At a petrochemical site in Europoort, HMVT successfully completed an extensive NAPL layer remediation within the estimated timeframe. The NAPL layer consisted of approximately 6,500 m2 of crude oil and was up to 80 cm thick in some places. It was located at a tank farmyard. The NAPL layer was also present under the tank.


The remediation was carried out through Multi-phase Extraction (MFE). In MFE soil air, contaminated groundwater and the NAFL layer are removed through a network of underground extraction filters by applying high negative pressure. In total, 440 extraction filters were installed at the location. Some of the filters were placed under the tank during the renovation of the tank mound. The tank was jacked up at the time. Through NAPL layer measurements and close monitoring of the process parameters, a continuous effort was made to use the installed system as optimally as possible. The extracted soil air was purified with two catalytic oxidation units. The contaminated groundwater was discharged into the industrial sewer via an oil-water separator. The pure product was periodically extracted from the oil-water separator and transported to a processor.


During a period of 3 years, more than 10.000 kg of crude naphtha was removed from the soil. After those 3 years, the NAPL layer had disappeared, and the volatile components were remediated from the groundwater. After a stop test, DCMR approved the achievement of the remediation objectives. HMVT is proud to have been able to complete this extensive remediation with good results.

More information

Please contact Ted Vendrig.

Scrubbing or “washing” vapors is one of the air purification techniques we often recommend and use. The scrubbing technique can be executed with water, whether or not with additives, or with an oil-based scrubbing liquid. Obviously, the type of scrubbing liquid will depend on the type of vapors to be cleaned in combination with the local situation. Each project is tailor-made. Therefore, pilot tests are often carried out to test a solution in practice.

We’ve purchased a handy test installation especially for pilot tests where scrubbing seems to be the solution. This little unit can be easily & quickly installed at a test-side, requires just a small footprint and connections. A perfect solution for testing the scrubbing process on a small scale. We often combine the use of our pilot installations with the use of continuous in- / effluent measurements of the vapor flows using mobile FID measurements.

More information

Would you like to know more about the possibilities of vapor treatment, control measurements or the execution of a pilot test?

Please contact Ted Vendrig via

Dear all,

HMVT wishes you all the best for 2021 and a happy, healthy environment to live in!

Like for many of you, 2020 was a tough year for HMVT. COVID-19 played a major role this year. After the hard first couple of months, we’ve found a way to continue our work. We work from home as much as possible and our projects outside also continue if the circumstances allow it. Also, we’ve invested in a Head Mounted Tablet that allows us to monitor projects remotely.

2021 will be different. We’re still looking for the best way to continue our projects, yet most projects already continue successfully. With COVID vaccines in sight, we hope to say goodbye to this virus for good.

HMVT is excited about a year in which we will contact a lot of our clients. Together we create a better world with our environmental solutions.

Countdown to an inspiring 2021

Gelukkig nieuwjaar

The corona crisis has greatly affected the world and HMVT is no exception. Although we work from home as much as possible, our projects outside also continue if the current situation allows it. It is simply not possible to just stop a remediation without consequences. Luckily, we can continue most of our projects in the Netherlands. However, it is difficult to physically be present at our project sites in foreign countries that are marked as code orange or red. For example, we had planned on building and starting up a sizeable, complex remediation installation for a multinational in the South of France in the beginning of April. But corona threw a spanner in the works: the project was postponed until the summer and we were just able to deliver everything to the location by truck when code orange went into effect again.

Remediation remotely

Although we were able to get the equipment to the location on time, we did not yet manage to complete the connection of all the pipes and electrical systems, testing, test runs, and start-up. After so many months of waiting, the customer really wanted to start the remediation. To make this possible, we are slowly partly handing over the construction of the remediation systems to local technicians. To accomplish this, we have first trained local technicians and went through the construction process with them in detail remotely while we remain in the Netherlands. Our ‘remote’ contractor is now leading, monitoring, and controlling the construction process while in the Netherlands. So, we have basically set up a digital control room.

Head Mounted Tablet

During construction, online meetings are organized daily to monitor the process and technicians are equipped on site with a “Head Mounted Tablet”. Via the Head Mounted Tablet, our remote operator can see what the technician sees on site, communicate with the technician, and share information via the tablet. This way, the entire construction process is completed with a team that is collaborating internationally. This innovative construction process started at the end of October. We hope to have the remediation installation up and running by the end of November.


By being able to finish this specific project in this resourceful way, we not only please the customer, but we are also taking the next step in the process of digitizing our service package. We can even use the knowledge and experience we have gained from this to assist our technicians at project locations when the restrictions are lifted, whether the project site is nearby or somewhere else in the world!

