Randy Holmes-Farley
01/24/2002, 11:32 AM
I was recently asked if there was any new information on ozone in seawater/tank water (in the AAOM forum).
Is there any new information regarding ozone kinetics in seawater?
From Aquarium Frontiers archives:
"It may be that the brominated organic products of ozonization and chlorination are especially toxic. Austin et al. (1996) indicate that bromoacetates are a major product of ozonization, and that they are capable of causing DNA damage. Although the chlorinated byproducts are toxic and carcinogenic, the brominated byproducts seem to be more potent (Parrish et al. 1996)."
Here was my response for anyone that's interested:
Here are some recent studies (1998-pres.) that might be of interest. They are both chemical and biological:
Oxidative cell damage in Kat-sod assay of oxyhalides as inorganic disinfection by-products and their occurrence by ozonation. Ueno H; Oishi K; Sayato Y; Nakamuro K Department of Biological Sciences, 1845 N. Fairmount, Wichita State University, Wichita, Kansas 67260-0026, USA ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY (2000 Jan), 38(1), 1-6.
Abstract:
Nine oxyhalides as possible inorganic disinfection by-products were tested for oxidative cell damage by Kat-sod assay with E. coli mutant strains deficient in the active oxygen-scavenging enzymes. Chlorine dioxide, chlorite, and iodate were highly cytotoxic, whereas in the presence of cysteine, bromate (BrO3-) and metaperiodate (IO4-) showed more growth inhibition toward the superoxide dismutase-deficient strains than the wild strain. BrO3- also showed oxidative mutagenicity with cysteine or glutathione ethyl ester in S. typhimurium TA 100. To identify oxyhalides formed by ozonation of raw water containing sea water, the occurrence of ozonation by-products of bromide and iodide was investigated. The results indicate that BrO3- is toxicologically one of the most remarkable oxyhalides detectable in drinking water because IO4- was not detected in the ozonated solution of iodide, and the ozonation condition to lower BrO3- is to keep it neutral in the presence of ammonium ion.
Oxidation of Iodide and Hypoiodous Acid in the Disinfection of Natural Waters. Bichsel, Yves; von Gunten, Urs. Swiss Federal Institute for Environmental Science and Technology EAWAG, Duebendorf, Switz. Environ. Sci. Technol. (1999), 33(22), 4040-4045.
Abstract:
In aq. oxidative processes with O3, Cl, or chloramine, naturally occurring I- can easily be oxidized to HOI which can react with natural org. matter (NOM) or be further oxidized to IO3-. Such processes can be of importance for the geochem. of I and for the fate of I in industrial processes (drinking water treatment, aquacultures). Whereas IO3- is the desired sink for I in drinking waters, iodoorg. compds. (esp. CHI3) are problematic due to their taste and odor. To assess the sink for I during oxidn. of natural waters, we detd. the kinetics of several oxidn. reactions of HOI. O3, Cl, and chloramine were tested as potential oxidants. O3 oxidized both HOI and OI- (kO3+HOI = 3.6 ´ 104/M-s; kO3+OI- = 1.6 ´ 106/M-s) in a fast reaction. Cl species oxidized HOI by a combination of 2nd- and 3rd-order reactions (k''HOCl+HOI = 8.2/M-s; k'''HOCl+HOI = 8.3 ´ 104/M2-s; kOCl-+HOI = 52/M-s). Monochloramine did not further oxidize HOI. The probability of the formation of iodoorg. compds. during drinking water disinfection therefore increases in the order O3<Cl<NH2Cl. In aquacultures, I- is transformed to IO3- within seconds to minutes in the presence of Cl or O3. In the surface boundary layer of seawater, O3 oxidizes I- to HOI but not to IO3-.
Modeling of nitrate and bromate in a seawater aquarium. Grguric, Gordan; Coston, Christopher J. Marine Science Program, Richard Stockton College, Pomona, NJ, USA. Water Res. (1998), 32(6), 1759-1768.
