Hydrophytes may play an important role in sewage disinfection in constructed wetlands

摘要

Double agar overlay (DAL) method was used to evaluate the inhibition of hydrophytes extracts on coliphages growth by the plaque forming unit (PFU) assay. The present research investigated allelopathic effects of extracts from different parts of five hydrophytes, Polygonum hydropiper, Polygonum orientate, Phragmites communis, Arundo donax and Typha latifolia on two coliphages, T4 and f2. The results showed that different hydrophytes inhibit coliphage (T4 and f2) to various extents, and the inhibitions of extracts from P. hydropiper were more effective on coliphage T4 and f2 than other hydrophytes. When the concentrations of extracts were 0.5g·L-1, the inhibition rate of P. hydropiper leaf on coliphage T4, f2 were 91, 93%, and the inhibition rate of P. hydropiper stem on coliphage T4, f2 were 65, 61% and the inhibition rate of P. hydropiper root on coliphage T4 f2 were 66,100%. The EC50 of P. hydropiper root on coliphage T4 was 0.6mg·L-1 and the EC50 on coliphage f2 was 7.6mg·L-1. The EC50 on coliphage T4, f2 of A. donax stem were 16 mg·L-1 and the EC50 on coliphage T4, f2 of T. latifolia leaf was 16, 20mg·L-1, respectively. The P. hydropiper root showed the greatest inhibition on coliphage. The allelochemicals produced by P. hydropiper should be isolated and evaluated in the following research. More research should be done to evaluate potential use of P. hydropiper in wastewater virus controlling.