6.5 Wastewater Treatment 6.5 Wastewater Treatment
Primary treatment Secondary treatment
Tertiary treatment - N, P Advanced treatment
Design of sedimentation basin ; overflow rate
Introduction to Environmental Engineering and Science , G.M. Masters & W.P.
Introduction to Environmental Engineering and Science , G.M. Masters & W.P. ElaEla, 2008, 2008
Chemical Treatment Chemical Treatment
용존 및 현탁 물질의 물리적 상태를 변환시켜 침전에 의해 제거할 수 있도록 화학약품을 첨가하는 것
목적 : 물리적 조작과 함께 사용되어 질소나 인을 제거;
화학적 침전
폐수의 2차 처리 공정을 완전히 하기 위함
- 명 반 : Al2(SO4)318H2O, Al2(SO4)3 14H2O - 염화철(III) : FeCl3
- 황산철(III) : Fe2(SO4)3, Fe2(SO4)3 3H2O - 황산철(II) : FeSO4 7H2O
- 석 회 : Ca(OH)2
Activated sludge process (biological aeration)
Activated sludge process (biological aeration)
생물학적 생물학적 처리 처리 공정 공정
활성
활성 슬러지슬러지 공정공정 (Activated Sludge Process)(Activated Sludge Process)
반응조 침전조 미생물 반송
미생물 반송
반응조 침전조 미생물 폐기
미생물 폐기
Trickling filter
Trickling filter
Rotating biological contactor
Rotating biological contactor
Sludge treatment
Sludge treatment –– 2% of the orginal volume, 97% water 2% of the orginal volume, 97% water
먹는 물 수질기준
국가명 한국 일본 미국(EPA) WHO 독일
계 55 51 98 96 49
미 생 물 4 2 5 1 2
유해 무기물질 16 17 19 17 19
유해 유기화학물질 12 9 29 28 7
농 약 4 2 27 32 4
일본, 유럽 등이 우리나라와 비슷하나 미국, WHO는 우리나라보다 많음.
미국과 WHO에서는 유해한 유기물질(농약, 화학약품, 소독부산물)에 대한 수질기 준 항목이 많음.
농 약 4 2 27 32 4
소독부산물 9 11 16 17 2
심미적인 영향 물질 9 10 9 2 6
방사성물질 - - 5 1 2
Disinfection byproducts structual formula Disinfection byproducts structual formula
THMs(Trihalomethanes) THMs(Trihalomethanes)
Cl Cl
Cl Cl Cl Cl
H C H
C ClCl
Br Br Cl Cl
H C H
C BrBr
Br Br Cl
Cl HH C
C
Br Br
Br Br Br Br
H C H
C
HANs(Haloacetonitriles) HANs(Haloacetonitriles)
ChloroformChloroform DichlorobromoDichlorobromo-- methane
methane DibromochloroDibromochloro-- methane
methaneBromoformBromoform
Cl
Cl Cl C
Trichloro- acetonitrile
C N Cl
H Cl
C
Dichloro- acetonitrile
C N Cl
H Br
C
Bromochloro- acetonitrile
C N Br
H Br
C
Dibromo- acetonitrile
C N
대표적 비 THMs계 DBPs Fomula
Haloacetic acids
C O Cl
Cl C H H OH
H C Cl O
C OH C
O Cl
Cl C Cl
OH Cl
Cl Cl C
Trichloro- C N
Cl H Cl
C C N
Haloacetonitriles
Dichloroacetic acid
Monochloroacetic acid
Dibromoacetic acid
Br C
O Br
C OH
H
Trichloroacetic acid
Monobromoacetic acid
H H C Br O
C OH Trichloro-
acetonitrile Dichloro- acetonitrile
Cl H Br C
Bromochloro- acetonitrile Br C N
H Br
C
Dibromo- acetonitrile
C N
Disinfection and Disinfection byproducts Disinfection and Disinfection byproducts
위험도
소독 부산물 미생물
소 독
6.4 Water Treatment System
6.4 Water Treatment System
Water Treatment Process Water Treatment Process
Screening
1. Mixing : Rapid Mixing
2. Coagulation, Alum (Al
2(SO
4)
318 H
2O), Ca(OH)
2,Na
2CO
33. Flocculation
4. Sedimentation, Sludge Processing
5. Filtration, Sand, Activated Carbon
6. Disinfection, Cl
2, NaOCl, Ca(OCl)
2,O
3Conventaional
Conventaional water treatment process? water treatment process?
표준식
표준식 정수 정수 처리 처리 공정이란 공정이란? ?
전 염소처리 후 염소처리
원
원
수수
혼화지 응집지 침전지 여과지 정수지
기존의 정수처리 공정 : 내분비계 장애물질 및 약성물질의 처리효율에 한계
응집 원수
침전
처리수 여과
후염소
분리막을 이용한 정수처리
처리수
원수
분리막 전처리 (오존 등)
(Option)
처리수 분리막을 이용한 고도정수처리 공정
Membrane Technology for the Separation: Classification
Water shortage problem
Water shortage population : 1.1 bilions in 2005 and 3 bilions in 2025
WHO reports that 3.4 million per year are killed by waterborne disease.(2005)
www.roplant.org21 5.3 billion
7.2~8.3 billion
1990 2025
World population
0.3 billion
2.4~3.2 billion
1990 2025
Water shortage population
Better to use seawater? How?
