Assessing the environmental impact of bone char production by in-situ emission monitoring and life cycle assessment

Abstract

Animal bone char has long been used as an adsorbent for removing fluoride from drinking water. It is particularly popular in developing countries owing to the readily available raw materials, simple manufacturing process, low cost, and ease of use on a household scale. Widespread production of bone char has been implemented, but the resultant impact on the environment has not been fully investigated and the sustainability of this technology is unknown.This paper aims to be the first primary research on the environmental impact of bone char production. A systematic life cycle assessment (LCA) of the bone char production process was undertaken, with primary data gathered from a bone char workshop in Tanzania. Results of in-situ emission monitoring show that the production of 1 kg of bone char directly generates 3.53 ± 0.16 kg of CO2, 134.57 ± 6.79 g of CO, and 3.85 ± 0.42 g of SO2. Life cycle impact assessment indicates that the transport stage has a major influence on most environmental impact categories under study, whereas the charring gas emissions are the largest contributor to climate change and terrestrial acidification. Sensitivity analysis suggests that increasing the loading capacity of the vehicle diminishes the negative impact of the transport stage. The environmental cost of producing 1 kg of bone char (0.25 €) outweighs its local market price (0.13 €).