Evaluation of electrokinetic-assisted phytoremediation efficiency of dibutyl phthalate contaminated soil by maize (Zea mays L.) under different electric field intensities.

The excessive accumulation of dibutyl phthalate (DBP) in soil poses a serious threat to soil ecosystems and crop safety production. Electrokinetic-assisted phytoremediation (EKPR) has been considered as a potential technology for remediating organic contaminated soils. In order to investigate the effect of different electric fields on removal efficiency of DBP, three kinds of electric fields were set up in this study (1 V·cm-1, 2 V·cm-1 and 3 V·cm-1). The results showed that 59 % of DBP in soil was removed by maize (Zea mays L.) within 20 d in low-intensity electric field (1 V·cm-1), and the accumulation of DBP in maize tissues decreased significantly compared to the non-electrified treatment group. Interestingly, it could be observed that the low-intensity electric field could maintain ion homeostasis and improve the photosynthetic efficiency of the plant, thereby relieving the inhibition of DBP on plant growth and increasing the chlorophyll content (94.1 %) of maize. However, the removal efficiency of DBP by maize decreased significantly under the medium-intensity (2 V·cm-1) and high-intensity electric field (3 V·cm-1). Moreover, the important roles of soil enzyme and rhizosphere bacterial community in low-electric field were also investigated and discussed. This study provided a new perspective for exploring the mechanism of removing DBP through EKPR.

Advances and research needs for disinfection byproducts control strategies in swimming pools.

The control of disinfection byproducts (DBPs) in swimming pools is of great significance due to the non-negligible toxicity and widespread existence of DBPs. However, the management of DBPs remains challenging as the removal and regulation of DBPs is a multifactorial phenomenon in pools. This study summarized recent studies on the removal and regulation of DBPs, and further proposed some research needs. Specifically, the removal of DBPs was divided into the direct removal of the generated DBPs and the indirect removal by inhibiting DBP formation. Inhibiting DBP formation seems to be the more effective and economically practical strategy, which can be achieved mainly by reducing precursors, improving disinfection technology, and optimizing water quality parameters. Alternative disinfection technologies to chlorine disinfection have attracted increasing attention, while their applicability in pools requires further investigation. The regulation of DBPs was discussed in terms of improving the standards on DBPs and their preccursors. The development of online monitoring technology for DBPs is essential for implementing the standard. Overall, this study makes a significant contribution to the control of DBPs in pool water by updating the latest research advances and providing detailed perspectives.

Removal of Di-n-butyl phthalate from aged leachate under optimal hydraulic condition of leachate treatment process and in the presence of its dominant bacterial strains.

The effects of hydraulic condition of reactor and the dominant degrading bacteria on the removal of di-n-butyl phthalate (DBP) from aged landfill leachate by anaerobic/anoxic/oxic (A/A/O) leachate treatment process were investigated. The optimal DBP removal (96.0%) was obtained from aged leachate when the hydraulic retention time (HRT) of the reactor was 3 d, internal reflux ratio of the reactor was 200%, and external reflux ratio of the reactor was 60%, respectively. The removal efficiency of DBP was significantly improved after the inoculation of the dominant DBP-degrading bacteria (Pseudomonas sp. W1) in the reactor. The mean removal efficiencies of DBP before and after inoculation were 94.1% and 97.7%, respectively. Furthermore, the inoculation of dominant DBP-degrading bacteria changed the original sludge structure and characteristics, which was more conducive to the removal of DBP. These results provide theoretical basis for the effective removal of DBP from aged leachate by the biological treatment process.