低温低浊水混凝特性及强化混凝技术

哈尔滨工业大学工学硕士学位论文

国内图书分类号：TU991.22

国际图书分类号：628.1

工学硕士学位论文

低温低浊水混凝特性及强化混凝技术

硕士研究生：肖峰

导师：马军教授

申请学位：工学硕士

学科、专业：市政工程

所在单位：市政工程系

答辩日期：2005年12月

授予学位单位：哈尔滨工业大学

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哈尔滨工业大学工学硕士学位论文

Classified Index：TU991.22

U.D.C:628.1

Dissertation for the Master Degree in Engineering.

COAGULATION CHARACTERISTIC AND ENHANCED COAGULATION TECHNOLOGY OF WATER WITH LOW-TEMPERATURE AND LOW-TURBIDITY

Candidate：Xiao Feng

Supervisor：Prof. Ma Jun

Academic Degree Applied for：Master of Engineering Specialty：Municipal Engineering Affiliation Dept. of Municipal Engineering Date of Defence：December, 2005

Degree Conferring Institution：Harbin Institute of Technology

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哈尔滨工业大学工学硕士学位论文

摘要

利用透光脉动、ferron-Al逐时分光光度法及剩余浊度测定等方法, 在实验室进行了低温低浊水混凝效果强化方面的研究，找出低温低浊情况下混凝不利的影响因素。

发现增加溶液的初始颗粒浓度(或初始浊度)会提高混凝反应速率, 但这种增加不是无限的。对于低温情况下,混凝过程中颗粒的聚集速率与其初始浓度(初始浊度)成线性关系。提高初始浊度(从3.30 ntu到9.30 ntu)能使聚集速率线性增加。但当初始浊度增加到16.50 ntu时,聚集速率逐渐保持不变。对于在室温条件下(17-21o C)，线性关系一直在整个初始浊度变化范围内(从3.30 ntu到16.50 ntu)保持线性关系。表明不同温度下，絮体形成的途径以结构有所不同。低温时，对絮体达到其最佳（或最大）尺寸时需要的颗粒浓度比常温要少。温度的升高会提高絮凝反应的聚集常数,但同时絮体破碎常数也随之升高。低温时絮凝反应发生的极为缓慢。

在pH值等于8.0情况下， ferron-Al逐时分光光度法测定结果显示，在实验条件下快速混合后水解铝的种类分布情况相似。在不同条件下具有高电荷高聚合度的水解铝浓度也非常相似。说明从混凝剂水解到聚合态水解产物的生成受温度和浊度影响不大。但透光脉动法(PDA)的测量结果说明，无论是高水温还是高浊度都能增加絮凝速率。说明从水解铝的聚合到晶核形成再到晶体成长步骤受温度和浊度的影响非常大，它是控制混凝效率的关键步骤。低温或低浊对絮体成长的抑制作用大于对无机混凝剂水解过程的抑制作用。

根据这一发现，发明了多相催化强化混凝技术，利用催化剂来强化聚集态的水解产物生成初级晶核和初级絮体，乃至可沉降的絮体。

后期对所这项技术的应用情况进行了对实际低温低浊水体的考察，发现强化混凝相对常规混凝有更强的对沉后和滤后有机物污染物（COD）以及

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哈尔滨工业大学工学硕士学位论文

藻类的去除效果。这主要是由于其对混凝剂的强化水解结晶作用，提高了混凝效果。

高锰酸盐预氧化剂投量为0.8和1.2 mg/L之间能强化对有机物和藻类的去除。沉淀后藻类去除率可高达90%以上，表明大量的藻类被高锰酸盐灭活而沉淀。

高锰酸盐预氧化能够起到助凝作用和助滤作用，从而强化低温低浊水的处理效果。

关键词混凝，透光脉动法(PDA)，ferron-Al逐时分光光度法，聚集速率，强化混凝

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哈尔滨工业大学工学硕士学位论文

Abstract

Coagulation characteristic in the condition of low temperature and low-turbidity is investigated by means of photometric dispersion analysis (PDA), ferron-Al timed spectrophotometry, and turbidity measurement at different flocculation period.

For the low temperature conditions (2o C, 5o C, and 8o C), a linear relationship between aggregation rate of coagulation and particle number concentration within certain limit is observed. Increasing initial turbidity within certain limit (from 3.30 ntu to 9.30 ntu) would increase the aggregation rate linearly. While aggregation rate remains roughly constant when particle number concentration surpasses the limit or initial turbidity increases from 9.30 ntu to 16.50 ntu. However, for the higher temperature condition (ambient temperature: 17-21o C), aggregation rate remains increase in the whole turbidity range (from 3.30 ntu to 16.50 ntu). Furthermore aggregation rate obtained from PDA curves could predict the optimum alum dosage.

In addition, mechanism of coagulation under conditions of low temperatures (2℃, 5℃, and 8℃), low turbidities (3.30 ntu, 5.30 ntu, and 9.30 ntu), and a normal pH value of 8.0 is investigated. Result of ferron-Al timed spectrophotometry shows that Al-hydrolyzed species present similar fraction after fast-mixing period in experimental conditions. Concentration of polymeric metal hydrolyzed species of high charge is very similar in different circumstances. Such results indicate that the approach from hydration of ion-based coagulant to polymerization is not significantly affected by temperature and turbidity. However, measured by photometric dispersion analysis (PDA), either higher temperature or larger initial turbidity is able to increase the aggregation rate. Result of PDA indicates that the

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