A circular approach for landfill leachate treatment: Chemical precipitation with biomass ash followed by bioremediation through microalgae

The aim of this work was to study an integrated approach for landfill leachate remediation comprising chemical precipitation with biomass bottom ash as a pre-treatment reduce color and turbidity followed by bioremediation through microalgae treatment effluent disposal. Optimal conditions were determined batch experiments found be 160 g L−1 dose, 96 h contact time, overhead agitation at 15 rpm particle size below 500 µm. These led removal efficiencies 74.3% oxygen demand 98.5% color. Large quantities sludge containing excess precipitated compounds formed during the pre-treatment. To minimize solid disposal, tested raw material cementitious aggregate substitute in mortar formulations. Following pre-treatment, inoculated six different species evaluate their ability grow such recalcitrant remediate it. After period 27 days concentration from 0.4 1.2 achieved microalgae. Removal range 18–62% COD, 63–71% N, 15–100% P. At end treatment, algal characterized regarding protein, lipid, fatty acids, carbohydrate, contents. This allows low-cost these effluents when compared present options that include inverse osmosis, valorization ash-rich precipitates improves sustainability overall process.