... -ammonia, de-phosphor as to 99%, it is ideal replacement for quartz sand and anthracite. The filtration materials of ceramic granule ... be used in waste -water secondary treatment through Bio-chemical method for the biology carrier as the pre-treatment of lightly pollutant ... resistanceUses 98%, 40%, 20%, 5% sulfuric acid solution to soak for 30 days, the loss in weight is smaller than 2 ...