Hao Zhang

• PhD
• Lancaster University

Cs-137 is the most released fission product in the marine environment. It is important to develop a robust in situ technique for its monitoring. The existing diffusive gradients in thin films (DGT) passive sampling techniques for in situ measurement of Cs+ have some limitations due to the ion competition and high pH of seawater. A new DGT sampler b...

The MONITOOL project (2017–2023) was carried out to describe the relationships between total dissolved and labile metal concentrations measured in spot water samples and in concurrently deployed Diffusive Gradients in Thin-films (DGTs) passive samplers, respectively. The ultimate aim was to adapt existing marine metal Environmental Quality Standard...

Mercury (Hg) is a global environmental concern that affects both humans and ecosystem. The comprehensive understanding of sources and dynamics is crucial for facilitating targeted and effective control strategies. Herein, a robust approach integrating Multivariate Statistics, Geostatistics, and Positive Matrix Factorization (PMF) was employed to qu...

Contaminated soil and groundwater can pose significant risks to human health and ecological environments, making the remediation of contaminated sites a pressing and sustained challenge. It is significant to identify key performance indicators and advance environmental management standards of contaminated sites. The traditional study currently focu...

Sensitivity analysis is a valuable method for evaluating the impact of model parameters on health risk characterization, thereby supporting the prediction of critical uncertainty factors. However, limitations arise in terms of cross-disciplinary discussions and in-depth analyses of previous research. To overcome these limitations, a systematic and...

Integrative passive samplers, such as DGT (Diffusive Gradients in Thin-films), are identified in European Technical Guidance Documents as promising tools to improve the quality of the assessment, in the context of the WFD (EU Water Framework Directive). However, DGT results cannot yet be used directly in a regulatory framework to assess the chemica...

Dear colleagues and friends, The book of abstract for DGT2023 is available now. Best regards, Dr. Josselin Gorny, Dr. Laureline Février and Pr. Hao Zhang

Heavy metal contaminations may cause severe toxic impacts to ecological systems and human health. Measurements of metals' bioavailable concentrations and toxicities simultaneously and in-situ in environments can advance the understanding of their hazardous effects. The diffusive gradients in thin-films (DGT) is an in-situ technique can measure meta...

Environmental context Monitoring uranium concentrations and speciation in aquatic systems is important for pollution control and for environmental studies. Although an in situ speciation technique based on diffusion and uptake of uranium has been developed, known as DGT, there were uncertainties over some parameters affecting the accuracy of the me...

The potential environmental risks of glucocorticoids (GCs) have attracted attention in the past few decades. In this study, a novel diffusive gradients in thin-films (DGT) device and analytical technique based on the second generation of polar enhanced phase (PEP-2), PEP-2-DGT, were developed for sampling and quantifying natural and synthetic GCs i...

It is important to identify key performance and core progress features of soil contamination management practices. Traditional research currently focuses on numerical statistics of contaminated sites but exhibits structural limitations regarding cross-assessment and in-depth analysis of published findings. Herein, we report a multidimensional persp...

[Please note that the article can be freely downloaded from https://authors.elsevier.com/c/1fW0wB8ccuoOJ before September 20, 2022 ] In order to move forward in the acceptance of a novel contaminant monitoring technique (Diffusive Gradients in Thin-films: DGT) for assessment of marine water bodies, sensu the WFD, an Inter-Laboratories Comparison (I...

Please note that the article and supplementary material can be freely downloaded from : https://doi.org/10.1016/j.marpolbul.2022.113715 This study investigates the relationships among Ni, Cd and Pb's different chemical forms determined by different methodologies in coastal and transitional waters across a broad geographical scale. Concentrations w...

The extraction of uranium from seawater has been successfully performed in batch mode on 15 selected biomaterials, including fruit, green vegetable and tuber samples. Theses biomaterial samples were contacted in static batches with Irish seawater (2.8 ppb U) for periods of 1–2 months. After sorption, both supernatants and HNO3 digests from the sorb...

Arsenic (As) has been observed to co-exist with atrazine (ATR) in soils worldwide. ATR, as an organic chemical, may affect the availability of As and further influence its uptake by organisms. Here we used a novel passive sampling technique, DGT (diffusive gradients in thin-films), to compare with other two conventional sampling approaches (soil so...

By facile controllable preparation, as-synthesized NTO and KTO exhibit remarkable electrochemical behavior for the applications of supercapacitors and capacitive deionization.

