TY - JOUR
T1 - A circular approach for landfill leachate treatment
T2 - Chemical precipitation with biomass ash followed by bioremediation through microalgae
AU - Viegas, Catarina
AU - Nobre, Catarina
AU - Mota, André
AU - Vilarinho, Cândida
AU - Gouveia, Luísa
AU - Gonçalves, Margarida
N1 - Funding Information:
info:eu-repo/grantAgreement/FCT/OE/SFRH%2FBD%2F131178%2F2017/PT#
info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDP%2F04077%2F2020/PT#
Project ALGAVALOR - Lisboa-01-0247-FEDER-035234, supported by Operational Programme for Competitiveness and Internationalization ( COMPETE2020 ), by Lisbon Portugal Regional Operational Programme (Lisboa 2020) and by Algarve Regional Operational Programme (Algarve 2020) under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund ( ERDF ); Red CYTED P319RT0025 - RENUWAL - Red Iberoamericana para el Tratamiento de Efluentes con Microalgas.
Publisher Copyright:
© 2021 Elsevier Ltd.
PY - 2021/6
Y1 - 2021/6
N2 - 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 to reduce color and turbidity followed by bioremediation through microalgae treatment for effluent disposal. Optimal pre-treatment conditions were determined through batch experiments and were found to be 160 g L-1 ash dose, 96 h of contact time, overhead agitation at 15 rpm and ash particle size below 500 μm. These conditions led to removal efficiencies of 74.3% for chemical oxygen demand and 98.5% for color. Large quantities of sludge containing excess biomass ash and precipitated compounds were formed during the pre-treatment. To minimize solid disposal, this sludge was tested as a raw material for cementitious and aggregate substitute in mortar formulations. Following the pre-treatment, the leachate was inoculated with six different microalgae species to evaluate their ability to grow in such a recalcitrant effluent and remediate it. After a period of 27 days biomass concentration from 0.4 to 1.2 g L-1 were achieved for the tested microalgae. Removal efficiencies were in the range of 18-62% for COD, 63-71% for N, and 15-100% for P. At the end of the treatment, algal biomass was characterized regarding protein, lipid, fatty acids, carbohydrate, and ash contents. This approach allows a low-cost remediation of these recalcitrant effluents when compared with the present options that include inverse osmosis, and the valorization of ash-rich precipitates and microalgae biomass improves the sustainability of the overall process.
AB - 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 to reduce color and turbidity followed by bioremediation through microalgae treatment for effluent disposal. Optimal pre-treatment conditions were determined through batch experiments and were found to be 160 g L-1 ash dose, 96 h of contact time, overhead agitation at 15 rpm and ash particle size below 500 μm. These conditions led to removal efficiencies of 74.3% for chemical oxygen demand and 98.5% for color. Large quantities of sludge containing excess biomass ash and precipitated compounds were formed during the pre-treatment. To minimize solid disposal, this sludge was tested as a raw material for cementitious and aggregate substitute in mortar formulations. Following the pre-treatment, the leachate was inoculated with six different microalgae species to evaluate their ability to grow in such a recalcitrant effluent and remediate it. After a period of 27 days biomass concentration from 0.4 to 1.2 g L-1 were achieved for the tested microalgae. Removal efficiencies were in the range of 18-62% for COD, 63-71% for N, and 15-100% for P. At the end of the treatment, algal biomass was characterized regarding protein, lipid, fatty acids, carbohydrate, and ash contents. This approach allows a low-cost remediation of these recalcitrant effluents when compared with the present options that include inverse osmosis, and the valorization of ash-rich precipitates and microalgae biomass improves the sustainability of the overall process.
KW - Bottom ash
KW - Landfill leachate treatment
KW - Microalgae
KW - Mortars
KW - Precipitation
KW - Wastewater treatment
UR - http://www.scopus.com/inward/record.url?scp=85101433422&partnerID=8YFLogxK
U2 - 10.1016/j.jece.2021.105187
DO - 10.1016/j.jece.2021.105187
M3 - Article
AN - SCOPUS:85101433422
SN - 2213-3437
VL - 9
JO - Journal of Environmental Chemical Engineering
JF - Journal of Environmental Chemical Engineering
IS - 3
M1 - 105187
ER -