Influence of Pseudomonas aeruginosa-based biopolymer on mitigating soil erosion and heavy metal dispersion.

Extreme weather phenomena caused by climate change have exacerbated soil erosion and the subsequent dispersion of pollutants. Pseudomonas aeruginosa is known to contribute to the remediation of polluted water and reduce the geochemical mobility of heavy metals in contaminated soil. However, studies on the influence of biopolymers produced by soil microbes and P.

Two-dimensional reactive transport model as a new approach for identifying the origins and contribution of arsenic in a soil and water system.

Distribution of arsenic (As) in the environment can occur through various paths, depending on the interrelationship between soil and surface water, and groundwater. This study aimed to identify the origins and pathways of As among various potential origins in soil and water systems using two-dimensional reactive transport models (2D RTMs) and to evaluate the contribution of each origin to the geochemical distribution of As in the study area, which included a reservoir, two streams, and two abandoned mines. The 2D RTMs were prepared by combining hydraulic and geochemical reactive models.

Potential of indigenous bacteria driven U(VI) reduction under relevant deep geological repository (DGR) conditions.

Understanding the biogeochemical U redox processes is crucial for controlling U mobility and toxicity under conditions relevant to deep geological repositories (DGRs). In this study, we examined the microbial reduction of aqueous hexavalent uranium U(VI) [U(VI)] by indigenous bacteria in U-contaminated groundwater. Three indigenous bacteria obtained from granitic groundwater at depths of 44-60 m (S1), 92-116 m (S2), and 234-244 m (S3) were used in U(VI) bioreduction experiments.

Discrimination methods for diesel origin by analyzing fatty acid methyl ester (FAME) composition in diesel-contaminated soil.

The biodiesel containing fatty acid methyl esters (FAMEs) are blended with refined diesel products. Here, we evaluate relative FAME composition ratio as a potential index to discriminate the pollution origin in diesel-contaminated soil. Artificially contaminated soil was prepared to mimic the release of petroleum products using four different refined diesels; in addition, the contaminated soil was put under natural weathering conditions.

Comparison of five extraction methods for evaluating cadmium and zinc immobilization in soil.

The remediation of soil contaminated with heavy metals is an ongoing environmental concern. Paddy soils contaminated with Cd and Zn were collected from around abandoned metals mines in Korea. Limestone and steel slag were mixed with the collected soil, as amendments for Cd and Zn immobilization.

Assessment and source identification of As and Cd contamination in soil and plants in the vicinity of the Nui Phao Mine, Vietnam.

This study investigated the contamination levels and sources of As and Cd vicinity area from Nui Phao mine that is one of the largest tungsten (W) open pit mines in the world. Soil and plant samples were collected from the study area to identify the concentrations of As and Cd using aqua-regia or HNO digestion. According to the Vietnamese agricultural soil criteria, all soil samples were contaminated with As and Cd.

Human health risk assessment of cadmium exposure through rice consumption in cadmium-contaminated areas of the Mae Tao sub-district, Tak, Thailand.

The Mae Tao sub-district is located in the Mae Tao watershed, an important cadmium (Cd)-contaminated area in Thailand. This study was conducted to (i) determine Cd concentrations in rice collected from households in the area, (ii) assess the Cd exposure and potential health risk (HQ) from rice consumption in local adults and (iii) investigate how the factors of individual characteristics and consumption behavior affect the level of HQ. A total of 159 rice samples were collected from households in all 6 villages of the Mae Tao sub-district for analysis of Cd by inductively coupled plasma mass spectrometry.

Reductive dissolution and sequestration of arsenic by microbial iron and thiosulfate reduction.

Iron oxide and oxy-hydroxide are commonly used for remediation and rehabilitation of arsenic (As)-contaminated soil and water. However, the stability of As sequestered by iron oxide and oxy-hydroxide under anaerobic conditions is still uncertain. Geochemical properties influence the behavior of As; in addition, microbial activities affect the mobility of sequestered As in soil and water.

Identification of the microbes mediating Fe reduction in a deep saline aquifer and their influence during managed aquifer recharge.

