一株芽孢杆菌产生物絮凝剂去除赤潮微藻的研究

Study on removing the red tide microalgae via bioflocculant produced by Bacillus sp. strain

以赤潮微藻米氏凯伦藻(Karenia mikimotoi)和塔玛亚历山大藻(Alexandrium tamarense)为受试对象,对一株芽孢杆菌WZ01所产的生物絮凝剂去除赤潮微藻的性能进行了研究。结果表明:芽孢杆菌WZ01所产生物絮凝剂对人工培养的米氏凯伦藻和塔玛亚历山大藻藻液均有去除能力,适宜的絮凝剂质量浓度为40.0~60.0 mg/L,絮凝时间为90~120 min,pH=7.5~8.5,在20~40℃范围内生物絮凝剂对2种微藻的絮凝率无显著区别;Ca^(2+)和Mg^(2+)浓度对生物絮凝剂去除2种微藻有一定影响,适宜浓度为4.0~6.0 mmol/L;适宜条件下生物絮凝剂对人工培养的米氏凯伦藻和塔玛亚历山大藻藻液的絮凝率均超过80.0%。研究表明,芽孢杆菌WZ01所产的生物絮凝剂在去除赤潮微藻方面有应用潜力。

In the present paper,we have made attempts to test ways to remove two kinds of red tide microalgae,Karenia mikimotoi and Alexandrium tamarense by using bioflocculant produced via Bacillus sp. WZ01 strain,through the single factor experiment, including the bioflocculant concentration, flocculation time,pH value,temperature,and the concentrations of Ca^（2＋）and Mg^（2＋）. As is known,in recent years,flocculants have widely been used to remove the red tide microalgae,especially,the bioflocculant,which is the most preferred one for its environmentfriendly features. The results of our study show that the two cultivated microalgae,that is, K. mikimotoi and A. tamarense,can be successfully removed by the said bioflocculant produced via Bacillus sp. WZ01 strain. According to the results of our experiment,the rate of flocculating tends to increase with the increase of the bioflocculant mass concentration from 0 to 60. 0 mg/L,and tends to decrease with the increase of the mass concentration higher than 60. 0 mg/L. The above said experimental results help us to conclude that the optimal mass concentration of the bioflocculant should be made between 40. 0 mg/L and 60. 0 mg/L,with a stabilized flocculating rate going up to be gained via 90 min treatment for K. mikimotoi,and 120 min for A. tamarense. What is more,no significant difference can be found for the flocculating rates of the two microalgae at a temperature interval between 20℃ and 40 ℃,which has also been found influenced by the concentration of Ca（2＋）and Mg（2＋）,with an optimal value staying between 4. 0 mmol/L and 6. 0 mmol/L. What is more,it would be quite possible to obtain the highest flocculating rate（ more than80%） under the optimal conditions as is described above. In conclusion,the results of our experiment indicate that the bioflocculant produced by Bacillus sp. WZ01 strain is fit for the purpose to remove the red tide microalgae.