Selecting Treatment Technologies for Small Rural Wastwater...
Transcript of Selecting Treatment Technologies for Small Rural Wastwater...
Selecting Treatment Technologies for Small Rural
Wastwater Treatment Systems within Bregalnica River
Basin Management Project in Macedonia
Darko Lefkov, Ministry of Environment and Physical Planning
Nikolcho Vangelov, Reto Bühler, Ivo Fölmli, EBP Schweiz AG
1-3 November 2017, Pristina, Kosovo
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Introduction – Bregalnica River Basin
Situated in Eastern Macedonia covers 17% of Macedonian territory with 15
municipalities
Many small rural settlements without wastewater treatment
Connection to regional WWTP not possible
Strong impact of untreated wastewater on regional water bodies
reducing the share of untreated wastewater
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Technical requirements
Reliability: robust system, continuously operational
Effectiveness: achieve effluent standards,
remove pollutants with strong impact on water bodies
Affordability: affordable for local population, minimal overall cost
Project requirements
Single system: knowhow exchange, one operator operates several small
WWTP
Low O&M costs: low energy consumption,
no permanent local presence of operator
Short implementation time
Requirements for Technology Selection
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Technologies for sWWTP
A basic WWTP consists of the following components:
• Mechanical treatment (screening, grit and grease removal, sedimentation)
• Biological treatment (primary, secondary and tertiary)
• Sludge treatment
• High investment cost
• High operation
• Complex technologies
The trickling filter, membrane bioreactor technologies and biogas reactors
were excluded from further evaluation
Exclusion of Inappropriate Technologies
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Primary treatment:
Secondary treatment: Tertiary treatment:
Anerobic baffled reactor
Constructed wetland
Polishing pond Source:
Compendium of Sanitation Systems and Technologies (Eawag, 2008)
Treatment Process Selection – System ABR
Grid and grease removal
Organics and solid removal
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Source: Compendium of Sanitation Systems and Technologies (Eawag, 2008)
Primary treatment:
Secondary treatment: Tertiary treatment:
Anaerobic pond
Facultative pond
Polishing pond
Treatment process selection – System Ponds
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Primary treatment:
Secondary treatment: Tertiary treatment:
Septic Tank
Rotating biological
contactor (RBC)
Polishing pond
Source:
Compendium of Sanitation Systems
and Technologies (Eawag, 2008)
Source:
Compendium of Sanitation Systems and Technologies (Eawag,
2008)
Source:
Walker Process Equipment
Division of McNish Corporation
Treatment Process Selection – System RBC
Grid and grease removal
Organics removal with aerobic
degradation
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
RBC: - highest investment and operational costs
- operational complexity
Ponds: - investment cost highly dependent on local land prices
Ponds: - project delays due to expropriation proceduress: -
ABR: + no mosquito problem as with ponds
ABR: + less affected by cold temperatures
Evaluation of the Systems ABR, Ponds, RBC
Name of Alternative ABR Ponds RBC
Investment costs 2 3 1
Operational costs 3 3 2
Land use 2 1 3
Operational complexity 2 3 1
Sludge stabilization 3 3 3
Integrated sludge storage 3 3 3
Process stability 3 2 2
Greenhouse gas emission 1 1 2
Overall evaluation 19 19 17
1-least advantageous; 3 – most advantageous
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
High organic removal
Reliable even at seasonal temperature chances
Affordable for local population
Simple and economic system (no permanent surveillance required, little
energy consumption)
Anerobic baffled reactor
Constructed wetland
Polishing pond Source:
Compendium of Sanitation Systems and Technologies (Eawag, 2008)
Most Appropriate System: ABR
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Treatment System Proposed by Tenders
Concept 1: Horizontal Flow Constructed Wetland (HFCW)
- primary treatment
- secondary treatment
- tertiary treatment
- sludge treatment
Concept 2: Vertical Flow Constructed Wetland (VFCW)
- primary treatment
- secondary treatment
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Construction Phase
Challenges during construction
• bulding permit procedure
• groundwater
• sufficent capacity for the implementation of both projects at same time
WWTP Kucicino
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
Construction Phase
- defect liability period
Wastewater Challenge, 1-3 November 2017, Pristina, Kosovo
Selecting Treatment Technologies for Small Rural Wastewater Treatment Systems within Bregalnica River Basin Management Project in Macedonia
THANK YOU FOR YOUR ATTENTION