Raw sewage sludge was characterized by XRD, FTIR, SEM, and TGA techniques and incinerated in temperature range 650-950• C for 2 h. The effect of incineration temperature on the microstructure and pozzolanic activity of the resultant ash was investigated by techniques mentioned above as well as Chapelle test. It was concluded that incineration of sewage sludge affects the microstructure and pozzolanic activity of the resultant ash. During incineration at temperatures lower than 800• C, amorphous silica captures fixed carbon resulting from incomplete combustion conditions whereas at higher temperatures crystallization of amorphous silica was enhanced. Hydration products formed from hydrothermal treatment of silica fume with lime is amorphous whereas that of sewage sludge ash is fibrous. Hence, incineration of sewage sludge ash must be optimized at 800• C to preserve the pozzolanic activity of the resultant ash.

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e aim of the present study is to investigate the hydration characteristics and the �re resistance of sewage sludge ash blended cement pastes by the determination of compressive strength, bulk density, and total porosity in addition to XRD and SEM techniques. Sewage sludge ash modi�es the hydration of cement because of its pozzolanic reaction with portlandite favoring the formation of crosslinked �brous calcium silicate of low Ca/Si ratio. Hence, it was concluded that thermal damage of cement pastes a�er the exposure to high treatment temperatures (i.e., crack formation and loss of mechanical properties) was effectively reduced with sewage sludge as content up to 20 wt% because of that the presence of crosslinked �brous calcium silicate strengthens the cement matrix.

The potential to remove or reduce the risk of Mn(II) from ground water through adsorption using Sugar Cane Bagasse (SCB) and Beet Pulp (BP) as a low cost natural wastes was investigated. The SCB and BP were characterized using Fourier transform infrared spectra (FT-IR) and Scanning Electron Microscope (SEM). The adsorption was taken in batch experiments under different parameters such as pH (2.0-10.0), weight of phase (0.25-2.5 g), contact times (10-180 min), initial concentration (2.0-10.0 ppm). Under the optimum conditions, the percentage removals of Mn(II) using SCB and BP were 62.5 and 86.36%, respectively. The rate limiting step of the adsorption was studied using different kinetic models such as pseudo-first-order, pseudo-secondorder adsorption equation, elovich equation and the intraparticle diffusion model. Kinetics data was best fitted with the pseudo-second-order type. This method has been successfully applied for reduce the risk of Mn(II) from ground water samples.