Numerical Modeling of Regional Ground Water Flow in the Deep-Brine Aquifers of the Palo Duro Basin, Texas Panhandle

A conceptual hydrogeologic model of the Palo Duro Basin, Texas Panhandle, subdivides the basin into three hydrogeologic units: the shallow Ogallala and Dockum aquifers, the Permian evaporite aquitard, and the deep confined, underpressured Permian and Pennsylvanian brine aquifer. The first permeable units beneath the thick Permian evaporite section are Wolfcamp strata composed of carbonates, shales, and arkosic sand and gravels (granite wash) with average effective permeability values of 8.9, 0.0001, and 8.6 md, respectively. Groundwaters in the Wolfcamp aquifer flow to the northeast toward the semi-impermeable, granitic Amarillo Uplift. This anomalous hydrologic condition (flow toward a low-transmissivity barrier) may result from the presence of highly permeable granite-wash deposits that flank the uplift and function as "hydrologic sinks." A two-dimensional, vertical-averaging finite-element model, incorporating the different lithologies and their different permeabilities as well as leakage through the overlying evaporite aquitard, has been used to simulate the observed potentiometric surface of the Wolfcamp aquifer. The conditions that best simulate the observed Wolfcamp potentiometric surface are a combination of specified head and no-flow conditions along the uplift, permeability values greater than 260 md for the granite-wash deposits that flank the uplift (in contrast to the average value of 8.6 md), and an increased permeability value of 50 md for the highly porous carbonate zone. The best estimate of the vertical permeability of the evaporite aquitard is 0.00008 md. Treating the whole deep-brine aquifer as a single permeable unit beneath the evaporite aquitard, groundwater flow is to the northeast toward the uplift with a slightly larger west-to-east component than that found when considering only flow in Wolfcamp strata. The conditions that best simulate the averaged potentiometric surface are those from the best simulation of Wolfcamp strata, with increased permeability values of 260 md for the Pennsylvanian granite-wash close to the uplift and 250 md for the high-porosity Pennsylvanian sandstone.Bureau of Economic Geolog

PERFLUOROOCTANE SULFONATE (PFOS) AND PERFLUOROOCTANOATE (PFOA) CONTAMINATION OF WATER ENVIRONMENT IN ASIAN COUNTRIES

Joint Research on Environmental Science and Technology for the Eart

The application of waste minimisation to business management to improve environmental performance in the food and drink industry

The food and drink industry is one of the major sectors in the UK and makes a significant contribution to national and regional economies. The sector produces a large amount of waste compared to other industries and it faces increasing demands to improve resource efficiency and environmental performance through European legislation and policy and UK waste strategy. Waste minimisation is considered to be one of the best approaches for improving sustainability performance in industry, including for the food and drink industry, as it achieves environmental, economic and social benefits by reducing waste at source, achieving cost savings and creating new employment opportunities

Heuristics for workforce planning with worker differences

This study considers decisions in workforce management assuming individual workers are inherently different as measured by general cognitive ability (GCA). A mixed integer programming (MIP) model that determines different staffing decisions (i.e., hire, cross-train, and fire) in order to minimize workforce related costs over multiple periods is described. Solving the MIP for a large problem instance size is computationally burdensome. In this paper, two linear programming (LP) based heuristics and a solution space partition approach are presented to reduce the computational time. A genetic algorithm was also implemented as an alternative method to obtain better solutions and for comparison to the heuristics proposed. The heuristics were applied to realistic manufacturing systems with a large number of machine groups. Experimental results shows that performance of the LP based heuristics performance are surprisingly good and indicate that the heuristics can solve large problem instances effectively with reasonable computational effort.

Landfill site characterisation at Kham Bon village, Muang district, Khon Kaen province, NE Thailand

The aim of the study is to characterise the Kham Bon landfill site. Hydrogeological and geochemical surveys were conducted and four boreholes were drilled. The hydraulic properties of the aquifer were tested, and soil, surface water and groundwater samples were collected at various times in the year. The physical and chemical properties of the samples, especially heavy metals, were analysed. The results indicated that Cd, Cr, Pb, Cu and Zn occurred in significant concentrations in the soil. The concentrations of Pb, Fe and Mn are high in surface water and groundwater. Moreover, the groundwater chemistry of the shallow aquifer was characterised by high concentrations of some ions. The major factors controlling leachate production and migration in this area are the seasonal variations in precipitation, the site topography, which controls the runoff patterns, and the soil type, which affects infiltration and solute transport to the water table. Copyright © 2009, Inderscience Publishers

Optimization for UV-photocatalytic degradation of paraquat over titanium dioxide supported on rice husk silica using Box-Behnken design

363-371The optimum conditions for UV-photocatalytic degradation of paraquat over titanium dioxide supported on rice husk silica (TiO2/RH-SiO2) catalyst, which is effected by four independent variables, namely initial paraquat concentration, pH of solution, titanium dioxide content (% TiO2) and catalyst loading,  have been evaluated. The TiO2/RH-SiO2 catalyst has been synthesized by colloidal impregnation method and calcined at 550 °C for 6 h. The Box-Behnken design, based on response surface methodology has been applied to design the experiment and analyze the data. Characterization of the catalysts is investigated by XRD, SEM, BET surface area and UV-DRS for explanation of reaction behaviour. The XRD patterns show a pure anatase crystalline phase at all TiO2 percentages, and the BET surface area of the catalysts is vastly decreased as the percentage of TiO2 is increased. The highest paraquat removal efficiency of 90.04% is obtained at 10 ppm initial paraquat concentration, 5.91 pH, 30 wt % TiO2 and 2.0 g/L catalyst loading

Riverbed clogging experiments at potential river bank filtration sites along the Ping River, Chiang Mai, Thailand

Riverbank filtration (RBF) is a process during which river water is subjected to subsurface flow prior to abstraction wells, often characterized by improved water quality. The induced infiltration of river water through the riverbed also creates a clogging layer. This decreases riverbed permeability and abstraction rates, particularly if the river water has high turbidity, as in Thailand. As Chiang Mai Province is one of the most favorable sites for future RBF construction in Thailand, two sites, Mae Rim and San Pa Tong, were selected to simulate clogging by using a channel experiment. The mobile experimental apparatus was set up at the bank of the river in order to use fresh river water. Riverbed sediment was used as channel bed and filling material for the columns. The aim was to simulate riverbed clogging using river water with high turbidity and determine the effect of clogging, which can be quantified using vertical hydraulic conductivity (Kv). An increase in channel flow velocity caused partial removal of a clogging layer in only the top 0.03 m of the sediment column. The combination of low channel flow and high turbidity leads to much more clogging than high channel flow and low turbidity. A complete manual removal of the external clogging layer led to an increase in Kv, but the initial Kv values were not recovered. The external clogging had a lower effect on Kv than internal clogging. For planning new RBF sites along high-turbidity rivers, reduction in Kv to estimate RBF well yield cannot be calculated based only on initial Kv but requires field experiments