Algicide In Traditional Chinese Medicine-Selection And Algicidal Effect Research

The occurrences of eutrophication are nowadays in a growing trend in China and algal blooms are becoming increasingly severe environmental problems, which poses great harm to water environment and ecological safety. Conventional algal inhibition method of physical, chemical and biological methods are usually unsatisfactory and likely to cause secondary pollution. This research focuses on the most common alga in water blooms Microcystis aeruginosa, treated with active substances extracted from 20 traditional Chinese medicine including Evodia Rutaecarpa, Cortex Periplocae, Fructus Xanthii, Fructus Toosendan, Rhizoma Curculiginis, Radix Sophorae Tonkinensis, Rhizoma Typhonii Gigantei, Rhizoma Pinelliae, Semen Armeniacae Amarum, Rhizoma Coptidis, Rhizoma Curcumae Longae, Cortex Fraxini, Radix Pulsatillae, Flos Syzygii Aromatici, Radix Glycyrrhizae, Galla Chinensis, Radix Clematidis, Fructus Arctii, Cortex Pseudolaricis, Radix Sophorae Flavescentis. Effective extracts were selected and their algae-lysing effect against Microcystis aeruginosa were observed in details.The algae-lysing effect against Microcystis aeruginosa shows that:extracts from Galla Chinensis, Evodia Rutaecarpa, Cortex Fraxini, Rhizoma Coptidis, Cortex Periplocae, Rhizoma Curcumae Longae has the best algae-lysing effect, with a removal rate of over 80% within 14 days in terms of chlorophyll a. Extracts from Fructus Xanthii, Radix Clematidis, Flos Syzygii Aromatici, Radix Glycyrrhizae, Radix Pulsatillae, Fructus Toosendan, Rhizoma Curculiginis have moderate algae-lysing effects against Microcystis aeruginosa, with chlorophyll removal rates ranging from 50%-80% within 14 days. Extracts from Radix Sophorae Tonkinensis, Rhizoma Typhonii Gigantei, Fructus Arctii, Rhizoma Pinelliae had unsatisfactory algae-lysing effects against Microcystis aeruginosa, with chlorophyll a removal rates of less than 30% within 14 days. Extracts from Semen Armeniacae Amarum, Cortex Pseudolaricis, Radix Sophorae Flavescentis are able to promote the growth of Microcystis aeruginosa, while the algae cells treated with extracts from Galla Chinensis, Evodia Rutaecarpa will cease from growing.Results from the study on the effect of extracts from Galla Chinensis, Evodia Rutaecarpa showed that:extracts from Galla Chinensis has a preferable algae-lysing effect against Microcystis aeruginosa with comparative fast lysing processes even at lower concentrations. The algae cells do not rupture during the algae-lysing process, which prevent the secondary pollution caused by the release of the intracellular substances. Extract from Evodia Rutaecarpa also has a preferable algae-lysing effect against Microcyslis aeruginosa, but the lysing process is moderate comparing with extract from Galla Chinensis. Algae cells can not be completely lysed during the treatment while the algae-lysing prcess will cause the release of the intracellular substances 24 to 48 h later, which contain large amounts of nitrogen and phosphorus.