CoFe2O4@Methylcelloluse as a New Magnetic Nano Biocomposite for Sonocatalytic Degradation of Reactive Blue 19

Journal of Polymers and the Environment - Reactive Blue 19 (RB19) removal from synthetic textile wastewater was investigated by using a CoFe2O4@methylcellulose (MC) activated with peroxymonosulfate...     

ANALYSIS OF ROCK STRESS AROUND A LIQUID WASTE INJECTION SYSTEM IN ILLINOIS1

: The danger to the environment associated with the injection of liquid industrial wastes into a deep, confined, subsurface rock formation may arise from the transport of the waste laterally or vertically in the formation. The pattern of lateral transport, which can take place as a result of convection as well as dispersion and diffusion, can be determined by an approximate analytical solution to the mass transport equation. Vertical transport may take place through both natural fractures and fractures created by hydrostatic stresses generated around the well during injection. To determine the stresses, we used the finite element method to get a numerical solution of the flow equation. We applied a solution of the flow equation to calculate the stress buildup and decay for the Jones & Laughlin Steel Corporation's injection well near Hennepin in Putnam County, Illinois. According to our computations, the stress buildup due to injection is about 0.16 pounds per square inch per foot - psi - (0.362 Newton per square centimeter per meter), which, added to normal pressure, makes an estimated total stress of 0.60 psi/ft (1.36 Newton/cm²/m). That pressure is insufficient to cause fracturing of the Cambrian Eau Claire aquitard, the confining bed for the disposal zone.     

The cut-off point for tympanic temperature as a heat strain index for evaluation of outdoor workers: a field study

Objectives. The aims of this study were (a) to assess the agreement coefficient between tympanic temperatures and the most popular and valid heat stress index, wet bulb globe temperature (WBGT), in outdoor environments; (b) to determine a cut-off point for tympanic temperature as a heat strain index for evaluation of outdoor workers. Methods. 1452 measurements of WBGT index and tympanic temperature were recorded for outdoor workers from nine different climatic regions. Consistency of the WBGT and tympanic temperature were tested. The cut-off point for tympanic temperature in outdoor environments regarding WBGT evaluation was suggested based on obtained sensitivity and specificity from a receiver operating characteristic curve. Results. The results showed that there were numerous situations in which WBGT exceeded the reference value, whilst the measured values of tympanic temperature rarely reached a permissible value for core temperature (38?°C). Therefore, appropriate consistency of results between the heat stress and strain indices was not achieved. Conclusion. The criterion of tympanic temperature equaling 37?°C was suggested as a cut-off point for tympanic temperature as a heat strain index for outdoor environment evaluation.     

Geochemical fractionation and pollution assessment of Zn,Cu, and Fe in surface sediments from Shadegan Wildlife Refuge,southwest of Iran

This research focuses on the fractionation and distribution patterns of heavy metals (Zn, Cu, and Fe) in surficial sediments collected from Shadegan Wildlife Refuge, the biggest wetland in southern part of Iran, to provide an overall classification for the sources of metals in the study area using a sequential extraction method. For this purpose, a four-step sequential extraction technique was applied to define the partitioning of the metals into different geochemical phases of the sediment. The results illustrated that the average total level of Zn, Cu, and Fe in surface sediments were 55.20 ± 16.04, 22.86 ± 5.68, and 25,979.01 ± 6917.91 μg/g dw, respectively. On the average, the chemical partitioning of all metals in most stations was in the order of residual >oxidizable-organic > acid-reducible > exchangeable. In the same way, the results of calculated geochemical indices revealed that Cu, Zn, and Fe concentrations are mainly influenced by lithogenic origins. Compared with consensus-based SQGs, Cu was likely to result in occasionally harmful biological effects on the biota.

     

Toxic responses of different organs following occupational exposure to sub-threshold limit value levels of paving asphalt fumes

The main purpose of this study was to ascertain whether occupational exposure to asphalt fumes, under normal working conditions, is associated with any hepatotoxic, nephrotoxic, or hematotoxic response. This was a cross-sectional study in which 210 subjects (80 exposed and 130 reference subjects) were investigated. Using standard methods, atmospheric concentrations of total particulate and benzene-soluble fractions of asphalt fumes were measured. Additionally, urine and blood samples were taken from subjects for complete blood count, white blood cell differential test, urinalysis, and routine biochemical tests of kidney and liver function. Both groups were similar as far as their demographic variables and smoking habits were concerned. The levels of exposure to total particulate and benzene-soluble fractions were estimated to be 0.9?±?0.2 and 0.32?±?0.09 mg m^?3, respectively (mean?±?SD), both of which being lower than the existing threshold limit values. Statistically, significant associations between exposure to asphalt fumes and changes in most liver and kidney function tests and complete blood count parameters provided circumstantial evidence in favor of the notion that exposure to sub-threshold limit value levels of total particulate and benzene-soluble fractions is associated with early liver and kidney dysfunction as well as hematological disorders.     

