Microalga-induced biocementation of martian regolith simulant: Effects of biogrouting methods and calcium sources

摘要

A microalga, Thraustochytrium striatum was studied for biocementation of Martian regolith simulant (MRS). Calcium acetate derived from simulated anaerobic digestion (AD) was tested to replace CaCl2 for making biocement. Biogrouting methods, calcium salt/urea molar ratios, and alternative calcium salt were investigated on biocementation with T. striatum. Of biogrouting methods, batch feeding produced columns with maximum unconfined compressional strength of 732 kPa while reducing hydraulic conductivity over 50% compared to the untreated MRS. The simulated AD-derived calcium acetate induced CaCO3 precipitate in biocementation. With T. striatum, calcium acetate could serve as carbon and calcium sources to generate CaCO3 precipitate without urea. (C) 2019 Elsevier Ltd. All rights reserved.