Coffee Spent Ground-Based Biochar's Properties and Application: A Systematic Review

Coffee is one of the most potential commodities in the world, being the second most traded commodity. Currently, it is consumed as the second-largest beverage around the world and has become part of the lifestyle of today's generation. As a result of the increasing number of its utilisation, it generates a considerable amount of waste, the coffee spent grounds (CSG) is one of the instances. In general, the CSG that are produced are only disposed of directly (landfill). On the other hand, CSG still contains carbohydrates, oil, nitrogen and carbon which have the potential to be used to produce several products as a means of valorization, including biodiesel, biopolymers, composites, compost and biochar. The purpose of this study was to systematically review the use of CSG as a feedstock of biochar, conditions of biochar production and application as an adsorbent of chemicals causing environmental damage. The research method used a systematic review of the selected journals on the topics, then was further analyzed both in the theory and content. The results of the literature review suggest that CSGs have potential use as a feedstock for biochar production and have been researched for an adsorbent on a wide range of pollutants. The CSG biochars are effective adsorbents for cadmium (II), Tetracycline, Metal Cu, Sulfamethoxazole compounds and are ineffective on Herbicide.