文档介绍：摘要
摘要
传统紫外消毒装置存在紫外线强度不均匀的缺点,以及灯管浸没在水中
引起的诸多问题。为了改善这些问题,构思了新型紫外消毒装置。为了合理
设计装置,讨论了影响紫外消毒效果的一些因素。在众多水质参数中,紫外
消毒系统的设计关键参数是穿透率和悬浮固体。当穿透率在 45%到 80%时,
穿透率(T,%)与吸收系数α之间的关系不仅满足对数关系同时也满足线性关
系。然而线性关系更准确表达了穿透率与吸收系数间的关系。线性关系计算
任意深度处紫外强度值与实际测量值基本一致。因此,在水质发生改变时,
通过简单的线性关系可以判定紫外消毒系统能否有效杀灭细菌。
由于新型紫外消毒装置同一深度处强度均匀,因此便于确定新型紫外
消毒装置消毒剂量的问题。首先由流量、流速确定水力停留时间;接着以杀
灭大肠杆菌紫外剂量作为依据,根据紫外消毒系统结构,计算最不利点的紫
外强度;然后由穿透率计算吸收系数;根据最不利点的紫外强度和吸收系数
可以计算入射强度;最后入射强度乘以时间即为系统的紫外剂量。
由于紫外消毒是水处理的末端工艺,因此讨论了前驱工艺如混凝是否会
影响紫外消毒的效果。不同絮凝剂对紫外线的吸收也不同。铁盐系列的絮
凝剂对波长为 254nm 的紫外线有较强的吸收,硫酸铝对紫外线强度的衰减几
乎没有影响,但是 PAC 对紫外线的吸收强度有所增加;有机高分子混凝剂
PAM 对紫外线也没有吸收。絮凝剂投加量 M(mg/L)与吸收系数β之间满足线
性关系。它们之间的关系可以用β=A+BM 表示,其中 A 可表示溶剂对紫外
的吸收系数,B 表示絮凝剂的阳离子或者某絮凝剂对紫外线的吸收系数,单
位为 L/。当铁盐系列的絮凝剂金属阳离子浓度小于时,紫外
吸收系数强弱顺序为硫酸亚铁>三氯化铁>硫酸铁>PAC;当铁盐系列的絮凝
剂金属阳离子浓度大于时,紫外吸收系数强弱顺序为三氯化铁>硫酸
亚铁>硫酸铁>PAC。不同絮凝剂引起的浊度与紫外强度衰减之间没有相关性。
关键词紫外消毒;紫外强度;穿透率;吸收系数;浊度
- I -
哈尔滨工业大学工学硕士学位论文
- II -
Abstract
Abstract
The traditional equipments of UV disinfection have some ings,
such as UV intensity non-uniform, some problems caused lamp submerged in
water. In order to improve the technology of UV disinfection, we conceived the
new equipment of UV disinfection. In order to design the excellent equipment,
we discussed the effect of some factors on UV disinfection. We draw a
conclusion that suspended solid and transmittance were the key factors in UV
disinfection system. When the range of transmittance was from 45% to 80% , the
relationship between transmittance and absorbance coefficient not only satisfied
the Napierian logarithm, but also satisfied linear relation. However, linear
relation was fitter than the Napierian logarithm relation. The theoretic UV
intensity calculated by linear relation was the same as the actual UV intensity.
Therefore, when the water quality was changed, only need to measure the
transmittance of water sample, then we can obtain that whether UV disinfection
system can be used to disinf