THE PARAMETERS OF ENERGY BIOMASS PLANTS FROM HYBRID CONSTRUCTED WETLAND WASTEWATER TREATMENT PLANTS

The aim of this paper was to estimate energy parameters of the plants obtained from constructed wetland installations. The subject of the study consisted of two plant species biomass: Jerusalem artichoke (Helianthus tuberosus) and giant miscanthus (Miscanthus x giganteus). The samples of ground plant parts, consisting of a mixture of stalk and leaves were taken in August to anaerobic fermentation. The research tests on productivity and physico-chemical composition of the plants were made after growing season. The yield of giant miscanthus amounted 4.21 Mg DM ha(-1) and 8.31 Mg DM ha(-1) for Jerusalem artichoke. The NCV ranged between 17.55-17.62 MJ.kg(-1) DM, and the GCV of analyzed plants biomass varied from 18.74 (giant miscanthus) to 18.80 MJ.kg(-1) DM (Jerusalem artichoke). Biomethane production during anaerobic fermentation was higher from Jerusalem artichoke biomass (75.46 m(3).Mg-1 FM) than from giant miscanthus (54.45 m(3).Mg-1 FM). The methane concentration in biogas was 51.55-54.07%. Due to results of biomass production per hectare it was possible to calculate biomethane production per hectare of each substrate. In this parameter Jerusalem artichoke also reached score -1540 m(3).ha(-1) which is over half times higher than substrate with value -801 m(3).ha(-1) for giant miscanthus.