Study On The Effect Of Eco-Floating Bed Of Epipremnum Aureum And Typha Orientalis On The Growth Of Two Algae

In recent years,China's ecological and environmental problems have become increasingly prominent.With the eutrophication of a large number of lakes and waters,the problem of algae flooding follows.In order to make better use of bio-ecological method to remove algae and to find effective and safe Antialgae substances in terrestrial plants,Epipremnum aureum and Typha orientalis were selected to construct ecological floating beds.The allelopathic effects of two plants and their combination of planting water and extracts on Microcystis aeruginosa and Chlorella vulgaris were studied.The main conclusions are as follows:(1)Experiments on the treatment of Microcystis aeruginosa and Chlorella vulgaris by plant floating bed planting showed that chlorophyll,Typha orientalis and their combined floating bed planting water had a good inhibition and removal effect on Microcystis aeruginosa.The removal capacity under the same biomass was Typha orientalis floating bed > combined floating bed > Epipremnum aureum floating bed.The average chlorophyll a content of Microcystis not affected by the three kinds of planting water.The growth of Chlorella vulgaris was not affected by the floating-bed planting water.Typha orientalis and combined floating-bed planting water could promote the growth of Chlorella vulgaris at low concentration and inhibit the growth of Chlorella vulgaris at high concentration.(2)The results showed that the four extracts of chlorophyll root,chlorophyll leaf,Typha orientalis root and Typha orientalis leaf could inhibit Microcystis aeruginosa at the concentration of 5 g/L to 40 g/L,and the inhibition increased with the increase of concentration.At the concentration of 40 g/L,the removal rates of Microcystis aeruginosa reached 92.4%,93.3%,86.5% and 91.0% respectively.The four extracts could significantly reduce the average chlorophyll a content in Microcystis aeruginosa cells at high concentrations,but only the chlorophyll root extract could significantly inhibit the average chlorophyll a content in Microcystis aeruginosa cells at low concentrations of 5 g/L or 10 g/L.(3)The experiments of adding extracts from different organs of plants into the algae solution of Chlorella vulgaris showed that both the extracts of Radix chlorophylla and Typha orientalis leaves could inhibit the growth of Chlorella vulgaris.The inhibition ability of Radix chlorophylla was higher than that of Typha orientalis leaves,but the effect fluctuated greatly and the highest inhibition concentration was 40g/L.The extracts of Radix chlorophylla could promote the growth of Chlorella vulgaris at low concentration and inhibit it at high concentration.The results showed that the Typha root extract could promote the growth of Chlorella vulgaris from 5 g/L to 40 g/L,and the highest rate was at 10 g/L.(4)Orthogonal test of algae treated with four mixed extracts showed that the removal efficiency of Microcystis aeruginosa was the best when the concentration of four extracts was the highest.Among them,the extracts of Radix chlorophyllae and Radix Typha orientalis played the main role,while the extracts of Radix chlorophylla and leaf Typha orientalis played the secondary role.The effect on chlorophyll a of Microcystis aeruginosa was as follows: Radix chlorophylla > Radix Typha orientalis > leaf > Typha orientalis.Leaves;the effects on the growth of Chlorella vulgaris: chlorophyll root > chlorophyll leaf > Typha orientalis root Typha orientalis leaf.When the concentration of each extract was between 0 and 10 g/L,the optimum concentration of chlorophyll leaf extract was 0 g/L,chlorophyll root extract was 10 g/L,Typha orientalis leaf extract was 2.5 g/L and Typha orientalis root extract was 0 g/L.(5)The results of co-culture experiment between plant ecological floating bed and algae show that the algae-inhibiting effect of plant ecological floating bed is not necessarily consistent with the allelopathic effect of planting water.Under co-culture conditions,the inhibition of Microcystis aeruginosa in the floating bed and the combined floating bed was higher than that in the Typha orientalis floating bed,and the inhibition ability of the high biomass group was higher than that of the corresponding low biomass group.The inhibition ability of co-cultured plant floating-bed Chlorella was higher than that of combined floating-bed chlorella.The inhibition ability of high-biomass floatingbed Chlorella was higher than that of low-biomass floating-bed chlorella.