Gaza wastewater treatment plant as a model for low cost wastewater treatment technology in semi-arid environment

Gaza Wastewater Treatment Plant (GWWTP) is a well-established facility, and was used to study the suitability of individual treatment components as possible low cost treatment systems for semi-arid regions in terms of removal efficiency. Samples were taken at weekly intervals over an 18 week period. During this period there were significant removals of BOD, COD and TSS. The removal efficiencies of BOD and TSS in the anaerobic component were 41% and 44% respectively, while BOD removal efficiencies in the bio-towers and aerated lagoons were 56% and 51% respectively. Calculations to predict the expected removal efficiencies of each individual component match those observed, based on analyzed samples, except for the anaerobic treatment facility where lagoons are partially filled with sludge, as a consequence of which the hydraulic retention time is less than assumed. Taken as a whole the average reductions for BOD, COD and TSS were 90, 86 and 88% respectively. All these reductions mean that the final effluent is able to satisfy the guidelines for discharge to the sea.