Stricter standards on sewage discharge have been applied in recent years because of the increased national supervision of energy saving and emissions reductions.
The Daqing Zhonglan Co used to have a sewage treatment capacity of 200 tons per hour, but, because of continued use in recent years, it was dealing with increased workloads it couldn't handle.
From Dec 2009 to April 2010, the amount of sewage discharge from the company was about 160 tons per hour, and at peak periods even reached 190 tons, which kept the sewage plant in a state of operation conditions.
Now, the new 700,000-ton-gasoline-and-diesel hydrogenation unit is expected to have a great effect on the sewage plant and, the company has set up a special technical group to cut the amount of sewage discharge.
And, thanks to the efforts and hard work, the technical group has cut the sewage discharge at three emission sites, and reduced it at five other sites.
The improvement is significant: by the end of last year, average sewage discharge was down from 160 to 126 tons.