碱清洗 meaning in English

alkali cleaning
alkaline cleaning

After 8 months of operation , 15 inspected quality indexes of the filtrate from filtration with the media met the standards for drinking water ( gb5749 - 85 ) , indicating that either darkened sand or its regenerated sands could be used as filter media as the new sand
黑化石英砂与其酸、碱清洗再生砂对待滤水水中浊度，铁、锰去除效果良好，运行8个月后检测的15项水质指标都达到《生活饮用水卫生标准gb5749 - 85 》要求，且与新砂滤料的处理效果相差无几。