More information

Want to know more? Please contact us via or ask for Paul Verhaagen or Marco van den Brand.

For an industrial customer in the south of the Netherlands, HMVT is conducting an extensive pilot test to find out which zeolite achieves the best results in a future air purification solution. This is necessary because organic hydrocarbons are released during the company’s core process. So, with a future expansion in mind, vapor cleaning must be scaled up. A possible way of vapor cleaning could be catalytic oxidation, during which the vapours are cleaned autothermally without the formation of nitrogen oxides. The released heat can be put to good use. So, this is a very environmentally friendly solution all around.


The main challenge here is that on the one hand we have to flatten the influent peaks while on the other hand we have to increase the average concentration somewhat so that a future catalytic oxidation unit can remain as small as possible and operate as economically as possible. However, no vapor is the same so before a final vapor cleaning installation will be implemented, we decided to test the effectiveness of various zeolites. To do this we use a mobile zeolite test unit, with which we can subject three different types of zeolites to adsorption and desorption tests over the course of several weeks. We monitor the results with semi-continuous FID measurements.

Want to learn about this topic?

View our wiki or contact Michiel Hennink or Marco van den Brand.

On Tuesday November 10, HMVT organized its first webinar as part of a series of webinars about HMVT’s expertise. This way, we still come together during corona times and we keep each other updated on the knowledge and skills in the field. Marco van den Brand and Michiel Hennink kicked off with the topic “Industrial vapor cleaning “.

There are five ways in which industrial vapor cleaning can be carried out: biological, adsorption, absorption, oxidation, or condensation. These five “flavours” form the palette with which experts clean industrial vapors. Combinations are possible. When do you use which technique and what are the advantages and disadvantages of these techniques? In this blog we briefly summarize the webinar. Would you like to receive the entire presentation, or do you want to know more? Send Marco an email.


Biodegradation has advantages and disadvantages. For example, the energy consumption is very low, and it often has only a small carbon footprint. However, biological vapor cleaning is very sensitive to moisture, temperature, acidity, and concentration peaks.


Adsorption, or “binding” a vapor on activated carbon or zeolite, is a robust technology. Zeolites are insensitive to combustion (which activated carbon is sensitive to) but are much more expensive. HMVT sometimes uses zeolites as a “peak shaver”.


With adsorption, also called “gas washing or scrubbing”, you kind of scrub the vapor clean. The washing liquid is often an acid, basic or oxidative, but oil can also provide a solution. Oil scrubbing is also used as a “peak shaver”.


With oxidation, a controlled “combustion” takes place, often at a high concentration and low flow. The advantage of this technique is that it leaves you with high purification yields. HMVT has a lot of experience with Katoxes, which provide low-temperature oxidation and are NOx-free. It is also possible to oxidize with cold plasma. This ensures low energy consumption and a small carbon footprint. HMVT will soon be conducting the first (odour) tests.


When condensing, you cool the vapors, causing the vapors to condense into liquid. This is possible with almost all vapors, but it requires a lot of energy.


After the webinar, HMVT received positive responses to the first webinar.

Klaas de Jong, Water and Process Technology Consultant at KWA Bedrijfsadviseurs: “In a short and powerful presentation, the various air treatment techniques were presented. Advantages and disadvantages of various techniques were briefly reviewed. Good to be informed again!”.

Marco is delighted with the positive reactions: “The first webinar was a success. It is nice to be able to share your subject of expertise with others as professionals. On to the next webinar!”

SAVE THE DATE: December 10, 2020

HMVT will continue the series of webinars with a webinar on Constructed Wetlands on Thursday December 10th, 2020. HMVT will soon provide a registration form. Already interested? Send Marco an email.

Preview of the presentation

It goes without saying that Japanese Knotweed is a very well-known pestilence. Many site owners are at a loss and are looking for effective methods to once and for all eradicate this highly invasive, and sometimes even harmful, plant for all kinds of underground and aboveground infrastructures. Until recently this was not possible with classic techniques. Thermal cleaning turns out to be the solution, according to research by HMVT.


HMVT, originally being an in-situ soil remediation company, has found a way of eradicating Japanese Knotweed. In the summer of 2020, in collaboration with Wageningen University & Research (WUR), a confidential test was carried out to see whether we could clear the soil of Japanese Knotweed using heating. In-situ thermal cleaning and remediation of soil are not new to us. We have been applying thermal remediation techniques to remediate contaminated sites for many years. We do this by using hot air injection or electrical resistance heat. By using our existing knowledge, we have been able to develop a method for successfully combating the Japanese Knotweed in the soil. For the test, we set up a temporary depot at a closed location in Rotterdam, which we heated by using of hot air injection. The WUR checked the results and came to a positive conclusion: the entire depot was free of Japanese Knotweed, even months after treatment.


