TY - JOUR
T1 - Phycoremediation of landfill leachate with the chlorophyte Chlamydomonas sp. SW15aRL and evaluation of toxicity pre and post treatment
AU - Paskuliakova, Andrea
AU - McGowan, Ted
AU - Tonry, Steve
AU - Touzet, Nicolas
N1 - Publisher Copyright:
© 2017 Elsevier Inc.
PY - 2018/1
Y1 - 2018/1
N2 - Landfill leachate treatment is an ongoing challenge in the wastewater management of existing sanitary landfill sites due to the complex nature of leachates and their heavy pollutant load. There is a continuous interest in treatment biotechnologies with expected added benefits for resource recovery; microalgal bioremediation is seen as promising in this regard. Toxicity reduction of landfill leachate subsequent to phycoremediation was investigated in this study. The treatment eventuated from the growth of the ammonia tolerant microalgal strain Chlamydomonas sp. SW15aRL using a N:P ratio adjustment in diluted leachate for facilitating the process. Toxicity tests ranging over a number of trophic levels were applied, including bacterial-yeast (MARA), protistean (microalgae growth inhibition test), crustacean (daphnia, rotifer) and higher plant (monocot, dicot) assays. Ammonia nitrogen in the diluted landfill leachate containing up to 158 mg l−1 NH4+-N (60% dilution of the original) was reduced by 83% during the microalgal treatment. Testing prior to remediation indicated the highest toxicity in the crustacean assays Daphnia magna and Brachionus calyciflorus with EC50s at 24 h of ~ 35% and 40% leachate dilution, respectively. A major reduction in toxicity was achieved with both bioassays post microalgal treatment with effects well below the EC20s. The microalgae inhibition test on the other hand indicated increased stimulation of growth after treatment as a result of toxicity reduction but also the presence of residual nutrients. Several concurrent processes of both biotic and abiotic natures contributed to pollutant reduction during the treatment. Modifying phosphate dosage especially seems to require further attention. As a by-product of the remediation process, up to 1.2 g l−1 of microalgal biomass was obtained with ~ 18% DW lipid content.
AB - Landfill leachate treatment is an ongoing challenge in the wastewater management of existing sanitary landfill sites due to the complex nature of leachates and their heavy pollutant load. There is a continuous interest in treatment biotechnologies with expected added benefits for resource recovery; microalgal bioremediation is seen as promising in this regard. Toxicity reduction of landfill leachate subsequent to phycoremediation was investigated in this study. The treatment eventuated from the growth of the ammonia tolerant microalgal strain Chlamydomonas sp. SW15aRL using a N:P ratio adjustment in diluted leachate for facilitating the process. Toxicity tests ranging over a number of trophic levels were applied, including bacterial-yeast (MARA), protistean (microalgae growth inhibition test), crustacean (daphnia, rotifer) and higher plant (monocot, dicot) assays. Ammonia nitrogen in the diluted landfill leachate containing up to 158 mg l−1 NH4+-N (60% dilution of the original) was reduced by 83% during the microalgal treatment. Testing prior to remediation indicated the highest toxicity in the crustacean assays Daphnia magna and Brachionus calyciflorus with EC50s at 24 h of ~ 35% and 40% leachate dilution, respectively. A major reduction in toxicity was achieved with both bioassays post microalgal treatment with effects well below the EC20s. The microalgae inhibition test on the other hand indicated increased stimulation of growth after treatment as a result of toxicity reduction but also the presence of residual nutrients. Several concurrent processes of both biotic and abiotic natures contributed to pollutant reduction during the treatment. Modifying phosphate dosage especially seems to require further attention. As a by-product of the remediation process, up to 1.2 g l−1 of microalgal biomass was obtained with ~ 18% DW lipid content.
KW - Biomass generation
KW - Landfill leachate
KW - Microalgae
KW - Phycoremediation
KW - Toxicity testing
UR - http://www.scopus.com/inward/record.url?scp=85029531875&partnerID=8YFLogxK
U2 - 10.1016/j.ecoenv.2017.09.010
DO - 10.1016/j.ecoenv.2017.09.010
M3 - Article
C2 - 28926816
AN - SCOPUS:85029531875
SN - 0147-6513
VL - 147
SP - 622
EP - 630
JO - Ecotoxicology and Environmental Safety
JF - Ecotoxicology and Environmental Safety
ER -