Valorization of agro-industrial waste in sustainable ceramic materialsTechnical and environmental analysis

Abstract

Increasingly tighter regulations regarding waste, the reduction of the non-renewable resources and its higher prices, the increasing demand for renewable energy sources and green chemicals, are pushing the manufacturing processes toward higher sustainability, to improve cost-effectiveness and meet customers demand, i.e., circular economy. Agro-industrial waste valorization is one of the current research areas that concerned a great deal of researchers over the past few years as a potential alternative of disposal for a wide range of waste/by-products in landfill sites. Landfill, incineration and composting are common technologies for waste disposal. However, they are not satisfactory treating organic waste due to the liberation of methane gas to the atmosphere, unpleasant odour, natural land transformation, high energy consumption and slow reaction kinetics. In fact, research efforts have also been oriented on techniques capable of decomposing organic matter, but, no valuable product can be generated. For that reason, recent research has focused on its utilization as energy source mostly, and recovery matter in alternative uses (e.g., pore forming agents, fertilizer, herbicide removal, silica adsorbent). This research is focused on the alternative uses of different local clay minerals through the valorization of waste/by-products available in the local agro-industry, as a replacement of primary resources to elaborate sustainable clay-based materials like lightweight aggregates (LWAS) for drainage layer in green roofing (LWASGR) and agronomic use (LWASAP).