With　the　enhancing　of　people＇s　environmental　awareness　in　recent　years,　especially　after　the　stressing　of　the　sustainable　development,　the　treatment　of　sludge　water　and　sludge　in　the　waterworks　is　increasingly　at　a　premium,　and　the　environmental　departments　have　also　raised　higher　and　higher　requirements　on　the　emission　and　treatment　of　production　waste　in　the　waterworks.　Many　of　Chinese　newly　built　large-scale　water-works　and　expansion　and　reconstruction　projects　of　water　works　have　also　begun　to　think　about　the　problem　of　sludge　water　and　sludge　treatment,　with　different　process　flows　adopted.　The　major　purpose　of　this　paper　is　to　treat　the　sewage　via　low　temperature　process.　Effect　of　DO,　internal　reflux　ratio　r,　external　reflux　ratio　R,　sludge　age　SRT,　sewage　temperature　and　pH　on　COD　removal　is　studied.　The　result　shows　that　the　best　COD　removal　was　95.8%　and　TP　removal　is　90.7%.　©　by　PSP