In this paper the degrading activity of enzymes derived from orange peels (Citrus x sinensis). grapefruit (Citrus paradise) and pineapple (Ananas comosus) on the organic matter in wastewater is evaluated. This activity is measured indirectly by quantifying the biochemical oxygen demand (COD) before and after degradation process based on a period of time using the HACH DR / 2010. and t... https://spencertifieders.shop/product-category/printers/