In this study, indigenous microbes enabling Fe reduction under saline groundwater conditions were identified, and their potential contribution to Fe release from aquifer sediments during managed aquifer recharge (MAR) was evaluated. Sediment and groundwater samples were collected from a MAR feasibility test site in Korea, where adjacent river water will be injected into the confined aquifer. The residual groundwater had a high salinity over 26.

Identification of refined petroleum products in contaminated soils using an identification index for GC chromatograms.

Hydrocarbons found in the environment are typically characterized by gas chromatography (GC). The shape of the GC chromatogram has been used to identify the source of petroleum contamination. However, the conventional practice of simply comparing the peak patterns of source products to those of environmental samples is dependent on the subjective decisions of individual analysts.

Targeted removal of trichlorophenol in water by oleic acid-coated nanoscale palladium/zero-valent iron alginate beads.

A new material was developed and evaluated for the targeted removal of trichlorophenol (TCP) from among potential interferents which are known to degrade removal activity. To achieve TCP-targeted activity, an alginate bead containing nanoscale palladium/zero-valent iron (Pd/nZVI) was coated with a highly hydrophobic oleic acid layer. The new material (Pd/nZVI-A-O) preferentially sorbed TCP from a mixture of chlorinated phenols into the oleic acid cover layer and subsequently dechlorinated it to phenol.

The role of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans in arsenic bioleaching from soil.

Bioleaching of As from the soil in an abandoned Ag-Au mine was carried out using Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans. A. ferrooxidans is an iron oxidizer and A.

Competitive inhibition of cytosolic Ca2+-dependent phospholipase A2 by acteoside in RBL-2H3 cells.

The aim of this study was to investigate whether acteoside isolated from Clerodendron trichotomum Thunberg may act as a selective inhibitor of phospholipase A(2) in RBL-2H3 cells. Acteoside dose-dependently inhibited 0.5 μM melittin-induced release of [(3)H]arachidonic acid, which was due to the inhibition of cytosolic Ca(2+)-dependent phospholipase A(2) (cPLA(2)) rather than secretory PLA(2) (sPLA(2)).

Intracellular Ca Mobilization and Beta-hexosaminidase Release Are Not Influenced by 60 Hz-electromagnetic Fields (EMF) in RBL 2H3 Cells.

The effects of extremely low frequency electromagnetic fields (EMF) on intracellular Ca(2+) mobilization and cellular function in RBL 2H3 cells were investigated. Exposure to EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h did not produce any cytotoxic effects in RBL 2H3 cells.

Stabilization of the As-contaminated soil from the metal mining areas in Korea.

The stabilization efficiencies of arsenic (As) in contaminated soil were evaluated using various additives such as limestone, steel mill slag, granular ferric hydroxide (GFH), and mine sludge collected from an acid mine drainage treatment system. The soil samples were collected from the Chungyang area, where abandoned Au-Ag mines are located. Toxicity characteristic leaching procedure, synthetic precipitation leaching procedure, sequential extraction analysis, aqua regia digestion, cation exchange capacity, loss on ignition, and particle size distribution were conducted to assess the physical and chemical characteristics of highly arsenic-contaminated soils.

Effect of Extremely Low Frequency Electromagnetic Fields (EMF) on Phospholipase Activity in the Cultured Cells.

This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase A(2) (PLA(2)), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.

Morinda citrifolia Inhibits Both Cytosolic Ca-dependent Phospholipase A(2) and Secretory Ca-dependent Phospholipase A(2).

This study investigated the effects of the methanol extracts of Morinda citrifolia containing numerous anthraquinone and iridoid on phospholipase A(2) (PLA(2)) isozyme. PLA(2) activity was measured using various PLA(2) substrates, including 10-pyrene phosphatidylcholine, 1-palmitoyl-2-[(14)C]arachidonyl phosphatidylcholine ([(14)C]AA-PC), and [(3)H]arachidonic acid (AA). The methanol extracts suppressed melittin-induced [(3)H]AA release in a concentration-dependent manner in RAW 264.