techniques in post treatment of abr effluents in treating municipal wastewater a literature review...
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Techniques in post treatment of ABR
effluents in treating municipal wastewater
A literature review of appropriate technologies for Nepal
Sanita Dhaubanjar’13Smith-Princeton Exchange Student 2011
PEI Health Grand Challenge
Project Title : Study on the water systems and delivery of water in Kathmandu Nepal
Organization: Oxford University Clinical Research Unit, Kathmandu, Nepal
Project Summary: The project would involve work with the epidemiology team of OUCRU-NP and the Engineering Department of Kathmandu City to GIS map all the water spouts, investigate the water delivery systems, and link this with the on-going molecular epidemiology of enteric fever in the city.
Developing a New Project
Project: Research on Wastewater treatment technologies
Organisation: Bio-Based and Green Energy Lab (BGEL) at Kathmandu University (KU)
Project Advisors: Dr Bivek Baral, Coordinator, BGEL
Department of Mechanical Engineering, KUEmail: [email protected]
Sunil Lohani
Assistant Professor
Department of Mechanical Engineering, KU
Email: [email protected]
Proposed Goals of Study
Literature review of Anaerobic Baffle Reactor (ABR) technology to Identify suitable pre and post treatment technology to supplement ABR as they effluent quality from ABR does not acceptable standards. Focus on less land intensive technologies.
Review different wastewater efmeet fluent standards around the world, especially in south-Asian countries like Nepal and suggest acceptable and reasonable effluent standards for Nepal.
Current status of wastewater treatment in Kathmandu, Nepal
Dhobighat Wastewater Treatment Plant
Kodku Wastewater Treatment Plant
Status of wastewater treatment
The 5 centralized WWTP that are not working. All plants were based primarily on aerobic degradation.
About 12 communities tried to implement decentralized Reed Bed Treatment. ENPHO and handful of private groups invested in constructed wetland based treatment.
Roughly 370 MLD of wastewater produced in the country of which the installed WWTP account for only 37 MLD (10% of total demand)
Identified Problems in Nepal
Technical inefficiencies Blocked sewers due to inadequate flushing and self cleaning Lack of filtration or sedimentation as pre-treatment Lack of institutional capacity to run WWTP Failure to design for combined sewer overflows (CSOs) Traditionally preferred system of waste stabilization ponds
not favored because of increased land cost, and advanced systems are not being constructed because of high capital and operational costs plus lack of technical expertise.
Administrative inefficiencies Overlapping responsibility between various government
sectors in maintenance of sewer systems. Lack of strict monitoring of wastewater discharge.
Anaerobic Baffle Reactor: Overview
Schematic cross-section of an up-flow ABR. Source: Morel & Diener (2006)
Highlights from review Optimal reactor conditions and supplements available in literature
to enhance performance
Suitable technologies found in literature Coagulation-Floccultaion using Zeolite/polymer columns Membrane Separation Technologies, espcecially Ultrafiltration Aerobic CSTRs Submergerd aerated bio-filter Dissolved air flotation Trickling filter Anaerobic filters Wetlands and aerated lagoons Soil Aquifier treatment (SAT) Anaerobic filters Down flowhanging sludge filters Activated Sludge processes UV/H2O2 Periodic Anaerobic Baffle Reactor for time varying loadings
Other Suggestions
Wastewater characterization
Identify and raise awareness about potential reuse of treated wastewater
Cost analysis of various combination of wastewater treatment
Surveys to understand the interests and knowledge of communities in managing their own wastes
My Learning experience
Valuable insight on starting and conducting researches and literature review
Increased efficiency in conducting searches using Journal Search Engines
Knowledge about wastewater treatment technologies and their appropriateness
Status of wastewater treatment in Nepal
Understand the importance of networking
Acknowledgements Dr. Baral and Prof. Lohani at Kathmandu
University
Dr Jeremy Farrar and Nepal’s team at OUCRU
PEI Health Grand Challenges