Persistent organochlorine pesticide and PCB residues in surface sediments of Lake Qarun,a protected area of Egypt

Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were determined in sediment samples collected from 34 locations in Lake Qarun, Egypt to elucidate their concentrations, distribution, possible sources and potential ecological risk. A total of 25 OCPs and 29 PCBs were identified and quantified. OCPs and PCBs were found to be ubiquitous pollutants in the aquatic environment of Lake Qarun, particular near urban areas reflecting the local usage and input of these pollutants. Total concentrations of OCPs and PCBs in sediments ranged from 1.01 to 164.8 ng g^?1 and 1.48 to 137.2 ng g^?1, respectively. Among OCPs, γ-HCH, heptachlor, aldrin, endrin, p,p′-DDE, oxy-chlordane and endosulfan I and II were the most abundant compounds. The composition of PCB congeners was dominated by the tri-, tetra-, penta- and hexa-chlorinated biphenyls. The ratios of certain metabolites (isomers) to their parent compounds (mixtures) indicated there are still new inputs of lindane, endrin, heptachlor and technical endosulfan to Qarun Lake, while the ratios of (p,p′-DDE + p,p′-DDD)/∑p,p′-DDTs indicate earlier usage of DDT. Contamination levels of PCBs and HCHs can be categorized as moderate to high compared to other urbanized regions worldwide. According to established sediment quality guidelines, γ-HCH, endrin and chlordanes would be more concerned OCP species for the ecotoxicological risk in Lake Qarun.     

Mineralization of particulate organic matter derived from coral-reef organisms in reef sediments of the Gulf of Aqaba

In situ and laboratory incubation experiments in a fringing reef in the Gulf of Aqaba were performed to study degradation rates of particulate organic matter in reef sediments. Coral mucus, clam eggs, and zooxanthellae were used as model particulate organic compounds for these experiments. Aerobic and anaerobic mineralization rates were calculated by dissolved inorganic carbon (DIC) and O₂ fluxes from the sediments under different particulate organic matter additions. Fast enhancement (approximately twofold) of O₂ and DIC fluxes were found with the addition of coral mucus and clam eggs compared with control incubations without addition. Most of the degradation is believed to have occurred anaerobically rather than aerobically (DIC:O₂ ratios were 4.3–28.1). Higher degradation rates of coral mucus and clam eggs were estimated in carbonate sediment than in silicate sediment (1.2–1.6-fold), which was attributed to the different physical and chemical properties of both sediments. Our study shows the significance of the reef sediment as a suitable site for microbial degradation of particulate organic material excreted from different reef community organisms. This may increase the regeneration of nutrients in the reef environment necessary to sustain high biological productivity.     

Investigation of integrated municipal solid waste management strategies for Oman: an assessment of waste diversion,electricity generation and greenhouse-gas emissions

Journal of Material Cycles and Waste Management - The need of an integrated municipal solid waste (MSW) management system to maximize resource recovery and simultaneously reduce greenhouse-gas...     

Modeling a sustainable Saudi Arabian economy: the real issues

This paper develops a macroeconomic framework for creating a competitive and sustainable Saudi Arabian economy, taking into account the interrelationships among social, environmental, and economic factors. The objective of the research is to build a model that will allow for evaluating the effects of a wide range of emissions abatement policies on economic growth and development. The research methodology is grounded in econometric modeling of the Saudi economy over the period 1980–2010. The estimated parameters of the model were used to project long-term gross domestic product (GDP) growth paths based on three environmental degradation abatement scenarios. The results suggest that the sustainability of economic growth in Saudi Arabia critically depends on aggressive emissions-reduction policies since policy scenarios corresponding to higher pollution cuts yielded higher, sustained long-term GDP. The results also broadly reject the Environmental Kuznets Curve (EKC) hypothesis, implying that a turning point in the relationship between CO₂ emissions and per capita GDP is yet to be attained.     

A blessing for the Yangtze River: optimization of Chinese regional policy planning for water yield and purification in the Three Gorges Reservoir Area

Environmental Science and Pollution Research - Land use/land cover (LULC) changes impact the structure and functioning of ecosystems, which consequently influences the provisioning of a range of...     

Cement-based batteries design and performance. A review

Environmental Chemistry Letters - Lithium batteries are increasingly used to store energy, but are limited by high cost, safety concerns, leaking of electrolytes, and low capacity....     

Application of titanium dioxide immobilized on a cellulosic material for the photocatalytic degradation of Acid Black 24 dye in a continuous flow cascade reactor

Environmental Science and Pollution Research - The aim of this work is the study of the photocatalytic degradation of Acid Black 24 dye (AB24), in a continuous flow cascade reactor, using titanium...     

Evaluating the groundwater potential of Wadi Al-Jizi,Sultanate of Oman,by integrating remote sensing and GIS techniques

Environmental Science and Pollution Research - Groundwater resources are highly stressed due to their overuse, especially in the arid region. This study is aimed at discovering potential...