摘要
南方地区水厂所用地表水源的一个显著特点是硬度低、碱度低、腐蚀性强。为了改善供水水质的化学稳定性,一般是向水中投加一定量的石灰。但是,单点过量的石灰投加会造成药耗增大、混凝沉淀效果不好、余铝超标等问题。该文通过采用在混凝阶段投加石灰、在滤后水中投加氢氧化钠的方法,调节水厂出水的pH值,使pH值调节对生产及水质的不利影响大幅降低。同时,对石灰及氢氧化钠的投加进行优化,证实在混凝阶段石灰的最佳投加点为混凝剂后1 min,最佳投加量为2.0 mg/L,最大投加量宜控制在6.0 mg/L以下;在滤后水中投加氢氧化钠可有效提高出厂水的pH值,氢氧化钠投加量约1.6 mg/L。
In south China, the significant feature of surface water source is low hardness, low alkalinity and strong corrosivity. A certain amount of lime was generally dosed into the water to improve the chemical stability of water quality. However, the over dosing of lime could cause such problems as PAC consumption increasing, sedimentation worsened, residual aluminum increased. To dose the lime in the coagulation stage and then add sodium hydroxide in the filtered water give a good result of pH Value adjustment without deterioration of the water quality. Meanwhile, it is proved that the best time to dose the lime is 1 minute after dosing PAC, the optimum dosage is 2.0 mg/L and should not exceed 6.0 mg/1. To dose NaOH into the filtered water is an effective way for pH Value adjustment. The dosage of sodium hydroxide is about 1.6 mg/L.
出处
《净水技术》
CAS
2010年第5期26-29,共4页
Water Purification Technology
关键词
PH值
余铝
石灰
氢氧化钠
pH Value residual aluminum lime sodium hydroxide （NaOH）
