Peter Ripley, Managing Director Of Acwa Services Reflects On The For The Next For The Environment
25 May 2010, News release from ACWA Services
Peter Ripley, Managing Director of ACWA Services reflects on the next decade for the environment.
In the era of global warming, diminishing water supplies and escalating fuel costs the actions described by renewable, recycle and reuse will feature regularly. Sustainable resourcing is already a key issue and will become more so. Government initiatives are necessary both to provide legislation to force the public into this course of action and to provide benefits for encouraging sustainable options.
The most common sources of renewable energy are the forces of nature, such as water, the wind, the sun, or natural biological processes such as organic degradation. While new technologies are continuously being developed for water (hydro, wave or tide) the other sources have been available for ages.
Biological processes have been harnessed for millennia but techniques have been improved such that refuse, byproducts, or wastewater are being increasingly utilised as a source of producing energy.
ACWA has developed anaerobic biological systems to convert waste (either solid or liquid) into biogas which is then used to provide heat, power or both. These generally operate by utilising naturally occurring bacteria to degrade organic material, converting it into methane and a fertilizer-rich digestate.
ACWA's hybrid anaerobic reactor, for example, is helping industries with high organic strength wastes in a wide variety of sectors to both improve their waste treatment and maximise their energy efficiency. Biogas from this system can be used for on-site heating or generating electricity by adding a combined heat and power unit.
The Government, through DEFRA and WRAP (Waste and Resources Action Programme) are actively pursuing the development of energy from waste and these actions need to be extended.
Recycle or Reuse
In order to enable continued population growth and the consequent increase in the demand for water the most sustainable method is to recycle or reuse the available supply. While the oceans carry an ample quantity and, according to climatologists an increasing volume of water, the process of making it potable by removing salt uses much energy and increases the salt concentration in the seawater.
A better method, pioneered by ACWA in the arid Middle East, treats wastewater to such a high standard that it can be reused for many purposes. Although the highly-treated "New Water" in Singapore uses some recycled treated wastewater for drinking this is not acceptable in most areas of the world. The commonest use of recycled water is for irrigation, usually for aesthetic or sports purposes, but increasingly for irrigation of crops. Other uses include washdown of vehicles or vessels, making concrete and as toilet flush-water.
In order to obtain such high quality water, solids are separated from the liquid using ultrafiltration, which incorporates membranes that prevent the passage of particles right down to the size of most bacteria. ACWA's Memtreat® membrane bioreactor is a good example of this kind of process, creating treated wastewater so pure that it can either be discharged to the environment without further treatment or used for any of the applications outlined above.
The cost of membrane treatment has been reducing so now it is very similar to conventional processes but has the additional advantages of producing excellent quality water, being an extremely robust process, generating much less byproduct, having a small footprint and needing little maintenance.
The Government has included this process in its list of technologies available for Enhanced Capital Allowances. In order to reclaim our environment from suffering further destruction, to enable it to recover and restore it to a sustainable level so it can regenerate itself, the world (with Government help) needs to renew, recycle and reuse.
For further information please email ACWA Services