ESTIMATING WATER BUDGET IN A REGIONAL AQUIFER USING HSPF‐MODFLOW INTEGRATED MODEL1

ABSTRACT: Integrated water resources management is important, especially in watersheds where substantial interactions exist between the ground and surface water sources. This management warrants the need for reliable estimates of both an overall basin water budget and hydrologic fluctuations between ground water and surface water sources. The objectives of this study were to estimate the total water budget and to simulate the effects of the management of water in the Big Lost River Basin in Idaho. The study used the FIPR Hydrological Model (FHM), a hydrological model developed by the University of South Florida for the Florida Institute of Phosphate Research (FIPR). The FHM is an integrated model that simulates the full water budget of the surface and ground water systems. It has two public domain components: Hydrological Simulation Program ‐ FORTRAN (HSPF) and Modular Three‐Dimensional Finite‐Difference Ground Water Flow Model (MODFLOW). This study quantified the hydrologic fluxes between ground water and surface water and determined a comprehensive and accurate water budget for the Big Lost River. The study showed an annual amount of 10.44 m3/sec leaves the basin and never to return to the system. The study is useful in developing and calculating the annual water budget in the Big Lost River, and this process should be applicable to estimating water budgets in other basins.     

EVAPOTRANSPIRATION CONCEPTUALIZATION IN THE HSPF‐MODFLOW INTEGRATED MODELS1

In 1988, the Florida Institute of Phosphate Research (FIPR) funded project to develop an advanced hydrologic model for shallow water table systems. The FIPR hydrologic model (FHM) was developed to provide an improved predictive capability of the interactions of surface water and ground water using its component models, HSPF and MODFLOW. The Integrated Surface and Ground Water (ISGW) model was developed from an early version of FHM and the two models were developed relatively independently in the late 1990s. Hydrologic processes including precipitation, interception, evapotranspiration, runoff, recharge, streamflow, and base flow are explicitly accounted for in both models. Considerable review of FHM and ISGW and their applications occurred through a series of projects. One model evolved, known as the Integrated Hydrological Model IHM. This model more appropriately describes hydrologic processes, including evapotranspiration fluxes within small distributed land‐based discretization. There is a significant departure of many IHM algorithms from FHM and ISGW, especially for soil water and evapotranspiration (ET). In this paper, the ET concepts in FHM, ISGW, and IHM will be presented. The paper also identifies the advantages and data costs of the improved methods. In FHM and IHM, ground water ET algorithms of the MODFLOW ET package replace those of HSPF (ISGW used a different model for ground water ET). However, IHM builds on an improved understanding and characterization of ET partitioning between surface storages, vadose zone storage, and saturated ground water storage. The IHM considers evaporative flux from surface sources, proximity of the water table to land surface, relative moisture condition of the unsaturated zone, thickness of the capillary zone, thickness of the root zone, and relative plant cover density. The improvements provide a smooth transition to satisfy ET demand between the vadose zone and deeper saturated ground water. While the IHM approach provides a more sound representation of the actual soil profile than FHM, and has shown promise at reproducing soil moisture and water table fluctuations as well as field measured ET rates, more rigorous testing is necessary to understand the robustness and/or limitations of this methodology.     

Determination of Hydrocarbons in Mussels from the Egyptian Red Sea Coast

Mussels (Brachidontes Sp.) collected in April 2000 from the Red Sea coastal of Egypt in order to determine the contamination by hydrocarbons. The study included 11 sampling stations covering about 450 Km of the Egyptian Red Sea coast for the first time. Total concentrations of 20 aliphatics (average 0.105 ng g(-1) of wet weight) and sixteen polycyclic aromatic hydrocarbons (PAHs) (average 5452 ng g(-1) of wet weight) were generally lower in comparison with those reported for some of the published surveillance and monitoring studies of coastal areas from various regions. These results suggest that the coastal area in the Red Sea of Egypt might be considered as a relatively unpolluted.     

