Lead distribution and its potential risk to the environment: lesson learned from environmental monitoring of abandon mine.

There are many abandon and existing mines (tin, lead and zinc) in the mountainous areas of Thailand. Toxic elements including heavy metals such as lead (Pb), cadmium (Cd) and arsenic (As) have been released and transported from the mining sites to the adjacent landscape. In Thong Pha Phum District, Kanchanaburi Province, Thailand Pb contamination in the vicinity of the mine has occurred which could lead to potential health problems in downstream communities.

Removal of trichloroethylene (TCE) contaminated soil using a two-stage anaerobic-aerobic composting technique.

The effect of organic carbon addition on remediation of trichloroethylene (TCE) contaminated clay soil was investigated using a two stage anaerobic-aerobic composting system. TCE removal rate and processes involved were determined. Uncontaminated clay soil was treated with composting materials (dried cow manure, rice husk and cane molasses) to represent carbon based treatments (5%, 10% and 20% OC).

Environmental factors influencing remediation of TNT-contaminated water and soil with nanoscale zero-valent iron particles.

This study evaluated the application of nanoscale metallic particles (nanoscale zero-valent iron (nZVI) particles) in the remediation of TNT in contaminated water and soil samples. The effects of treatment dosages of synthesized nZVI particles and reaction time on degradation rate of TNT were determined. The synthesized nZVI particles (99.

Total Hg and methyl Hg distribution in sediments of selected Louisiana water bodies.

Sediment samples (543) collected from selected Louisiana streams and lakes were analyzed for total Hg and methyl Hg content. The average total Hg content among 543 samples was 92.3 +/- 95.

Mercury contamination and potential impacts from municipal waste incinerator on Samui Island, Thailand.

In recent years, mercury (Hg) pollution generated by municipal waste incinerators (MWIs) has become the subject of serious public concern. On Samui Island, Thailand, a large-scale municipal waste incinerator has been in operation for over 7 years with a capacity of 140 tons/day for meeting the growing demand for municipal waste disposal. This research assessed Hg contamination in environmental matrices adjacent to the waste incinerating plant.

Cadmium concentration in sea bottom sediment and its potential risk in the upper Gulf of Thailand.

Untreated or partially treated waste water discharge from industrial and domestic sources entering the Upper Gulf of Thailand have been reported to increase cadmium concentration in bottom sediment. This study was directed at providing a better understanding of cadmium transformation in the sediment from the area. Sediment samples collected from Chao Phraya River mouth (CPY), Bang Pakong River mouth (BPK) and Klong Dan estuary (KD) located in the Upper Gulf of Thailand were analyzed for cadmium concentration in various sediment particle size fractions.

Total and methyl mercury in wetland soils and sediments of Louisiana's Pontchartrain Basin (USA).

Accumulation of methylmercury (MeHg) in aquatic biota is a primary toxicological concern associated with Hg contamination in the environment. This study reports total mercury (THg) and MeHg measurements in 11 swamp and 24 marsh soils/sediments in wetlands surrounding Lake Pontchartrain and Lake Maurepas located in Louisiana's Pontchartrain Basin. The salinity level ranged from fresh, brackish to salt water.

Total Hg, methyl Hg and other toxic heavy metals in a northern Gulf of Mexico estuary: Louisiana Pontchartrain basin.

Concentration of total Hg, methyl Hg, and other heavy metals were determined in sediment collected along a salinity gradient in a Louisiana Gulf Coast estuary. Surface sediment was collected at established coordinates (n = 292) along a salinity gradient covering Lake Maurepas, Lake Pontchartrain, Lake Borgne and the Chandeleur Sound located in the 12,170 km(2) Pontchartrain basin estuary southeastern coastal Louisiana. Lake Maurepas sediment with lower salinity contained higher levels of methyl Hg (0.

Influence of anaerobic co-digestion of sewage and brewery sludges on biogas production and sludge quality.

This research investigated operating parameters and treatment efficiency for the digestion of sewage and brewery sludge. The prime objective of this study was to enhance the quality of treated sludge for use as agriculture fertilizer and to enhance biogas production, a by-product that can be used as an energy source. Three bench-scale completely stirred tank reactor (CSTR) anaerobic digesters were operated at mesophilic condition (36+/-0.

Paraquat adsorption, degradation, and remobilization in tropical soils of Thailand.

Paraquat adsorption, degradation, and remobilization were investigated in representative tropical soils of Yom River Basin, Thailand. Adsorption of paraquat in eight soil samples using batch equilibration techniques indicated that adsorption depended on soil characteristics, including exchangeable basic cations and iron content. Multiple regression analysis indicated significant contribution of exchangeable calcium percentage (ECP), total iron content (TFe) and exchangeable sodium percentage (ESP) to paraquat sorption (Q).

Total mercury and methylmercury in freshwater and salt marsh soils of the Mississippi river deltaic plain.

Mercury entering wetland environments can be microbially methylated to methylmercury. The purpose of this study was to investigate the historical rate of mercury accumulation and distribution of total and methylmercury in soil profile of Louisiana coastal marshes. Two sediment cores each were taken from Louisiana freshwater marsh and salt marsh.

Evaluation of extraction procedures for removing lead from contaminated soil.

Soil extraction of lead contaminated soil collected from sites near an abandoned battery recycling and secondary lead-smelting factory was investigated for potential use in decontaminating soil at the sites. A fractionation study was conducted to elucidate soil retention mechanism for Pb at the site. Three soil pits were selected from an area surrounding the factory based on level of Pb contamination.

Phytoaccumulation of lead by sunflower (Helianthus annuus), tobacco (Nicotiana tabacum), and vetiver (Vetiveria zizanioides).

The ability of three plant species: Helianthus annuus, Nicotiana tabacum, and Vetiveria zizanioides for phytoaccumulation of Pb was studied. Plants were grown in hydroponic solution containing Pb(NO3)2 at concentration of 0.25 and 2.

Arsenic uptake by native fern species in Thailand: effect of chelating agents on hyperaccumulation of arsenic by Pityrogramma calomelanos.

Nineteen native fern species collected from an area in Thailand with high arsenic concentration in soil and in ground water as a result of tin mining was screened for elevated arsenic concentration in fronds. Two species of fern were found to contain elevated arsenic in their fronds in nature: Pityrogramma calomelanos (108-1156 microg g(-1) dried weight) and Pteris vittata (79 microg g(-1) dried weight). Under hydroponic culture Pityrogramma calomelanos (a silver back fern) accumulated arsenic in its shoot at rate of 4616 microg(-1) (dried weight).

Factors governing adsorption and distribution of copper in Samut Prakarn coastal sediment, Thailand.

The Chao Phraya River (near Bangkok) discharges into Gulf of Thailand. Sediment in near shore areas of the gulf contained elevated Cu levels as a result of industry and urban inputs into the region. Adsorption and fractionation studies were conducted for determining availability and retention of Cu in the sediment.

Metal leachability from sewage sludge-amended Thai soils.

Determining mobility and availability of metals in sewage sludge amended soil is an environmental concern. Potential leachability and bioavailability of metals following sludge applied to agricultural soil was evaluated. Geochemical forms of metal occurring in sludge-amended soil were subjected to fractionation for understanding heavy metal transformation and remobilization in sludge-amended soil.