化学氧化剂对水华蓝藻的控制研究

对比了过氧化氢（H₂O₂）、高铁酸钾（K₂FeO₄）和过碳酸钠（Na₂CO₄）3种氧化剂对自然水体中群体蓝藻生长和光合活性的影响.结果发现，3种氧化剂对蓝藻均有快速的抑制效应，且随着氧化剂浓度的增加抑制效果增强.相同氧化剂浓度下，H₂O₂对水华蓝藻的去除能力强于K₂FeO₄和Na₂CO₄，对蓝藻光合系统Ⅱ的最大光量子产量（F_v/F_m）和有效光量子产量（F_v'/F_m'）的抑制效果也更显著.H₂O₂对不同浓度水华蓝藻的控制实验结果表明，初始藻细胞浓度对H₂O₂控藻效果影响较大，细胞密度越大，H₂O₂降解率增加，抑藻效果急剧下降.当初始藻密度为10μg/L和100μg/L，5mg/L H₂O₂的48h降解率分别为64.9%和97.5%，对藻细胞F_v/F_m的抑制率分别为10%和1%.因此，实施H₂O₂控制蓝藻水华的措施应该尽量在蓝藻水华形成早期，即藻密度较低的时候使用.

Research on the Control of Chemical Oxidants over Water-Blooming Cyanobacteria

Algaecide treatment is a management strategy to control cyanobacterial blooms. This study assessed three oxidizers such as hydrogen peroxide (H₂O₂), potassium ferrate (K₂FeO₄) and sodium percarbonate (Na₂CO₄), on mitigating cell numbers and inhibiting the photosynthetic activity of cyanobacteria colonies collected from natural lake. Addition of those three algaecides could disrupt cyanobacteria cells and inhibit the maximum (F_v/F_m) and actual (F_v'/F_m') quantum yield of cyanobacteria, and the inhibitory effect was enhanced when the concentration of algaecides increased. Cyanobacteria cells tended to be more sensitive to H₂O₂, in comparison with other two algaecides. In addition, H₂O₂ decomposed more rapidly, and mitigating efficiency as well as the inhibitory effect of photosynthetic activity declined when cyanobacteria biomass increased. When the initial cell density was 10and 100μg/L, the inhibition rate of 5mg/L H₂O₂ on the maximum quantum yield of cyanobacteria was 10% and 1%, while the degradation rate was 64.9% and 97.5%, respectively. These results indicated that using H₂O₂ for cyanobacterial bloom control should be exerted when cyanobacteria biomass is relatively low, since the low dosage could function well at the early stage of cyanobacterial bloom.