Abstract:
Closed marine systems where there is no significant primary productivity and water changes are impractical exhibit increasing nitrate concns. over time. At the Living Seas artificial seawater aquarium, nitrate concn. reached 9700mM after 5 yr of operation. Concern about potential toxic effects assocd. with a further increase led to the development of a batch denitrification system, sep. from the Main Tank of the aquarium. The system was installed in early 1991 and after 350 days of operation, nitrate concn. in the aquarium decreased to 3200mM. Two models are applied to the empirical nitrate data - one designed specifically for nitrate and one originally developed for bromate. Both models have correlations greater than 0.95 with the empirical nitrate data over the period studied. The models were used to det. the steady state nitrate concn. in the aquarium: the first model predicts 850mM, assuming no idle time between denitrification runs. The second model predicts 2300mM, with the actual idle times taken into account. Potentially toxicity and carcinogenicity of bromate has been of concern in recirculating seawater aquaria, where bromate is produced from oxidn. of bromide during ozonation. By late 1990, bromate concn. in The Living Seas reached 4.6mM. After the installation of the denitrification system, bromate concn. has been controlled by the balance between ozonation and denitrification processes. We developed a model based on the existing kinetic data regarding bromate formation during ozonation and an empirically detd. rate of bromate loss during denitrification. The model predicts a bromate concn. of 3.6mM by early 1994, in reasonable agreement with the obsd. value of 3.4mM. The eventual steady state bromate concn. predicted by the model is 0.7mM. Verification of the model with the obsd. bromate and nitrate data from The Living Seas shows that it is a useful tool for predicting concns. of redox-reactive chem. species in a closed seawater system.
In addn., empirical data from this study suggest that denitrification can be used to control bromate concns. in seawater aquaria that employ ozone for disinfection.
Physiological effect of seawater treated by ozone on Chlorella sp. Wang, Chenggang; Tang, Xiaohua; Zheng, Bo; Ma, Shen. Shandong Marine Scientific and Technical Academy, Tsingtao, Peop. Rep. China. Shuichan Xuebao (2001), 25(2), 151-155.
Abstract:
The effects of seawater treated by ozone on reprodn., chlorophyll-a content, DNA and RNA content in Chlorella sp. were studied. Meanwhile, NH4+-N, NO2--N and NO3--N content in the seawater were analyzed. The results showed as follows: a certain concn. of ozone treatment could increase reprodn. and chlorophyll-a content, but higher concn. of ozone treatment could inhibit reprodn. of Chlorella sp.; DNA content showed relative stability, RNA content was more sensitive to ozone treatment than DNA content, and ozone treatment could increase RNA content; HN4+-N and NO2--N content decreased in seawater by ozone treatment, while NO3--N content increased compared with that in control seawater.
Qualitative assay of residual oxidants in seawater and effect of several oxidants on Japanese flounder, Paralichthys olivaceus, eggs. Mimura, Gen; Nagamitu, Takako; Nagase, Toshiya; Namba, Kenji. Ebara Jitugyo Aquaculture Engineering Lab, Nakahara, Kawasaki, Kanagawa, Japan. Suisan Zoshoku (1998), 46(4), 579-587. CODEN: SUZOAV ISSN: 0371-4217.
Abstract:
n attempt was made to quantify oxidants by measuring trihalogenated methanes generated from reacting resorcin with TRO (total residual oxidants). The results showed that the residual oxidants in OPO (ozone-producted oxidants) seawater, TRC (total residual chlorine) seawater and electrolyzed seawater were mostly hypobromous acid. When seawater contg. hydrogen peroxide or povidone-iodine was treated with resorcin, no trihalomethane was detected. In addn., when NaClO was added to seawater dild. 3-30 times with distd. water, both chlorine-contg. and bromine-contg. oxidants were detected. Delayed hatching was obsd. frequently in Japanese flounder eggs exposed to OPO seawater, TRC seawater or electrolyzed seawater. Occurrence of the delayed hatching increased rapidly when the oxidant concn. increased to 2 mg O3/l or higher. No increment in dead eggs was obsd. When the eggs were exposed to seawater contg. hydrogen peroxide or povidone-iodine, few delayed hatching of eggs were found. Most of the eggs that failed to hatch died.
