Investigation of the association between pesticide exposure and the prevalence of type 2 diabetes in Shahedieh population in Yazd

Environmental Science and Pollution Research - This study aimed to investigate the effect of exposure to pesticides and the prevalence of type 2 diabetes (T2D). In a cross-sectional study with a...     

Recent advances in thin film composites membranes for brackish groundwater treatment with critical focus on Saskatchewan water sources

Drinking water scarcity is an ever-increasing global concern. This issue appears as a greater threat to the countries with no access to sea water resources or rivers, since their potential water resources are only limited to ground waters only. There are serious concerns with the treatment of ground water resources, including landfill leachates, agricultural contaminations (pesticides, herbicides, and fertilizers), and rural contaminations. Membrane separation has been proved to be the governing technology in water and wastewater treatment plants, as these methods are responsible for more than half of the market share of the world's desalination capacity. This study intends to offer a holistic view of the groundwater contamination with specific focus on Saskatchewan province in Canada, and the recent efforts in the groundwater treatment using thin film composite membrane technology. This study begins with an introduction of the general aspects of ground water and membrane separation, polluting agents, and their sources. It is followed by a discussion of Saskatchewan's groundwater status and various issues. Furthermore, the recent research that became available since 2010 is reviewed in details and the results are summarized with respect to purification efficiency. Different affecting parameters in a groundwater-thin film composite system are synthesized and an in-depth overview is presented.     

Biofilm growth-percolation models and channeling in biofilter clogging

Biomass accumulation is a load-limiting factor in the operation of biofilters used for air pollution control. As the biofilm thickens, portions at the base are no longer exposed to contaminants and oxygen and, thus, provide no treatment. Smaller pores are filled with biomass so that air no longer flows into them. As airflow paths are restricted, air may be prevented from reaching some pores even before they are filled. Eventually blockage becomes sufficiently widespread so that increasing head loss and decreasing removal efficiency require that the system be shut down. Optimization of biofilter design requires a better understanding of the mechanisms by which biofilters clog. In this work, a numerical percolation model of the blockage process was developed for application to biofilters. It allows comparison of pore blockage histories for various pore size distributions and predicts biomass accumulation, head loss, and treatment efficiency as a function of time, as well as total time, until blockage prevents further operation. Although the model was reasonably accurate in predicting the time before complete clogging, it underestimated intermediate values of head loss. Observations of a clogged biofilter suggest that this occurs because clogging later in the process is nonuniform at scales that are large in comparison with individual pores.     

Performance enhancement of a solar still using a V-groove solar air collector—experimental study with energy,exergy, enviroeconomic,and exergoeconomic analysis

Environmental Science and Pollution Research - This paper intended to evaluate the performance of a new design of solar still integrated with a V-groove solar air collector. In this system, an air...     

Assessing energy efficiencies,economy, and global warming potential (GWP) effects of major crop production systems in Iran: a case study in East Azerbaijan province

Environmental Science and Pollution Research - Efficient use of energy in farming systems is one of the most important implications for decreasing greenhouse gas (GHG) emissions and mitigating...     

Spatio-temporal modeling of striped-bass egg, larval movement, and fate in the San Francisco Bay-Delta

Most models developed for the movement and fate of eggs and larvae of aquatic species are based on a particle tracking approach. Although this method has many advantages due to its high flexibility, particle tracking may become computationally intensive for complex geometries and when large numbers of particles are needed to simulate the population properly. In continuous models based on advection and dispersion mechanisms, the computational burden is independent of the size of the population. We developed a continuous fate and transport model for striped bass eggs and larvae in the San Francisco Bay-Delta. The model predicts the concentration of eggs and larvae at any location over time. The method of moments was used to account for the effect of temperature and age on the transition of eggs to larvae and larvae to juveniles. Egg and larval mortality were represented as functions of temperature, and eggs also experienced settling mortality. The fate and transport model used the same one-dimensional spatial grid as the existing Delta Simulation Model II (DSM2) hydrodynamics model. DSM2 output of flow rates, water depths, and cross-sectional areas were inputted into the fate and transport model to determine transport. The model was applied to striped bass eggs and larvae data collected during years 1990-1994; agreement between the modeled and the measured data was acceptable in most cases. Exploratory simulations were performed to demonstrate how the model could be used to evaluate the effects on egg and larval survival and total juvenile production of water diversions for supply and agricultural use and changes in the long-term mean water temperature. The model can be further used to examine the impact of various operation strategies in the San Francisco Bay-Delta, where diversion losses of early life stages of fishes remain a major management issue.     

Reliable method for prediction of the flash point of various classes of amines on the basis of some molecular moieties for safety measures in industrial processes

This work presents a novel, reliable and simple method of estimating the flash point of various types of flammable amines, which are important for safety measures in industrial processes. Different amines include aliphatic amines such as primary, secondary, tertiary and cyclic amines as well as aromatic amines and hetero arenes containing nitrogen heteroatom. The proposed correlation is based on the contribution of some specific molecular moieties and functional groups, which can easily be used for any types of amines. Intermolecular forces are important in the new method, which are counted by two increasing and decreasing parameters. The root mean square (rms) deviation is 18 K for different classes of amines including 133 diverse compounds. The estimated flash points have been compared with one of the best available predictive methods, which gives much lower value of the rms deviation.     

Approximation of a radial diffusion model with a multiple-rate model for hetero-disperse particle mixtures

An innovative method is proposed for approximation of the set of radial diffusion equations governing mass exchange between aqueous bulk phase and intra-particle phase for a hetero-disperse mixture of particles such as those occurring in suspension in surface water, in riverine/estuarine sediment beds, in soils and in aquifer materials. For this purpose the temporal variation of concentration at several uniformly distributed points within a normalized representative particle with spherical, cylindrical or planar shape is fitted with a 2-domain linear reversible mass exchange model. The approximation method is then superposed in order to generalize the model to a hetero-disperse mixture of particles. The method can reduce the computational effort needed in solving the intra-particle mass exchange of a hetero-disperse mixture of particles significantly and also the error due to the approximation is shown to be relatively small. The method is applied to describe desorption batch experiment of 1,2-dichlorobenzene from four different soils with known particle size distributions and it could produce good agreement with experimental data.