Combined effects of deltamethrin, temperature and salinity on oxidative stress biomarkers and acetylcholinesterase activity in the black tiger shrimp (Penaeus monodon)

This study aimed to investigate the interactions of two abiotic factors (temperature and salinity) and deltamethrin (pyrethroid pesticide) exposure on some oxidative stress biomarkers as well as on acetylcholinesterase activity (AChE) in hepatopancreas, gills and muscle of black tiger shrimp (Penaeus monodon). A combination of three temperatures (24, 29 and 34 °C), two salinities (15 and 25 ppt), and the absence or presence of 0.1 μg L⁻¹ deltamethrin was applied on shrimp during 4 d under laboratory conditions. Lipid peroxidation level (LPO) and glutathione S-transferase activity (GST) were not affected by combined effect of temperature, salinity and deltamethrin in any of the studied tissues. Deltamethrin impaired other tested oxidative stress biomarkers, i.e. total glutathione (tGSH), catalase (CAT), glutathione peroxidase (GPx). tGSH level significantly increased in hepatopancreas due to deltamethrin exposure mainly at 34 °C, while pesticide effects on tGSH and CAT activity in gills were influenced by both temperature and salinity. In addition, GPx activity in hepatopancreas decreased after deltamethrin treatment mainly at 24 °C. Finally, AChE in muscle was strongly inhibited by deltamethrin at all tested temperatures and salinities. These novel findings demonstrate that interactions between abiotic factors and a commonly used pesticide exposure should be taken into account when analyzing some widespread biomarkers in black tiger shrimp.     

Occurrence and behavior of emerging contaminants in surface water and a restored wetland

Pollution mitigation is an important target for restored wetlands, and although there is much information in relation to nutrient removal, little attention has been paid to emerging contaminants. This paper reports on the occurrence and attenuation capacity of 17 emerging contaminants in a restored wetland and two rivers in North-East Denmark. The compounds belong to the groups of pharmaceuticals, fragrances, antiseptics, fire retardants, pesticides, and plasticizers. Concentrations in surface waters ranged from 2 to 1476 ng L⁻¹. The compounds with the highest concentrations were diclofenac, 2-methyl-4-chlorophenoxyacetic acid (MCPA), caffeine, and tris(2-chloroethyl) phosphate (TCEP). The herbicide concentrations increased after a rain-fall event, demonstrating the agricultural run-off origin of these compounds, whereas the concentration of the other emerging contaminants was rather conservative. The mitigation capacity of the restored wetland for the compounds ranged from no attenuation to 84% attenuation (19% on average). Hence, restored wetlands may be considered as a feasible alternative for mitigating emerging contaminants from river waters.     

Exposure assessment of lead to workers and children in the battery recycling craft village,Dong Mai,Vietnam

Human exposure to lead (Pb) due to uncontrolled Pb-acid battery recycling has been an environmental health issue in newly developed industrial regions. We conducted a human monitoring survey in Dong Mai, a battery recycling village in Vietnam, to assess exposure status to Pb. Lead level was measured in hair, blood and urine samples of residents in Dong Mai and two reference sites during 4 years spanning 2007–2011. In Dong Mai, Pb levels in three matrixes were significantly higher than those in reference sites. Blood Pb levels of all adults and children exceeded 10 μg/dL, the Centers for Disease Control and Prevention definition of an elevated blood Pb level. Clear increase of urinary δ-aminolevulinic acid (ALA) level with increasing blood Pb level indicated disruption of heme synthesis. One adult exceeded 100 μg/dL of blood Pb, where encephalopathy is of concern. The blood Pb levels achieved various toxic effect threshold values, and elevated blood Pb was not limited to recycling workers, but was also in children and women of reproductive age. Serious pollution status of Dong Mai village suggests an importance of further monitoring surveys in various developing Asian countries.     

Simulated Impacts of Climate Change on Current Farming Locations of Striped Catfish (Pangasianodon hypophthalmus; Sauvage) in the Mekong Delta,Vietnam

In Vietnam, culturing striped catfish makes an important contribution to the Mekong Delta’s economy. Water level rise during rainy season and salt intrusion during dry season affect the water exchange and quality for this culture. Sea level rise as a consequence of climate change will worsen these influences. In this study, water level rise and salt water intrusion for three sea level rise (SLR) scenarios (i.e., +30, +50, and +75 cm) were simulated. The results showed that at SLR +50, the 3-m-flood level would spread downstream and threaten farms located in AnGiang, DongThap and CanTho provinces. Rising salinity levels for SLR +75 would reduce the window appropriate for the culture in SocTrang and BenTre provinces, and in TienGiang’s coastal districts. Next to increasing dikes to reduce the impacts, the most tenable and least disruptive option to the farming community would be to shift to a salinity tolerant strain of catfish.     

