All Posts

Wastewater Treatment Odours – Causes, Effects & Solutions

Wastewater Treatment Odours – Causes, Effects & Solutions

Wastewater Treatment Plant Odours Are Common.

shutterstock_114887479

Causes

Rising Temperatures

Temperatures are rising as we come into the summer months and with this, the temperature of the wastewater also increases. As a result, aerobic bacteria become more active and begin digesting BOD and other nutrients at a faster rate. The warmer the water becomes, the more active they are and the more oxygen they consume. This results in low dissolved oxygen.

Anoxic Zones

Low dissolved oxygen coupled with rising temperatures can lead to an increase in anoxic zones at the bottom of wastewater aeration basins. Anaerobic digestion releases sulphur dioxide, along with a variety of other noxious gases that are the causes of wastewater odour.

Effects
Treatment Deficiencies

Odour is often a sign that more anaerobic digestion is occurring than there should be. Given that aerobic digestion is a much faster process than anaerobic digestion, it is likely that the wastewater is being under-treated.

Unhappy staff and locals

When gases are released from wastewater treatment plants they result in a very pungent odour which will directly affect WWTP operators and, when carried by winds, to people who live or work nearby.

Solutions

Increase Oxygen Supply

Increasing oxygen supply ensures that the aerobic bacteria have the oxygen they need to aerobically digest BOD. This will help to control odours as anaerobic digestion will slow down.

Wastewater Circulation

Ensuring dissolved oxygen is reaching the very bottom of an aeration basin is key to avoiding odour as this is where the odour-causing anaerobic digestion occurs. By circulating the wastewater effectively, you can create nearly equal dissolved oxygen throughout. This in turn will promote odour-free aerobic digestion.

Aeration technologies currently in use are not always effective at increasing oxygen supply and ensuring circulation throughout. Surface aerators only circulate to a shallow depth of the water column and do not increase dissolved oxygen in deeper water bodies. Coarse and fine bubble diffusers do a better job of increasing dissolved oxygen but struggle in combating anoxic zones. The OxyMem MABR can achieve up to 99% oxygen transfer efficiency, produces up to 50% less sludge than current technologies and in turn, reduces odour significantly.

In summary, treatment plants collects effluent flow from municipal and industrial sources for treatment. The level of treatment from each plant varies, but the one thing they all have in common is that they cause a smell!

 

 

Subscribe to stay informed

*Environment  *Legislation  *Socio-economics  *Technology

Related Posts

How to cut emissions from wastewater?

How to cut emissions from wastewater? On the 21st of September we not only celebrate Zero Emissions Day, but also we are asked to curb our emissions for 24 hours whenever it's possible.

Best time to plant a tree is today…

Best time to plant a tree is today… ...if you didn't plant it already. As one Chinese proverb says: The best time to plant trees was 20 years ago, the second-best time is today. Seasons and geographies may influence. In Ireland for example, the Agriculture and Food Development Authority recommends tree planting between November and March. Trees are dormant during this period and can be safely planted as bare-rooted trees. Planting outside of this seasonal window might be possible if using different variety of trees or techniques. Monty Don, a writer, broadcaster and gardening guru, gives a lot of advice and information on how and when to plant trees successfully, but the main recommendation is always to plant small, young trees as early as possible, i.e. 'now', whether you are enriching public spaces, your own garden or perhaps a large re-forestation area. Trees grow slowly, best start today.

OxyMem MABR Deployment and Retrofit

OxyMem MABR Deployment and Retrofit As easy as one, two, three… OxyMem MABR is and extremely easy means of enhancing treatment on an existing wastewater treatment plant. Upgrading and enhanced ammonia removal has never been easier. Individual modular MABR units (modules) are easy to load, transport and deploy. How and why?