Engineering of Water Quality Control Theory and performance of Deep-Bed Filtration
Engineering of Water Quality Control Theory and Performance of Deep-Bed Filtration
1. An overview of potable Water filtration 1.1 Concept of filtration The filtration processes discussed in here are used primarily to remove particulate material from water
1. An overview of potable Water filtration 1.1 Concept of filtration The filtration processes discussed in here are used primarily to remove particulate material from water
the classification of filtration filtration style granular bed filtration precoat filter filter media sand, anthracite coal GAC de filtration hydraulic: gravity filters pressure filters rate of filtration: rapid granular bed filter, slow sand filter distribution of deposit: depth filtration, cake filtration
the Classification of filtration: filtration style: granular bed filtration, precoat filter filter media: sand, anthracite coal , GAC, DE filtration hydraulic: gravity filters, Pressure filters rate of filtration: rapid granular bed filter, slow sand filter distribution of deposit: depth filtration, cake filtration
Dominant Mechanisms, Performance, and Applications (1)Cake filtration Cake filtration of particulates involves physical removal by straining at the surface The mechanism of cake filtration is largely physical straining Chemical pretreatments such as coagulation and sedimentation are not generally provided The source water must be of quite good quality
Dominant Mechanisms, Performance, and Applications (1) Cake filtration ▪ Cake filtration of particulates involves physical removal by straining at the surface. ▪ The mechanism of cake filtration is largely physical straining. ▪ Chemical pretreatments such as coagulation and sedimentation are not generally provided. ▪ The source water must be of quite good quality
(2)Slow sand filtration The surface cake of accumulated particulates includes a variety of living and dead micro-and macroorganisms The biological metabolism of the organisms enhances removal of particulates As the filter cake develops, the cake itself assumes a dominant role in particulate removal Because of this filtrate turbidity improves as the filter run progresses, and deterioration of the filtrate turbidity is normally not observed at the end of the filter cycle
(2) Slow sand filtration ▪ The surface cake of accumulated particulates includes a variety of living and dead micro- and macroorganisms. ▪ The biological metabolism of the organisms enhances removal of particulates. ▪ As the filter cake develops, the cake itself assumes a dominant role in particulate removal. ▪ Because of this, filtrate turbidity improves as the filter run progresses, and deterioration of the filtrate turbidity is normally not observed at the end of the filter cycle