Up to this day I still can vividly remember a routine in my elementary school:the daily school-wide morning calisthenics. It started at about 7:45 am in the school courtyard.Our physical education teacher stood on the...Up to this day I still can vividly remember a routine in my elementary school:the daily school-wide morning calisthenics. It started at about 7:45 am in the school courtyard.Our physical education teacher stood on the concrete stage where our principal would give her talk at school assemblies.All children and teachers would follow the teacher’s lead to do the eight-segment national calisthenics in unison with loud music from loudspeakers affixed on trees around the courtyard.When I visited the school last May,I saw that students still performed the routine faithfully but with a different set of展开更多
Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly...Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly handled and disposed, it may produce extensive health hazards. On the other hand, this sludge has benefit for plants and soils. Sludge samples were collected over a 12 month period from sewage treatment plants （STP＇s）, i.e, Khairathabad and Meeralam Tank, Hyderabad, India and analyzed for C, H, N, S by elementar analyzer, P, K, Ca, Mg by spectrophotometer and heavy metals like Zn, Pb, Ni, Cu, Cd by atomic absorption spectrophotometer. The sludge contained approximately 50% organic matter and 1-4% inorganic carbon. Organic and inorganic carbon, organic nitrogen, inorganic phosphorous, Ca and Mg were found to be present in sludge at a relatively constant concentration with respect to sampling time. Inorganic N, organic P, K, and all metals were found to be quite variable with time when sludge produced from different STP＇s.展开更多
文摘Up to this day I still can vividly remember a routine in my elementary school:the daily school-wide morning calisthenics. It started at about 7:45 am in the school courtyard.Our physical education teacher stood on the concrete stage where our principal would give her talk at school assemblies.All children and teachers would follow the teacher’s lead to do the eight-segment national calisthenics in unison with loud music from loudspeakers affixed on trees around the courtyard.When I visited the school last May,I saw that students still performed the routine faithfully but with a different set of
文摘Sludge production is an avoidable problem arising from the treatment of wastewater. The sludge remained after municipal wastewater treatment contains considerable amounts of various contaminants and if is not properly handled and disposed, it may produce extensive health hazards. On the other hand, this sludge has benefit for plants and soils. Sludge samples were collected over a 12 month period from sewage treatment plants （STP＇s）, i.e, Khairathabad and Meeralam Tank, Hyderabad, India and analyzed for C, H, N, S by elementar analyzer, P, K, Ca, Mg by spectrophotometer and heavy metals like Zn, Pb, Ni, Cu, Cd by atomic absorption spectrophotometer. The sludge contained approximately 50% organic matter and 1-4% inorganic carbon. Organic and inorganic carbon, organic nitrogen, inorganic phosphorous, Ca and Mg were found to be present in sludge at a relatively constant concentration with respect to sampling time. Inorganic N, organic P, K, and all metals were found to be quite variable with time when sludge produced from different STP＇s.