Acute toxicity of ozone-exposed seawater and chlorinated seawater for Japanese flounder, Paralichthys olivaceus, eggs, larvae and juveniles. Mimura, Gen; Katayama, Yasuto; Ji, Xiangrong; Xie, Jialin; Namba, Kenji. Ebara Jitsugyo Aquaculture Engineering Lab, Nakahara, Kawasaki, Kanagawa, Japan. Suisan Zoshoku (1998), 46(4), 569-578.
Abstract:
The toxic effects of exposure to ozone-exposed seawater and chlorinated seawater were investigated in eggs and larvae aged 3-15 days and juveniles aged 44 days in the setting stage of Japanese flounder, Paralichthys olivaceus. For eggs, the 50% no-hatching concn. of OPO and TRC after 1 min exposure were both about 2.2 mg O3/l. The 24-h LC50 values of OPO and TRC in larvae aged 3-15 days were both 0.02-0.05 mg O3/l. The 24-h LC50 values of OPO and TRC for juveniles aged 44 days in the setting stage were both 0.14-0.15 mg O3/l. Light microscopy of branchial tissues showed detachment of the epithelium of the secondary lamellae after exposure to OPO or TRC. SEM of branchial tissues showed cell swelling and cell destruction of the secondary lamellae after exposure to OPO or TRC. The toxicity of OPO and TRC and damage to branchial tissue caused by OPO and TRC were exactly alike.
Bromine activation in the troposphere by the dark reaction of O3 with seawater ice. Oum, K. W.; Lakin, M. J.; Finlayson-Pitts, B. J. Department of Chemistry, University of California, Irvine, CA, USA. Geophys. Res. Lett. (1998), 25(21), 3923-3926.
Abstract:
There is increasing evidence that Br2 atoms play a role in tropospheric chem. in the marine boundary layer. In addn., they are believed to lead to rapid depletion of surface level O3 in the Arctic at polar sunrise. While mechanisms have been proposed for recycling Br2 atoms from sea salt particles, the initial reaction(s) leading to the formation of Br atom precursors is not known. Formation of gaseous Br2 from the reaction of seawater ice with O3 in the dark is reported. These observations suggested this reaction is a potential source of tropospheric photolyzable Br2 in high latitude coastal regions in winter. In addn., it may be the source of the photolyzable Br2 gas measured recently in the Arctic by G.A. Impey, et al. (1997), believed to be responsible for O3 destruction at polar sunrise.
Evaluation of ozone disinfection from view points of inactivation disinfection effects and byproducts formation. Hatatatsu, Toshika; Suzuki, Yutaka. Advanced Wastewater Treatment Division, Public Works Research Institute, Ministry of Construction, Tsukuba, Ibaraki, Japan. WEFTEC 2000, Annu. Conf. Expo. Water Qual. Wastewater Treat., 73rd (2000), 4273-4287.
Abstract:
O3 has strong disinfecting power, but it might produce toxic byproducts, such as aldehydes and bromate ions. Inactivation effects and byproducts formation by O3 disinfection when O3 was used for wastewater disinfection were examd. There were few problems with residual O3 or ozonation byproducts and their toxicity, even if the inactivation level was as high as -4 log to -5 log coliform group survival ratio. Byproduct concns. increased and toxicity was higher when seawater was added. The presence of Br- is the key factor which causes O3 disinfection to form toxic byproducts.
Toxicity of ozonated sea water to Penaeus chinensis and Paralichthys olivaceus. Jiang, Guoliang; Liu, Yun; Yang, Dong; Lu, Yan. College of Marine Life Sciences, Ocean University of Qingdao, Tsingtao, Peop. Rep. China. Haiyang Kexue (2001), 25(3), 11-13.
Abstract:
The toxicity of ozonized sea water to the Penaeus chinensis and Paralichthys olivaceus was studied. The results showed that the tolerance of shrimp for residual ozone levels was much higher than that of the fish, the shrimp would live 48 h in ozone water ³ 1mg/L, while fish could not live more than 3 h. Concn. lethal to 50% of sample fish of Bastard halibut for 48 h was 0.13 mg/L. Compared with other disinfecting method, the ozonation is a good treatment method for intensive aquaculture with suitable level.
