The setting is a large waste management facility on the outskirts of a major city in Western Europe. The plant had a significant odour problem. Complaints from local residents were increasing, and employees were also complaining more and more about the stench. The plant manager saw the need for action and explored the various options available on the market. After a comprehensive analysis of the alternatives, he contacted ACAT, the official European distributor of OMI Industries’ Ecosorb® product line. “We then worked quickly to find the best and most cost-effective solution for our customer,” says Luca Faggionato of ACAT airtech in Milan.

As a first step, ACAT installed a high-pressure system at the site’s entrance gate, through which the bulldozer enters the facility. “Using a sensor, we programmed the machine to spray Ecosorb® as soon as the gate opens. This effectively neutralises the escaping odours.” To treat the outdoor waste piles, ACAT has also installed a high-pressure system with a fan on each bulldozer. This can be switched on during waste treatment to neutraise the odours.

Extensive measuring

To measure odour emissions, air samples were taken at various distances from the odour source. A local laboratory then analysed the samples. “Based on this, we selected the most suitable Ecosorb® product,” says Faggionato. ACAT then installed three control systems: one at the entrance gate and two on the bulldozers. The aim was to reduce odour emissions by 50 per cent. Measuring began in the summer, when higher temperatures also

intensified the odours. The dosage of Ecosorb® was 0.5 l/h. An investment in reputation The results are extremely positive, reports Luca Faggionato: “Our customer is very satisfied with our solution, from the user-friendliness to the effectiveness of Ecosorb®. The number of complaints about unpleasant odours has decreased significantly, as have the odours themselves – and all this without the use of aggressive chemicals. So, it wasn’t just an investment in the quality of life for local residents, but also in the company’s reputation.”

Experts with many years of experience

ACAT’s experts have been working intensively to combat unpleasant odours for many years. “The odour problem in Europe is getting worse every year. Now there are also corresponding laws that restrict emissions. Odours are a problem that affects all sectors, especially those close to residential areas. At ACAT, we can draw on years of experience working with customers in the asphalt, plastics and water treatment industries, and the waste management industry also benefits greatly from this,” explains Faggionato (ACAT airtech).

What specific products does ACAT offer?

The most suitable product depends on the specific odour problem. “With Ecosorb ®, we have a tailored solution for every situation.” Ecosorb® has been extensively tested over many years for its safety for the environ – ment and humans. It has been clearly established that the product is non-toxic, biodegradable and organic. It does not mask odours but actively neutralises them and is also safe for the environment. ACAT also offers fogging systems specially developed for use with ACAT products. The spectrum ranges from pipes with high-pressure nozzles to atomising fans and large vapour phase systems. Furthermore, ACAT’s experts analyse the odours before and after treatment using special measuring instruments. ●

Due to the high temperature in the long and warm summer season, from the first period of running of the sewage plant, sometimes an unpleasant odor problem appeared.

Chemic Ltd., a company actively involved in Malta in the startup of new companies, new technologies and supply of water treatment chemicals, contacted ACAT to find a solution to control the odor problem.

ACAT personnel through a survey of the plant handled the problem and offered a full service with dosing equipment system and ECOSORB®, the product to neutralize the odor.

Primarily, ACAT offered a long test in a part of the plant (primary settlement and flocculation area).

Thanks to the good result of this test, WSC issued a tender to treat all areas of the plant in order to avoid any single odor problem for the future. Chemic in cooperation with ACAT won the tender and installed the full equipment.

The ECOSORB® DOSING SYSTEMS named HPS were installed in the following different areas of the sewage treatment plant observed like odor sources:

1. Pumping station
2. Primary settlement and flocculant plant
3. B.A.F. Biological aerated filter
4. Sludge thickening and dewatering building
5. Waste wash water tanks
6. Digested sludge storage tank

In Ta’ Barkat the full equipment installed

is composed of:

• 6 HPS Box
• around 300 nozzles, 4 micron orifice diameter
• 800 meters of pipeline

HPS BOXES

(high-pressure systems) are the systems of choice for most outdoor installations and even some indoor installations.

These systems run on 70 bar of pressure, providing a good atomization (misting) through patented nozzle design, easily installed. A digital dosing pump is included into the HPS box along with the electrical box control and hydraulic one. The atomization nozzles are commonly installed in a flexible polyamide hose, with  a large selection of nozzle spacing’s. Standard brass or stainless steel fittings can be used throughout the system.

To correctly size and specify a Hydraulic High Pressure system, one must first define the area to be covered and the location of the atomizing nozzles in order to cause Ecosorb® to come into contact with the malodor. If the installation is open air, the engineer must consider nozzle location in relation to the odor source, areas to be protected from the odors (neighbors), prevailing and secondary wind conditions. Often, we place a nozzle line with controls around the entire perimeter of an odor source, such as a wastewater pond.

