Author: Annatoria Chinyama, Tendai Toma
Department of Civil and Water Engineering, National University of Science and Technology, P.O Box AC939, Ascot, Bulawayo, Zimbabwe
Understanding the Poor Performance of Urban Sewerage Systems – A Case of Coldstream High Density Suburbs, Chinhoyi, Zimbabwe
The population of Coldstream High Density Suburbs in Chinhoyi, Zimbabwe is increasing and the sewerage system shows signs of poor performance. The frequency of reported sewerage system blockages in the suburb increased from 43 per month to 65 per month between April 2012 and March 2013. The suburb has also been experiencing water shortages. An increasing population and low water supply versus overflowing sewage is a potential health risk.
The main objective of this paper was to investigate the causes of the sewer system poor performance. This was achieved by assessing the sewer system infrastructure as well as the operation of the system. The impact of the behaviour of residents on the performance of the system was also discussed. The main components of the infrastructure (manholes and sewers) were physically checked for soundness. The operation of the system was assessed by a hydraulic analysis of discharge, depth of flow and velocity of flow in the sewers. Questionnaires were used to investigate the impact of the behaviour of residents on the performance of the sewer system.
It was found that 4% of the components of the sewer system infrastructure were below standard and the collector main sewer was the one mainly affected. 68% of the sewers along the collector main had velocity of flow below 0.6m/s and all the sewers had depth of flow below 50%. Of the residents interviewed, 90% dumped solid wastes in the sewers and 43% did so because they were unaware of the impact.
It was concluded that the sewer system failed to meet standard because the sewer system fails to self-cleanse the solid waste dumped by residents in the sewers due to water shortages. It is recommended that the municipality raises awareness among residents and some of the infrastructure should be rehabilitated. more…
The talk is titled: Wastewater, a resource or a weapon of mass destruction?
Valérie shows us how to turn recycled wastewater into a commoditized resource, improve water sanitation, provide efficient water usage, and reduce price volatility.
Valérie Issumo is the CEO of Prana Sustainable Water company (http://www.pranasustainablewater.ch) . An economist, she worked for 15 years as a soft commodities trader and as a trainer in Belgium, Uruguay, Cameroon and Switzerland. Throughout her career she has fought for sustainability and risk mitigation in the entire value chain of traded goods. She is a university lecturer and also a consultant for food security, socially responsible investments, pricing ecosystems and the assessment of water interdependencies. Valérie holds an MBA, has studied at various international water centres, and was a recipient of the Prize of the Belgian Minister of Foreign Trade.
Prana Sustainable Water is acting for the following challenges:
- Reducing the 80% untreated wastewater (UNEP) by matching offers and pre-paid demands of treated water allowing to finance sanitation and restore the public water quality as common good for not hindering growth and strategies.
- Water is the underlying commodity of every goods or services: please check www.cdproject.net/water and www.waterfootprint.org: : Prana Sustainable Water has designed Ethical Water Titles© – futures contracts – to commoditize treated wastewater as tradable resource on the Ethical Water Exchange platform or commodities exchange for water procurement and price security.
- Scaling-up clean technologies for wastewater:the members of Prana Sustainable Water Club active in wastewater can benefit organized markets through solvent demands of recycled water via Ethical Water Titles© allowing to leapfrog the leverage effects solving simultaneously water, health, economic, environmental and social issues.
- Offset water consumption : wastewater can be recycled on an infinite basis. Prana Sustainable Water boosts responsible productions or services prioritizing reuse water with the automatic respect of the Water Exploitation Index growingblue.com and storing part of recycled wastewater into green water bnks© for philanthropy, reforestation and production of green/rain water, energy, public services like fires..etc…
- Defense and food security Our motto is to incentivize responsible water use to produce:
- what makes sense (prioritizing commoditized recycled water from wastewater for Human Rights, for water footprints of functional food or with high nutritional value and ecosystems services),
- where it makes sense (according to the impact),
- how it makes sense (with treated wastewater and sludge energy).
Prana Sustainable Water site pages
When looking at sanitation/wastewater treatment and making it economically feasible for more parts of the world, this is very interesting research. Some will say it has roots in the fact that there is “gold” in out crap…
Related links to this research:
…On May 1, a panel of judges awarded the $100,000 National University Clean Energy Business Challenge prize to the Stanford team for its project to convert nitrogen waste into nitrous oxide that is then used for clean power generation….
A new process for the removal of nitrogen from wastewater is introduced. The process involves three steps: (1) partial nitrification of NH4+ to NO2−; (2) partial anoxic reduction of NO2− to N2O; and (3) N2O conversion to N2 with energy recovery by either catalytic decomposition to N2 and O2 or use of N2O to oxidize biogas CH4. Steps 1 and 3 have been previously established at full-scale. Accordingly, bench-scale experiments focused on step 2. Two strategies were evaluated and found to be effective: in the first, Fe(II) was used to abiotically reduce NO2− to N2O; in the second, COD stored as polyhydroxybutyrate (PHB) was used as the electron donor for partial heterotrophic reduction of NO2− to N2O. ….
Normally, we want to discourage these gases from forming,” said Craig Criddle, a professor of civil and environmental engineering and senior fellow at the Woods Institute for the Environment at Stanford. “But by encouraging the formation of nitrous oxide, we can remove harmful nitrogen from the water and simultaneously increase methane production for use as fuel.
- Total N2O emissions-which are believed to come primarily from nitrogen fertilizers used in agricultural production-would account for about 8 percent of California’s total greenhouse gas emissions. (familysurvivalprotocol.com)
- 1st International IWA Conference on Holistic Sludge Management (washlink.wordpress.com)
- Major Advance in Generating Electricity From Wastewater (wakingtimes.com)
- Major Advance in Generating Electricity From Wastewater (myscienceacademy.org)
- The Final Frontier of Water and Wastewater Treatment: Sludge Management Equipment Market Set to Reach $9.9 Billion by 2017 (prweb.com)