Dear Anghel, If you could give me more details of your plant and what you are removing, i.e. sewage or industrial effluent, I will try to assist. My email is don@lansonmicrobe.co.uk
What sort of wwtp do you have? What are the mal-odours which are occurring?
There are several mal-odours associated with WWTP. The most common ones are those associated with sulphur compounds. These can range from Hydrogen sulphide, which is bad egg, through mercaptans, which is rotting cabbage, to rotten feet, carbon disulphide. These occur under anaerobic conditions. There are rotting fish odours, which are amines and these may be a mixture of yeast and or Pseudomonads. Different parts of a wwtp are more likely to generate the odours. So sludge processes are more likely to generate mal odours than an aerated system. The other area would be poor mixing and aeration.
Without further information it is difficult to advise.
Controlling odours is one of the most important - and yet most challenging - aspects of wastewater treatment. Foul odours are often a source of complaints, igniting objections from plant workers and neighbours alike.
Type of odour
Common odours lingering in and around treatment plants smell like rotten eggs, ammonia, or garlic, among other things. Sometimes the odor is described as earthy or organic.
How to reduce odour. step by step
There are two main types of technologies to treat odour: physical/chemical and biological. Physical/chemical technologies remove bad-smelling emissions by changing them with chemicals (chemical scrubbers), burning (incinerators) and by adsorbing the emissions with carbon. Biological technologies remove emissions using filter systems, made partially or completely from organic materials (bio filters), that pass the emissions upwards whilst simultaneously trickling a cleansing solution downwards (bio trickling filters). Other biological technologies aerate the sludge or sewage with fine bubbles (activated sludge diffusion). The first step in solving any odour problem is identifying the source. Odours could be coming from raw wastewater exposed to air at the influent pump station and primary clarifier stage. The only place you may find these are at the excess sludge treatment, where air circulation over a small activated carbon filter can do the job.
Bio filtration and active carbon filtration require the most materials. Incineration requires the most energy because it uses natural gas. Bio filtration uses the largest amount of land, with a footprint seven times greater than that of bio trickling filters and 25 times that of chemical scrubbers. However, bio trickling filters have the highest water consumption at 0.052 litres per m3 of treated gas per hour.
Two widely-applicable, emerging odour control technologies, known as activated sludge recycling (ASR) and oxidized ammonium recycling (OAR), have significant potential for WWTPs with low investment and operating costs. Although these technologies have been discussed in technical forums and applied at some WWTPs with promising results, they have not been explored using a systematic approach.
Activated sludge recycling.
oxidized ammonium recycling
There are many odours control technologies in the marketplace and no single, universally ideal solution exists. Some plants use deodorizing misting systems to target volatilized odours compounds in the air. Others choose to add chemicals directly to the water that react with odours-causing compounds. Fine-tuning the treatment process itself is another odour control tactic, albeit a more complex one.
Often the simplest approach to odour control is quite literally covering the problem. Many wastewater treatment plants choose to seal the source of odours - whether that’s a tank, basin, or lagoon - with an industrial-grade cover, thereby preventing the diffusion of odour vapours.
“Capture and treat” technology is an even more powerful odour control solution. This involves capturing odours by containing them with a cover, and then withdrawing and treating the collected foul air. Once the air is conveyed in a ductwork system, it can be treated by a variety of technologies such as a bio filter, wet scrubber, carbon filter, proprietary media, etc.
Covers not only reduce odour emissions but also help contain harmful greenhouse gases and minimize evaporation so that less water and chemicals need to be used in the wastewater treatment process.
Bacterial treatments with off-the-shelf biological consortium products are the answer. I have written on this topic, defending the use of biological products (bioaugmentation products) in WWTPs, as a standard practice, in order to achieve and maintain optimum performance of operations.
This may not be easy to do, since in many countries, including Brazil, there is strong resistance to using a biological product treatment regimen, often mistakenly viewed as a costly practice. Even sanitary authorities have reservations about the use of bioaugmentation products, and, naturally, chemical suppliers leverage this fact in order to plug their products, which are often less effective, have many undesirable side effects, and may be even more expensive.
Furthermore, many companies offering such solutions tend to be very unprofessional in their claims and explanations, as some responses herein demonstrate, with untenable claims. This notwithstanding, the more professional suppliers will be able to offer products that are more effective, and, in some cases, quite specific for certain WWTP applications.
It would be unfortunate if the poor practices of some less scrupulous suppliers resulted in discrediting effective solutions. In most cases, any WWTP will be able to improve efficiency or other parameters, including odor problems, cost of operations, etc., with a biological product that is well matched to the operating conditions.
The selection of a biological product should consider whether the supplier can offer adequate, prompt and effective technical support and problem solving.
Good luck!
