This book briefly explains on reuses the effluent treatment sludge from a waste water treatment plant in textile factories to make hollow concrete blocks. The main objectives are to increase the value of the treatment sludge from a textile waste water treatment plant and to make a sustainable and profitable disposal alternative for the sludge. Attempts were made to utilize the municipal waste sludge as a fine aggregate in concrete mix for hollow concrete blocks. This practical book presents the results of these studies on potential applications of the textile waste treatment sludge for beneficial uses. A concrete block is used as a building material in the construction of walls. The results in this study show that the ETP sludge mixtures can be used to produce hollow non-load bearing concrete blocks.