The effect of hydroxyl radical(·OH) on microalgae in ballast water is experimentally investigated. An ?OH plasma generator, which has a thin plate discharge Ag electrode covered by two α-Al2 O3 dielectric layers...The effect of hydroxyl radical(·OH) on microalgae in ballast water is experimentally investigated. An ?OH plasma generator, which has a thin plate discharge Ag electrode covered by two α-Al2 O3 dielectric layers, is built. The plasma generator is filled with O2 and gaseous H2 O and is powered by a homemade power supply. ?OH radicals are generated by a series of plasma reactions and then dissolved into ballast water to kill microalgae. The maximum density of the killed microalgae is about 11 000 cells per milliliter. At this density, the microalgae are not reactivated at the 48th hour and the 120th hour in the treated ballast waters, and the content of chlorophyll in these microalgae decreases by 100%. The water quality returns to a normal level after 120 hours without secondary pollution of aquatic organisms and environment. These results show that the requirements of the D-2 ballast water discharge standard defined by the International Maritime Organization(IMO) are satisfied with the proposed treatment, and that ·OH is an ideal substance for killing microalgae during ballast water replacement of ships.展开更多
基金Project supported by National Natural Science Foundation of China(NSFC)for Distinguished Young Scholar(61025001)National Technology Support Project of China(2013BAC06B00)+1 种基金Special Fund for Marine Scientific Research in the Public Interest(201305027-5)Fundamental Research Fund for the Central Universities(3132013316)
文摘The effect of hydroxyl radical(·OH) on microalgae in ballast water is experimentally investigated. An ?OH plasma generator, which has a thin plate discharge Ag electrode covered by two α-Al2 O3 dielectric layers, is built. The plasma generator is filled with O2 and gaseous H2 O and is powered by a homemade power supply. ?OH radicals are generated by a series of plasma reactions and then dissolved into ballast water to kill microalgae. The maximum density of the killed microalgae is about 11 000 cells per milliliter. At this density, the microalgae are not reactivated at the 48th hour and the 120th hour in the treated ballast waters, and the content of chlorophyll in these microalgae decreases by 100%. The water quality returns to a normal level after 120 hours without secondary pollution of aquatic organisms and environment. These results show that the requirements of the D-2 ballast water discharge standard defined by the International Maritime Organization(IMO) are satisfied with the proposed treatment, and that ·OH is an ideal substance for killing microalgae during ballast water replacement of ships.
