Palm wastes valorization for wastewaters treatment

Abstract

Various palm trees are cultivated worldwide and contribute to the economic development of different countries mainly located in Asia, America, and Africa. The main species include oil palm, date palm and coconut palm. These palm trees and their processing fruits generate huge amounts of biowastes that could be turned into values in different domains such as energy recovery, agricultural soil amendment and environment preservation. In this chapter, the latest developments on palm derived wastes conversion into efficient adsorbents for wastewaters treatment are reviewed. The impact of the nature of the palm waste, as well as the physico-chemical-thermal modification procedure on the derived carbonaceous materials (biochars, hydrochars and activated carbons) are analyzed. The adsorbents performance under various experimental conditions, for the pollutants and nutrients capture is also summarized.\rThis chapter shows that the properties of the palm-derived adsorbents depend not only on the nature of the feedstock, but especially on the employed modification method. The best removal efficiencies for both organic and mineral pollutants from wastewaters were obtained for hybrid modification methods and relatively high activation temperatures. Moreover, it is shown that further investigations on the modifications methods optimization, especially the activated agent nature (CO2, H2O, HNO3, etc.) and the thermal conditions (temperature, and residence time) is required. The test of pilot dynamic set-ups (such as columns and continuous stirring tank reactors) for the removal of pollutants from real contaminated wastewaters is also well recommended. Finally, the test of the reuse of loaded-palm-derived adsorbents with nutrients recovered form wastewaters in agriculture would be an excellent option towards the sustainability and the circular economy promotion.