Prof. Cleveland M. Jones, DSc.
Researcher – INOG (Instituto Nacional de Óleo e Gás/CNPq)
I agree fully with what you are saying. We are operational for 17 years now in the European market, have a network of distributors in over 20 EU countries and have seen these cowboys come and go over the years. The only way to be successful with bioaugmentation is to have in depth knowledge on what Bacteria and fungi can and cannot do. Also it is important to understand the treatment system in which you are dosing. Thanks for your comment, it is important to make people aware of this.
The best way to reduce odor is to install a suitable Odor removal plant. All the chemicals you use must thought effective must be continously used. But odor control plants is the best solution for this problem.
If it the flow is low then use activated carbon type ODU if higher flow use Biological type.
We manufacture both type. Pls. visit our website www.waterengrs.com or contact us
The best way to reduce odor is to install a suitable Odor removal plant. All the chemicals you use must thought effective must be continously used. But odor control plants is the best solution for this problem.
If it the flow is low then use activated carbon type ODU if higher flow use Biological type.
We manufacture both type. Pls. visit our website www.waterengrs.com or contact us
Typically these odours come from primary clarifiers and sludge dewatering operations. In certain cases anaerobic digesters are a source of odours as well.
We can offer microbial additives which are aimed at converting the odorous compounds emitted by the wastewaters. We have cases were an addition of these products into the primary clarifiers reduces H2S levels all across the treatment plant well into the sludge dewatering building. Besides H2S it also reduces odours created by volatile short chained fatty acids.
This is what we call the liquid phase treatment approach. Alternatively we can offer a system which neutralises airborne odorous compounds. Not by spraying a water mixture of an odour neutralising compound but by creating a dry vapour of a particular mixture of odour neutralising ingredients. This dry vapour approach is much more effective than the water mist spray. Odour molecules react directly with the odour neutralising compounds and do not first have to dissolve into the water droplet. The results is less product consumption and a higher effectiveness.
If you like more information please do not hesitate to contact me at, r.wagenveld@qmes.nl
You should rethink your options: instead of masking bad odors, you should try to prevent them.
A well designed, dimensioned, constructed and operated (!) WWTP or STEP does NOT produce bad smells. The only place you may find these are at the excess sludge treatment, where air circulation over a small activated carbon filter can do the job.
In an over-dimensioned pump pit the wastewater stays too long and goes septic.
If you have a header tank, recirculate a generous part of you MLSS and mix well. This prevents bad odors, fights bulking sludge and provokes (at least partial) de-nitrification.
Make sure your aerated tank is well mixed to avoid anaerobic pockets.
Another place where you can have odors is the final clarifier, if settled sludge is not removed completely, stays in pockets at the bottom and goes septic. Then starts to float as black, H2S rich sludge.
Would You contact http://www.wodociagi.slupsk.pl/o-spolce/nasze-obiekty/oczyszczalnia/. They solve that problem.. Słupsk WWTP /Poland, Pomerania region
You can use some odor masking chemicals or u can install Odor control unit which will have activated carbon media as the odor adsorbing media, an air blower , required ducting & back washing / re activating facility for the carbon media. Hope this will help u. In case of any further details in depth required, please drop us a mail to- info@purewaterqatar.com. Shaji
There are many products that counter the smell. The anaerobic conditions can be mitigated with a few of the comments below. Jean Marius is the highest qualified person in the European theatre using microbial odor and pathogenic control. The one system I am already familiar with is the biogenerator/biodigester. Eros Kaw has vast knowledge in this area. I work all biodegrading problems using the microbial species called Archaea. It reduces all of the compounds into their elemental form. This way it will eliminate the odor the first hour it enters the oxygenating tank. No pathogens and no toxic materials. Just clean mineralized water to do with as you wish.
The most common odor associated with wastewater collection and treatment is caused by release of hydrogen sulfide gas (H2S). Hydrogen sulfide is produced by anaerobic bacteria that grows beneath the slime layer in wastewater collection systems with long residence time and are corrosive to concrete, steel and equipment such as pumps. Agitation of the wastewater liberates H2S and produces odors at very low ppm levels and deadly at levels above 2000 ppm. Foul odors may also be attributed to oxygen depleted aerobic wastewater processes. One of the least expensive methods to reduce H2S forming bacteria is to elevate the pH/Alkalinity by addition of Magnesium Hydroxide. Elevating the pH/alkalinity from 7 to 8 eliminates H2S and corrosion by 80% and provides alkalinity for nitrification within the treatment plant. Other chemistries such as calcium or sodium nitrate are effective, however they are more expensive.
My experience: We planted some trees around the lagoon to minimize the smell. Install some fountain pumps to spray water in the air.It shall create beauty & also remove smell.