Linking chromium (Cr) speciation with its stability in soils is vital because insoluble Cr(VI) and chemical adsorbed Cr(VI) could hinder the remediation efficiency and release Cr(VI) for a prolonged period of time. In this study, we investigated key Cr species to probe the mechanisms controlling the release of insoluble Cr(VI) at Cr-contaminated si...

This protocol was developed based on the knowledge acquired in the framework of the Interreg MONITOOL project (EAPA_565/2016) where extensive sampling campaigns were performed in transitional and coastal waters covering eight European countries. It provides detailed procedures and guidelines for the sampling of these waterbodies by concurrent colle...

This good practice guide is focused on the DGT devices, which are the most widely used passive sampler for metals, covering the following aspects: ■ Principle ■ Handling passive sampling devices for metals ■ Estimation of appropriate field deployment time ■ A Good Practice Guide for the Use of DGTs ■ Passive sampling device preparation and assembly...

Sustainable approaches to rice cultivation that apply less irrigation and chemical fertilisers are required to increase crop resource use efficiency. Although alternate wetting and drying (AWD) has been widely promoted as a water-saving irrigation technique, its interactions with phosphorus (P) nutrition have attracted little attention. Vegetative...

: Sustainable approaches to rice cultivation that apply less irrigation and chemical fertilisers are required to increase crop resource use efficiency. Although alternate wetting and drying (AWD) has been widely promoted as a water-saving irrigation technique, its interactions with phosphorus (P) nutrition have attracted little attention. Vegetativ...

Dissolved organic matter (DOM) can play a major role in determining availability of pollutants to aquatic biota. Equilibrium dialysis is the most commonly used method to assess the interaction between DOM and organic contaminants. However, results obtained through this method can be affected by confounding factors linked to the diffusion of DOM thr...

This document provides guidance on best practice for the use of Diffusive Gradient in Thin films (DGT) passive samplers devices in sampling of transitional and coastal waters for water quality monitoring. The methodology to be addressed in this guide was developed by the consortium of the European Union's Interreg MONITOOL Project in order to ensur...

A major gap in understanding nanomaterials behaviour in the environment is a lack of reliable tools to measure their available concentrations. In this research we use diffusive gradients in thin films (DGT) for measuring concentrations of zinc oxide nanoparticles (ZNO NPs) in soils. Available nanoparticle concentrations were assessed by difference,...

Oil spillages lead to the formation of hydrocarbon and metal mixtures possessing effects on alkane-degrading bacteria that are responsible for the bioremediation of oil-contaminated soils and waters. Studies of bacterial responses to the mixture of petroleum and metal can inform appropriate strategies for bioremediation. We employed a luminescent b...

Carbon-based materials are important desirable materials in areas such as supercapacitors and capacitive deionization. However, traditional commercial materials are heterogeneous and prone to agglomeration in nanoscale and have structural limitation of electrochemical and desalination performance due to poor transport channels and low capacitance o...

The current study evaluates the effect of seawater physico-chemical characteristics on the relationship between the concentration of metals measured by Diffusive Gradients in Thin films (DGT) passive samplers (i.e., DGT-labile concentration) and the concentrations measured in discrete water samples. Accordingly, Inductively Coupled Plasma Mass Spec...

Information on how key environmental conditions such as natural dissolved organic matter (DOM) and water pH alter the possible risks posed by pharmaceuticals (PPCPs) is still scarce. In our previous study, the presence of natural DOM at high pH reduced the toxicity of a mix of waterborne PPCPs to algae. DOM-complexation and pH effect on speciation...

Ecological memory (EM) recognizes the importance of previous stress encounters in promoting community tolerance and thereby enhances ecosystem stability, provided that gained tolerances are preserved during non-stress periods. Drawing from this concept, we hypothesized that the recruitment of tolerant species can be facilitated by imposing an initi...

We report the complex spatial and temporal dynamics of hyporheic exchange flows (HEFs) and nitrogen exchange in an upwelling reach of a 200 m groundwater‐fed river. We show how research combining hydrological measurement, geophysics and isotopes, with nutrient speciation techniques provides insight on nitrogen pathways and transformations that coul...

Extensive and long-term use of per- and polyfluoroalkyl substances (PFASs) has caused their widespread distribution in aquatic systems. A new diffusive gradients in thin-films (DGT) passive sampling method based on weak anion exchanger (WAX) binding layer is developed here for monitoring five perfluoroalkyl carboxylic acids (PFCAs), five perfluoroa...