Effect of seawater treated with ozone on content of protein, amino acid and carbohydrate in Chlorella sp. Wang, Chenggang; Tang, Xuexi; Zheng, Bo; Tang, Xiaohua. Shandong Marine Science and Technology Academy, Tsingtao, Peop. Rep. China. Haiyang Kexue (2001), 25(2), 15-17, 23.
Abstract:
The effects of seawater treated by ozone on contents of protein, amino acids, and carbohydrate were studied in Chlorella sp. at the different growth stages. The results showed as follows: a certain dosage of ozone treatment could increase the content of protein and amino acids, but decrease the content of carbohydrate. The proportion of necessary amino acids for fish to the total amino acids in the microalgae did not exhibit significant change compared with control group. Ozone treatment of Chlorella sp. could promote the whole nutrient level.
Effects of ozone-produced oxidants on ventilation of the pearl oyster, Pinctada fucata martensii. Yamamoto, Ken-Ichi; Kondo, Masakazu; Handa, Takeshi; Nakamura, Masatoshi. National Fisheries University, Shimonoseki, Yamaguchi, Japan. Suisan Zoshoku (2000), 48(3), 509-516.
Abstract:
To evaluate the effect of ozone-produced oxidants (OPO) on the ventilation of the pearl oyster, Pinctada fucata martensii, the ventilation vol. (Vg), the gill cilia movement (SP) and the surface structure of gills were examd. after exposure to ozonized seawater for 24 h. Vg was examd. every 3 h during exposure to the seawater of OPO 0.70 mg O3/L. Also the day when Vg recovered to the level of the control after exposure (DY) was examd. In the 24 h, Vg and SP decreased with an increase in the OPO concn., and showed zero at 0.58 mg O3/L or more. DY was under 23 days at 0.42 mg O3/L or below, and 10-80 days at 0.58-0.70 mg O3/L. However, at 0.58-0.70 mg O3/L, 20% of the individuals used for the expt. died 5-76 days later. Every 3 h, Vg decreased with time. DY was under 23 days within 12 h and 25-80 days at 24 h. The damages of the gills were postulated to progress in the order: the frontal cilia disappeared, the lateral cilia disappeared, the ciliary disk collapsed, and the gill filaments disappeared from the tip.
Analysis of residual ozone (in fresh water) or residual oxidants (in seawater) by spectrophotometry with DPD reagent. Anon. UK. Res. Discl. (2000), 438(Oct.), P1800-P1801.
Abstract:
Adaptation of a spectrophotometric method for the detn. of free chlorine in water to the detn. of O3 and other oxidants is described. The method uses N,N-diethyl-p-phenylenediamine in the presence of KI as the reagents. The detn. limit of the method is 0.014 mg O3/L.
Surface disinfection of Atlantic halibut Hippoglossus hippoglossus eggs with ozonated sea-water inactivates nodavirus and increases survival of the larvae. Grotmol S; Totland G K Department of Aquaculture, Institute of Marine Research, Bergen, Norway. sindre.grotmol@imr.no DISEASES OF AQUATIC ORGANISMS (2000 Jan 14), 39(2), 89-96.
Abstract:
Disinfection by ozonation of sea-water may reduce the risk of transmission of nodavirus, a major fish pathogen, via Atlantic halibut Hippoglossus hippoglossus eggs. In the present study, eggs at 4 d prior to hatching were exposed to nodavirus and then to ozonated sea-water using different concentrations (0.3 to 10 mg l-1) and exposure times (0.5 to 10 min). None of the larvae from virus-exposed eggs washed with ozonated sea-water developed viral encephalopathy and retinopathy (VER), which was detected in all dead larvae from eggs exposed to nodavirus but not washed with ozonated sea-water. In the non-treated control group about 20% of the dead larvae developed the disease. This suggests that the halibut eggs taken from a large-scale production facility were already contaminated with nodavirus. The egg groups which had been treated with 4 mg O3 l-1 for 0.5 min or with lower total ozone exposures had a higher survival and no adverse effects on the development of the larvae after hatching were observed. Although a slight delay in hatching was found, after 2 d the cumulative hatching had normalised. In the egg groups with high total exposure (4 mg O3 l-1 for 1 min or higher total ozone exposures) a pronounced negative effect on hatching was observed. Our results indicate that the egg surface may be important in the transfer of nodavirus and that nodavirus associated with the surface of the egg may be inactivated by ozonated sea-water.
