And New York is not alone. Nearly 800 American cities rely on decrepit systems that collect storm-water run-off, industrial waste and human sewage in the same pipes.

这种现象并不仅仅出现在纽约，在美国有将近800个城市依靠破旧的排水系统，使用同一个管道来收集暴雨径流水，工业废水和人用污水。

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New conditioning agent for sewage treatment has been studied to replace the old one in Zhongyuan oilfield due to high cost and high volume of waste mud of the old one.

中原油田污水处理所用处理剂导致高成本、高污泥量，研制利用新药剂替代原用药剂。

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With the Municipal Sewage treatment Plants discharge more and more sludge, the sludge has become a new solid waste pollution on the environment, so the sludge treatment is necessary.

随着城市污水处理厂排放的剩余污泥越来越多，污泥已经成为一种新的固体废弃物，对环境造成了污染，因此对污泥进行处理是非常必要的。

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