Adsorption and desorption of natural and synthetic hormones using biochar

Natural steroidal oestrogens are hormones produced by the endocrine systems of humans and livestock that elicit specific effects on endocrine activity at very low concentration. Synthetic oestrogens are structurally similar, man-made pharmaceuticals designed to mimic natural hormones. Both forms of oestrogen are organic, persistent and regularly detected as pollutants of surface waters and sewage sludges due to incomplete removal during water and sewage treatment processes. Numerous studies have shown oestrogens in the environment to be potent endocrine disrupters, unintentionally disturbing the biological development/functioning of many species (eg causing feminisation). As global water demand necessitates reuse of wastewaters and food scarcity encourages use of manures/sewage sludges as fertilisers, oestrogens - given their range of effects at low-dose - pose a threat to all consumers. Biochar is a form of charcoal created through pyrolysis or gasification of carbon-based biomass, predominantly of plant origin. The resultant carbon-rich product can potentially enrich soils by helping to retain essential nutrients, whilst simultaneously storing carbon. This research seeks to determine whether biochar may act as a suitable, low-tech, low-cost medium to sequester environmental oestrogens from wastewaters and soils. Natural (17b-estradiol, oestrone) and synthetic (17a-ethinyl estradiol, mestranol) oestrogens have been selected for study.