In the fourth quarter of 2020 we will conduct a second pilot test, this time to treat a plot on site (in-situ) in Amsterdam. Here the Japanese Knotweed grows on a slope and threatens the local infrastructure.

Patent application

In the meantime, we have filed a patent application for the in / ex-situ thermal cleaning of soil that contains remnants of Japanese Knotweed.

More information

Would you like to know more about our solution for contamination with Japanese Knotweed? Send us a message via

HMVT gives their intern Michaela Bhend the floor:

Michaela has been part of the HMVT team as an intern from July. For her master’s Earth Surface and Water at the University of Utrecht she is doing research into Constructed Wetlands as a treatment method for industrial wastewater. The goal of her master’s research: improving the design model for the construction of Constructed Wetlands to make it even more efficient. The aim is to predict more effectively the requirements for each specific remediation case. “What gets me excited about this assignment is that nature-based water treatment systems are gaining more traction in the world. Companies want to remediate more sustainably thus a Constructed Wetland is a fantastic solution.

How are you experiencing your time at HMVT? “Understanding the complex processes within Constructed Wetlands has been quite a challenge since it was a  completely new subject for me. The great thing is that I immediately felt as part of the team and experienced my colleagues at HMVT as very approachable and supportive. Visiting project sites and seeing the treatment systems first-hand are valuable learning experiences for me. That’s the great thing about HMVT: they provide not only tailored consulting but also steer the implementation of the remediation projects. Seeing this whole process makes it so educational! ”

HMVT wishes her good luck with her intenship.

Together with its American partner TRS, HMVT has conducted a successful test to purify soil contaminated with PFAS. The test concerned land from the former Soesterberg air base, a location that will be redeveloped into a nature reserve, recreation area and homes in the future. As a result of the former activities, however, the soil and groundwater have become contaminated with PFAS, in this case mainly the substance PFOS.

Redevelopment of the site will be necessary to redevelop the area. However, PFOS / PFAS are very resistant substances and the soil and groundwater are very difficult to remediate. In this context, market parties were asked for remediation ideas and were given the opportunity to conduct experiments with the soil. The PFAS problem is also very important in America. Our partner TRS is specialized in remediation of soils by means of heating and has established that with sufficient heating of the soil the PFAS molecules can be evaporated from the soil. The crux here is that the soil must be kept at a sufficient temperature for a sufficient period of time so that all PFAS can evaporate from the soil. It is known that when the soil is brought to 350 to 400 Degrees Celsius for about 7 days, almost all PFAS can evaporate from the soil. The PFAS vapors are cooled, causing the PFAS to condense in the released soil moisture. This soil moisture must either be processed externally or cleaned locally. Any remaining PFAS vapors can be cleaned with activated carbon.

In May, we collected approximately 13 liters of soil from the site and subjected it to an evaporation test. The result is that heating at 350 Degrees Celsius for approx. 7 days reduces PFAS concentrations of more than 1,000 µg / kgds to below detection level. Completely in line with expectations, this means that a remediation result of more than 99.9% has been obtained. A very good result, of course.

The soil heating method is based on Conductive Heating. The beauty of this heating method is that it does not depend on the type of soil. It does not matter whether it concerns clay, loam, sand or rocky soil: every grain, all pores are heated. This PFAS soil remediation technology is therefore extremely suitable for releasing the difficult clay and loam soils in the Netherlands.

Would you like to know more about this PFAS soil remediation technique?

Please contact Marco van den Brand

Implementing a new water or air treatment, soil remediation – this is always nerve-racking. Does it actually work? What are the precise costs? Will we achieve the necessary results to adhere to permit requirements? How much of the chemicals is used up? How much waste (e.g. sludge) is produced? And can the treatment be improved?

This is where our test lab comes in: there we can do trials on a small scale in order to investigate these questions. This is applied in our own projects but can also be done for external clients. We can conduct the testing ourselves but if you prefer to do it yourself we also rent out our test lab and other facilities for a reasonable price. Various consultancy firms have already made use of this service. It will help you gain a better understanding of the matter and you can be very flexible in your test set-up.

Our test lab is conveniently located at our headquarters in Ede and equipped with all necessary tools and materials. These include tubes and hoses, clutches, various pumps, connectors and connection pieces but also various chemicals (such as acids and bases, hydrogen peroxide etc.), different types of activated carbon, filters, gas bottles (e.g. nitrogen). We also have various measurement devices available for PID, FID, pH, EC, redox and more.

If you are interested in implementing or improving a new treatment system (air, water) or a soil remediation technique we recommend to test it first on a small scale to prevent annoying setbacks later on. Click here for more information: