Pilot-scale experimental study on the enhanced natural attenuation of complex organic contaminants based on the recharge of electron acceptors.

Anaerobic biodegradation plays a crucial role in attenuating organic contaminants in natural aquifers, where the concentration and type of electron acceptors directly determine the stages and rates of degradation progress. In this study, nitrate depletion was monitored in a simulated pilot-scale aquifer contaminated with toluene and trichloroethylene, while sulfate became the new periodic electron acceptor, accompanied by a decrease in the contaminant attenuation rate. Consequently, nitrate was injected into the contaminated plume in stages, and the hydro- and biochemical impacts were further monitored.

Insights into the characteristics of changes in dissolved organic matter fluorescence components on the natural attenuation process of toluene.

Natural attenuation (NA) is of great significance for the remediation of contaminated groundwater, and how to identify NA patterns of toluene in aquifers more quickly and effectively poses an urgent challenge. In this study, the NA of toluene in two typical soils was conducted by means of soil column experiment. Based on column experiments, dissolved organic matter (DOM) was rapidly identified using fluorescence spectroscopy, and the relationship between DOM and the NA of toluene was established through structural equation modeling analysis.

Unlocking the potential of surface modification with phosphate on ball milled zero-valent iron reactivity:Implications for radioactive metal ions removal.

Numerous investigations have illuminated the profound impact of phosphate on the adsorption of uranium, however, the effect of phosphate-mediated surface modification on the reactivity of zero-valent iron (ZVI) remained enigmatic. In this study, a phosphate-modified ZVI (P-ZVI) was prepared with a facile ball milling strategy, and compared with ZVI, the U(VI) removal amount (435.2 mg/g) and efficiency (3.

Co-migration behavior of toluene coupled with trichloroethylene and the response of the pristine groundwater ecosystems - A mesoscale indoor experiment.

Experimental scale and sampling precision are the main factors limiting the accuracy of migration and transformation assessments of complex petroleum-based contaminants in groundwater. In this study, a mesoscale indoor aquifer device with high environmental fidelity and monitoring accuracy was constructed, in which dissolved toluene and trichloroethylene were used as typical contaminants in a 1.5-year contaminant migration experiment.

Core-Shell MnFe Nanocatalyst Derived from Prussian Blue Analogs for Peroxymonosulfate Activation: Nonradical Mechanism and Bimetallic Valence Cycle.

Sulfamethazine (SAT) is widely present in sediment, soil, rivers, and groundwater. Unfortunately, traditional water treatment technologies are inefficient at eliminating SAT from contaminated water. Therefore, developing an effective and ecologically friendly treatment procedure to effectively remove SAT is critical.

Diurnal variation in the urban thermal environment and its relationship to human activities in China: a Tencent location-based service geographic big data perspective.

The main factor of the formation and deterioration in China's urban thermal environment is human activity, which is difficult to describe and measure. A new perspective on the effect of human activity on the urban thermal environment can be obtained by examining the interaction between location-based service (LBS) data and the urban thermal environment in China. However, relevant research is still limited.

Natural phosphorus-ferromanganese ore-based composites for the simultaneous remediation of arsenic- and lead-co-contaminated groundwater: synergistic effectiveness, kinetics, and mechanisms.

Natural phosphorus-ferromanganese ore (NPO-NFMO) based composites by mechanical ball milling method, applying for the simultaneous remediation of arsenic (As) and lead (Pb) co-contaminated groundwater. Kinetic behavior adopted pseudo-second-order adsorption mechanism attaining equilibrium in 120 min over a wide pH range (2.0-6.

Characteristics of persulfate gel materials in groundwater remediation: Column and tank experiments investigations.

Using persulfate and environment-friendly gel solution as raw materials, persulfate gel sustained-release material (PGSR) and persulfate gelatin gel sustained-release material (G-PGSR) were developed. The main purpose of this study was to evaluate the potential of PGSR and G-PGSR in sustained release, migration and removal performance through column and tank experimental investigations. Results showed that the maximum release rates of PGSR and G-PGSR in water columns were 1.

Anthropogenic perturbation enhances the release of geogenic Mn to groundwater: Evidence from hydrogeochemical characteristics.

High geogenic Mn groundwater is widespread around the world and has also proved to be harmful to human health, especially to the IQ of Children. The natural release of Mn from aquifer sediments in slightly reducing condition is believed to be the primary cause. However, there isn't enough evidence to prove that anthropogenic activities promote the reductive release of Mn.

A novel thermosensitive persulfate controlled-release hydrogel based on agarose/silica composite for sustained nitrobenzene degradation from groundwater.

The increasing risk of organic contamination of groundwater poses a serious threat to the environment and human health, causing an urgent need to develop long-lasting and adaptable remediation materials. Controlled-release materials (CRMs) are capable of encapsulating oxidants to achieve long-lasting release properties in aquifers and considered to be effective strategies in groundwater remediation. In this study, novel hydrogels (ASGs) with thermosensitive properties were prepared based on agarose and silica to achieve controlled persulfate (PS) release.

Efficient utilization of biogenic manganese oxides in bioaugmentation columns for remediation of thallium(I) contaminated groundwater.

Little attention has been paid to the in situ-generated biogenic manganese oxides (BMnOx) for practical implementation in continuous groundwater remediation systems. The enrichment effects of manganese oxidizing bacteria (MOB) in bioaugmentation columns and the in situ-generated BMnOx for continuous thallium(I) (Tl(I)) removal from groundwater were investigated. Results indicated that Pseudomonas Putida MnB1 (strain MnB1) attached on the groundwater sediments (GS) can achieve a maximum of 97.

Exogenous-organic-matter-driven mobilization of groundwater arsenic.

The potential release capacity of arsenic (As) from sediment was evaluated under a high level of exogenous organic matter (EOM) with both bioreactive and chemically reactive organic matters (OMs). The OMs were characterized by FI, HIX, BIX, and SUVA fluorescence indices showing the biological activities were kept at a high level during the experimental period. At the genus level, Fe/Mn/As-reducing bacteria (, , , and ) and bacteria (, , , and ) that can participate in metabolic transformation using EOM were identified.

Preparation and properties of the persulfate gel materials and application for the remediation of 2,4-dinitrotoluene contaminated groundwater.

This study aims to develop persulfate new gel sustaining-release material (PGSR) and gelatin-gel sustaining-release material (G-PGSR) that can be injected into aquifers and slowly release SO to groundwater. Compatibility and miscibility of colloidal silica gels and gelatin with SO were tested. Morphologies of the as-prepared PGSR and G-PGSR were observed by scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FT-IR).

Nitrogen addition increases the ecological and human health risks of PAHs in different fractions of soil in sewage-irrigated area.

Nitrogen (N) is one of the most important nutrients required by soil and crops. N addition improves soil quality and fertility. However, long-term N addition changes the soil environment, which may affect the adsorption and accumulation of organic pollutants in soil.

Ferrous oxalate covered ZVI through ball-milling for enhanced catalytic oxidation of organic contaminants with persulfate.

Zero-valent iron (ZVI), with high reduction capacity and cost effectiveness, has been widely used as an activator for persulfate in remediation of organic pollutants. However, the existence of inherent iron oxide shell blocked the transfer of proton and further reduced its reactivity. In present study, a novel persulfate (PS) activator BZVI@OA was synthesized via ball milling ZVI with oxalic acid dihydrate.

Microwave-assisted functionalization of PAN fiber by 2-amino-5-mercapto-1,3,4-thiadiazol with high efficacy for improved and selective removal of Hg from water.

Mercury (Hg) contamination in water is associated with potential toxicity to human health and ecosystems. Many research studies have been ongoing to develop new materials for the remediation of Hg pollution in water. In this study, a novel thiol- and amino-containing fibrous adsorbent was prepared by grafting 2-amino-5-mercapto-1,3,4-thiadiazol (AMTD) onto PAN fiber through a microwave-assisted method.

[Different Responses of Soil Microbial Community Structure to Irrigation with Treated Wastewater from Domestic and Industrial Sources].

To investigate the long-term effects of irrigation with treated domestic and industrial wastewater on the microbial community structure of the soil, Illumina MiSeq high-throughput sequencing technology was applied. Groundwater irrigated soil was used as a control. The effects of soil environmental factors and their interactions on the microbial community structure were investigated.

Hydrogeochemical and statistical analysis of high fluoride groundwater in northern China.

Understanding the formation of high fluoride (F) groundwater in water-scarce northern China is critical for the sustainable development of the region. This study investigates the effects of F enrichment in groundwater from seven typical regions of northern China, including Datong, Guide, Junggar, Yinchuan, Taiyuan, and Tarim basins and the North China Plain. A literature survey of 534 samples of selected regions showed that 45.

A comparative study on the treatment of 2,4-dinitrotoluene contaminated groundwater in the combined system: efficiencies, intermediates and mechanisms.

In this study, scrap irons (SI)/granular activated carbons (GAC) micro-electrolysis treatment and persulfate-releasing materials (PRM) treatment were employed to construct the combination reduction and oxidation system to treat 2,4-dinitrotoluene (2,4-DNT) contaminated groundwater. The 2,4-DNT treatment efficiencies in the PRM pre-treatment before SI/GAC micro-electrolysis treatment (FM-1 = PRM + SI/GAC) and SI/GAC micro-electrolysis pre-treatment before the PRM treatment (FM-3 = SI/GAC + PRM) were investigated in two separated columns. As control groups, the separated SI and GAC instead of the SI/GAC mixture were used in another two separated columns (FM-2 = PRM + SI + GAC; FM-4 = SI + GAC + PRM).

Groundwater nitrate pollution risk assessment of the groundwater source field based on the integrated numerical simulations in the unsaturated zone and saturated aquifer.

Groundwater pollution risk assessment in the groundwater source field (GSF) is crucial to ensure groundwater quality safety. A systematic method of assessing groundwater pollution in the GSF was established by combining the numerical models of groundwater flow and solute transport in the vadose zone and aquifer. It is featured by revealing the paramount fate of contaminant from the surface to receptor "well (wells)" via the pathway of vadose zone and aquifers.

Groundwater pollution early warning based on QTR model for regional risk management: A case study in Luoyang city, China.

Groundwater pollution early warning has been regarded as an effective tool for regional groundwater pollution prevention, especially in China. In this study, the systemic model was established to assess the groundwater pollution early warning by integrating the present situation of groundwater quality (Q), groundwater quality trend (T) and groundwater pollution risk (R). The model integrated spatial and temporal variation of groundwater quality, and combined the state and process of the groundwater pollution.

Distribution, formation and human-induced evolution of geogenic contaminated groundwater in China: A review.

The sustainability of groundwater usage faces quality problem caused by anthropogenic activity as well as geogenic contamination. With varied climate zones, geomorphology and geological background, China faces a variety of geogenic contaminated groundwater (GCG) reported known as high TDS, Fe, Mn, As, F, I, NH, U, Cr and low I, Se, etc., may still exist some others not fully known yet.

Dechlorination of Excess Trichloroethene by Bimetallic and Sulfidated Nanoscale Zero-Valent Iron.

Nanoscale zerovalent iron (nZVI) likely finds its application in source zone remediation. Two approaches to modify nZVI have been reported: bimetal (Fe-Me) and sulfidated nZVI (S-nZVI). However, previous research has primarily focused on enhancing particle reactivity with these two modifications under more plume-like conditions.

Raw hematite based Fe(III) bio-reduction process for humified landfill leachate treatment.

Microorganisms from paddy soils and raw hematite are used for enhancing natural Fe(III) bio-reduction, in order to remove macromolecular organic pollutants from humified landfill leachate. Based on batch experiments, 60% of refractory organics can be adsorbed by hematite in 12 days. In the presence of Fe(III)-reducing bacteria, 489.