Experimental Research On Ozone Disinfection

With the gradual development of large-scale and intensive livestock production,thorough and normative disinfection has been bacome the primary task in feeding management.And effective disinfectant and proper disinfection method is the most importion factor to ensure disinfection effection.Ozone(O3)was regard as the strongest commercially and practical bactericidal agent.Considering the broad-spectrum antibacterial and cleaning properties for a disinfectant,the findings point at ozone sterilization as a promising method,but still in an initial phase of investigation.Further experimental studies are needed to provide broader evidence regarding the possibilities and limitations of ozone sterilization.For the purpose we tested the germicidal efficacy of different ways of ozone water and examined the destruction of ozone on the Eimeria tenella and helminth eggs(Ascaris suum).In addition,we explored the feasibility of ozone disinfection in aquaculture wastewater treatment.The results showed that:(1)It is conducted by suspension quantitative germicidal test,carrier immersion quantitative germicidal test and carrier spray quantitative germicidal test to determine the disinfection effectiveness of ozone water.The result of suspension quantitative germicidal test showed that 3 mg/L ozone water could kill 100% of Escherichia coli and Staphylocaccus aureus in suspension with 3 min treatment,and 10 mg/L ozone water completely killed the spores of Aspergillus niger,Candida albicans,and spores of Bacillus subtilis var niger in the suspension for 3 min,5 min,and 10 min respectively.The result of carrier immersion quantitative germicidal test showed that 3 mg/L ozone water could kill 100% of Staphylocaccus aureus on carrier with 5 min treatment,5 mg/L ozone water could kill 100% of Escherichia coli on carrier with 5 min treatment,10 mg/L ozone water could kill 100% of the spores of Aspergillus niger and the spores of Bacillus subtilis var niger on carrier with 10 min treatment,15 mg/L ozone water could kill 100% of the Candida albicans on carrier with 10 min treatment.The result of carrier spray quantitative germicidal test showed that spray disinfection of 15 mg/L ozone water with 15 min,the killing rate of the five test strains was less than 40%,and the samples on carrier could not be effectivel eliminated.(2)The result of ozone treatment on Eimeria tenella oocysts: the saturated ozone-water concentration of treatment for unsporulate E.tenella oocysts and sporulate E.tenella oocysts were 7 mg/L.With increasing of treatment duration,the sporulated ratio of immature oocyst gradually declined.The sporulated ratio of immature E.tenella ooocysts after 70 min and 90 min of ozone-water treatment declined to 5 %and 0%,respectively.The sporulated oocysts after the ozone-treatment could decrease the bloody stool scores and OPG(oocysts per gram)of feces and relieve the pathological changes of cecum.The ACI(anti-coccidial index aci)after 60 and 90 min of ozone treatment were156.2 and 162.5,respectively.And unsporulate E.tenella oocysts with 50mg/L ozone gas treatment,which of sporulated ratio declined unappernt.(3)The result of ozone treatment on Ascaris suum eggs: the saturated ozone-water concentration of treatment for Ascaris suum eggs were 7 mg/L.the egg hatchability after 60 min and 90 min of ozone-water treatment declined to 20 %and 12.7%,respectively.(4)The result of ozone disinfecion on swine wastewater: ozone gas concentration of treatment for swine wastewater were 200 mg/L.When the ozone gas flow through the swine wastewater at the rate of 1L/min with 15 min,the COD value and the number of fecal coliforms of the flocculated water have reached the current national standards.After 30 minutes,the original water samples have also met the discharge standards.