Residue levels of organochlorine pesticides in some ecosystem components of Manzala Lake

To evaluate the organochlorine pesticide (OCP) contamination of Manzala Lake, its ecosystem was investigated during the winter season (December to March). The studied ecosystem components were water, sediment, aquatic weeds, and fishes in four locations. The samples were analyzed by gas chromatography with electron capture detector. Pollutant levels of total OCPs showed significantly high levels in the water areas of Round road (46.253 ng/ml), Port-Said Damietta road (19.301 ng/ml), followed by Bughas El-Rasoah (5.539 ng/ml), then Ashtoum El Gamel (natural reserve area now) (0.289 ng/ml). Organochlorines were detected in sediment only in Round road (3.359 μg/kg) and Port-Said Damietta road (0.171 μg/kg) by significant order while they were undetectable in Ashtoum El Gamel and Bughas El-Rasoah. Total OCPs in aquatic weeds ranged between 0.194 μg/kg in Port-Said Damietta and 0.026 μg/kg in Ashtoum El Gamel. While OCPs were 0.160 and 0.153 μg/kg in Round road and Bughas El-Rasoah, respectively. Concerning fish muscles OCPs were significantly higher in the Round road area (0.397 μg/kg) followed by the Port-Said Damietta road (0.258 μg/kg), and finally, Ashtoum El Gamel samples (0.126 μg/kg). The results revealed the direct relation for the accumulation of OCPs between studied ecosystem parameters at the Manzala Lake during the winter season. Results also demonstrated that fish samples collected from the Manzala Lake in the studied areas were contaminated with levels of organochlorines, not higher than the maximum permissible level recorded by FAO/WHO, and that the public is not at risk with fish consumption.     

COMPARATIVE STUDY OF FRESH-SALT WATER INTERFACES USING FINITE ELEMENT AND SIMPLE APPROACHES

ABSTRACT: The fresh-salt water interface in artesian aquifers has been investigated by various techniques on the basis of its analogy to the free surface in earth dams or cores of dams. Although various approximations are used, some more or less exact solutions exist. One of the simple methods, that would appeal to practical workers, was developed by the analysis of hydraulic forces. However, this method has not been checked thoroughly due to the lack of wide ranges of coverage by the more or less exact solutions. In this paper a suggested finite element method is used for the purpose of comparing with the method of hydraulic forces. The presented procedure eliminates some of the difficulties and uncertainties in current finite element procedures. Both methods proved to be in close agreement. Moreover, the hydraulic heads along the upper boundary of the artesian aquifer were found to be in close agreement with Dupuit's equation. The results of this investigation would greatly simplify the more complex management problems when the effects of discharge and/or recharge wells are added to the natural flow effects.     

Experimental study of the stack geometric parameters effect on the resonance frequency of a standing wave thermoacoustic refrigerator

Thermoacoustic refrigeration is an emerging technology that makes use of acoustic power to pump heat. The resonance frequency is important for the performance of thermoacoustic refrigerators, as it affects the temperature difference across the stack. This paper aims to optimize the performance of thermoacoustic refrigerators by experimentally investigating the effect of the stack geometric parameters (i.e. stack position, stack length, and the stack size) on the resonance frequency of a standing wave loudspeaker driven thermoacoustic refrigerator. Celcor Ceramic stacks of normalized positions of 0.764, 1.05, 1.43, and 1.72, normalized lengths of 0.076, 0.114, 0.153, and 0.191, and two porosities of 0.8 and 0.85 are used. The clarification of the relationship between the stack geometric parameters and the resonance frequency of the thermoacoustic refrigerator is presented. Moreover, the coefficient of performance of the thermoacoustic refrigerator is observed to increase at the resonance frequency of each stack configuration.     

