Wastewater stabilization ponds (WSP)-An ideal lowcostsolution for wastewater treatment around theworld

Abstract

The world has derived many benefits from the western industrial and technological revolution, also caused enormous damages to the environment and ecological system. To repair the damage the whole world has turned back to the natural solutions to solve many problems and Wastewater Stabilization Pond (WSPs) is one of them. The world is now committed and united to protect the environment. Traditional practices are being rapidly replaced by Ecologically Sustainable Development (ESD). Water Conservation, Greywater Recovery and Recycle are now a global agenda. Bangladesh should follow the concepts even more vigorously as she is the worst sufferer of Greenhouse gas effect. Global warming facing the most serious challenges in supplying fresh water particularly to urban areas. Stabilization Ponds reaps the benefits of the natural forces of biodegradation, utilizing energy released by naturally occurring microorganisms through their metabolic activities in treating different types of wastewater. Stabilization Ponds are very environmentally friendly and is a great contributor in achieving ESD. Stabilization pond works in all climatic conditions (except very low temperature) but it works exceptionally well in warm temperate ideal for Bangladesh. Stabilization ponds is an ideal low cost, low maintenance, require no or very little energy, and no special expertise is required either to construct or to maintain them for its proper functioning. This low-cost technology should be considered as a blessing for Bangladesh. Anaerobic ponds very effectively treat heavy organic loading (Example: BOD loading 4250 mg/L) utilizing Anaerobic bacteria. The principal biological reactions occurring are acid formation and methane fermentation. The generation of methane (CH4) can easily be captured as BIOGAS and has the potential to become a viable green energy source for Bangladesh. Facultative ponds receive medium to low organic loading (BOD5 200 mg/L in the present case study). The bottom layer is maintained anaerobic, but the surface layer is kept aerobic through photosynthesis and surface aeration. BOD removal is higher than the anaerobic pond. Maturation Pond is the last in the multi-cell series of WSPs and is designed to remove pathogenic bacteria, left over nutrients and possibly algae, preparing recycled water ready for utilization.