The comparison of performances of a sewage treatment system before and after implementing the cleaner production measure

The cleaner production practice has been advocated greatly in industrial field, including sewage treatment process. This study investigated the performance changes of the largest sewage treatment plant, i.e. Gaobeidian sewage treatment plant in Beijing, China, before and after a cleaner production measure being implemented using emergy and money based indicators. This cleaner production measure redesigned the original primary clarifier to raise the ratio of C/N through strengthening its function of hydrolytic acidification and then realized the removal of nitrogen and phosphorus simultaneously in the following biological reactors without supplement of external carbon resource and no reagent use for removal of phosphorus, compared to the original craft. However, the investment and energy consumption is also enhanced slightly. The results show that the resource efficiency and environmental performance are all improved to different degree after the cleaner production measure was implemented. Therefore, cleaner production practice should be also advocated in wastewater treatment field. Furthermore, some suggestions are put forward to further strengthen the sustainability of this sewage treatment plant.