| 摘要: |
| 针对化学药剂和粘土絮凝法治理赤潮存在的问题，2002年8月在胶州湾近岸进行了海上围隔杀灭赤潮生物的试验。采用强电离放电的物理方法，将空气中O2和海水中H2O电离离解成OH-等自由基，溶解到一部分海水中形成高浓度的羟基溶液，喷洒在围隔内水面上，其比值浓度为4.2mg/L。当海水中羟基浓度达到0.68mg/L时，赤潮生物叶绿素a含量低于检测的最低值。24h后检测杀死灰甲多甲藻、光甲多甲藻、多纹膝沟藻等33种赤潮生物，其致死率达99.8%，其中藻类孢子的致死率达100%，海水水质亦有明显的改善。试验结果表明，羟基溶液是目前治理赤潮可行的、有效的新方法。 |
| 关键词: 赤潮生物,羟基溶液,围隔试验 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金重点资助项目，600310001号；国家重大基础研究前期研究专项，2002CCC00900号 |
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| TREATMENT OF RED TIDE WITH HYDROXYL RADICALS IN ENCLOSURE EXPERIMENT |
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BAI Xi-Yao1, BAI Min-Dong1, Lü Ji-Bin2, YANG Bo1, ZHOU Xiao-Jian1
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1.Environmental Engineering Research Institute，Dalinn Maritime University;2.Key Laboratory for the Environmental Science and Engineering of Ocean Ecology，Sate Ocean Administration of China
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| Abstract: |
| At present, main methods for remediating red tide in the world are clay coagulation and CuSO4 medication. However, problems are: (1) excess of toxicity coagulants or CuSO4 medicament that would damage the ocean ecosystem; (2) their residuals that are hard to break up and harmful to other organisms; (3) long time process that takes 20min—24hours but is unable to apply in large-scale red tide in ocean.
The author tried to improve the remediation and studied a new method. With the physical method of strong dielectric barrier discharge, O2 in air and H2O in seawater are ionized and decomposed into a large number of activated particles such as OH-, O2, HO2-, HO3-; and so on, and then are dissolved into a part of seawater with the mass transfer efficiency of 98.8% to produce high dissolved hydroxyl radical (OH) concentration of 4.2mg/L. Hydroxyl radical, as the strongest activated particle, occurs all kinds of biochemistry reactions with big molecules of biology and organisms about 1.0s duration, which belong to a dissociative radical reaction as 109 times reaction rate as conventional medicament.
A special procedure based on the strong dielectric barrier discharge and plasma chemical reaction discussed above is designed. An enclosure experiment performed in a funnel-like polyethylene filmed parachute hanging in the sea surface in Jiaozhou Bay, Shandong Province, China. Highly dissolved hydroxyl radical is sprayed to the seawater from the enclosure to kill the red tide organisms. 31 kinds of red tide microorganisms in 6.0m3 fencing are as follows: Nitzschia sp., Chaetoceros lorenzianus, Ch.curvisetus, Skeletonema costatum, Asterionella japonica, Thalassiosina sp., Ch.affinis and so on. As a result, when dissolved hydroxyl radical concentration is 0.68mg/L, the sum of red tide microorganisms decreased from 11.74 x 106/ml to 0.028 x 106/ml. and the killing efficiency reached to 99.89% . 27 kinds of red tide microorganism, such as Ch.curvisetus, Nitzschia sp., Skeletonema costatum, Thalassiosina sp. and so on, were reduced to the lowest limit of measure. Chlorophyll-a was very low beyond the test limit. In addition, hydroxyl radicals can improve the water quality of ocean by purification. Nitrite and ammonium salt decreased 197 times and 60 times respectively, COD reduced to 0, turbidity reduced by 50%, and DO was up to 77.2% due to the decomposition of the residual hydroxyl radicals. Further Bodies of red tide organism were decomposed into C02, H20 and inorganic salts. Therefore, killing of red tide organism using hydroxyl radicals is a “green” method leaving no any minus-effect to ocean environment and ocean biology. |
| Key words: Red tide organisms, Hydroxyl radical, Enclosure experiment |
