An 8.1 km section of Bell Run and its tributaries in Pennsylvania, USA, was restored from acidic to alkaline conditions by applying alkaline sand to the streambed.

• 用在河床上施加碱性沙子的方法；对美国宾夕法泥亚州Bell Run 一段长8.；1km；水体pH值由酸性到碱性的河流断面及其支流进行治理恢复。