Tetrabromobisphenol A (TBBPA) is currently the most widely used brominated flame retardant (BFR). To date, the toxic effects of TBBPA remains poorly understood in aquatic organisms, especially in bivalves. The objective of this experiment was to examine bioaccumulation and multibiomarker responses in the scallop Chlamys farreri exposed to TBBPA under laboratory conditions. The results showed that TBBPA was rapidly accumulated in and then eliminated from the gill and digestive gland of the scallops. TBBPA exposure invoked alterations in the detoxification system and induced oxidant stress and biomacromolecule damages in the gill and digestive gland of C. farreri. Additionally, glutathione-S-transferase (GST) activity, lipid peroxidation (LPO) level, cytochrome b5 (Cyt b5) content, and DNA strand break had good correlations with TBBPA accumulation levels in the gill and digestive gland of C. farreri. Summarizing, these results enabled us to hypothesize several toxic mechanisms of TBBPA and select potential biomarkers for TBBPA pollution monitoring.

The residues of organochlorine pesticides (OCPs) in 29 pine needle samples of typical regions (including Shihezi, Beitun, and Kanas) in Northern Xinjiang was determined with a gas chromatograph equipped with an electron capture detector. Total OCPs concentrations in pine needles ranged from 2.94 to 186 ng/g dry weight, with a mean concentration of 39.63 ng/g. The results indicated that Beitun was the most polluted region while Kanas was the least polluted one. Hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) were the predominant species in samples. Analysis of the sources of contamination showed that HCHs in the needles were derived from an old mixed source of technical HCHs or lindane. For DDTs, it was suspected to have recent application at some sites, which were derived mainly from a mixture of technical DDTs and dicofol containing DDT impurities. Categorical principal component analysis was performed in finding out more about the degradation behavior of DDTs and HCHs, which was identical with the results of source analysis.

New, sustainable, and low-cost materials that can simultaneously remove a range of wastewater contaminants, such as heavy metals and pharmaceutical residues, are needed. In this work, modified biochars were produced by dip-coating hickory or bagasse biomass in carbon nanotube (CNT) suspensions with or without sodium dodecylbenzenesulfonate (SDBS)-aided dispersion prior to slow pyrolysis in a N₂ environment at 600 °C. The sulfapyridine (SPY) and lead (Pb) sorption ability of pristine hickory (HC) and bagasse (BC) biochars and the modified biochars with (HC-SDBS-CNT and BC-SDBS-CNT, respectively) and without (HC-CNT and BC-CNT) SDBS was assessed in laboratory aqueous batch single- and binary-solute system. The greatest removal of SPY and Pb was observed for HC-SDBS-CNT (86 % SPY and 71 % Pb) and BC-SDBS-CNT (56 % SPY and 53 % Pb), whereas HC-CNT, BC-CNT, and the pristine biochars removed far less. This can be attributed to the fact that surfactant could prevent the aggregation of CNTs and thus promote the distribution and stabilization of individual CNT nanoparticle on the biochar surface to adsorb the contaminants. The observation of no significant change in Pb sorption capacities of the surfactant-dispersed CNT-modified biochars in the presence of SPY, or vice versa, was indicative of site-specific sorption interactions and a lack of significant competition for functional groups by the two sorbates. These results suggest that products of hybrid technologies, such as biochars modified with CNTs, can yield multi-sorbents and may hold excellent promise as a sustainable wastewater treatment alternative.

Arsenic (As) is recognized as a toxic pollutant in soils of many countries. Since phosphorus (P) and sulphur (S) can influence arsenic mobility and bioavailability, as well as the plant tolerance to As, phytoremediation techniques employed to clean-up As-contaminated areas should consider the interaction between As and these two nutrients. In this study, the bioavailability and accumulation of arsenate in the species Brassica juncea were compared between soil system and hydroponics in relation to P and S concentration of the growth substrate. In one case, plants were grown in pots filled with soil containing 878 mg As kg⁻¹. The addition of P to soil resulted in increased As desorption and significantly higher As accumulation in plants, with no effect on growth. The absence of toxic effects on plants was likely due to high S in soil, which could efficiently mitigate metal toxicity. In the hydroponic experiment, plants were grown with different combinations of As (0 or 100 μM) and P (56 or 112 μM). S at 400 μM was also added to the nutrient solution of control (−As) and As-treated plants, either individually or in combination with P. The addition of P reduced As uptake by plants, while high S resulted in higher As accumulation and lower P content. These results suggest that S can influence the interaction between P and As for the uptake by plants. The combined increase of P and S in the nutrient solution did not lead to higher accumulation of As, but enhanced As translocation from the root to the shoot. This aspect is of relevance for the phytoremediation of As-contaminated sites.