Biogeochemical gradient forms in vadose zone, yet little is known about the assembly processes of microbial communities in this zone under petroleum disturbance. This study collected vadose zone soils at three sites with 0, 5, and 30 years of petroleum contamination to unravel the vertical microbial community successions and their assembly mechanis...

The occurrence of endocrine disrupting chemicals (EDCs) in the aquatic environment is a global concern. In this study, we employed two different passive samplers Diffusive Gradients in Thin-films (DGT) and Chemcatcher for in situ measurement of 8 phenolic EDCs in the East River of the Pearl River system over one-year. These data were assessed along...

The diffusive gradients in thin films (DGT) is an in situ passive sampling technique that confronts many of the challenges associated with current sampling methods used for emerging contaminants in aquatic systems. This study combined the DGT technique and traditional grab sampling to explore the sources and environmental fate of emerging contamina...

Sustainable approaches to rice cultivation that apply less irrigation and chemical fertilisers are required to increase crop resource use efficiency. Although alternate wetting and drying (AWD) has been widely promoted as a water-saving irrigation technique, its interactions with phosphorus (P) nutrition have attracted little attention. Vegetative...

The diffusive gradients in thin films (DGT) passive sampling technique has been increasingly used to provide time-weighted average concentrations of the bio-relevant fraction of organic contaminants in waters, with high spatial and temporal resolutions at low cost. This study investigated the effects of biofouling and compound degradation/loss duri...

Fungi-associated phytoremediation is an environmentally friendly and cost-efficient approach to removal potential toxic elements (PTEs) from contaminated soils. Many fungal strains have been reported to possess PTE-biosorption behaviour which benefits phytoremediation performance. Nevertheless, most studies are limited in rich or defined medium, fa...

Trace element behavior in flooded/lowland rice soils, is controlled by root-zone iron oxidation. Insoluble iron species bind/capture toxic elements, i.e. arsenic. However, it was recently observed that within this territory of arsenic immobilization lies a zone of prolific iron release, accompanied by a significant flux of arsenic in close proximit...

Studying nanomaterials' ecotoxicology is not new but there are still gaps in our understanding of their fate in the environment. A major challenge is lack of reliable tools to measure available concentrations of nanoparticles (NPs) in soil and water. Diffusive gradient in thin-films (DGT) is a robust technique for measuring concentration of trace m...

Ferrihydrite has been prevalently used in soil remediation as an effective amendment for in situ immobilization of arsenic (As). However, its poorly crystalline structure is unstable and can pose the risk of re-releasing As into soil. In this study, sequential extraction was coupled with a newly-established method, chelex-metsorb diffusive gradient...

The diffusive gradients in thin films (DGT) passive sampler has emerged as a powerful tool for measuring in situ concentrations of organic contaminants in waters with appropriate spatial and temporal resolution at low cost. This study addresses the property range of compounds which can be routinely sampled with the present design of DGT device. Sor...

Psychiatric pharmaceuticals are widely distributed in the aquatic environment and have attracted recent attention due to their potential for environmental effects. A robust and reliable in situ passive sampling approach, the diffusive gradients in thin-films (DGT) technique, is developed here to measure 14 psychiatric pharmaceuticals. A new binding...

Traditional extraction methods (soil solution and solvent extraction) are simple to use and conventionally employed to assess pesticide chemical form and bioavailability in soils. However, whilst convenient for regulatory testing, it has been suggested that these approaches may be too crude or are poor predictors of bioavailability, due to their ar...

The buffering of phosphorus concentrations in soil solution by the soil solid phase is an important process for providing plant root access to the nutrients. Accordingly, the size of labile solid phase-bound phosphorus pool and the rate at which it can resupply concentrations in the dissolved phase can be important variables in determining when the...

It is essential to monitor pesticides in the environment to help ensure water and soil quality. The diffusive gradients in thin-films (DGT) technique can measure quantitative in-situ labile (available) concentrations of chemicals in water, soil and sediments. This study describes the systematic development of the DGT technique for 9 current pestici...

In seawater, trace metals occur in many forms: free ion, labile and non-labile complex, colloid, associated with particles, but only free ions and very labile metal complexes can cross the phytoplankton membrane and be assimilated. In this paper we review the most appropriate determination methods for those metal species, addressing particularly in...

