Wastewater Odour and Corrosion Control

As a growing number of ventures embrace environmental sustainability and economic practicality, more and more businesses are resorting to wastewater technologies. They are finding, however, that traditional septic tank systems often pose odour and corrosion problems that undermine the advantages of wastewater reuse.

Odour: Nuisance and Human Safety Issues

Owners of conventional septic tank systems often find themselves in a nauseating predicament, sometimes literally, when odours and gases from the tank blow into the business – or worse, the home. The culprit in this olfactory offensive is hydrogen sulphide. The bane of municipal wastewater systems, it is produced when organic material decomposes. Hydrogen sulphide is easily recognised by its “rotten egg” smell.

This unpleasant by-product is an inevitable result that occurs at practically every point in a septic system – from interceptors, force mains, and lift stations all the way to holding tanks, mechanical mine dewatering equipment, and drying beds. The gas is extremely toxic; at low concentrations, hydrogen sulphide has been seen to cause fatigue, headaches, eye and throat irritation, and other ailments. Hydrogen sulphide is said to be the leading cause of death among sanitary sewer system workers, who quickly acclimatise to the foul and pungent odour so that they may no longer recognise when it is present.

Corrosion: Environmental, Systemic, and Economic Harm

Another by-product of hydrogen sulphide gas in a wastewater environment is sulfuric acid, which is created when hydrogen sulphide interacts with the moisture from the wastewater, most typically condensed on sewer walls, and sulphur oxidising bacteria proliferate. In systems where no air is present, permanganate directly oxidises the hydrogen sulphide. In aerobic systems, there is some direct oxidation by permanganate and the resulting manganese dioxide further catalyses the reaction.

The danger posed by corrosion as a result of hydrogen sulphide gas converting into sulfuric acid may appear less immediately, but unchecked, has the potential to cause calamitous, corrosive damage to pipes and other equipment, which in turn exposes the environment to hazardous waste. Not only are these complications costly to contain or fix, but in some cases, impossible to fully remedy.

Traditional septic tank systems don’t do much by way of reduction of microorganisms or concentrated nutrients, although it can occur if the matter moves through natural soil. There are a number of factors that may affect efficacy: the properties of the actual soil, how long it takes to travel through the soil, and environmental conditions around the leach drain or soak well.

Aqua Nova: An Alternative Solution

The Aqua-Nova Domestic Sewage Treatment Plant, which we introduced last month in our blog spotlight, works through a multi-stage digestion process that uses bacteria and enzymes that occur naturally. Soil contamination can then be further reduced through a final filtration stage whereby the water flows through a clarifier and then, if necessary, over chlorine tablets ensuring an environmentally sound product.

The Aqua-Nova waste water solutions offer different models, which achieve differing qualities of treated effluent, so customers in Australia have choices and can install Aqua-Nova systems in most locations. The minimum requirement for water quality is less than 20mg/L BOD5 and less than 30mg/L Suspended Solids. With further disinfection, filtration, or membrane systems – or a combination thereof – a water quality of less than 10mg/L BOD5, 10mg/L Suspended Solids, and 10CFU/100ml E.Coli can be achieved.

The Aqua-Nova Domestic Sewage Treatment Plant is safe and reliable, allowing owners to maximise the reuse of effluent wastewater and minimise the contamination conventional septic tank systems can precipitate on surrounding land and water. The two-tank system prevents the raw wastewater and treated effluent from mixing. Since the lids are accessible at ground level, workers have safe access to perform system maintenance. Additionally, there will be no smell if the Aqua-Nova wastewater treatment system is properly maintained and operated in accordance with the Owner’s Manual.

Allied Pumps is happy to assist with your local health or other regulatory authority requirements for these wastewater treatment systems, such as application approval processes, equipment data submissions, as well as system manufacture, installation, and commissioning. Contact us for more information.