الفهرس 
IntroductioOnly 14 pages are availabe for public view
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Abstract
This twelve months pilot-scale study revealed the effect of various types of media on the removal of contaminants from wastewater in planted constructed wetland models. The obtained results demonstrate that media variation has a significant effect on the removal efficiency of pollutants. The best removal efficiencies (88% for both BOD and COD, 88.5% for TSS, 78% for ammonia, 85% for phosphate, 72% for Zn2+, 71% for both Fe3+ and Mn2+, 64% for Pb2+ and 41% for Cd2+) were achieved when the media was a mixture of plastic and polystyrene foam. The expected mechanisms for these results are; the addition of polystyrene foam improved the aeration condition necessary for promoting the aerobic oxidation condition of organic matters, oxidizing ammonia, and nitrifying bacteria. The produced treated water were convenient with the stated regulations for domestic wastewater discharge in Egypt and suitable for use in many secondary needs such as irrigation of gardens and playground and cleaning roads instead of using river Nile water. The study revealed that the constructed wetland systems offer an economic benefit for wastewater treatment since there is no or less energy required for the operating system. The most important results of this research are: Plastic gave the highest reduction rate of pollutants in all tested samples, followed by gravel in second order and rubber in third. Polystyrene foam increased the efficiency of all media used in this experiment with all tested samples, after mixing it with each medium. The plastic/polystyrene mixture is considered the best medium used in this study. Effect of flow and flow rate on treatment efficiency was explained, as the lower flow rate increased the percentage of removal efficiency of different pollutants, and vice versa. The study demonstrated the ability of horizontal sub-surface flow constructed wetlands to treat different pollutants in wastewater at different concentrations and at very low construction and maintenance cost compared to conventional systems.