In Egypt, water treatment industry consumes about 365,000 tons of aluminum sulfate as coagulant and produces more than 100 million tons of semidried sludge per year. The common disposal system of alum sludge in Egypt is to discharge it into natural water bodies. Toxic nature of free and complexed aluminum species to aquatic life, stringent environmental regulations on disposal of sludge into water bodies and costs of the chemicals used in water treatment process and sludge treatment led to evaluate coagulant recovery and subsequent reuse. The present work aimed at aluminum metal recovery from sludge obtained from El-Shiekh Zayd water treatment plant by acidification method to produce aluminum sulfate coagulant. Sludge from drying beds was characterized and sulfuric acid was selected as the acidic leaching medium and effect of five variables were tested: acid concentration (N), sludge weight (g), mixing speed (rpm), temperature (o C) and leaching time (min) was studied. Moreover, the process efficiency was evaluated at different operating conditions. Then optimum conditions were applied to get maximum recovery for aluminum sulfate. Maximum recovery is 94.2 % at acid concentration 1.5 N, sludge weight 5 g, mixing speed 60 rpm, temperature 60 o C and leaching time 40 min.

Adsorbable organic halide (AOX) compounds known with their toxic effect, produced as by-product for drinking water disinfection. The present work studied the removal of pentachlorophenol (PCP) as a model AOX compound in water. The use of a locally prepared date-pit activated carbon (DPAC) as adsorbent of pentachlorophenol from aqueous solutions was examined over pH range (2-11) and at different temperatures 25, 35, 45 and 55˚C. Langmuir, Frendulich, Temkin and Redlich-Peterson isotherm models were tested for modeling the adsorption isotherm at equilibrium. date-pit activated carbon examined by Elemental Analysis and FTIR.