Abstract:
To guide ecological restoration of salinized eutrophic water, salt-tolerant abilities of five wetland plants, namely Scirpus validus, Thalia?dealbata, Iris ensata var. hortensis, Typha orientalis and Lythrum salicaria were compared by hydroponic experiments and two plants were finally chosen for water purification effect tests. The results showed that five plants could endure a certain degree of salinity, among which Scirpus validus and Lythrum salicaria were more adaptable to salt stress. A slight salinity (2.5‰) was conducive to the removal of ammonia nitrogen, total nitrogen and total phosphorus. The removal rates of phosphorus and ammonia nitrogen of Lythrum salicaria were higher under low salinity, but got worse at salinities above 5.0‰. Under higher salinity, Scirpus validus grew better, whose removal rates of nitrate nitrogen, total nitrogen and phosphorus were 39.5%~55.0%, 33.6%~38.5% and 63.9%~90.2% respectively. Under 0‰~5‰ salinity, Lythrum salicaria and Scirpus validus could be used as alternative plants to purify water. Scirpus validus was the better choice in remedying eutrophic water above 5.0‰ salinity.