Improvement of sedimentation effect by laying of short2tube filling in sedimentation basins ZHU Liang , TIAN Yu2lan , YAN Hui ( College of Environmental Science and Engineering , Hohai Univ. , Nanjing 210098 , China) Abstract : Some conclusions are drawn from laboratory tests : the laying of short2tube filling in the horizontal2flow sedimentation basin , vertical2flow sedimentation basin , and SBR