亚洲 日韩 国产 有码,CHINESE青年大学生GAY,国产精品日韩专区第一页,国产成人综合久久精品推荐,无遮无挡女白浆视频免费,浏览器观看B站视频的最佳设置,国产剧情强姦玩弄丝袜脚,欧美日韩视频777888,小泽玛利亚办公室高潮,国产丝袜脚足J在线视频播放,终于刺破了最后一层障碍高清,国产精品国产AV片国产,国产麻豆精品一区二区三区 ,白丝脚一区二区三区,国产成人综合久久精品推荐,久久亚洲日韩看片无码

The pH range applicable to aluminum sulfate is related to the hardness of raw water. When treating soft water, the suitable pH is 5 to 6.6. When treating hard water, the suitable pH is 6.6-7.2, and the high-hard water is treated. The suitable pH is 7.2-7.8. The water temperature range for aluminum sulfate is 20 ° C ~ 40 ° C. Aluminum sulfate is less corrosive, easy to use, and cost-effective.