Xử lý nước thải bằng hệ thống đất ngập nước kiến tạo hay còn gọi là xử lý nước thải bằng hệ thống đất ngập nước nhân tạo. Đây là một hình thức xử lý nước thải dựa vào vùng đầm lầy, than bùn hoặc vùng nước tự nhiên hay nhân tạo, ngập nước thường xuyên hoặc từng thời kỳ, là nước tĩnh, nước chảy, chảy ngọt, nước lợ hay nước mặn, bao gồm cả những vùng biển mà độ sâu mực nước khi thủy triều ở mức thấp nhất không vượt quá 6m.
Trang 1CONSTRUCTED WETLANDS:
An Overview of the Technology
Presented by:
ROUX ASSOCIATES, INC.
Environmental Services and Management
Presentation For:
Peconic River Remedial Alternatives
Workshop
Walter H Eifert Principal Hydrologist
December 12 & 13, 2000
Trang 2What Is A Constructed Wetland?
What Is A Constructed Wetland?
Saturated Substrates
Definition:
A designed and man-made complex of:
Emergent and Submergent Vegetation Animal Life
Water That Simulates Natural Wetlands
Trang 3FILENAME.PPT
Trang 5FILENAME.PPT
Trang 11BIOLOGICAL BIOLOGICAL
PHYSICAL PHYSICAL
through plants to root zone
through plants to root zone
O 2
O 2
CHEMICAL
Treated Water
Treated Water
Planting Substrate
Planting Substrate
Influent
Contaminant Removal Mechanisms:
Multiple Processes At Work
Trang 12Bacterial Metabolism Plant Metabolism Plant Absorption Natural Die-Off
Trang 13Heavy Metals Suspended and Colloidal Materials Pathogens
Trang 14Types of Constructed Wetlands
Free Water Surface Systems
Marsh - Pond - Meadow Sequence
1
2 Subsurface Flow Systems
Engineered cells containing gravel, soil and.or sand treatment media
Trang 15Effluent Collection System
Effluent Collection System
To Pond or Receiving System
To Pond or Receiving System
Influent Distribution System
Influent Distribution System
Organic Substrate
Organic Substrate
Outflow Control Structure
Outflow Control Structure
Inflow Control Structure
Inflow Control Structure
2”-12”
Flow
Free Water Surface Wetland:
Marsh Component
Trang 171’- 6’ Varying
Depths
Flow
Emergent Vegetation
Emergent Vegetation
Submergent Vegetation
Submergent Vegetation
Outflow Collection System
Outflow Collection System
Impervious Barrier
Impervious Barrier
Outflow Control
Outflow Control
Marsh Pond Meadow
To Receiving System
To Receiving System
Weir
Free Water Surface Wetland:
Open Water Pond
Trang 19Planting Surface
Planting Surface
Meadow Plants
Meadow Plants
Weir
Saturated Water Level
Saturated Water Level
Effluent Collection System
Effluent Collection System
To Receiving System
To Receiving System
Influent Distribution System
Influent Distribution System
Mixed Porus Media
Mixed Porus Media
Outflow Control Structure
Outflow Control Structure
Flow
Marsh Pond Meadow
Impervious Barrier
Impervious Barrier
Free Water Surface Wetland:
Meadow
Trang 21Rip-Rap Planting
Substrate
Planting Substrate Rip-Rap
Water Level
Hydraulic Gradient
Effluent Collection System
Water Level
To Receiving System
Effluent Collection System
Influent Distribution
System
Treatment Media (gravel, sand, soil)
Influent Distribution System
Outflow Control Structure
Treatment Media (gravel, sand, soil)
Inflow
Control
Structure
Outflow Control Structure
Trang 24CASE STUDIES
BASF, Williamsburg, Virginia City of Glen Cove, New York
CASE STUDIESBASF, Williamsburg, Virginia
City of Glen Cove, New York
Trang 25! COC’s: Zinc, Iron, and Acidity
! Typical Zinc influent: 800 mg/L
! Typical Zinc effluent: 0.10 to 1.5 mg/L
Trang 26BASF, Williamsburg Pre-Construction Photo
Trang 27BASF, Williamsburg CW Site Plan
Trang 28BASF, Williamsburg
Trang 29BASF, Williamsburg
Trang 30BASF, Williamsburg
Trang 31BASF, Williamsburg
Trang 32BASF, Williamsburg
Trang 33BASF, Williamsburg
Trang 34BASF, Williamsburg
Trang 35BASF, Williamsburg
Trang 36BASF, Williamsburg
Trang 37BASF, Williamsburg
Trang 38BASF, Williamsburg
Trang 39Typical Nitrogen Influent:
Projected Nitrogen Removal:
Treatment Design Flow Rate:
First Flush Hydraulic Retention Time:
Hydraulic Design Flow Rate:
Construction Completion Expected:
TSS, Nitrogen, Lead, and Copper 4.24 mg/l
45 lbs/day Base Flow = 8 cfs First Flush = 25 cfs
12 Hours
450 cfs April 2001
Trang 40G L E
C O
E A V
HE ND
RI CK A
VE .
RT
E 10 7
R T 1
C
HA R
LE S
S T.
10 ft x 8 ft Culvert
Twin 12 ft x 6 ft Culverts
Proposed Pedestrian Path
Creek
L .I.
R .R .
Trang 41PRECONSTRUCTION Debris Waste and Iron Stained Seep Area
PRECONSTRUCTION Debris Waste and Iron Stained Seep Area
Trang 42PRECONSTRUCTION Severely Eroded Hillside
PRECONSTRUCTION Severely Eroded Hillside
Trang 43UNDER CONSTRUCTION Stop Log Structure and Diversion Channel
UNDER CONSTRUCTION Stop Log Structure and Diversion Channel
Trang 44POST- CONSTRUCTION Completed Micropool
POST- CONSTRUCTION Completed Micropool
Trang 45Advantages of Constructed Wetland Treatment Systems
Advantages of Constructed Wetland Treatment Systems
Tolerant of fluctuating hydraulic and contaminant loading rates
Very low operation and maintenance costsEasy to maintain
Can be designed to provide habitat enhancements and contaminant mitigation
Inexpensive to construct
Provide increased educational opportunities
Trang 46Potential Disadvantages of Constructed
Wetland Treatment Systems
Potential Disadvantages of Constructed
Wetland Treatment Systems
Require relatively large land areas Lack precise design criteria
Potential vector control concerns