Although strong in vivo-in vitro correlations (IVIVCs) between relative bioavailability (RBA) and bioaccessibility of soil Pb were well reported, knowledge on the fractions of bioaccessible Pb in simulated gastrointestinal (GI) fluids that are available for absorption into the systemic circulation is limited. Here, Pb-RBA in 14 Pb-contaminated soil...

Phosphorus concentration in soil solution phase (PDET), effective soil phosphorus concentration (PE), and desorption rate constant (k−1) in four soil depths with ruzigrass and different P application rates, in 2014 and 2015.

This study deals with further and systematic laboratory evaluation of the already known ammonium 12-molybdophosphate (AMP)-diffusive gradient in thin film (DGT) method, which is used for measuring total Cs concentration in environmental waters. This study confirms that the AMP-binding gel is not stable for pH > 6. In order to reveal a potential imp...

The use of grasses as cover crops in the off-season of cash crops under no-till has been largely adopted. However, soil phosphorus (P) uptake was previously shown to be reduced when ruzigrass is introduced in the rotation, affecting the viability and sustainability of this cropping system. The objective of this study was to assess the effect of ruz...

Ferrihydrite is commonly used as an amendment to remove or stabilize arsenic (As) in water, soils, and sediments due to its high specific surface area (>200 m²/g). However, its instability under oxic or anoxic conditions sometimes limits its efficiency for arsenic adsorption. This study employed a two-step sequential extraction method and the diffu...

To better understand the environmental impact of ubiquitous perfluoroalkyl substances (PFASs) in waters, reliable and robust measurement techniques are needed. As one of the most widely used passive sampling approaches, diffusive gradients in thin-films (DGT) is not only easy to handle but also provides time-weighted analyte concentrations. Based o...

Tropical grasses grown as cover crops can mobilize phosphorus (P) in soil and have been suggested as a tool to increase soil P cycling and bioavailability. The objective of this study was to evaluate the effect of tropical grasses on soil P dynamics, lability, desorption kinetics and bioavailability to soybean, specifically to test the hypothesis t...

Background Phosphorus (P) fertilizer is usually applied in excess of plant requirement and accumulates in soils due to its strong adsorption, rapid precipitation and immobilisation into unavailable forms including organic moieties. As soils are complex and diverse chemical, biochemical and biological systems, strategies to access recalcitrant soil...

Aims Intercropping can improve plant yields and soil phosphorus (P) use efficiency. This study compares inter- and intra-species intercropping, and determines whether P uptake and shoot biomass accumulation in intercrops are affected by soil P availability. Methods Four barley cultivars (Hordeum vulgare L.) and three legume species (Trifolium subt...

Background The dynamics of phosphorus (P) in the environment is important for regulating nutrient cycles in natural and managed ecosystems and an integral part in assessing biological resilience against environmental change. Organic P (Po) compounds play key roles in biological and ecosystems function in the terrestrial environment being critical t...

The article “Organic phosphorus in the terrestrial environment: a perspective on the state of the art and future priorities”, written by Timothy S George et al., was originally published with incorrect affiliation information for one of the co-authors, E. Klumpp.

The mobility of arsenic (As) in soil depends on its sorption/desorption processes on soil particles. Plant uptake locally lowers As concentration in soil pore water, which would trigger resupplies of As from soil solid phase. To better understand the fate of As in soil system after its inputs into soil and its subsequent dynamic processes, diffusiv...

Changes in soil rhizosphere properties after growing the Cd hyperaccumulator Noccaea caerulescens and the Ni hyperaccumulator Thlaspi goesingense were investigated. Dissolved organic carbon content increased in the rhizosphere, but there were no significant changes in the solution concentrations of Cd and Ni. Concentrations of these metals extracte...

Citrate and phytase root exudates contribute to improved phosphorus (P) acquisition efficiency in Nicotiana tabacum (tobacco) when both exudates are produced in a P deficient soil. To test the importance of root intermingling in the interaction of citrate and phytase exudates, Nicotiana tabacum plant-lines with constitutive expression of heterologo...

A passive water sampler based on the diffusive gradients in thin-films (DGT) technique was developed and tested for 3 groups of endocrine disrupting chemicals (EDCs, including oestrogens, alkyl-phenols and bisphenols). Three different resins (hydrophilic-lipophilic-balanced (HLB), XAD18 and Strata-XL-A (SXLA)) were investigated for their suitabilit...