Potentially toxic elements in soil of the Khyber Pakhtunkhwa province and Tribal areas,Pakistan: evaluation for human and ecological risk assessment

Environmental Geochemistry and Health - Potentially toxic elements (PTEs) contaminations in the soil ecosystem are considered as extremely hazardous due to toxicity, persistence and bioaccumulative...     

Available solar energy for flat-plate solar collectors mounted on a fixed or tracking structure

The solar energy received by a flat plate collector is calculated for various tracking modes: fixed, inclination depending on the season or the month; variable inclination with fixed azimuth, variable azimuth with fixed inclination and double tracking. At first, we take into account only the sun position and then, we use validated radiation models for estimating the ground solar radiation. Using a tracker is questionable particularly if the additional costs are taken into account. A good solution to increase the available solar energy is to change seasonally the inclination, that is, 4 times per year.     

Vehicle Occupant Exposure to Carbon Monoxide

Abstract

This paper focuses on the auto commuting micro-environment and presents typical carbon monoxide (CO) concentrations to which auto commuters in central Riyadh, Saudi Arabia were exposed. Two test vehicles traveling over four main arterial roadways were monitored for inside and outside CO levels during eighty peak and off-peak hours extending over an eight month period. The relative importance of several variables which explained the variability in CO concentrations inside autos was also assessed. It was found that during peak hours auto commuters were exposed to mean CO levels that ranged from 30 to 40 ppm over trips that typically took between 25 to 40 minutes. The mean ratio of inside to outside CO levels was 0.84. Results of variance component analyses indicated that the most important variables affecting CO concentrations inside autos were, in addition to the smoking of vehicle occupants, traffic volume, vehicle speed, period of day and wind velocity. An increase in traffic volume from 1,000 to 5,000 vehicles per hour (vph) increased mean CO level exposure by 71 percent. An increase in vehicle speed from 14 to 55 km/h reduced mean CO exposure by 36 percent. The number of traffic interruptions had a moderate effect on mean concentrations of CO inside vehicles.     

The roles of biological interactions and pollutant contamination in shaping microbial benthic community structure

Biological interactions between metazoans and the microbial community play a major role in structuring food webs in aquatic sediments. Pollutants can also strongly affect the structure of meiofauna and microbial communities. This study aims investigating, in a non-contaminated sediment, the impact of meiofauna on bacteria facing contamination by a mixture of three PAHs (fluoranthene, phenanthrene and pyrene). Sediment microcosms were incubated in the presence or absence of meiofauna during 30 days. Bioremediation treatments, nutrient amendment and addition of a hydrocarbon-degrading bacterium, were also tested to enhance PAH biodegradation. Results clearly show the important role of meiofauna as structuring factor for bacterial communities with significant changes observed in the molecular fingerprints. However, these structural changes were not concomitant with changes in biomass or function. PAH contamination had a severe impact on total meiofaunal abundance with a strong decrease of nematodes and the complete disappearance of polychaetes and copepods. In contrast, correspondence analysis, based on T-RFLP fingerprints, showed that contamination by PAH resulted in small shifts in microbial composition, with or without meiofauna, suggesting a relative tolerance of bacteria to the PAH cocktail. The PAH bioremediation treatments were highly efficient with more than 95% biodegradation. No significant difference was observed in presence or absence of meiofauna. Nutrient addition strongly enhanced bacterial and meiofaunal abundances as compared to control and contaminated microcosms, as well as inducing important changes in the bacterial community structure. Nutrients thus were the main structural factor in shaping bacterial community composition, while the role of meiofauna was less evident.     

Microbial community responses to bioremediation treatments for the mitigation of low-dose anthracene in marine coastal sediments of Bizerte lagoon (Tunisia)

Purpose

The main goals of this study were to investigate (1) the behavior of microbial communities in response to low-dose bioavailable anthracene addition in lightly contaminated sediment from Bizerte Lagoon and (2) the effects of bioremediation treatments on microbial biomass, activity, and community structure.