GLOBAL WATER ISSUES AND THE WORLD WATER COUNCIL1

ABSTRACT: The key events and the process that led to the creation of the World Water Council on World Water Day 1996 are reviewed and its characteristics summarized. The development of this new organization is discussed in the context of the major global trends in water and water-related issues, viz. growing water scarcity with its links to limits on food production and demographic patterns. In response to the need to find solutions to these pressing water issues, the development of a Technical Program based on the deliberations of the founding member organizations and a number of short-term activities have been outlined to demonstrate the evolution of the Council in this first year of its existence. Given the importance of complementarity between the Council and the Global Water Partnership, an attempt has been made to articulate the mutually-reinforcing roles of the two organizations.     

Identifying municipal solid waste management opportunities in Al-Bayda City,Libya

In Libya, municipal solid waste management is one of the services provided by the authorities to keep the county clean. This study was conducted in the City of Al-Bayda, located in the eastern part of Libya, as there have been several major problems facing the city in dealing with solid waste management. One of these problems is the generation, collection, handling, transportation, recycling, and disposal of municipal solid waste (MSW). This study has identified that the ongoing disposal of MSW to poorly engineered “dump sites” on the outskirts of the city is unsustainable and will not meet the demands of the growing population and increasing urbanization currently experienced within Al-Bayda. Factors impacting the decision-making and operational processes of MSW include lack of resources and services that significantly affect the disposal of waste, an inadequate number of waste collection containers making the distance to these containers for many households excessive, and thus leading to an increasing likelihood of dumping solid waste in open areas and roadsides. The study recommends that the city government of Al-Bayda should identify synergies and increase partnership-working arrangements with the private sector to ensure efficient management of MSW within the city area.     

The role of some feed additives in fish fed on diets contaminated with cadmium

The decline of cadmium pollution in fish farms is needed by any adequate method. The present study was designed to explore the effect of dietary cadmium contamination and its amelioration by using dietary clay, probiotic (Bactocell®), vitamin C, and vitamin E supplementation in Nile tilapia fish diet on growth rate, feed efficiency, blood components, and cadmium residues. Fish were separated into 15 groups, each group of fish was stocked into three aquaria and each contains 20 fishes. The fish of the first five groups were fed the basal diet, the second five groups were fed the basal diet contaminated with 25 mg cadmium/kg, and the third five groups were fed the same diet contaminated with 50 mg cadmium/kg. Within each dietary cadmium level, the first group was fed the diet without any supplementation, the second was fed the diet supplemented with natural clay (bentonite) at level 3%, the third group was fed the diet supplemented with 1 g Bactocell®/kg, the fourth group was fed the diet supplemented 50 mg vitamin E/kg, and the fifth group was fed the diet supplemented with 100 mg vitamin C/kg. Live body weight, daily body weight gain, and feed intake of Nile tilapia decreased significantly (P < 0.001) with increasing dietary cadmium level, while feed conversion was impaired. Fish group fed on diets contaminated with 50 mg cadmium/kg recorded the lowest live body weight and weight gain. Serum total protein and albumin concentration significantly (P < 0.001) decreased, while serum creatinine, AST, and ALT significantly (P < 0.001) increased with increasing cadmium level in fish diets. Blood hemoglobin and total erythrocyte (RBCs) significantly (P < 0.001 or 0.05) decreased with cadmium contamination in fish diets, while leukocytes were insignificantly affected. Body cadmium residues increased significantly (P < 0.001) by increasing cadmium level in fish diets. Live body weight, daily body weight gain, and feed intake of Nile tilapia increased significantly (P < 0.001) with feed additive supplementation in diets, also while feed conversion improved. Fish group fed on diets supplemented with probiotic Bactocell® or natural clay recorded higher body weight and gain rate than the other experimental groups. Serum total protein, blood hemoglobin, and total erythrocyte increased, while urea-N, creatinine, ALT, AST, and leukocytes decreased as affected with the feed additive supplementation. Feed additive supplementation in fish diets significantly (P < 0.001) decreased cadmium residues in fish bodies. Irrespective of dietary cadmium level, feed additive supplementation in fish diet improved the growth rate and decreased the concentrations of serum creatinine and ALT. The obtained results indicated that feed additive supplementation could modify the function of the kidney and liver in fish exposed to the cadmium toxicity.     

