Development of Suppression and Reduction System for Toxic Cyanobacteria in Asia Pacific Region

本研究在泰国的实验池中，考察了沟槽种植水生植物去除营养物与生物反应器固定食肉性微动物相结合的杂交系统对微囊藻等有害蓝藻的抑制效果。将现场未使用的废塑料制成的肌瘤载体填充到生物反应器中，并在通道中种植可食用水生植物Puckboong。该混合系统对有毒微囊藻的去除率进行了长期考察，结果表明该生物反应器的去除率达到95%以上。实验池中几乎未检测到的微动物高密度聚集到生物反应器的载体表面，并观察到大量捕食微囊藻的微动物群落。微囊藻捕食微囊藻后，有可能微囊藻毒素残留在生物反应器中。采用高效液相色谱法（HPLC）对生物反应器出水进行分析，未检出微囊藻毒素。这一结果表明，有能力产生酶的微生物动物或细菌在生物反应器中分解微囊藻毒素。由于微囊藻毒素在生物反应器出水进入河道后被完全分解，提高了水生植物作为食品的安全性。硝态氮和氨态氮的平均去除率分别为40%和30%。另外，长出来的部分蒲蒲大约两周就能从河道中收获一次。通过清除从河道中生长出来的蒲公，可以对池塘水中的营养物质进行适当的管理。此外，该混合系统的主要材料证实在泰国容易获得。

In this study, suppressing effect to harmful cyanobacteria, such as Microcystis by hybrid system which has combined channel planting hydrophyte for removal of nutrients and bioreactor fixing predacious microanimals was examined on experiment pond in Thailand. The fibroid carrier produced with waste plastic which had become unused in the locale was filled to the bioreactor, and Puckboong as eatable hydrophyte had been planted to the channel. The removal ability of toxic Microcystis was examined for a long term by this hybrid system, as a result the bioreactor achieved removal ratio more than 95%. Microanimal almost not detected on the experiment pond was gathered with high dense to the surface of carrier in bioreactor, and a lot of the microanimal community preying on Microcystis was observed. There is a possibility that microcystin remains in the bioreactor after the microanimal preys on Microcystis. As a result of the analysis that used high price performance liquid chromatography (HPLC), microcystin was not detected from outflow water of the bioreactor. This result suggests having the ability to produce enzymes by which either the microanimal or the bacteria in the bioreactor decomposes microcystin. The safety of hydrophyte as for food has improved because microcystin was completely decomposed though outflow water of the bioreactor enters the channel. The average removal ratio of nitrate-nitrogen and ammonium-nitrogen in the channel was 40% and 30% respectively. Moreover, a part of Puckboong that grew up was able to be harvested from the channel once about two weeks. Proper management to remove the nutrient from the pond water became possible by taking out Puckboong that grew up from the channel. In addition, the main material of this hybrid system confirmed obtaining was easy in Thailand.