The treatment of brewery wastewater for reuse by integration of coagulation/flocculation and sedimentation with carbon nanotubes ‘sandwiched’ in a granular filter bed

A semi-continuous laboratory scale water treatment plant used in the treatment of brewery wastewater. •Brewery wastewater was treated by integration of various treatment processes.•Coagulation/flocculation and sedimentation improved efficiency of filter.•Added CNTs to coagulation/flocculation tanks and filter bed enhanced performance. The unavailability of adequate fresh and clean water is a major driver to finding new effective methods for treating wastewater for reuse. For example, the brewery industry is one industry that requires the use of large volumes of clean water in its beer production. However, a large amount of effluent generated during the brewing process is largely polluted by both organic and chemical impurities. Therefore, there is need to purify brewery wastewater from an environmental perspective when wastewater is discharged back into the environment and from an economic standpoint where a lot of water go into the production process. This study deals with the integration of treatment systems and devices in order to reduce turbidity and chemical oxygen demand (COD) in brewery wastewater for re-use. For this purpose, a semi-continuous laboratory scale water treatment plant (semi-continuous LSWTP) was used. Several treatment schemes were evaluated in the semi-continuous LSWTP. As expected, the presence of coagulation/flocculation and sedimentation steps was found to improve the efficiency of the semi-continuous LSWTP. Particularly, the treatment scheme in which carbon nanotubes (CNTs) were added to both the coagulation/flocculation tanks and the filter bed was found to be the best option for the treatment of brewery wastewater. This treatment scheme removed 96.0% of COD and residual turbidity of only 5NTU remained in the effluent.