Pressure control for minimizing leakage in water distribution systems

In the last decades water resources availability has been a major issue on the international agenda. In a situation of worsening scarcity of water resources and the rapidly increasing of water demands, the state of water losses management is part of manâs survival on earth. Leakage in water supply networks makes up a significant amount, sometimes more than 70% of the total water losses. The best practices suggest that pressure management is one of the most effective way to reduce the amount of leakage in a water distribution system. The approach presented in this study is aimed at modeling leakage as a function of pressure and pipe length, calibrating leakage coefficient, using fixed pressure reducing valves (PRVs) to develop pressure fluctuation and developing WaterCAD scenarios to minimize leakage through the most effective settings of PRVs. This approach was applied on a district metered area (DMA) in Alexandria, Egypt. The application of this approach produced some encouraging results, where the leakage through DMA was dropped by 37% for the best scenario. Thus, this approach is recommended as a decision support tool for determining a desirable solution for leakage reduction. Keywords: District measure area, Infrastructure leakage index, Leakage, Pressure management, Water supply network

Treatment of drainage water containing pharmaceuticals using duckweed (Lemna gibba).

AbstractThe potential use of duckweed (Lemna gibba) system to remove pharmaceuticals from drainage water (DW) was investigated. The system achieved removal of 66.12±1.4%, 47.50±2.0% and 66.50±1.7% for 1000μg/L of acetaminophen (ACT), diclofenac (DFC), and progesterone (PRG), respectively. The uptake rate (kr1) of ACT, DFC, and PRG was significantly decreased from 0.884±0.12 to 0.199±0.02, from 0.528±0.02 to 0.152±0.01 and from 0.719±0.03 to 0.264±0.01 at increasing the initial concentration from 1 to 1000μg/L, respectively. Moreover, the duckweed uptake contributed the major removal pathway followed by duckweed sorption and microbial degradation for ACT, DFC and PRG