Is there any new information regarding ozone kinetics in seawater?
From Aquarium Frontiers archives:
"It may be that the brominated organic products of ozonization and chlorination are especially toxic. Austin et al. (1996) indicate that bromoacetates are a major product of ozonization, and that they are capable of causing DNA damage. Although the chlorinated byproducts are toxic and carcinogenic, the brominated byproducts seem to be more potent (Parrish et al. 1996)."
Here was my response for anyone that's interested:
Here are some recent studies (1998-pres.) that might be of interest. They are both chemical and biological:
Oxidative cell damage in Kat-sod assay of oxyhalides as inorganic disinfection by-products and their occurrence by ozonation. Ueno H; Oishi K; Sayato Y; Nakamuro K Department of Biological Sciences, 1845 N. Fairmount, Wichita State University, Wichita, Kansas 67260-0026, USA ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY (2000 Jan), 38(1), 1-6.
Abstract:
Nine oxyhalides as possible inorganic disinfection by-products were tested for oxidative cell damage by Kat-sod assay with E. coli mutant strains deficient in the active oxygen-scavenging enzymes. Chlorine dioxide, chlorite, and iodate were highly cytotoxic, whereas in the presence of cysteine, bromate (BrO3-) and metaperiodate (IO4-) showed more growth inhibition toward the superoxide dismutase-deficient strains than the wild strain. BrO3- also showed oxidative mutagenicity with cysteine or glutathione ethyl ester in S. typhimurium TA 100. To identify oxyhalides formed by ozonation of raw water containing sea water, the occurrence of ozonation by-products of bromide and iodide was investigated. The results indicate that BrO3- is toxicologically one of the most remarkable oxyhalides detectable in drinking water because IO4- was not detected in the ozonated solution of iodide, and the ozonation condition to lower BrO3- is to keep it neutral in the presence of ammonium ion.
Oxidation of Iodide and Hypoiodous Acid in the Disinfection of Natural Waters. Bichsel, Yves; von Gunten, Urs. Swiss Federal Institute for Environmental Science and Technology EAWAG, Duebendorf, Switz. Environ. Sci. Technol. (1999), 33(22), 4040-4045.
Abstract:
In aq. oxidative processes with O3, Cl, or chloramine, naturally occurring I- can easily be oxidized to HOI which can react with natural org. matter (NOM) or be further oxidized to IO3-. Such processes can be of importance for the geochem. of I and for the fate of I in industrial processes (drinking water treatment, aquacultures). Whereas IO3- is the desired sink for I in drinking waters, iodoorg. compds. (esp. CHI3) are problematic due to their taste and odor. To assess the sink for I during oxidn. of natural waters, we detd. the kinetics of several oxidn. reactions of HOI. O3, Cl, and chloramine were tested as potential oxidants. O3 oxidized both HOI and OI- (kO3+HOI = 3.6 ´ 104/M-s; kO3+OI- = 1.6 ´ 106/M-s) in a fast reaction. Cl species oxidized HOI by a combination of 2nd- and 3rd-order reactions (k''HOCl+HOI = 8.2/M-s; k'''HOCl+HOI = 8.3 ´ 104/M2-s; kOCl-+HOI = 52/M-s). Monochloramine did not further oxidize HOI. The probability of the formation of iodoorg. compds. during drinking water disinfection therefore increases in the order O3<Cl<NH2Cl. In aquacultures, I- is transformed to IO3- within seconds to minutes in the presence of Cl or O3. In the surface boundary layer of seawater, O3 oxidizes I- to HOI but not to IO3-.
Modeling of nitrate and bromate in a seawater aquarium. Grguric, Gordan; Coston, Christopher J. Marine Science Program, Richard Stockton College, Pomona, NJ, USA. Water Res. (1998), 32(6), 1759-1768.
