二次微絮凝工艺在饮用水生产中的应用

Application of secondary micro-flocculation in drinking water production

结合生产工艺现状,天津塘沽中法供水有限公司所辖水厂采用二次微絮凝工艺,在原有加药方式基础上增加了沉淀后二次投药点,以期改善过滤效果.结果表明,采用FeCl3作为二次微絮凝混凝剂,在投加量为4 ～6 mg/L的条件下能保证出厂水浊度≤0.2 NTU.在实际应用中,二次微絮凝工艺可使滤后水浊度降低40％,同时制水药剂单耗较一次加药方式可降低18％左右.由于该絮凝方式对滤池的运行周期有较大影响,因此需要加强滤池运行及反冲洗优化管理,以保持水质稳定.

Combined with the current situation of production process, the secondary micro- flocculation process was adopted by the waterworks which managed by Tianjin Tanggu Sino French Water Supply Co., Ltd. The secondary dosage point after sedimentation was added based on or/ginal dosage way in order to improve the filtration effect. The results indicated that the outfow turbidity was no more than 0.2 NTU under the condition of dosing 4 to 6 mg/L and adopting FeC13 as secondary micro-flocculation coagulant. The turbidity of filtered water could be reduced 40% by secondary miero-flocculation process in actual application. The unit consumption of chemical could be reduced 18% compared with one-time dosing method. Due to the great influence on operation period in filter by this flocculation method, it was needed to improve filter operation and optimal management of backwash in order to maintain the water quality.