How to solve water scarcity?
RO membrane for desalination
22
UNESCO, 2009
Seawater desalination (Using RO membrane)
MSF (Multistage flush) Process
RO (Reverse Osmosis) Process
Introduction
MSF 40%
MED 3%
Other 2%
Distribution of desalination production capacity by process technology for the world
23
RO 44%
ED 6%
VC 5%
Philippe et al., 2009
In 1999 approximately 78% of the world’s seawater desalination capacity was made up of MSF plants while RO represented 10%
RO (Reverse Osmosis) Process : low energy, low construction cost, simple process
Production process Price (won/m3) Groundwater purification (MF) 200 ~ 300
Waste water reuse (MF+RO) 200 ~ 400
RO desalination 600 ~ 800
MSF desalination 900 ~ 1400
Water price using membrane processes
Seawater desalination (Using RO membrane)
Won/m3
24
Types of water Price (won/m3)
Tap water 100 ~ 7000
Industrial water 100 ~ 700 Ultrapure water 5000 ~ 10,000
Mineral water 200,000 ~ 3,000,00
91 96 99 01
MSF desalination
Groundwater purification
Waste water reuse
A worldwide water price
Decrease of water price by Membrane and process technologies
Toray co., 2007
Major components of membrane fouling
- Salt precipitation - Colloidal particulates - Organics
- Microorganisms
Vrouuwenvelder et al., 2003
Khedr et al., 2000
Biofouling + organic fouling : 58%
Biofouling causes :
- Declining membrane flux
- Increasing energy requirements - Elevating salt passage
- Membrane biodegradation
25
Total Configuration of desalination plant
CO2 RO process
Post-
treatment process
To high pressure
NaHSO
3
Chlorine
Cartridge
NaHCO3
Pretreatment process
Point of measuring SDI/MFI
26
Cl2
Media filter
tank Acid
tank e
Ferric chlorid
e
Filtrate clear
well
pump
Acid tank Acid tank
Scale
r
Scale
inhibito r Filter backwash pump
Cartridge filter
SEA WATER
MF/UF materials : Cellulose acetate (CA), Polyvinylidene fluoride (PVDF), Polyacrylonitrile (PAN), Polypropylene (PP), Polysulfone (PS), Polyethersulfone (PES)
RO/NF materials : Cellulose acetate (CA),Polyamide (PA)
Membrane materials
27
Manufacturing of composite polyamide membrane
Polysulfone polymer Solvent
Polysulfone casting solution
Polysulfone casting on polyester backing material
MPD solution TMC solution
Interfacial polymerization on polysulfone layer
Polysulfone casting
Membrane
28
*MPD : metaphenylenediamine
*TMC : trimesoyl chloride
Interfacial polymerization on polysulfone layer
Solvent evaporation and heat annealing
casting
Standard commercial TMC/MPD polyamide membrane
Seperation systemstechnology, inc., 1999 Polysulfone
(40µm) Polyamide (0.2µm)
Hybrid Membrane Processes
Chemical
Chemical flocfloc formed and recovered by MF or UFformed and recovered by MF or UF
Natural organic matter (NOM) from raw water Natural organic matter (NOM) from raw water
Chemically Assisted Membranes Chemically Assisted Membranes
Sorbents + Membranes Sorbents + Membranes
Powdered adsorbents in MF/UF circuit Powdered adsorbents in MF/UF circuit
Trace organics (POPs) from water Trace organics (POPs) from water
Sorbents + Membranes Sorbents + Membranes
Membrane Bioreactors Membrane Bioreactors
Bioreactor with MF or UF membranes Bioreactor with MF or UF membranes
Biodegradable organics from wastewater
Biodegradable organics from wastewater
Where hybrid systems fit Where hybrid systems fit- -
Membranes for Water & Wastewater Membranes for Water & Wastewater
Sea water Sea water
Water Production Water Production
Hybrid Systems
Sea water Sea water
Surface Water Surface Water
Secondary Effluent Secondary Effluent
(MF) MF/UForN+RO
MF + ROF AOT Water Production
Water Production
Domestic &
Domestic &
Industrial Industrial
use use MBR
Biological Waste Biological Waste Membrane Bioreactor
Membrane Bioreactor ReuseReuse
Recovered Water Recovered Water Membranes
Liquid Waste Liquid Waste
Industrial liquid Industrial liquid Effluents
Effluents Recovered Recovered
Resources Resources
MBR (Membrane Coupled Biological System )
Permeate(Effluent) Retentate
Membrane Unit Activated Sludge
Reactor
Influent
Principle of MBR?
하폐수 유입 MBR 여과수정밀여과막(MF) / 한외여과막(UF)
활성슬러지 반응조
(중수도)
분리막 생물반응조 (MBR)
처리수 유기물질 유해미생물박테리아 조류
물
처리수 분리막
흡입펌프 가동
공기및수류
Water reuse process 오산환경사업소 처리시설
1단 유입수 1단 유입수 2단 유입수