The loads of organic matter, microorganisms, detergents and antibiotics in liquid hospital effluents make them complex environments, raising numerous health and ecological questions. Investigations of mycobacteria in ...The loads of organic matter, microorganisms, detergents and antibiotics in liquid hospital effluents make them complex environments, raising numerous health and ecological questions. Investigations of mycobacteria in water lack adequate techniques. This study is the first part of a pilot project aimed at developing an optimized protocol for the isolation of mycobacteria from hospital effluents, as a prelude to more in-depth investigation in this matrix. The aim was to compare the performance of two decontamination methods, three culture media and two incubation temperatures generally proposed in the literature, in order to identify the most effective methods in each case, as well as possible areas for improvement in the isolation of these germs from this environmental matrix. The results show that liquid hospital effluent can be decontaminated using both the NaOH method (4%;for 30 min.) and the CPC method (0.05%;for 30 min.), with the same mycobacteria recovery efficiency. Despite the low concentration, decontamination with CPC killed more mycobacteria and sufficiently eliminated contaminating germs. In contrast, decontamination with NaOH was less harmful to mycobacteria, but did not remove many contaminating germs. On the other hand, LJG medium performed better than LJGF medium and LJGP medium for the growth of mycobacteria in hospital waters. Finally, there was no difference in performance between the two incubation temperatures of 30℃ and 37℃. The results of this study show that further evaluation of existing protocols is required in order to optimize methods for the pre-treatment of hospital effluent for the isolation of mycobacteria.展开更多
A novel water treatment technique, based on a combination of electrospraying and pulsed corona discharge, has been used for bio-decontamination of wastewater. The electrospraying process has been found to increase the...A novel water treatment technique, based on a combination of electrospraying and pulsed corona discharge, has been used for bio-decontamination of wastewater. The electrospraying process has been found to increase the surface area of the treated wastewater, and hence increases the efficiency of the corona treatment process. The phase diagram of the discharge, which characterizes the discharge regimes, has been identified experimentally. The survival ratio of the microorganisms has been investigated experimentally as a function of the applied voltage and the numbers of treatment runs using air and oxygen as working gases. Microorganism surface has been examined using scanning electron microscope (SEM), which enabled in understanding the decontamination mechanisms of the treated microorganism. A complete decontamination has been achieved after only one run for an applied voltage higher than 16 kV when the discharge system was operated in oxygen gas. Optical emission spectrum of the electrosprayed water confirmed the existence of OH-radicals responsible for decontamination process.展开更多
Earthworms promises to provide cheaper solutions to several social, economic and environmental problems plaguing the human society. Earthworms can safely manage all municipal and industrial organic wastes including se...Earthworms promises to provide cheaper solutions to several social, economic and environmental problems plaguing the human society. Earthworms can safely manage all municipal and industrial organic wastes including sewage sludge and divert them from ending up in the landfills. Their body work as a ‘biofilter’ and they can ‘purify’ and also ‘disinfect’ and ‘detoxify’ municipal and several industrial wastewater. They reduce the BOD & COD loads and the TDSS of wastewater significantly. They can even remove the EDCs (endocrine disrupting chemicals) from sewage which is not removed by the conventional sewage treatments plants. Earthworms can bio-accumulate and bio-transform many chemical contaminants including heavy metals and organic pollutants in soil and clean-up the contaminated lands for re-development. Earthworms restore & improve soil fertility by their secretions (growth hormones) and excreta (vermicast with beneficial soil microbes) & boost ‘crop productivity’. They have potential to replace the environmentally destructive chemical fertilizers from farm production. The ‘protein rich’ earthworm biomass is being used for production of ‘nutritive feed materials’ for fishery, dairy & poultry industries. They are also being used as ‘raw materials’ for rubber, lubricant and detergent industries. The bioactive compounds isolated from earthworms are finding new uses in production of ‘life saving medicines’ for cardiovascular diseases and cancer cure.展开更多
文摘The loads of organic matter, microorganisms, detergents and antibiotics in liquid hospital effluents make them complex environments, raising numerous health and ecological questions. Investigations of mycobacteria in water lack adequate techniques. This study is the first part of a pilot project aimed at developing an optimized protocol for the isolation of mycobacteria from hospital effluents, as a prelude to more in-depth investigation in this matrix. The aim was to compare the performance of two decontamination methods, three culture media and two incubation temperatures generally proposed in the literature, in order to identify the most effective methods in each case, as well as possible areas for improvement in the isolation of these germs from this environmental matrix. The results show that liquid hospital effluent can be decontaminated using both the NaOH method (4%;for 30 min.) and the CPC method (0.05%;for 30 min.), with the same mycobacteria recovery efficiency. Despite the low concentration, decontamination with CPC killed more mycobacteria and sufficiently eliminated contaminating germs. In contrast, decontamination with NaOH was less harmful to mycobacteria, but did not remove many contaminating germs. On the other hand, LJG medium performed better than LJGF medium and LJGP medium for the growth of mycobacteria in hospital waters. Finally, there was no difference in performance between the two incubation temperatures of 30℃ and 37℃. The results of this study show that further evaluation of existing protocols is required in order to optimize methods for the pre-treatment of hospital effluent for the isolation of mycobacteria.
文摘A novel water treatment technique, based on a combination of electrospraying and pulsed corona discharge, has been used for bio-decontamination of wastewater. The electrospraying process has been found to increase the surface area of the treated wastewater, and hence increases the efficiency of the corona treatment process. The phase diagram of the discharge, which characterizes the discharge regimes, has been identified experimentally. The survival ratio of the microorganisms has been investigated experimentally as a function of the applied voltage and the numbers of treatment runs using air and oxygen as working gases. Microorganism surface has been examined using scanning electron microscope (SEM), which enabled in understanding the decontamination mechanisms of the treated microorganism. A complete decontamination has been achieved after only one run for an applied voltage higher than 16 kV when the discharge system was operated in oxygen gas. Optical emission spectrum of the electrosprayed water confirmed the existence of OH-radicals responsible for decontamination process.
文摘Earthworms promises to provide cheaper solutions to several social, economic and environmental problems plaguing the human society. Earthworms can safely manage all municipal and industrial organic wastes including sewage sludge and divert them from ending up in the landfills. Their body work as a ‘biofilter’ and they can ‘purify’ and also ‘disinfect’ and ‘detoxify’ municipal and several industrial wastewater. They reduce the BOD & COD loads and the TDSS of wastewater significantly. They can even remove the EDCs (endocrine disrupting chemicals) from sewage which is not removed by the conventional sewage treatments plants. Earthworms can bio-accumulate and bio-transform many chemical contaminants including heavy metals and organic pollutants in soil and clean-up the contaminated lands for re-development. Earthworms restore & improve soil fertility by their secretions (growth hormones) and excreta (vermicast with beneficial soil microbes) & boost ‘crop productivity’. They have potential to replace the environmentally destructive chemical fertilizers from farm production. The ‘protein rich’ earthworm biomass is being used for production of ‘nutritive feed materials’ for fishery, dairy & poultry industries. They are also being used as ‘raw materials’ for rubber, lubricant and detergent industries. The bioactive compounds isolated from earthworms are finding new uses in production of ‘life saving medicines’ for cardiovascular diseases and cancer cure.