Application of ultrasound irradiation in landfill leachate treatment

Environmental Science and Pollution Research - Landfilling is known to be the most widely used method in municipal solid waste management in many countries. Landfill leachate containing different...     

IDENTIFICATION OF AN OPTIMAL GROUNDWATER MANAGEMENT STRATEGY IN A CONTAMINATED AQUIFER1

A groundwater hydraulic management model is used to identify the optimal strategy for allocating limited fresh-water supplies and containing wastes in a hypothetical aquifer affected by brine contamination from surface disposal ponds. The present cost of pumping from a network of potential supply and interception wells is minimized over a five-year planning period, subject to a set of hydraulic, institutional, and legal constraints. Hydraulic constraints are formulated using linear systems theory to describe drawdown and velocity variables as linear functions of supply and interception well discharge decision variables. Successful validation of the optimal management strategy suggests that the model formulation can feasibly be applied to define management options for locally contaminated aquifer systems which are used to fulfill fresh-water demands.     

APPLICATION OF LINEAR SYSTEM'S THEORY AND LINEAR PROGRAMMING TO GROUND WATER MANAGEMENT IN KANSAS1

ABSTRACT: A ground water management model based on the linear systems theory and the use of linear programming is formulated and solved. The model maximizes the total amount of pound water that can be pumped from the system subject to the physical capability of the system and institutional constraints. The results are compared With analytical and numerical solutions. Then, this model is applied to the Pawnee Valley area of south-central Kansas. The results of this application support the previous studies about the future ground water resources of the Valley. These results provide a guide for the ground water resources management of the area over the next ten years.     

The role of burnout syndrome as a mediator for the effect of psychosocial risk factors on the intensity of musculoskeletal disorders: a structural equation modeling approach

This study examined the hypothesis that burnout syndrome mediates effects of psychosocial risk factors and intensity of musculoskeletal disorders (MSDs) among hospital nurses. The sample was composed of 415 nurses from various wards across five hospitals of Iran's Hamedan University of Medical Sciences. Data were collected through three questionnaires: job content questionnaire, Maslach burnout inventory and visual analogue scale. Results of structural equation modeling with a mediating effect showed that psychosocial risk factors were significantly related to changes in burnout, which in turn affects intensity of MSDs.     

ANALYSIS OF PUMPING TESTS: SIGNIFICANCE OF WELL DIAMETER,PARTIAL PENETRATION,AND NOISE1

ABSTRACT: The nonlinear least squares (NLS) method was applied to pumping and recovery aquifer test data in confined and unconfined aquifers with finite diameter and partially penetrating pumping wells, and with partially penetrating piezometers or observation wells. It was demonstrated that noiseless and moderately noisy drawdown data from observation points located less than two saturated thicknesses of the aquifer from the pumping well produced an exact or acceptable set of parameters when the diameter of the pumping well was included in the analysis. The accuracy of the estimated parameters, particularly that of specific storage, decreased with increases in the noise level in the observed drawdown data. With consideration of the well radii, the noiseless drawdown data from the pumping well in an unconfined aquifer produced good estimates of horizontal and vertical hydraulic conductivities and specific yield, but the estimated specific storage was unacceptable. When noisy data from the pumping well were used, an acceptable set of parameters was not obtained. Further experiments with noisy drawdown data in an unconfined aquifer revealed that when the well diameter was included in the analysis, hydraulic conductivity, specific yield and vertical hydraulic conductivity may be estimated rather effectively from piezometers located over a range of distances from the pumping well. Estimation of specific storage became less reliable for piezometers located at distances greater than the initial saturated thickness of the aquifer. Application of the NLS to field pumping and recovery data from a confined aquifer showed that the estimated parameters from the two tests were in good agreement only when the well diameter was included in the analysis. Without consideration of well radii, the estimated values of hydraulic conductivity from the pumping and recovery tests were off by a factor of four.