Odour control in the Kingdom

Carbon adsorbers installed by Siemens at a Saudi wastewater treatment plant.
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After comparing chemical and biological treatment options, Saudi Arabia’s National Guard decided that it would be more cost-effective to install two biological systems at its bases in Taif. The ZABOCS biological treatment systems fit the military’s requirements: a green technology, it would not necessitate hazardous chemicals. The systems would also require little maintenance, and could reduce H2S as well as other organic compounds.

Biological odour control systems such as biofilters, biotrickling filters, and bioscrubbers are designed to promote the growth of sulfur-oxidising bacteria. These organisms, in turn, break down odorous
compounds.

The systems will require constant nutrient replenishment and water as well as eventual media replacement.

Bioscrubbers have a smaller footprint than biofilters, although in general, biological treatment systems have a larger footprint than other vapour-phase odour control technologies. Capital costs are also higher, but operating costs are minimal as biological treatment does not require an on-going chemical supply.

Operating costs are also not proportional to H2S concentration, meaning these systems are well suited to high H2S applications.

Activated Carbon

A well-known Saudi refining company was contemplating installing activated carbon systems for H2S removal at its facility in Riyadh.

Siemens recommended installing six carbon adsorber odour control systems containing Midas® OCM carbon media. After entering the vessels, foul air flows through a densely packed bed of activated carbon that removes H2S and other odour-causing organic constituents. The media is virgin bituminous coal-based and not impregnated. It has a very high adsorption capacity exceeding 0.30 g of H2S or VOC adsorption for each cubic centimetre of carbon, giving it a capacity four to five times greater than other types of media.

Additionally, Midas media has a high ignition temperature, no dangerous pH problem when spent, and a low pressure drop. The media does not require water or chemicals – only electrical power, to operate. Carbon changeout is the primary maintenance required.

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No single odour control technology is best in all applications. Each technology has its advantages, and will be favoured in certain applications. Although cost is important, it should not always be the deciding factor. When performance is most important, hybrid solutions that combine multiple technologies are often the best choice. Examples of such systems include chemical followed by carbon; biological followed by carbon; biological followed by chemical; and biological followed by chemical followed by carbon.

The Ministry of Water and Electricity has authorised installation of all three kinds of vapour-phase odour control technologies at the North Jeddah sewage treatment plant. As the plant is located near an airport, thorough and reliable odour control treatment is a must. Once completed, this will be one of the largest odour control installations in the whole of Saudi Arabia.

Conclusion

Continued population and industrial growth and an increasingly hot and arid climate will ensure that the Kingdom of Saudi Arabia’s odour control needs progress well into the future. To find the right solution, working with a reliable and accessible product and service provider is key. The provider should thoroughly understand the facility’s needs and ideally suggest several solution options that address the facility’s odour concerns. The solution provider should also be willing and able to work with those area contractors that are most familiar with local needs and government requirements.

Siemens Water Technologies’ Odour Control Capabilities

Siemens Water Technologies (formerly USFilter RJ Environmental Products) has been designing and building odour control systems for municipal and industrial customers since 1991. The company’s principal engineers have been working in the odour control field since its inception in the 1970s. Siemens offers a full range of vapour-phase odour control technologies including biological systems, biotrickling filters, chemical scrubbers, and a variety of activated carbon adsorption systems.

About the Author

Georgios Ioannou, PE, is an odour control technical sales manager at Siemens Water Technologies. His territory includes Europe, the Middle East, and Africa. He holds a MSc degree in Mechanical Engineering, and has worked for Siemens since 1998. Georgios is located in Athens, Greece, and can be contacted at (+30) 6936101300 or at Georgios.Ioannou@siemens.com.