Methods

Sediment microcosms amended with 1 ppm anthracene were incubated in triplicate during 30 days. Biostimulation (addition of nitrogen and phosphorus fertilizer) and bioaugmentation (inoculation of a hydrocarbonoclastic bacterium) were used as bioremediation treatments. Bacterial biomass was estimated using flow cytometry. Sediment oxygen consumption was measured with oxygen microelectrodes. Bacterial community structure was assessed by molecular fingerprints (terminal restriction fragment length polymorphism; T-RFLP) analysis.

Results

Anthracene contamination resulted in a significant reduction of bacterial abundance with an impact on cell integrity. Concomitantly, sediment oxygen consumption was strongly inhibited. Correspondence analysis on T-RFLP data indicated that bacterial community structures from anthracene-contaminated microcosms were different from that of the control. Interestingly, the changes observed in microbial biomass, structure, and activities as a result of anthracene contamination were not alleviated even with the use of biostimulation and combination of biostimulation and bioaugmentation strategy for anthracene bioremediation. Nevertheless, both treatment methods resulted in different community structures relative to the contaminated and control microcosms with the appearance of distinct populations.

Conclusion

Anthracene spiking severely affected microbial communities, suggesting dominance of nontolerant populations in this lightly-contaminated sediment. Although biostimulation and/or bioaugmentation treatments did not alleviate the anthracene toxic effects, the changes observed in microbial population and structure suggest that the proposed treatments might be promising to promote bacterial growth. Further works are still required to propose a more efficient strategy to stimulate biodegradation that takes into account the complex interactions between species for resource access.     

Production of bio-fertilizer by biotransformation of poultry waste enriched with molasses and algae

This research work consists on valorizing poultry waste by biotransformation into biofertilizers, associating this agro-industrial waste with algae (abundant natural resources) and molasses (a by-product of the sugar refining industry) ensuring a good contribution of nutritional chemical elements and obtaining a balanced formulation. A total of seven different formulations of the above three components, were examined in a simplex centroid design. A fungal inoculum of Aspergillus niger was used as a fermentation agent for better quality of biotransformation. The monitoring of this biotransformation is ensured during 15 days by following the evolution of physicochemical and microbiological parameters and, to understand the bioconversion of the simple compounds of the biofertilizer mixture such as short aliphatic chains, sugar, and amino acids into soluble mineral compounds, a Fourier transform infrared spectroscopy (FTIR) analysis was carried out before and after biotransformation. Finally, germination and fertilization tests were performed to evaluate the efficiency of the final product on a barley crop. The overall results of the present study showed that the mixture which contained 68.75% poultry waste, 12.5% molasses, and 18.75% algae presented the better microbiological and chemical safety criteria required for a good biofertilizer according to NF U44-551 standard.     

Protective effects of quercetin against sodium fluoride-induced oxidative stress in rat erythrocytes

Protective effects of quercetin against oxidative stress induced by sodium fluoride intoxication in rat erythrocytes were evaluated. Rats were divided into five groups consisting of 10 in each for this experiment. The animals of group I received water and standard diet to serve as control group, the animals of groups II and III were treated with quercetin (10 and 20?mg?kg^?1 body weight), administrated intraperitoneally for 7 days followed by sodium fluoride (600?ppm) in drinking water for the next 7 days. The animals of group IV were treated with vitamin C (10?mg?kg^?1) intraperitoneally for 7 days followed by sodium fluoride treatment for next 7 days serving as positive control group. The animals of group V were treated only with sodium fluoride (600?ppm) for the same time and were used as control group. Blood sample were collected via retro-orbital puncture. The antioxidant enzymes, superoxide dismutase, and catalase, as well as the levels of reduced glutathione and lipid peroxidation end products were measured in erythrocytes. There was a significant increase in lipid peroxidation along with a decrease in superoxide dismutase activity in the erythrocytes of sodium fluoride-treated animals. Quercetin treatment prior to fluoride administration normalized the levels of all parameters measured in the rat erythrocytes.