Direct analysis of valuable by-products in cork wastewater

Abstract

Cork sector plays an important economic role in several Mediterranean regions whose manufacturing process consists of several stages involving waste generation, mainly industrial water or cork boiling wastewater (CBW). These waste products have traditionally been considered as simple pollutants, but CBW contains interesting compounds for recovery, however, their chemical characterization is long, difficult and expensive due to the high organic load. This work studied an advanced valorization of CBW through a sequential process. In a first step, a wide range of phenolic compounds were analyzed in CBWs, identifying the most interesting ones for commercial purposes. Furthermore, the phenolic fraction was separated by green techniques and the supernatant studied to detect and quantify remained by-products, highlighting low molecular weight polyphenols together with significant concentrations of carbohydrates made up of glucose, galactose and arabinose among others. In conclusion, we propose a methodology that offers a quick and efficient way to analyze the most important by-products in CBWs and a design of a recovery and purification process by eco-friendly and efficient techniques.

Keywords

• Cork
• Wastewater
• By-products
• Chromatography
• Analysis