For example, this installation might be along a fence or roofline. Overall, the most effective wastewater plant surrounded by nozzle system misting equipment placement is to place the atomization nozzles as close to the odor source as possible. Nozzle spacing is not critical, as long as we consider that Ecosorb® must simply come into contact with the malodor.

A conservative suggestion is to space the nozzles 2 to 3 meter apart.

 ECOSORB®:

ECOSORB® has proven to chemically convert foul and potentially harmful gases into non-odorous, non-toxic by products. Some tests has verified that Ecosorb is effective in the breakdown and reduction of hydrogen sulfide, ammonia, sulphur dioxide, ethyl and methyl mercaptans – potentially toxic gases which comprise the most common sources of odour.

Ecosorb Technology

Ecosorb products are a blend of essential oils, food grade emulsifiers and water; they are effective, safe to use, biodegradable and harmless to the environment. There are currently two product lines, oil- based (essential oils + plant-based thinner) and water-based (essential oils + water + surfactant). The former are used as additives in areas such as asphalt, plastics and recycling. The latter, on the other hand, are sprayed into the air to neutralize those odors arising from industries such as WWT, asphalt, plastics, fertilizers, refineries, tanneries and medical cannabis cultivation.

Asphalt vs Ecosorb 606 A

The treatment of asphalt odor both in the atmosphere and directly in the bitumen is ACAT’s workhorse. Throughout Europe there are now many companies that rely on our technology and over the years have confirmed this potential.

The main application is in bitumen mixing tanks where our Ecosorb 606 A, after being mixed with 0.03% (300 ppm) of asphalt, through adsorption and absorption reactions captures odor-causing molecules and traps them forever. The result is an asphalt that no longer has that annoying, pungent odor.

To better substantiate our argument, I report an odor concentration test conducted in Japan to quantify the effects of the Ecosorb 606 A additive in a common paving asphalt.

Samples were collected from the vent of a tank receiving fresh untreated bitumen and from the vent of a tank receiving bitumen treated with the Ecosorb additive at a dose rate of 0.01% (100 ppm).

A team of six prequalified and certified odor assessors were tasked with quantifying the odor index of bagged samples using a dilution technique and a sensory technique.

From the odor index, its concentration is calculated mathematically.

The six panelists were instructed to smell the collected sample gas at various dilutions with clean air and identify at which dilution they could no longer smell what was in the bag. To vary the dilution ratio for the test, decreasing amounts of sample gas were added to 3 liters (3000 ml) of clean air. For the first 300 ml of sample air was added to 3 liters of clean air presenting a dilution ratio of 10 (3000 ml/300 ml). The odor concentration of gases from untreated asphalt is 4000!

The odor concentration of gases from treated asphalt is 160! A 96% reduction in perceived odor!

Other applications in asphalt fields

Other applications include the neutralization of odor from exhaust stacks and truck loading and unloading areas. In both cases, our technology involves the use of a water-based

product from the Ecosorb 606 line, sprayed through a pre- dimensioned high-pressure system (HPS).

The table below shows the results obtained at an asphalt production site. In this case a nozzles ring was installed at the top of the gas exhaust stack. The efficiency of Ecosorb products is not only certified by a personal perception of an improvement in odor intensity but is also guaranteed by industrial data and therefore real!

Preview

This factory produces bitumen thanks to two

ovens of 20 tons each. The airflow of these ovens, after dust filter, goes to the chimney.

 Problem

In the case the factory uses recycled asphalt, there are odour problems in the airflow, caused by the various components that remain in this recycled asphalt, for instance: tires, oils and other. This situation produces continuous complaints from the neighborhoods that live close to the factory.

Therefore, the odour problem is one of the priorities for continuing to work without problems with the people and with the environmental police.

 Solution

We install a ring with 5 nozzles (2 micron hole) into the pipe after the dust filter and before the blower, that dose a mix ECOSORB® 606 + WATER.

 Olfactometric test

In cooperation with a laboratory company (PROGRESS Milano) we made olfactometric test for estimating the efficacy of the treatment with ECOSORB® 606. They put an olfactometric unit into the pipe, 3 meters before the end of the chimney. Find the results of the test in the schedule below

 Conclusion

The results obtained, demonstrate that ECOSORB® 606 is the solution for solving the odour problems and the claims of the neighborhoods.

In this moment the factory doses around 500 ml/h of ECOSORB® 606, and the odour is reduced more than 50%.