Ecological and agriculture impacts of bakery yeast wastewater use on weed communities and crops in an arid environment

Environmental Science and Pollution Research - The goal of this study was to evaluate the impact of using yeast wastewater (YW) on weed communities. The study showed that all ecological parameters...     

Evaluation of energy savings by using high efficiency motors in a thermal power station

This paper presents potential energy savings by installing high-efficiency motors instead of existing ones and their impact on greenhouse gases emissions reductions. This research study of the energy efficiency of electric motors has been performed in a typical thermal power plant. In the literature, the focus has been mainly on separate and away electric motors from operating facilities. The important advantage of this paper over other studies is that it uses the actual motors’ efficiency in the evaluation. The gains both in terms of electrical energy savings and in terms of financial economy by using high-efficiency motors have been discussed. As a result, the energy saving can be expected as 12.6% at the operating rate. This excellent result also reduces greenhouse gas emission by 1,423 tons every year. The analysis of the data provided an overview on energy losses often generated by the degradation and rewinding of electrical motors. This study represents very encouraging results that will help energy managers of industrial plants to become more involved in energy efficiency strategies.     

New Poly(aniline-<Emphasis Type="Italic">co</Emphasis>-<Emphasis Type="Italic">o</Emphasis>-phenylenediamine)/Kaolinite Microcomposites for Water Decontamination

Copolymers of aniline and o-phenylenediamine/kaolinite composites were synthesized by 5:1 molar ratios of the respective monomers with different percentages of nanoclay via modified in situ chemical co-polymerization. The results were verified by measuring the FT-IR and UV–vis absorption spectra for PANI-o-PDA/kaolinite composites. The thermal behaviour of the copolymer and composites was studied. PANI-o-PDA/kaolinite composites were thermally more stable than pure copolymer. Surface morphology of copolymer composites was recorded at different magnification power by SEM which revealed whitish micrometric beads distributed all over the field with particle size in the range of 0.122–0.233 μm. This work demonstrates that the PANI-o-PDA/kaolinite composites particles can be considered as potential adsorbents for hazardous and toxic metal ions of water from lake El-Manzala, Egypt. All of Cd(II), Cu(II), and Pb(II) posed dangerous health risk to the local population via fish consumption.     

Spatial and temporal projected distribution of four crop plants in Egypt

This study focuses on the management of the local agroecosystems in order to adapt planting or sowing practices for the projected climate change scenarios. It is projected that there will be increased air temperature throughout all four seasons in the coming 100 years, from the southern towards the northern parts of Egypt. The objective of this study is to investigate the influence of that increased air temperature on the spatial and temporal distribution of four of the major economic crops in Egypt. The study species are cotton (Gossypium barbadense L., cv. Giza 89), wheat (Triticum aestivum L., cv. Gemiza 9), rice (Oryza stiva L., cv. Sakha 101) and maize (Zea mays L., cv. Hybrid 10). Optimum air temperature allowing maximum growth for each of the study crop cultivars and the current and projected air temperature patterns in the future years were used for projection of the seasonal and crop distribution maps in the years 2005, 2025, 2050, 2075 and 2100. Results showed that sowing dates of a target crop may be managed in order to allow maximum predicted planting area in the same region. The current maximum area suitable for planting the Cotton crop in Egypt (104 thousand Fadden/year; one Fadden = 0.96 hectare or 0.42 acre) showed few variations over the coming hundred years. In this case, the sowing dates should be changed from the hotter months (February to April) to the cooler months (January to February). Alternatively, a great reduction in the area planted by Wheat crop was predicted in the coming 100 years. Despite the early planting, a reduction of about 147 thousand Fadden/year was projected by the year 2075. On the other hand, with earlier sowing dates, the maximum areas that are planted by Rice and Maize may not be greatly affected by the projected increase in air temperature.