Enhancement of EAPR Treatment Using Double Aeration System and Uptake by Pakcoy (Brassica rapa subsp. chinensis)

Abstract

This study was aimed at investigating the effect of electro-assisted and double aeration (EAPR-DA) system to enhance the lead removal in water and uptake by Pakcoy (Brassica rapa subsp. Chinensis). Variable regimes were created by 2 V of constant DC voltage using 2D stainless steel cathode-pot and Ti anode electrode, and aeration level of 10 L/min. The effectiveness of EAPR-DA, EAPR, phyto-aeration, and phytoremediation on the treatment was compared and evaluated by measuring the decrease of lead concentration in the water and accumulated in the plant using flame Atomic Absorption Spectroscopy. Plant stress was evaluated by phytomorphology changed and measurement chlorophyll content using UV-Vis Spectroscopy after the acetone extraction. The results showed that the EAPR-DA system using Pakcoy has a great ability to decrease the lead concentration in water compared with the EAPR, phyto-aeration, and phytoremediation. The removal ability in each reactor was 82.5%, 78.75%, 72.5%, and 61.875% respectively for EAPR-DA, EAPR, phytoremediation. and phyto-aeration. Excessive aeration in the root zone might inhibit lead adsorption by a plant in the phyto-aeration system. In general, the accumulation of lead in plant growth hydroponically has a large concentration in the roots compared to the shoot except for the EAPR-DA system which high adsorption of lead concentration in the shoot part. The BC (1.13) and TF (1.97) value of the EAPR-DA system was higher than the other systems, showing aeration can enhance high adsorption of lead in the root and then transported it into the shoots part. High chlorophyll total (54.89±14.31 mg/mL) and low chlorophyll a/b ratio (1.21±0.38) in the plant under the EAPR-DA system showed that the double aeration in the electro-assisted system encourages the high tolerance of the plant to the lead concentration.