Use of Stabilized Textile ETP Sludge as Partial Replacement of Cement

Abstract

Contaminated textile effluent treatment plant (ETP) sludge with heavy metals has become a major environment issue. One of the possible ways to using the sludge is in building materials. However, ETP sludge contains heavy metals, that affect mechanical properties of concrete when used. Some heavy metals that affect human health and is associated to have caused serious diseases which interrupts kidney, nervous system and blood vessels. In this study, appropriate treatment technology such as stabilization method are being used and to some extent, it is capable of controlling these metals. The object of the study is to stabilized sludge so as to control leaching of heavy metal. One of the main objectives of this study is to evaluate utilizing stabilized effluent treatment plant sludge in cement mortars. For stabilization, Low-grade MgO is used in this study. Low-grade MgO is an economically feasible alternative in the stabilization of heavy metal from contaminated sludge. The cement is replaced with 5%, 10% and 15% with or without stabilize textile ETP sludge. The compressive strength of mortar cube and sorptivity of a cylinder with the use of textile ETP as a partial replacement with cement is evaluated. The microstructure of the mortar mix was analyzed by Scanning electron microscopy (SEM). The leachability of heavy metals was analyzed by Inductively coupled plasma atomic emission spectroscopy (ICP-AES). At different percentage of stabilization of textile ETP sludge with LG-MgO, pH was measured by pH meter. It was observed that with an increase in the percentage of replacement of cement with textile ETP sludge in a mortar the compressive strength reduces gradually whereas the use of stabilized sludge lead to increase in the compressive strength compared to control mix. The maximum compressive strength was achieved in 5% replacement level. The cement stabilized sludge mortar samples meet the required strength for structural as well as nonstructural applications. The water absorption, sorptivity decreases with increase in replacement level of stabilized textile ETP sludge.