Abstract:
Closed marine systems where there is no significant primary productivity and water changes are impractical exhibit increasing nitrate concns. over time. At the Living Seas artificial seawater aquarium, nitrate concn. reached 9700mM after 5 yr of operation. Concern about potential toxic effects assocd. with a further increase led to the development of a batch denitrification system, sep. from the Main Tank of the aquarium. The system was installed in early 1991 and after 350 days of operation, nitrate concn. in the aquarium decreased to 3200mM. Two models are applied to the empirical nitrate data - one designed specifically for nitrate and one originally developed for bromate. Both models have correlations greater than 0.95 with the empirical nitrate data over the period studied. The models were used to det. the steady state nitrate concn. in the aquarium: the first model predicts 850mM, assuming no idle time between denitrification runs. The second model predicts 2300mM, with the actual idle times taken into account. Potentially toxicity and carcinogenicity of bromate has been of concern in recirculating seawater aquaria, where bromate is produced from oxidn. of bromide during ozonation. By late 1990, bromate concn. in The Living Seas reached 4.6mM. After the installation of the denitrification system, bromate concn. has been controlled by the balance between ozonation and denitrification processes. We developed a model based on the existing kinetic data regarding bromate formation during ozonation and an empirically detd. rate of bromate loss during denitrification. The model predicts a bromate concn. of 3.6mM by early 1994, in reasonable agreement with the obsd. value of 3.4mM. The eventual steady state bromate concn. predicted by the model is 0.7mM. Verification of the model with the obsd. bromate and nitrate data from The Living Seas shows that it is a useful tool for predicting concns. of redox-reactive chem. species in a closed seawater system.
In addn., empirical data from this study suggest that denitrification can be used to control bromate concns. in seawater aquaria that employ ozone for disinfection.
Physiological effect of seawater treated by ozone on Chlorella sp. Wang, Chenggang; Tang, Xiaohua; Zheng, Bo; Ma, Shen. Shandong Marine Scientific and Technical Academy, Tsingtao, Peop. Rep. China. Shuichan Xuebao (2001), 25(2), 151-155.
Abstract:
The effects of seawater treated by ozone on reprodn., chlorophyll-a content, DNA and RNA content in Chlorella sp. were studied. Meanwhile, NH4+-N, NO2--N and NO3--N content in the seawater were analyzed. The results showed as follows: a certain concn. of ozone treatment could increase reprodn. and chlorophyll-a content, but higher concn. of ozone treatment could inhibit reprodn. of Chlorella sp.; DNA content showed relative stability, RNA content was more sensitive to ozone treatment than DNA content, and ozone treatment could increase RNA content; HN4+-N and NO2--N content decreased in seawater by ozone treatment, while NO3--N content increased compared with that in control seawater.
Qualitative assay of residual oxidants in seawater and effect of several oxidants on Japanese flounder, Paralichthys olivaceus, eggs. Mimura, Gen; Nagamitu, Takako; Nagase, Toshiya; Namba, Kenji. Ebara Jitugyo Aquaculture Engineering Lab, Nakahara, Kawasaki, Kanagawa, Japan. Suisan Zoshoku (1998), 46(4), 579-587. CODEN: SUZOAV ISSN: 0371-4217.
Abstract:
n attempt was made to quantify oxidants by measuring trihalogenated methanes generated from reacting resorcin with TRO (total residual oxidants). The results showed that the residual oxidants in OPO (ozone-producted oxidants) seawater, TRC (total residual chlorine) seawater and electrolyzed seawater were mostly hypobromous acid. When seawater contg. hydrogen peroxide or povidone-iodine was treated with resorcin, no trihalomethane was detected. In addn., when NaClO was added to seawater dild. 3-30 times with distd. water, both chlorine-contg. and bromine-contg. oxidants were detected. Delayed hatching was obsd. frequently in Japanese flounder eggs exposed to OPO seawater, TRC seawater or electrolyzed seawater. Occurrence of the delayed hatching increased rapidly when the oxidant concn. increased to 2 mg O3/l or higher. No increment in dead eggs was obsd. When the eggs were exposed to seawater contg. hydrogen peroxide or povidone-iodine, few delayed hatching of eggs were found. Most of the eggs that failed to hatch died.
Acute toxicity of ozone-exposed seawater and chlorinated seawater for Japanese flounder, Paralichthys olivaceus, eggs, larvae and juveniles. Mimura, Gen; Katayama, Yasuto; Ji, Xiangrong; Xie, Jialin; Namba, Kenji. Ebara Jitsugyo Aquaculture Engineering Lab, Nakahara, Kawasaki, Kanagawa, Japan. Suisan Zoshoku (1998), 46(4), 569-578.
