一、问题的提出从我国第一条营业性质的铁路建成至今已有一百多年了,目前全国的营业铁路已长达7．5万公里。火车从蒸汽机车发展为内燃机车,又从内燃机车发展到电气机车,虽自身已经不再喷云吐雾,不再挥撒煤灰,可是有统计数字表明,铁路客车上乘客,每天从列车厕所直接排到路基上的粪便量,已经超过了三千吨。 First, the issue raised From the first commercial nature of our railway has been completed more than a hundred years, and now the country’s commercial railway has up to 75,000 km. The development of steam locomotives from diesel locomotives to diesel locomotives and the development of electric locomotives from diesel locomotives have stopped sprinkling fog and no longer discharging ash. However, statistics show that passengers on railway passenger trains travel daily from train toilets The amount of manure discharged directly to the embankment has exceeded 3,000 tons.