Dispersants, usually blending with several surfactants and a solvent, are used to enhance oil spill dispersion as small droplets in water column. Although there is growing acceptance of dispersants as a counter measur...Dispersants, usually blending with several surfactants and a solvent, are used to enhance oil spill dispersion as small droplets in water column. Although there is growing acceptance of dispersants as a counter measure to marine oil spills around the world, the two major issues with the dispersants are their toxicity to marine life and dispersion effectiveness (DE) for crude-oil, especially for heavy oil. To develop more efficient and less toxic dispersants, two kinds of sorbitol derivant nonionic surfactant (polysorbate 85 and sorbeth-40 tetraoleate), two kinds of glycolipid biosurfactants (rhamnolipid and sophorolipid) and less toxic solvent ethylene glycol butyl ether were chosen in this study, and two dispersant formulations were optimized by uniform design methods. Effects of dispersant-to-oil ratio, temperature, salinity and pH on the performance of the two optimized dispersants were investigated. The two dispersants had high dispersion effectiveness (DE) for heavy crude oil, while both dispersants keep high DE at the dispersant-to-oil ratio below 1:25 and the temperature above 5 ℃. In addition, the two dispersants also performed well in a wide range of salinity and pH values. Finally, toxicity tests revealed that the two dispersants showed low toxicity to two kinds of fish (Danio rerio and Microgobius gulosus).展开更多
采用菌丝生长速率法在室内测定了6种杀菌剂对甘薯黑斑病菌(Ceratocystis fimbriata Ellis et Halsted)的毒力,结果表明,1%枯草芽孢杆菌可湿性粉剂和2%宁南霉素对甘薯黑斑病菌菌丝生长的抑制效果居前2位,其中后者对该病菌的EC50值为0.30...采用菌丝生长速率法在室内测定了6种杀菌剂对甘薯黑斑病菌(Ceratocystis fimbriata Ellis et Halsted)的毒力,结果表明,1%枯草芽孢杆菌可湿性粉剂和2%宁南霉素对甘薯黑斑病菌菌丝生长的抑制效果居前2位,其中后者对该病菌的EC50值为0.30μg/mL。探讨了7种药剂对甘薯苗期黑斑病的防治效果,结果显示:以50%甲基托布津可湿性粉剂800倍液对苗期黑斑病的防治效果最佳,防效达100%。展开更多
文摘Dispersants, usually blending with several surfactants and a solvent, are used to enhance oil spill dispersion as small droplets in water column. Although there is growing acceptance of dispersants as a counter measure to marine oil spills around the world, the two major issues with the dispersants are their toxicity to marine life and dispersion effectiveness (DE) for crude-oil, especially for heavy oil. To develop more efficient and less toxic dispersants, two kinds of sorbitol derivant nonionic surfactant (polysorbate 85 and sorbeth-40 tetraoleate), two kinds of glycolipid biosurfactants (rhamnolipid and sophorolipid) and less toxic solvent ethylene glycol butyl ether were chosen in this study, and two dispersant formulations were optimized by uniform design methods. Effects of dispersant-to-oil ratio, temperature, salinity and pH on the performance of the two optimized dispersants were investigated. The two dispersants had high dispersion effectiveness (DE) for heavy crude oil, while both dispersants keep high DE at the dispersant-to-oil ratio below 1:25 and the temperature above 5 ℃. In addition, the two dispersants also performed well in a wide range of salinity and pH values. Finally, toxicity tests revealed that the two dispersants showed low toxicity to two kinds of fish (Danio rerio and Microgobius gulosus).
文摘采用菌丝生长速率法在室内测定了6种杀菌剂对甘薯黑斑病菌(Ceratocystis fimbriata Ellis et Halsted)的毒力,结果表明,1%枯草芽孢杆菌可湿性粉剂和2%宁南霉素对甘薯黑斑病菌菌丝生长的抑制效果居前2位,其中后者对该病菌的EC50值为0.30μg/mL。探讨了7种药剂对甘薯苗期黑斑病的防治效果,结果显示:以50%甲基托布津可湿性粉剂800倍液对苗期黑斑病的防治效果最佳,防效达100%。