Abstract:
The toxic effects of exposure to ozone-exposed seawater and chlorinated seawater were investigated in eggs and larvae aged 3-15 days and juveniles aged 44 days in the setting stage of Japanese flounder, Paralichthys olivaceus. For eggs, the 50% no-hatching concn. of OPO and TRC after 1 min exposure were both about 2.2 mg O3/l. The 24-h LC50 values of OPO and TRC in larvae aged 3-15 days were both 0.02-0.05 mg O3/l. The 24-h LC50 values of OPO and TRC for juveniles aged 44 days in the setting stage were both 0.14-0.15 mg O3/l. Light microscopy of branchial tissues showed detachment of the epithelium of the secondary lamellae after exposure to OPO or TRC. SEM of branchial tissues showed cell swelling and cell destruction of the secondary lamellae after exposure to OPO or TRC. The toxicity of OPO and TRC and damage to branchial tissue caused by OPO and TRC were exactly alike.
Bromine activation in the troposphere by the dark reaction of O3 with seawater ice. Oum, K. W.; Lakin, M. J.; Finlayson-Pitts, B. J. Department of Chemistry, University of California, Irvine, CA, USA. Geophys. Res. Lett. (1998), 25(21), 3923-3926.
Abstract:
There is increasing evidence that Br2 atoms play a role in tropospheric chem. in the marine boundary layer. In addn., they are believed to lead to rapid depletion of surface level O3 in the Arctic at polar sunrise. While mechanisms have been proposed for recycling Br2 atoms from sea salt particles, the initial reaction(s) leading to the formation of Br atom precursors is not known. Formation of gaseous Br2 from the reaction of seawater ice with O3 in the dark is reported. These observations suggested this reaction is a potential source of tropospheric photolyzable Br2 in high latitude coastal regions in winter. In addn., it may be the source of the photolyzable Br2 gas measured recently in the Arctic by G.A. Impey, et al. (1997), believed to be responsible for O3 destruction at polar sunrise.
Evaluation of ozone disinfection from view points of inactivation disinfection effects and byproducts formation. Hatatatsu, Toshika; Suzuki, Yutaka. Advanced Wastewater Treatment Division, Public Works Research Institute, Ministry of Construction, Tsukuba, Ibaraki, Japan. WEFTEC 2000, Annu. Conf. Expo. Water Qual. Wastewater Treat., 73rd (2000), 4273-4287.
Abstract:
O3 has strong disinfecting power, but it might produce toxic byproducts, such as aldehydes and bromate ions. Inactivation effects and byproducts formation by O3 disinfection when O3 was used for wastewater disinfection were examd. There were few problems with residual O3 or ozonation byproducts and their toxicity, even if the inactivation level was as high as -4 log to -5 log coliform group survival ratio. Byproduct concns. increased and toxicity was higher when seawater was added. The presence of Br- is the key factor which causes O3 disinfection to form toxic byproducts.
Toxicity of ozonated sea water to Penaeus chinensis and Paralichthys olivaceus. Jiang, Guoliang; Liu, Yun; Yang, Dong; Lu, Yan. College of Marine Life Sciences, Ocean University of Qingdao, Tsingtao, Peop. Rep. China. Haiyang Kexue (2001), 25(3), 11-13.
Abstract:
The toxicity of ozonized sea water to the Penaeus chinensis and Paralichthys olivaceus was studied. The results showed that the tolerance of shrimp for residual ozone levels was much higher than that of the fish, the shrimp would live 48 h in ozone water ³ 1mg/L, while fish could not live more than 3 h. Concn. lethal to 50% of sample fish of Bastard halibut for 48 h was 0.13 mg/L. Compared with other disinfecting method, the ozonation is a good treatment method for intensive aquaculture with suitable level.
Effect of seawater treated with ozone on content of protein, amino acid and carbohydrate in Chlorella sp. Wang, Chenggang; Tang, Xuexi; Zheng, Bo; Tang, Xiaohua. Shandong Marine Science and Technology Academy, Tsingtao, Peop. Rep. China. Haiyang Kexue (2001), 25(2), 15-17, 23.