Apart from the conventional polyethylene and the bio-based or mainly bio-based biodegradable in soil mulching films, polyethylene mulching films of controlled degradation in soil are already used in agriculture. The use of special pro-oxidants as additives is expected to accelerate the abiotic oxidation and the subsequent chain scission of the polymer under specific UV radiation or thermal degradation conditions, according to the literature. The role of pro-oxidants in the possible biodegradation of polyethylene has been theoretically supported through the use of controlled laboratory conditions. However, results obtained in real soil conditions, but also several laboratory test results, are not supporting these claims and the issue remains disputed. Mulching films made of linear low-density polyethylene (LLDPE) with pro-oxidants, after being used for one cultivation period in an experimental field with watermelon cultivation, were buried in the soil under real field conditions. This work presents the analysis of the degradation of the mulching films during the cultivation period as compared to the corresponding changes after a long soil burial period of 8.5 years. The combined effects of critical factors on the photochemical degradation of the degradable mulching LLDPE films with pro-oxidants under the cultivation conditions and their subsequent further degradation behaviour in the soil are analysed by testing their mechanical properties and through spectroscopic and thermal analysis.

Previous research has revealed that agricultural intensification in the Chao Lake Valley since the 1980s has led to significant heavy metal and phosphorus (P) contamination of estuarine sediments in this region. However, the pore water plays a more important role than do sediments in the cycling of nutrients and metals in estuarine ecosystems. Average concentrations of Cd, Cr, Ni, Pb, and P in the pore water of estuarine sediments were 0.634, 3.11, 4.98, 3.98, and 49.9 μg L⁻¹, respectively. Average diffusive fluxes of these elements from the pore water to overlying water were −0.015, 0.058, 0.768, −0.238, and 20.0 μg m⁻² d⁻¹, respectively. Compared with similar studies, the values of heavy metal fluxes were low, indicating minimal diffusion between sediments and overlying waters; however, P diffusion from the sediment pore water to overlying water was high, indicating that the sediments may be a direct source of P to overlying water. Since P is a major cause of algal blooming in agricultural estuaries of Chao Lake, the obtained results could be useful in developing effective management strategies to control pollution in the Chao Lake Valley.

The oxidation of diclofenac (DCF), a non-steroidal anti-inflammatory drug and emerging water pollutant, with chlorine dioxide was investigated under simulated water disinfection conditions. The reaction kinetics as functions of the initial concentrations of DCF, different nitrogenous species, and different pE values were experimentally determined. The results demonstrated that DCF reacted rapidly with ClO₂, where more than 75 % of DCF (≤3.00 μM) was removed by 18.94 μM ClO₂ within 60 s. All of the reactions followed pseudo first-order kinetics with respect to DCF, and the rate constant, k ₒbₛ, exhibited a significant decrease from 4.21 × 10⁻² to 8.09 × 10⁻³ s⁻¹, as the initial DCF concentration was increased from 1.00 to 5.00 μM. Furthermore, the degradation kinetics of DCF was clearly dependent on nitrogen-containing ion concentrations in the reaction solution. Ammonium and nitrite ions inhibited the DCF degradation by ClO₂, whereas nitrate ion clearly initiated its promotion. In contrast, the inhibitory effect of NO₂ ⁻ was more robust than that of NH₄ ⁺. When the values of pE were gradually increased, the transformation of NH₄ ⁺ to NO₂ ⁻, and subsequently to NO₃ ⁻, would occur, the rate constants were initially decreased, and then increased. When NH₄ ⁺ and NO₂ ⁻ coexisted, the inhibitory effect on the DCF degradation was less than the sum of the partial inhibitory effect. However, when NO₂ ⁻ and NO₃ ⁻ coexisted, the actual inhibition rate was greater than the theoretical estimate. These results indicated that the interaction of NH₄ ⁺ and NO₂ ⁻ was antagonistic, while the coexistence of NO₂ ⁻ and NO₃ ⁻ was observed to have a synergistic effect in aqueous environments.

