Effect of salt and sodium concentration on the anaerobic methanisation of the halophyte Tripolium pannonicum

The halophyte species Sea Aster (Tripolium pannonicum) was grown with different concentrations of artificial seawater. In a second experiment, T. pannonicum was cultivated with a nutrient solution containing different concentrations of NaCl. This halophyte biomass was used to determine the biogas production potential. According to the findings, it is possible to produce high yields of methane using biomass from halophytes cultivated in the presence of salt. Biogas and methane yield are influenced by the salt content of the plant tissue, however, high concentrations of salt in the anaerobic reactors itself inhibit the biogas and methane production. The highest methane yield is obtained using plant substrates grown at 22.5 g L−1 sea-salt with a value of 313 cm3 g−1 of VS. When treating T. pannonicum with different concentrations of NaCl, biogas and methane yields are highest when using plant substrates grown at 30 g L−1 to produce values of 554 cm3 g−1 of VS and 447 cm3 g−1 of VS, respectively. Other research was carried out to study the effect of sodium on the biogas and methane yields using substrate from T. pannonicum cultured under non-saline conditions and adding different amounts of NaCl to the anaerobic reactors. Adding NaCl to the reactors decreases the biogas and methane production but using a salt-adapted inoculum increases the biogas yield in comparison to the non-adapted inoculum.