Abstract:
The effects of seawater treated by ozone on contents of protein, amino acids, and carbohydrate were studied in Chlorella sp. at the different growth stages. The results showed as follows: a certain dosage of ozone treatment could increase the content of protein and amino acids, but decrease the content of carbohydrate. The proportion of necessary amino acids for fish to the total amino acids in the microalgae did not exhibit significant change compared with control group. Ozone treatment of Chlorella sp. could promote the whole nutrient level.
Effects of ozone-produced oxidants on ventilation of the pearl oyster, Pinctada fucata martensii. Yamamoto, Ken-Ichi; Kondo, Masakazu; Handa, Takeshi; Nakamura, Masatoshi. National Fisheries University, Shimonoseki, Yamaguchi, Japan. Suisan Zoshoku (2000), 48(3), 509-516.
Abstract:
To evaluate the effect of ozone-produced oxidants (OPO) on the ventilation of the pearl oyster, Pinctada fucata martensii, the ventilation vol. (Vg), the gill cilia movement (SP) and the surface structure of gills were examd. after exposure to ozonized seawater for 24 h. Vg was examd. every 3 h during exposure to the seawater of OPO 0.70 mg O3/L. Also the day when Vg recovered to the level of the control after exposure (DY) was examd. In the 24 h, Vg and SP decreased with an increase in the OPO concn., and showed zero at 0.58 mg O3/L or more. DY was under 23 days at 0.42 mg O3/L or below, and 10-80 days at 0.58-0.70 mg O3/L. However, at 0.58-0.70 mg O3/L, 20% of the individuals used for the expt. died 5-76 days later. Every 3 h, Vg decreased with time. DY was under 23 days within 12 h and 25-80 days at 24 h. The damages of the gills were postulated to progress in the order: the frontal cilia disappeared, the lateral cilia disappeared, the ciliary disk collapsed, and the gill filaments disappeared from the tip.
Analysis of residual ozone (in fresh water) or residual oxidants (in seawater) by spectrophotometry with DPD reagent. Anon. UK. Res. Discl. (2000), 438(Oct.), P1800-P1801.
Abstract:
Adaptation of a spectrophotometric method for the detn. of free chlorine in water to the detn. of O3 and other oxidants is described. The method uses N,N-diethyl-p-phenylenediamine in the presence of KI as the reagents. The detn. limit of the method is 0.014 mg O3/L.
Surface disinfection of Atlantic halibut Hippoglossus hippoglossus eggs with ozonated sea-water inactivates nodavirus and increases survival of the larvae. Grotmol S; Totland G K Department of Aquaculture, Institute of Marine Research, Bergen, Norway. sindre.grotmol@imr.no DISEASES OF AQUATIC ORGANISMS (2000 Jan 14), 39(2), 89-96.
Abstract:
Disinfection by ozonation of sea-water may reduce the risk of transmission of nodavirus, a major fish pathogen, via Atlantic halibut Hippoglossus hippoglossus eggs. In the present study, eggs at 4 d prior to hatching were exposed to nodavirus and then to ozonated sea-water using different concentrations (0.3 to 10 mg l-1) and exposure times (0.5 to 10 min). None of the larvae from virus-exposed eggs washed with ozonated sea-water developed viral encephalopathy and retinopathy (VER), which was detected in all dead larvae from eggs exposed to nodavirus but not washed with ozonated sea-water. In the non-treated control group about 20% of the dead larvae developed the disease. This suggests that the halibut eggs taken from a large-scale production facility were already contaminated with nodavirus. The egg groups which had been treated with 4 mg O3 l-1 for 0.5 min or with lower total ozone exposures had a higher survival and no adverse effects on the development of the larvae after hatching were observed. Although a slight delay in hatching was found, after 2 d the cumulative hatching had normalised. In the egg groups with high total exposure (4 mg O3 l-1 for 1 min or higher total ozone exposures) a pronounced negative effect on hatching was observed. Our results indicate that the egg surface may be important in the transfer of nodavirus and that nodavirus associated with the surface of the egg may be inactivated by ozonated sea-water.