6.5 wastewater treatmentocw.snu.ac.kr/sites/default/files/note/6286.pdf · 2018-01-30 ·...
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6.5 Wastewater Treatment6.5 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 TreatmentChemical 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)3�18H2O, 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)
�� 생물학적생물학적 처리처리 공정공정
활성활성 슬러지슬러지 공정공정 (Activated Sludge Process)(Activated Sludge Process)
침전조반응조
미생물 반송미생물 반송
침전조반응조
미생물 폐기미생물 폐기
Trickling filterTrickling filter
Rotating biological contactor Rotating biological contactor
Sludge treatment Sludge treatment –– 2% of the orginal volume, 97% water2% 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 수질기준 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 formulaDisinfection byproducts structual formula
�� THMs(Trihalomethanes)THMs(Trihalomethanes)
ClCl
ClCl
ClCl
HHCC ClCl
BrBr
ClCl
HHCC BrBr
BrBr
ClClHH
CC
BrBr
BrBr
BrBr
HHCC
�� HANs(Haloacetonitriles)HANs(Haloacetonitriles)
ChloroformChloroform DichlorobromoDichlorobromo--methanemethane
DibromochloroDibromochloro--methanemethane
BromoformBromoform
Cl
Cl
Cl
C
Trichloro-acetonitrile
C N Cl
H
Cl
C
Dichloro-acetonitrile
C N Cl
H
Br
C
Bromochloro-acetonitrile
C NBr
H
Br
C
Dibromo-acetonitrile
C N
대표적 비 THMs계 DBPs Fomula
Haloacetic acids
C
O
Cl
Cl
C
H
OHH
H
C
Cl O
C OH C
O
Cl
Cl
C
Cl
OHCl
Cl
Cl
C
Trichloro-
C N
Cl
H
Cl
C C N
Haloacetonitriles
Dichloroacetic acid
Monochloroacetic acid
Dibromoaceticacid
Br C
OBr
C OH
H
Trichloroacetic acid
Monobromoaceticacid
H
H
C
Br O
C OH
Trichloro-acetonitrile Dichloro-
acetonitrile
Cl
H
Br
C
Bromochloro-acetonitrile
C NBr
H
Br
C
Dibromo-acetonitrile
C N
Disinfection and Disinfection byproductsDisinfection and Disinfection byproducts
위
험
도
소독 부산물미생물
소 독
6.4 Water Treatment System6.4 Water Treatment System
Water Treatment ProcessWater Treatment Process
Screening
1. Mixing : Rapid Mixing
2. Coagulation, Alum (Al2(SO4)3 18 H2O), Ca(OH)2, Na2CO3
3. Flocculation
4. Sedimentation, Sludge Processing
5. Filtration, Sand, Activated Carbon
6. Disinfection, Cl2, NaOCl, Ca(OCl)2, O3
ConventaionalConventaional water treatment process?water treatment process?표준식표준식 정수정수 처리처리 공정이란공정이란??
전 염소처리 후 염소처리
원원수수
혼화지 응집지 침전지 여과지 정수지
기존의정수처리공정 : 내분비계장애물질및약성물질의처리효율에한계
응집
원수
침전처리수
여과
후염소
분리막을 이용한 정수처리
처리수
원수
분리막전처리 (오존 등)
(Option)
처리수
분리막을이용한고도정수처리공정
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)
21www.roplant.org
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
22UNESCO, 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 desa
linatio
n
Groundwater p
urifica
tion
Waste w
ater reu
se
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 biodegradation25
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
tanke
Ferric
chlorid
e
Filtrate
clear
well
pump
Acid
tank
Acid
tank
Scale
r
Scale
inhibito
r
Filter backwash pump
Cartridge
filter
SEA WATER
�MF/UFmaterials : Cellulose acetate (CA), Polyvinylidene fluoride (PVDF), Polyacrylonitrile (PAN),
Polypropylene (PP), Polysulfone (PS), Polyethersulfone (PES)
� RO/NFmaterials : 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 waterNatural organic matter (NOM) from raw water
Chemically Assisted MembranesChemically Assisted Membranes
Sorbents + MembranesSorbents + Membranes
Powdered adsorbents in MF/UF circuitPowdered adsorbents in MF/UF circuit
Trace organics (POPs) from waterTrace organics (POPs) from water
Sorbents + MembranesSorbents + Membranes
Membrane BioreactorsMembrane Bioreactors
Bioreactor with MF or UF membranes Bioreactor with MF or UF membranes
Biodegradable organics from wastewaterBiodegradable organics from wastewater
Where hybrid systems fitWhere hybrid systems fit--Membranes for Water & WastewaterMembranes for Water & Wastewater
Sea waterSea waterWater ProductionWater Production
Hybrid
Systems
Sea waterSea water
Surface WaterSurface Water
Secondary EffluentSecondary Effluent
(MF)
+ROMF/UForN
FMF + RO AOT
Water ProductionWater Production
Domestic & Domestic &
Industrial Industrial
useuse
MBRBiological WasteBiological Waste
Membrane BioreactorMembrane Bioreactor ReuseReuse
Recovered WaterRecovered Water
Membranes
Liquid WasteLiquid WasteIndustrial liquidIndustrial liquid
EffluentsEffluents Recovered Recovered
ResourcesResources
MBR (Membrane Coupled Biological System )
Permeate(Effluent)
Retentate
Membrane Unit
Activated Sludge
Reactor
Influent
Principle of MBR? 하폐수 유입MBR 여과수
정밀여과막(MF)
/ 한외여과막(UF)
활성슬러지 반응조
(중수도)
분리막 생물반응조
(MBR)
처리수
유기물질 유해미생물박테리아 조류물
처리수
분리막
흡입펌프
가동
공기및수류
Water reuse process 오산환경사업소 처리시설
1단 유입수 1단 유입수2단 유입수