Chemical elements that are either present naturally in the soil or introduced by pollution are more usefully estimated in terms of "availability" of the element, since it is this property that can be related to mobility and uptake by plants. A good estimate of the immediately available fraction can be achieved by measuring the concentration, or act...

The effect of exogenous phosphate (P, 200 mg⋅kg-1 soil) on the lability and phytoavailability of arsenic (As) was studied using the diffusive gradients in thin films (DGT) technique. Lettuce were grown on the As-amended soils following the stabilization of soil labile As after 90 days incubation. Phosphate (P) application generally facilitated plan...

Widespread use of organic chemicals in household and personal care product (HPCPs) and their discharge into aquatic systems means reliable, robust techniques to monitor environmental concentrations are needed. The passive sampling approach of diffusive gradients in thin-films (DGT) is developed here and demonstrated to provide in situ quantitative...

Zymographic methods for the 2D distribution of phosphatase activity in soils have markedly advanced our understanding of root-soil-microbiota interactions. Robust quantitative approaches for 2D assays, which use 4-methylubelliferyl phosphate (4-MUP), are needed to advance a mechanistic understanding of enzyme behaviour and distribution in soils. We...

Deposition of particulate organic matter (POM) induces diagenetic hot spots at the sediment-water interface (SWI). Here we explore the effects of intensive POM degradation for metal mobilization at the SWI. By using a combined planar optode-DGT (diffusive gradient in thin-films) sensor we obtained simultaneous measurements of dissolved O2 and trace...

DGT (Diffusion Gradients in Thin films) was designed to sample trace metals in situ at their natural concentrations. The set-up and the experimental deployment conditions were established to allow interpretation of a linear accumulation of metal with time using a simple expression based on a steady-state flux under perfect sink conditions. However,...

As the world’s population increases, demands on staple crops like rice (Oryza sativa L.) will also increase, requiring additional fresh water supplies for irrigation of rice fields. Safe alternate wetting and drying (AWD) is a water management technique that is being adopted across a number of countries to reduce the water input for rice cultivatio...

Background and Aims Plant acquisition of endogenous forms of soil phosphorus (P) could reduce external P requirements in agricultural systems. This study investigated the interaction of citrate and phytase exudation in controlling the accumulation of P and depletion of soil organic P by transgenic Nicotiana tabacum plants. Methods N. tabacum plant...

Nitrate (NO3-N), the main plant/microbial nitrogen source, has a fast turnover in soil driven by species transformation (nitrification/denitrification) and phyto/microbiota-assimilation. The technique of diffusive gradients in thin films (DGT) is capable of a robust, low disturbance measurement of NO3-N, but it has not been implemented due to the a...

Root exudation of phytase could improve the ability of plants to access organic forms of soil phosphorus (P), thereby minimizing fertilizer requirements and improving P use efficiency in agroecosystems. After 75 days growth in a high available P soil, shoot biomass and P accumulation, soil pH, and rhizosphere P depletion were investigated in Nicoti...

1. Background and Objectives: Plant growth and productivity depend greatly on water and mineral nutrient availability in the soil and their capture by the roots. It is necessary to better understand how plants cope with combined suboptimal water and mineral nutrient supply to better manage crops (Kudoyarova et al. 2015). Phosphorus is an essential...

The mobility and resupply of inorganic phosphorus (P) from the solid phase were studied in 32 soils from the UK. The combined use of diffusive gradients in thin films (DGT), diffusive equilibration in thin films (DET) and the ‘DGT-induced fluxes in sediments’ model (DIFS) were adapted to explore the basic principles of solid-to-solution P desorptio...

Hexavalent chromium (CrVI) is much more toxic and mobile than the trivalent species (CrIII) and consequently, in situ monitoring of CrVI can improve the understanding of Cr biogeochemistry and toxicity in ecosystems. The passive diffusive gradients in thin-films (DGT) technique is a powerful tool for determining metal(loid) speciation, but a bindin...

Hexavalent chromium (CrVI) is much more toxic and mobile than the trivalent species (CrIII) and consequently, in situ monitoring of CrVI can improve the understanding of Cr biogeochemistry and toxicity in ecosystems. The passive diffusive gradients in thin-films (DGT) technique is a powerful tool for determining metal(loid) speciation, but a bindin...