摘要
宁东水厂的水源水在水库大坝加高的过程中水质发生变化，造成水处理难度加大、沉淀池跑矾。为了在水源水质发生变化的情况下保证出厂水水质，通过烧杯试验对四种常用混凝剂的混凝效果进行研究，并使用高锰酸钾进行预氧化。结果表明，水源水中的有机物主要是腐殖酸类物质，分子质量集中在1—4ku之间。随着混凝剂投量的增加，剩余浊度呈现逐渐下降的趋势，当投量超过20mg／L时，体系出现一定程度的返浊现象。随着高锰酸钾投量的增加，浊度去除率呈现逐渐上升的趋势，当投量达到0．7mg／L时，继续增加KMnO4的投量对于浊度的去除并没有明显的改善。在混凝效果达到最优的条件下，投加0．5mg／L的高锰酸钾可以明显改善絮体的沉降性，降低沉后水浊度。改性聚合氯化铝（HACC）形成的絮体的沉降性较好，分形维数较高，上清液浊度下降较快，经过3．0h的沉降后，上清液浊度达到0．49NTU。
The source water quality of Ningdong Water Treatment Plant changed when the dam was in heightening, which made water treatment more difficult and caused alum lost from the sedimentation tank. In order to ensure the finished water quality in the case of the change of source water quality, the efficiency of four conventional coagulants was investigated in jar tests, and the pre-oxidation was performed using potassium permanganate. The results indicated that the main organic compounds in source water were humic acid-like substances, and their molecular weights were mainly between 1 and 4 ku. With increasing the coagulant dosage, the residual turbidity decreased. When the coagulant dosage was more than 20 mg/L, the recurrence of turbidity was observed. With increasing the dosage of KMnO4, the removal efficiency of turbidity increased gradually. When the dosage reached to 0.7 mg/L, continuous increase in dosage of KMnO4 had no obvious effect on improvement of turbidity removal. Under the opti- mal conditions, the addition of KMnO4 of 0.5 mg/L could significantly improve the settleability of flocs and decrease the turbidity of settled water. The flocs formed by HACC had better settleability, higher fractal dimension and quicker decrease of turbidity in supernatant than those of the other three coagulants, and the supernatant turbidity could reach 0.49 NTU after settling for 3.0 h.
出处
《中国给水排水》
CAS
CSCD
北大核心
2016年第9期45-49,共5页
China Water & Wastewater
关键词
有机物
混凝
预氧化
分形维数
organic matter
coagulation
pre-oxidation
fractal dimension
