In this work three H 2 S scavengers were prepared by reacting monoethanolamine with formaldehyde in different ratios (1:1, 2:1 and 2:3) to give MF1, MF2 and MF3, respectively. The chemical structures of the prepared scavengers were confirmed by FT-IR spectroscopy. The effect of reaction time (the time required for completing the reaction between the scavenger and the H 2 S gas) has been studied for the three prepared scavengers. The effects of concentration and temperature have been studied on the scavenging efficiency of H 2 S using three prepared products and two commercial products EPRI-710 and EPRI-730. The surface and thermodynamic parameters of the prepared scavengers were determined at 25°C including, surface tension (c), and effectiveness, maximum surface excess (C max ) and minimum surface area (A min ). Also, the standard free energy of micellization and adsorption was recorded. The results show that the efficiency of scavengers increased with increasing reaction time up to 50 min. Also, as concentration of scavengers and temperature increased, the removal efficiency of the scavengers increased. By comparing the efficiency of the prepared products with the commercial products EPRI-710 and EPRI 730, it was found that, MF3 exhibited a similar efficiency comparing with the commercial scavenger EPRI 730 (currently used in the field) at different concentrations and temperatures. ª 2014 Production and hosting by Elsevier B.V. on behalf of Egyptian Petroleum Research Institute.

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In Egypt, water treatment consumes about 365 000 tons of aluminum sulfate and produces more than 100 million tons of sludge per year. The common disposal system of sludge in Egypt is to discharge it into natural waterways. Toxicity of aluminum, environmental regulations and costs of chemicals used in water treatment and sludge treatment processes led to an evaluation of coagulant recovery and subsequent reuse. The present work aimed at aluminum recovery from sludge of El-Shiekh Zayd water treatment plant (WTP) to produce aluminum sulfate coagulant. Sludge was characterized and the effect of five variables was tested and the process efficiency was evaluated at different operating conditions. Maximum recovery is 94.2% at acid concentration 1.5 N, sludge weight 5 g, mixing speed 60 rpm, temperature 60 °C and leaching time 40 min. Then optimum conditions were applied to get maximum recovery for aluminum sulfate and compared to commercial coagulant on raw water of El-Shiekh Zayd (WTP).

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