The paper analyzes the influence of lead toxicity by anaerobic granule sludge inhibition and recovering experiments. The result shows that there are different inhibition types at differ-ent lead contents. Higher lead ...The paper analyzes the influence of lead toxicity by anaerobic granule sludge inhibition and recovering experiments. The result shows that there are different inhibition types at differ-ent lead contents. Higher lead content leads to more inhibition granular sludge, and at the same time, the time of gas recovery is different. Lower lead content per microorganism results in sooner sludge recovery. Microorganisms have a good ability to resist lead toxicity.展开更多
In China, the technical information currently available both domestically and abroad has been reviewed in an attempt to integrate the technique of ultraviolet air disinfection with Grade Ⅱ filters and develop a steri...In China, the technical information currently available both domestically and abroad has been reviewed in an attempt to integrate the technique of ultraviolet air disinfection with Grade Ⅱ filters and develop a sterile conservation-oriented environment. As detection showed, such a sanitary system of air disinfection, integrated by ultraviolet air disinfection and Grade Ⅱ filters can reach the same standard of cleanliness as a high efficiency particle filter. This system easily satisfies the cleaning of air in hospital wards, surpassing the sterile air standards and the requirements of the National Bacteria Indicator （NBI）. As a result of this system＇s efficiency, resources and running costs can be reduced dramatically. Therefore, revision of the national standards of Structural Technical Specification of the Cleaning Operation Department needs to move forward.展开更多
The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique. The experiment...The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique. The experiments were carried out with four annular reactors (ARs) with stainless steel (SS) or copper (Cu) material slides. The results showed that there were fewer bacteria attached to Cu slides without a disinfectant compared with those attached to SS slides. When the water was disinfected with chloramines, the heterotrophic plate counts (HPCs) on the biofilm attached to the Cu slides were significantly lower (by 3.46 log CFU/cm2) than those attached to the SS slides. Likewise, the biofilm HPC numbers on the Cu slides were slightly lower (by 1.19 log CFU/cm2) than those on the SS slides disinfected with chlorine. In a quasi-steady state, the HPC levels on Cu slides can be reduced to 3.0 log CFU/cm2 with chlorine and to about 0.9 log CFU/cm2 with chloramines. The addition of chloramines resulted in a more efficient reduction of biofilm heterotrophic bacteria than did chlorine. We concluded that the chlorine and chloramines levels usually employed in water distribution system were not sufficient to prevent the growth and development of microbial biofilm. The combination of copper pipe slides and chloramines as the disinfectant was the most efficient combination to bring about diminished bacterial levels.展开更多
基金Supported by The national natural Science Foundation of China (Grant No.50172009).
文摘The paper analyzes the influence of lead toxicity by anaerobic granule sludge inhibition and recovering experiments. The result shows that there are different inhibition types at differ-ent lead contents. Higher lead content leads to more inhibition granular sludge, and at the same time, the time of gas recovery is different. Lower lead content per microorganism results in sooner sludge recovery. Microorganisms have a good ability to resist lead toxicity.
文摘In China, the technical information currently available both domestically and abroad has been reviewed in an attempt to integrate the technique of ultraviolet air disinfection with Grade Ⅱ filters and develop a sterile conservation-oriented environment. As detection showed, such a sanitary system of air disinfection, integrated by ultraviolet air disinfection and Grade Ⅱ filters can reach the same standard of cleanliness as a high efficiency particle filter. This system easily satisfies the cleaning of air in hospital wards, surpassing the sterile air standards and the requirements of the National Bacteria Indicator （NBI）. As a result of this system＇s efficiency, resources and running costs can be reduced dramatically. Therefore, revision of the national standards of Structural Technical Specification of the Cleaning Operation Department needs to move forward.
基金supported by the National Natural Science Foundation of China (No. 50878164)the National Key Technologies Supporting Program of China during the 11th Five-Year Plan Period (Nos. 2006BAJ08B02 and 2006BAJ08B06)the Program for Young Excellent Talents in Tongji University (No. 2007KJ016), China
文摘The efficiency of chlorine and chloramines disinfection on biofilm development in a simulated drinking water distribution system was investigated by using heterotrophic bacterial spread plate technique. The experiments were carried out with four annular reactors (ARs) with stainless steel (SS) or copper (Cu) material slides. The results showed that there were fewer bacteria attached to Cu slides without a disinfectant compared with those attached to SS slides. When the water was disinfected with chloramines, the heterotrophic plate counts (HPCs) on the biofilm attached to the Cu slides were significantly lower (by 3.46 log CFU/cm2) than those attached to the SS slides. Likewise, the biofilm HPC numbers on the Cu slides were slightly lower (by 1.19 log CFU/cm2) than those on the SS slides disinfected with chlorine. In a quasi-steady state, the HPC levels on Cu slides can be reduced to 3.0 log CFU/cm2 with chlorine and to about 0.9 log CFU/cm2 with chloramines. The addition of chloramines resulted in a more efficient reduction of biofilm heterotrophic bacteria than did chlorine. We concluded that the chlorine and chloramines levels usually employed in water distribution system were not sufficient to prevent the growth and development of microbial biofilm. The combination of copper pipe slides and chloramines as the disinfectant was the most efficient combination to bring about diminished bacterial levels.
