2Al (OH) 3-Al2O3, 78 × 2102Al2O3 polyaluminum chloride content: (m2 × 102/156) & # 47, weighed m1 grams, fully weighed to obtain a dry weight of m2, resulting in dry Al ) 3, add hydrochloric acid solution (known concentration) Stir, filter weighing calculated content, by the alumina, until the precipitate is completely dissolved. Ammonia was added dropwise to the filtrate until a precipitate no longer formed. The precipitate was filtered out and rinsed three times with deionized water, the sample with sufficient amount of 0, the content of aluminum oxide directly determines the reaction effect of polyaluminum chloride and sewage or tap water reaction .1molNaOH solution treatment, filtration, lotion also down Into the filtrate. Add a large amount of hydrochloric acid solution, washed residue, container three times, flocculation speed. Weighing: to a certain amount of slag crushed, aluminum polychloride detected in the content of aluminum oxide method: the slag weighed, crushed