Constructed wetlands for the treatment of cyanotoxins: initial results

TY - ABST

T1 - Constructed wetlands for the treatment of cyanotoxins: initial results

AU - Martinez I Quer, Alba

AU - Johansen, Anders

AU - Arias, Carlos Alberto

AU - Carvalho, Pedro N

N1 - Conference code: 9

PY - 2021/9

Y1 - 2021/9

N2 - Events of drought and higher temperatures are occurring more often in our environment. This, together with the increased use of fertilizer in agriculture, is leading to the eutrophication and shortage of freshwater reservoirs [1]. Water withdrawn for agricultural usage accounts globally for around 72% of the total surface and groundwater extraction [2]. Irrigation water quality standards suffer from a lack of regulation worldwide. When episodes of water scarcity occur, more vulnerable populations are forced to irrigate their crops with cyanotoxin-polluted water. Consequently, indirect or direct human consumption of cyanotoxins happen, which may lead to several cytotoxic pathologies. We propose the application of vertical flow (VF) constructed wetlands (CWs) as a biotechnology to treat water for irrigation. The hypothesis is that VF systems can remove cyanotoxins while preserving the nutrients from the eutrophic bodies. Initial studies suggested CWs to be a promising technology. Nevertheless, the mechanisms underlying cyanotoxins removal are still unknown [3,4]. We set up thirty-two 12-L unsaturated vertical flow mesocosm systems with three different set-up parameters: gravel vs. sand, Phragmites australis vs. Juncus effusus and presence vs. absence of cyanotoxins. Synthetic water mimicking a eutrophic surface water body (containing 10 µg/L of microcystin-LR and cylindrospermopsin) feeds the mesocosms systems. We have carried out three sampling campaigns analyzing end-point quality water parameters (TOC, TN, pH...) and quantification of the cyanotoxins using LC-MS/MS. At present, we are processing data for identification of cyanotoxin transformation products and developing metagenomic studies to start understanding the perturbance and mechanism of the system when cyanotoxins are added. Initial results indicated a robust set-up system with many possibilities for further development in this recently started PhD project. Also, the potential interdisciplinary possibility to couple advanced environmental chemistry, biofilm studies and metagenomics. The first results will be shown at the conference.

AB - Events of drought and higher temperatures are occurring more often in our environment. This, together with the increased use of fertilizer in agriculture, is leading to the eutrophication and shortage of freshwater reservoirs [1]. Water withdrawn for agricultural usage accounts globally for around 72% of the total surface and groundwater extraction [2]. Irrigation water quality standards suffer from a lack of regulation worldwide. When episodes of water scarcity occur, more vulnerable populations are forced to irrigate their crops with cyanotoxin-polluted water. Consequently, indirect or direct human consumption of cyanotoxins happen, which may lead to several cytotoxic pathologies. We propose the application of vertical flow (VF) constructed wetlands (CWs) as a biotechnology to treat water for irrigation. The hypothesis is that VF systems can remove cyanotoxins while preserving the nutrients from the eutrophic bodies. Initial studies suggested CWs to be a promising technology. Nevertheless, the mechanisms underlying cyanotoxins removal are still unknown [3,4]. We set up thirty-two 12-L unsaturated vertical flow mesocosm systems with three different set-up parameters: gravel vs. sand, Phragmites australis vs. Juncus effusus and presence vs. absence of cyanotoxins. Synthetic water mimicking a eutrophic surface water body (containing 10 µg/L of microcystin-LR and cylindrospermopsin) feeds the mesocosms systems. We have carried out three sampling campaigns analyzing end-point quality water parameters (TOC, TN, pH...) and quantification of the cyanotoxins using LC-MS/MS. At present, we are processing data for identification of cyanotoxin transformation products and developing metagenomic studies to start understanding the perturbance and mechanism of the system when cyanotoxins are added. Initial results indicated a robust set-up system with many possibilities for further development in this recently started PhD project. Also, the potential interdisciplinary possibility to couple advanced environmental chemistry, biofilm studies and metagenomics. The first results will be shown at the conference.

M3 - Conference abstract for conference

T2 - WETPOL 2021: 9th International Symposium on Wetland Pollutants Dynamics and Control

Y2 - 13 September 2021 through 18 September 2021

ER -