, Zn, Co), MPs, turbidity, pH, conductivity, and health risk assessment in the water treatment plant in Kielce, Poland. Zn had the highest concentrations throughout the water treatment facility, whereas Cd, Pb, and Co had lower concentrations (< 0.1 µg/L). The order of the concentrations among the specified PTEs was like Zn˃Cu˃Ni˃Cr˃Cd˃Pb and Co. The minimum turbidity was 0.34, and the maximum was 1.9 NTU. The range of pH in water samples was 6.51-7.47. The conductivity was 1,203-1,445 ms in water samples. These identified MPs were categorized into fiber and fragments. The color of these identified MPs was blue, red, black, green, and transparent. The minimum and maximum size of the MPs was 196 and 4,018 µm, while the average size was 2,751 ± 1,905 µm. The average concentration of MPs per liter of the water treatment plant was 108.88 ± 55.61. The elements listed are C, O, Na, Mg, Al, Si, K, Ca, and Ti. Fe and Zn were the predominant elements seen using EDX. HQ values of the PTEs were less than one for adults and children. The human health risk associated with all detected PTEs revealed that the HQ values exhibit a satisfactory degree of non-carcinogenic adverse health risk. HI values for adults and children age groups were less than one. In most water treatment samples, the carcinogenic value exceeds the threshold value of 10-6. The PTEs and MP concentrations in drinking water should be periodically monitored to minimize consumers' environmental pollution and health risks.


Subject(s)
Environmental Monitoring , Microplastics , Water Pollutants, Chemical , Water Purification , Water Pollutants, Chemical/analysis , Poland , Microplastics/analysis , Water Purification/methods , Humans , Risk Assessment , Drinking Water/chemistry , Metals, Heavy/analysis , Adult
16.
J Environ Sci (China) ; 143: 126-137, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38644011

ABSTRACT

Radioisotope leaking from nuclear waste has become an intractable problem due to its gamma radiation and strong water solubility. In this work, a novel porous ZnFC-PA/PSF composite sphere was fabricated by immobilization of ferrocyanides modified zinc phytate into polysulfone (PSF) substrate for the treatment of Cs-contaminated water. The maximum adsorption capacity of ZnFC-PA/PSF was 305.38 mg/g, and the removal efficiency of Cs+ was reached 94.27% within 2 hr. The ZnFC-PA/PSF presented favorable stability with negligible dissolution loss of Zn2+ and Fe2+ (< 2%). The ZnFC-PA/PSF achieved high-selectivity towards Cs+ (Kd = 2.24×104 mL/g) even in actual geothermal water. The adsorption mechanism was inferred to be the ion-exchange between Cs+ and K+. What's more, ZnFC-PA/PSF worked well in the fixed-bed adsorption (E = 91.92%), indicating the application potential for the hazardous Cs+ removal from wastewater.


Subject(s)
Water Pollutants, Chemical , Adsorption , Water Pollutants, Chemical/chemistry , Water Purification/methods , Sulfones/chemistry , Polymers/chemistry , Porosity , Cesium/chemistry , Waste Disposal, Fluid/methods , Zinc/chemistry , Wastewater/chemistry
17.
J Environ Sci (China) ; 143: 1-11, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38644008

ABSTRACT

Potential health risks related to environmental endocrine disruptors (EEDs) have aroused research hotspots at the forefront of water treatment technologies. Herein, nitrogen-doped titanium dioxide/schwertmannite nanocomposites (N-TiO2/SCH) have been successfully developed as heterogeneous catalysts for the degradation of typical EEDs via photo-Fenton processes. Due to the sustainable Fe(III)/Fe(II) conversion induced by photoelectrons, as-prepared N-TiO2/SCH nanocomposites exhibit much enhanced efficiency for the degradation of bisphenol A (BPA; ca. 100% within 60 min under visible irradiation) in a wide pH range of 3.0-7.8, which is significantly higher than that of the pristine schwertmannite (ca. 74.5%) or N-TiO2 (ca. 10.8%). In this photo-Fenton system, the efficient degradation of BPA is mainly attributed to the oxidation by hydroxyl radical (•OH) and singlet oxygen (1O2). Moreover, the possible catalytic mechanisms and reaction pathway of BPA degradation are systematically investigated based on analytical and photoelectrochemical analyses. This work not only provides a feasible means for the development of novel heterogeneous photo-Fenton catalysts, but also lays a theoretical foundation for the potential application of mineral-based materials in wastewater treatment.


