The present research deals with the global challenge of managing industrial sludge with respect to sustainability and circular economy principles. It focuses on raw industrial sludge (IS-R) conversion into valuable biochars that can serve as efficient adsorbents for pharmaceuticals in industrial wastewater. Three biochars were produced through sludge pyrolysis at 750 °C either without modification (IS-R-B), or after pre-treatment with 1 M solution of ZnCl2 (IS–ZnCl2–B) or FeCl3 (IS–FeCl3–B). Compared to the pristine biochar, the modified sludge-derived biochars (SDBs) showed improved structural, textural, and surface chemical properties. As a result, IS-ZnCl2-B and IS-FeCl3-B had AMX adsorption capacities of 31.9 and 32.1 mg g−1 which were 41.2% and 42.0% higher than the non-modified biochar, respectively. Moreover, both modified SDBs effectively removed AMX under various experimental conditions, including the presence of competitive ions and over a wide pH range. The AMX removal was found to be spontaneous, endothermic, and primarily controlled by chemical reactions on a monolayer system. These findings suggest that biochars generated from pyrolysis of salt-modified industrial sludge can be used as effective materials for removing pharmaceuticals from water. Therefore, this study supports the concepts of circular economy and sustainable development by offering engineering solutions.
ASJC Scopus subject areas
- Environmental Chemistry
- Pharmaceutical Science
- Management, Monitoring, Policy and Law