filter r bed过虑床;过滤层
bilayer filter double bed filter双层过滤器
submerged aerobic biofilm filter-bed淹没式好氧生物膜滤床
rapid sand filter bed快速滤清器
trickling filter bed散水滤床
biological filter bed生物滤床
filter bed thickness滤床厚度
filter deep-bed厚床滤器
N(名词) a layer of sand or gravel in a tank or reservoir through which a liquid is passed so as to purify it 过滤砂砾层 → compare bacteria bed