Bioremediation of wastewater effluents using ashes and microalgae

Agricultural and industrial effluents which contain several macronutrients and
micronutrients, have a huge potential for eutrophication of water bodies due to its high organic load. For
this reason their treatment is essential to avoid problems like pollution of water streams and air and
contamination of soil and water with pathogens. The growth of microalgae in the effluents is a method of
performing the remediation of these effluents with the advantage of obtaining a biomass that can be used
as fertilizers or feed, not requiring substantial use of arable land, and contributing to reduce atmospheric
CO2 levels [1, 2]. Nevertheless, some agricultural effluents with high organic loads or landfill leachates
with high concentrations of organic and inorganic contaminants, are difficult to remediate with microalgae
due to their high optical density, presence of toxic contaminants and high microbiological contamination.
In this work the pretreatment of recalcitrant effluents with biomass ashes was tested in order to reduce the
organic load and optical density of a manure effluent from a pig production industry and a landfill leachate,
and thus allow the bioremediation of the treated effluents with different microalgae