Subject(s)
Benzhydryl Compounds , Iron Compounds , Nanocomposites , Nitrogen , Phenols , Titanium , Water Pollutants, Chemical , Titanium/chemistry , Benzhydryl Compounds/chemistry , Phenols/chemistry , Nanocomposites/chemistry , Water Pollutants, Chemical/chemistry , Nitrogen/chemistry , Catalysis , Iron/chemistry , Hydrogen Peroxide/chemistry , Endocrine Disruptors/chemistry , Water Purification/methods
18.
J Hazard Mater ; 470: 134198, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38608582

ABSTRACT

A novel Ag3PO4/ZnWO4-modified graphite felt electrode (AZW@GF) was prepared by drop coating method and applied to photoelectrocatalytic removal of harmful algae. Results showed that approximately 99.21% of chlorophyll a and 91.57% of Microcystin-LR (MCLR) were degraded by the AZW@GF-Pt photoelectrocatalytic system under the optimal operating conditions with a rate constant of 0.02617 min-1 and 0.01416 min-1, respectively. The calculated synergistic coefficient of photoelectrocatalytic algal removal and MC-LR degradation by the AZW@GF-Pt system was both larger than 1.9. In addition, the experiments of quenching experiments and electron spin resonance (ESR) revealed that the photoelectrocatalytic reaction mainly generated •OH and •O2- for algal removal and MC-LR degradation. Furthermore, the potential pathway for photoelectrocatalytic degradation of MC-LR was proposed. Finally, the photoelectrocatalytic cycle algae removal experiments were carried out on AZW@GF electrode, which was found to maintain the algae removal efficiency at about 91% after three cycles of use, indicating that the photoelectrocatalysis of AZW@GF electrode is an effective emergency algae removal technology.


Subject(s)
Electrodes , Graphite , Marine Toxins , Microcystins , Silver Compounds , Graphite/chemistry , Graphite/radiation effects , Microcystins/chemistry , Microcystins/isolation & purification , Catalysis , Silver Compounds/chemistry , Phosphates/chemistry , Oxides/chemistry , Electrochemical Techniques , Tungsten/chemistry , Chlorophyll A/chemistry , Zinc/chemistry , Water Purification/methods , Chlorophyll/chemistry , Photochemical Processes , Harmful Algal Bloom
19.
J Hazard Mater ; 470: 134235, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38608585

ABSTRACT

The misuse of aromatic amines like 4-chloroaniline (4-CA) has led to severe environmental and health issues. However, it's difficult to be utilized by microorganisms for degradation. Nano-zero-valent iron (nZVI) is a promising material for the remediation of chloroaniline pollution, however, the synergistic effect and mechanism of nZVI with microorganisms for the degradation of 4-CA are still unclear. This study investigated the potential of 4-CA removal by the synergistic system involving nZVI and 4-CA degrading microbial flora. The results indicate that the addition of nZVI significantly enhanced the bio-degradation rate of 4-CA from 43.13 % to 62.26 %. Under conditions involving 0.1 % nZVI addition at a 24-hour interval, pH maintained at 7, and glucose as an external carbon source, the microbial biomass, antioxidant enzymes, and dehydrogenase were significantly increased, and the optimal 4-CA degradation rate achieved 68.79 %. Additionally, gas chromatography-mass spectrometry (GC-MS) analysis of intermediates indicated that the addition of nZVI reduced compounds containing benzene rings and enhanced the dechlorination efficiency. The microbial community remained stable during the 4-CA degradation process. This study illustrates the potential of nZVI in co-microbial remediation of 4-CA compounds in the environment.


Subject(s)
Aniline Compounds , Biodegradation, Environmental , Iron , Water Pollutants, Chemical , Aniline Compounds/chemistry , Aniline Compounds/metabolism , Iron/chemistry , Iron/metabolism , Water Pollutants, Chemical/metabolism , Water Pollutants, Chemical/chemistry , Water Purification/methods , Bacteria/metabolism , Metal Nanoparticles/chemistry
20.
Sci Total Environ ; 927: 172257, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38608912

ABSTRACT

Waterborne pathogens threaten 2.2 billion people lacking access to safely managed drinking water services, causing over a million annual diarrheal deaths. Individuals without access to chlorine reagents or filtration devices often resort to do-it-yourself (DIY) methods, such as boiling or solar disinfection (SODIS). However, these methods are not simple to implement. In this study, we introduced an innovative and easily implemented disinfection approach. We discovered that immersing aluminum foil in various alkaline solutions produces alkali-treated aluminum foil (ATA foil) that effectively adsorbs Escherichia coli (E. coli), Salmonella, and Acinetobacter through the generated surface aluminum hydroxide. For example, a 25 cm2 ATA foil efficiently captures all 104E. coli DH5α strains in 100 mL water within 30 min. Using a saturated suspension of magnesium hydroxide, a type of fertilizer, as the alkaline solution, the properties of the saturated suspension eliminate the need for measuring reagents or changing solutions, making it easy for anyone to create ATA foil. ATA foils can be conveniently produced within mesh bags and placed in household water containers, reducing the risk of recontamination. Replacing the ATA foil with a foil improves the adsorption efficiency, and re-immersing the used foil in the production suspension restores its adsorption capacity. Consequently, ATA foil is an accessible and user-friendly alternative DIY method for underserved communities. Verification experiments covering variations in the water quality and climate are crucial for validating the efficacy of the foil. Fortunately, the ATA foil, with DIY characteristics similar to those of boiling and SODIS, is well-suited for testing under diverse global conditions, offering a promising solution for addressing waterborne pathogens worldwide.


Subject(s)
Disinfection , Drinking Water , Water Purification , Drinking Water/microbiology , Drinking Water/chemistry , Disinfection/methods , Water Purification/methods , Water Microbiology , Water Supply
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