Mining activities result in extensive soil degradation by removing the top soil, disturbing soil structure and altering microbial communities. Rehabilitation of spent mine sites through revegetation thus requires proper soil amendments. In this study, a pot trial was conducted to investigate the effects of a jarrah biochar on the growth and nutrient status of a native legume, Acacia tetragonophylla, grown in a mixture of topsoil and mine rejects. Two biochar application rates (37 and 74 t ha⁻¹) and two types of biochar, namely nutrient-enriched and non-enriched, were tested. We measured the soil pH and electrical conductivity, the carbon (C) and nitrogen (N) contents and C and N isotope composition (δ¹³C and δ¹⁵N) of soil and plants, the foliar phosphorus content and the growth and leaf biomass of the plants. Whilst no significant effect of biochar was observed on plant growth, biochar amendment affected soil properties and plant nutritional status. The highest rate of biochar application increased soil pH, C content and C/N ratio, and decreased soil δ¹³C. Biochar application also enhanced photosynthetic N use efficiency, as showed by the increase in foliar C/N ratio, and biological N fixation rates, as indicated by foliar δ¹⁵N. These positive effects were not observed when biochar was nutrient-enriched due to the associated increase in soil N. Revegetation of mine sites with acacia in combination with biochar amendment constitutes a plausible alternative to the wide use of N fertiliser through the supply of additional N to the system, even though other nutrients may be required in order to enhance plant early growth.

Phthalates may be present in food due to their widespread presence as environmental contaminants or due to migration from food contact materials. Exposure to phthalates is considered to be potentially harmful to human health as well. Therefore, determining the main source of exposure is an important issue. So, the purpose of this study was (1) to measure the release of diethyl phthalate (DEP) in bottled water consumed in common storage conditions specially low temperature and freezing conditions; (2) to evaluate the intake of DEP from polyethylene terephthalate (PET) bottled water and health risk assessment; and (3) to assess the contribution of the bottled water to the DEP intake against the tolerable daily intake (TDI) values. DEP migration was investigated in six brands of PET-bottled water under different storage conditions room temperature, refrigerator temperature, freezing conditions (40 °C ,0 °C and −18 °C) and outdoor] at various time intervals by magnetic solid extraction (MSPE) using gas chromatography–mass spectroscopy (GC-MS). Eventually, a health risk assessment was conducted and the margin of exposure (MOE) was calculated. The results indicate that contact time with packaging and storage temperatures caused DEP to be released into water from PET bottles. But, when comprising the DEP concentration with initial level, the results demonstrated that the release of phthalates were not substantial in all storage conditions especially at low temperatures (<25 °C) and freezing conditions. The daily intake of DEP from bottled water was much lower than the reference value. However, the lowest MOE was estimated for high water consumers (preschooler > children > lactating women > teenagers > adults > pregnant women), but in all target groups, the MOE was much higher than 1000, thus, low risk is implied. Consequently, PET-bottled water is not a major source of human exposure to DEP and from this perspective is safe for consumption.

Drought and salinity are the main abiotic stresses limiting crop yield and quality worldwide. Improving food production in drought- and salt-prone areas is the key to meet the increasing food demands in near future. It has been widely reported that silicon (Si), a second most abundant element in soil, could reduce drought and salt stress in plants. Here, we reviewed the emerging role of Si in enhancing drought and salt tolerance in plants and highlighted the mechanisms through which Si could alleviate both drought and salt stress in plants. Silicon application increased plant growth, biomass, photosynthetic pigments, straw and grain yield, and quality under either drought or salt stress. Under both salt and drought stress, the key mechanisms evoked are nutrient elements homeostasis, modification of gas exchange attributes, osmotic adjustment, regulating the synthesis of compatible solutes, stimulation of antioxidant enzymes, and gene expression in plants. In addition, Si application decreased Na⁺ uptake and translocation while increased K⁺ uptake and translocation under salt stress. However, these mechanisms vary with plant species, genotype, growth conditions, duration of stress imposed, and so on. This review article highlights the potential for improving plant resistance to drought and salt stress by Si application and provides a theoretical basis for application of Si in saline soils and arid and semiarid regions worldwide. This review article also highlights the future research needs about the role of Si under drought stress and in saline soils.