Arbuscular mycorrhizal fungi enhance both absorption and stabilization of Cd by Alfred stonecrop (Sedum alfredii Hance) and perennial ryegrass (Lolium perenne L.) in a Cd-contaminated acidic soil

A greenhouse pot experiment was conducted to compare the phytoextraction efficiencies of Cd by hyper-accumulating Alfred stonecrop (Sedum alfredii Hance) and fast-growing perennial ryegrass (Lolium perenne L.) from a Cd-contaminated (1.6 mg kg⁻¹) acidic soil, and their responses to the inoculations of two arbuscular mycorrhizal (AM) fungal strains, Glomus caledonium 90036 (Gc) and Glomus mosseae M47V (Gm). Ryegrass and stonecrop were harvested after growing for 9 and 27 wk, respectively. Without AM fungal inoculation, the weekly Cd extraction by stonecrop (8.0 μg pot⁻¹) was 4.3 times higher than that by ryegrass (1.5 μg pot⁻¹). Both Gc and Gm significantly increased (P < 0.05) root mycorrhizal colonization rates, soil acid phosphatase activities, and available P concentrations, and thereby plant P absorptions (except for Gm-inoculated ryegrass), shoot biomasses, and Cd absorptions (except for Gm-inoculated stonecrop), while only Gc-inoculated stonecrop significantly accelerated (P < 0.05) the phytoextraction efficiency of Cd by 78%. In addition, both Gc and Gm significantly decreased (P < 0.05) phytoavailable Cd concentrations by 21–38% via elevating soil pH. The results suggested the potential application of hyper-accumulating Alfred stonecrop associated with AM fungi (notably Gc) for both extraction and stabilization of Cd in the in situ treatment of Cd-contaminated acidic soil.     

Chromate reduction on humic acid derived from a peat soil--exploration of the activated sites on HAs for chromate removal

Humic substances are a major component of soil organic matter that influence the behavior and fate of heavy metals such as Cr(VI), a toxic and carcinogenic element. In the study, a repetitive extraction technique was used to fractionate humic acids (HAs) from a peat soil into three fractions (denoted as F1, F2, and F3), and the relative importance of O-containing aromatic and aliphatic domains in humic substances for scavenging Cr(VI) was addressed at pH 1. Spectroscopic analyses indicated that the concentrations of aromatic C and O-containing functional groups decreased with a progressive extraction as follows: F1>F2>F3. Cr(VI) removal by HA proceeded slowly, but it was enhanced when light was applied due to the production of efficient reductants, such as superoxide radical and H(2)O(2), for Cr(VI). Higher aromatic- and O-containing F1 fraction exhibited a greater efficiency for Cr(VI) reduction (with a removal rate of ca. 2.89 mmol g(-1) HA under illumination for 3 h). (13)C NMR and FTIR spectra further demonstrated that the carboxyl groups were primarily responsible for Cr(VI) reduction. This study implied the mobility and fate of Cr(VI) would be greatly inhibited in the environments containing such organic groups.     

TiO2/β-SiC foam-structured photoreactor for continuous wastewater treatment

Introduction

This study of photocatalytic degradation of wastewater was carried out in alveolar cell ??-SiC foam-structured photocatalytic reactors working in a recirculation mode. The immobilization of TiO2 on ??-SiC foams was efficiently obtained through a sol?Cgel technique in acidic conditions.

Discussion

In order to optimize degradation yields obtained by the foam-structured prototype reactor for the photocatalytic water treatment, the operating conditions of the photoreactor have been investigated and the efficiency of the process was evaluated by measuring the photocatalytic degradation of Diuron (3-(3,4-dichlorophenyl)-1,1-dimethyl-urea)) under UV irradiation. Kinetic studies were carried out by investigating the influence of different parameters controlling the reaction (TiO2 loading and ??-SiC foam cell size). The ageing of TiO2/??-SiC foam photocatalytic materials and the mineralization (TOC, Cl?, NO3? and NH4+) of Diuron were investigated.     

铁阳极电化学对直接大红4BE模拟废水脱色

对铁阳极电化学处理直接大红4BE染料废水脱色率和脱色能耗的影响因素进行研究。考察了电流密度、染料溶液初始pH值、染料初始浓度和支持电解质Na2SO4浓度对脱色性能的影响。结果表明,电流密度、染料废水初始pH、染料初始浓度、支持电解质浓度对脱色率和脱色能耗产生较大影响。在电流密度1.667 mA/cm2、pH值6.54、染料浓度50mg/L、Na2SO4浓度0.01 mol/L、温度20℃、搅拌速度600 r/min、电解时间60 min条件下,脱色率达到92.1%,脱色能耗1.298 kWh/kg染料、铁阳极消耗量41 mg/400 mL染料模拟废水。     

The efficacy and cytotoxicity of iron oxide-carbon black composites for liquid-phase toluene oxidation by persulfate

Environmental Science and Pollution Research - This study evaluated the oxidation of toluene (TOL) by persulfate (PS) in aqueous solution in the presence of a Fe3O4-carbon black (CB) composite...     

Influence of soil conditions on dissolved organic matter leached from forest and wetland soils: a controlled growth chamber study

This study investigated the effects of various soil conditions, including drying-rewetting, nitrogen deposition, and temperature rise, on the quantities and the composition of dissolved organic matter leached from forest and wetland soils. A set of forest and wetland soils with and without the nitrogen deposition were incubated in the growth chambers under three different temperatures. The moisture contents were kept constant, except for two-week drying intervals. Comparisons between the original and the treated samples revealed that drying-rewetting was a crucial environmental factor driving changes in the amount of dissolved organic carbon (DOC). The DOC was also notably increased by the nitrogen deposition to the dry forest soil and was affected by the temperature of the dry wetland soil. A parallel factor (PARAFAC) analysis identified three sub-fractions of the fluorescent dissolved organic matter (FDOM) from the fluorescence excitation–emission matrices (EEMs), and their compositions depended on drying-rewetting. The data as a whole, including the DOC and PARAFAC components and other optical indices, were possibly explained by the two main variables, which were closely related with the PARAFAC components and DOC based on principal component analysis (PCA). Our results suggested that the DOC and PARAFAC component information could provide a comprehensive interpretation of the changes in the soil-leached DOM in response to the different environmental conditions.