BACKGROUNDBiofiltration is a technique to remove volatile organic compounds (VOCs) from waste gas streams. It can be regarded as a sustainable treatment technology with low operational costs and good performance. The treatment of hydrophobic compounds is however difficult, due to the low mass transfer towards the water phase on top of the biofilm present on the packing material. To overcome this mass transfer limitation, a hydrophobic silicone foam was added to a conventional biofilter containing compost and wood dowels.RESULTSThe biofilter was operated for 180 days to treat acetone, hexane and dimethyl sulphide at an empty bed residence time of 57 s with inlet load varying up to 4.5 g m3 h‐1. The highest removal efficiency of acetone, dimethyl sulphide and hexane was, respectively, 99%, 80% and 50%. The affinity of the target compounds towards the packing material was quantified in terms of the packing material‐to‐air partitioning coefficient, which was measured using a SIFT‐MS based breakthrough approach. These experiments revealed that hexane has a 20 to 100 times higher affinity for silicone foam than compost and wood. Microbial community analysis was performed on the different substituents of the packing material at the inlet and outlet. No significant differences in relative abundance were observed between the types of packing materials. Comparison with literature revealed the presence of bacterial strains that were not yet reported in biofilter studies.CONCLUSIONSilicone foam in a biofiltration set‐up showed good performances against the degradation of the target VOCs and mass transfer to the packing material can be increased. © 2018 Society of Chemical Industry

This study analyzed e-waste management and capacity need assessment for both the city of Kigali and secondary cities in Rwanda. Questionnaires were used to obtain primary data. Data collected during this study have been analyzed using the Statistical Package for Social Sciences (SPSS v.2020). Using qualitative and quantitative data on e-waste management, this study showed that a large number of respondents used repair and reuse (38.1%) and the main environmental concerns were found to be waste management problems (reported by 77.3% of respondents), water pollution (36.2%), and air pollution (20%), whereas regarding health effects, chronic diseases were the major concern (21.6%). Results showed a significant association between education levels and awareness and dissemination, with respect to Rwanda’s e-waste legislation and general e-waste knowledge. This study showed a need for urgency to introduce an extended producer responsibility (EPR) approach. It recommends the introduction of a disposal fee for every sale of electrical and electronic equipment (EEE).