Efficiency of water purification from the food industry using biochar

Today, more than in the past, water is considered a very valuable resource. Efforts to use it efficiently are growing. One method of using water efficiently is wastewater treatment. Well-treated water minimises negative impacts after discharge into a watercourse, i.e., within or adjacent to aquatic ecosystems, or can be reused, for example, in the form of drinking water. This study focuses on the possibility of treating food industry water using biochar as a sorption medium. Biochar from wood pulp (100%) was used for the experiments. The wastewater collected was a mixture from two production plants, focussing on aspics, fish spreads, or cheese processing. The aim of the experiments was to evaluate the efficiency of the sorption properties of a specific type of biochar in terms of its weighting of different masses for an identical volume of wastewater and also in terms of different sorption times (time dependence). The efficiency was addressed in the context of the determination of the chemical oxygen demand with the oxidising agent potassium dichromate (CODCr method). The highest efficiency was achieved in the experiment with a load of 2 g of sorption reagent per litre of wastewater. No trend was demonstrated in the efficiency change with respect to the time of contact of the sorbent with the water.