Acid modification of waterworks sludge for dye removals: synthetic and real textile wastewater

Application of modified water treatment residuals in water and wastewater treatment: A review

“…For example, Barbooti and Zahraw [ 113 ] observed a mass loss of 16.56% during thermal treatment of the Al-WTR due to the thermal decomposition of the organic content and the possible decomposition of some carbonates. This mass loss is attributed to the conversion of organic matter to inorganic carbon so as to increase Al content for better adsorption and coagulation [ 6 , 101 ]. Spade et al [ 111 ] used pre-wetting of WTRs prior to thermal treatment which resulted in a mass loss of more than 25% and a significant volume gain due to the expansion of micropores caused by moisture evaporation.…”

“…pH pzc is one of the important parameters affecting adsorption process in aqueous phase [ 53 , 82 ]. It is the pH at which net surface charge on the surface become neutral and the numbers of positive and negative charges of the adsorbent are equal [ 6 ]. The pH pzc value aids in interpretation of the adsorption potential of modified WTRs under different pH values [ 1 , 51 ].…”

“…pH pzc of 7.6 for raw WTRs was changed to 6.0 and 5.0 respectively during thermal treatment and combined thermal and acid treatment respectively. This reduction of pH pzc was due to insertion of H + ions to the surface of acid activated WTRs [ 6 ].…”

“…Chantaramanee et al [ 6 ] reported the use of thermal and acid activated WTRs for the removal of methylene blue (MB). Results showed 90% MB removal at 40 g/L of thermally activated WTRs dosage.…”

“…Management of water treatment residuals has emerged as a major issue in recent years due to its large quantity and disposal constraints. At present, most of these residuals are disposed of in landfills or discharged into water bodies [ 4 , 5 ], which is least desired in waste management hierarchy [ 6 ]. However, with the realization of the negative impacts of their carefree disposal, policymakers are planning stricter control on their disposal [ 7 , 8 ].…”