More and more dairies are now facing a problem: how to dispose of their liquid waste products. Spreading slurry is not a realistic option any more for the agricultural industry due to the problems of overfertilisation or hygiene. The challenge for dairies is that their liquid waste products generally have a very high organic load. Wastewater accumulates, typically, as a result of cleaning and rinsing processes in production. Local rural treatment plants where most dairies are located are not designed to cope with such high organic loading.
EnviroChemie is working with a large dairy in Morocco which is part of an international food group to find an alternative route: instead of disposing of all the liquid waste, the company is turning it into biogas. To achieve this, EnviroChemie has installed an anaerobic Biomar bioreactor, metabolising the liquid waste and resulting in methane (CH4), i.e. biogas, and carbon dioxide (CO2).
The anaerobic process saves more energy than aerobic processes. The highly loaded wastewater flow from production is pretreated separately in the anaerobic reactor. This reduces the load on the aerobic wastewater treatment process, saving energy for the aeration of the aerobic biological mass. In general, this reduces electricity consumption by up to 30 per cent.
Furthermore the biogas can be used as an energy source. The dairy in Morocco uses it to produce steam to heat and pasteurise the milk. The dairy reduces its oil consumption by approximately 30 per cent. However, there is still a certain amount of solid residue and liquid waste at the end of the process, but overall it is significantly less. The dairy is therefore not only reducing the load on their wastewater plant but also making considerable savings in terms of disposal costs.
EnviroChemie’s experts conducted a series of comprehensive tests and studies in advance in order to develop the best solution for the dairy and to explore the limits of the system. Following this, they suggested not only feeding in the whey from the main production into the Biomar bioreactor but also using other products as well, such as the floatation sludge and the sludge from the existing biological treatment plant. In addition to approximately 80 cubic metres of whey, around 160 cubic metres of other liquid waste are also added. Up to 12 cubic metres of returned product and exhausted milk is also used a day.
EnviroChemie has manufactured the plant in Germany and delivered it as complete modules. In many cases, this overcomes specific issues with building legislation or environmental regulations and reduces the build time on site.

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With its headquarters in the Lake Constance region, fruit processing company Fidel Dreher manufactures a range of juices, concentrates and purées. As a by-product of handling apples, the facility produces approximately 136,500 m³ of wastewater each year, which has been treated in batches by means of an aerobic biological cleaning process and discharged indirectly via a municipal sewage treatment plant.
The company had ambitions to expand its production capacity, which meant plans were put into place to extend the existing wastewater treatment plant. In addition to generating biogas from the wastewater to be treated, the aim here was to transition to a continuous wastewater treatment process. The new plant was kitted out to the highest quality standards with the latest technology in line with Fidel Dreher’s company philosophy firmly in mind. Not only did the new features include a Biomar AHPx anaerobic high-performance reactor complete with innovative gas discharge system, but the entire facility came equipped with fieldbus technology and its own remote access system to two separate servers. This remote access system makes it possible to operate the plant remotely, not to mention manage information and alarms via e-mail and text message. What’s more, the separate servers facilitate a clear distinction between the controls and data recording, thereby ensuring maximum plant security in the event of a server failure.
When it came to actually building the plant, the fact that space was at such a premium posed a real challenge. This meant that both the conversion and new construction work had to take place during normal operation, with old plant parts having to be dismantled before new ones could be built in their place. To ensure the safe treatment of the sewage water was not compromised, the new plant was built and put into operation over three construction phases within a time frame of just seven months. It was during this period that the plant controls were permanently adapted to suit the changing conditions.
“Time wasn’t on our side, so we had to go without a hydraulic start-up using clear water,” explained a Fidel Dreher employee. “As a result, the warm start-up took place directly with original wastewater during normal operation. The process proved successful and was completed on schedule.”
The entire plant has been in operation since October 2016. The wastewater pre-treatment takes place via drum screen and flotation, before biogas generation and a COD breakdown of approximately 90% takes place in the anaerobic Biomar AHPx high-performance reactor.
Before being discharged into the sewerage system, the wastewater is treated via an aerobic activation stage with sludge separation until the requisite indirect discharger quality is achieved. The biogas obtained through this process is then desulphurised and dried. It is then used during operation to generate steam as well as energy and heat via a CHP. The innovate bioreactor allows up to 3600 m³ of biogas to be generated on a daily basis, which equates to an output of up to 1000 kW.
As the wastewater treatment plant borders directly on a residential area, great care was taken during the planning phase to ensure proper sound insulation and keep noise to a minimum. This involved all of the extracted air being treated via biofilters, and low-noise components – such as soundproof ventilators and gas flares – being used. And to top it all off, even the supply and exhaust air system for this plant building have been designed with soundproof technology.

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EnviroChemie is a specialist in providing solutions for all tasks relating to process water treatment. For 40 years, we have been providing consultancy, prefabricating plants at our own locations and installing them at client locations. Plants range from small compact plants to individual, customer specific system solutions with several hundred cubic metres capacity per hour. We ship our plants, which are "Made in Germany", throughout the world.
Depending on industry and country, clients have different requirements for their process water. These can be plants for the generation of fully deionised water for thermal plants such as turbines, but also pure water for production.
If the water is not only used as a solvent for resources, we also supply plants that recycle both the water and the resources. An example of this is our plant for a porcelain and ceramics factory. By means of ultra-filtration, we recover the glaze from the aqueous suspension. This is concentrated further and recycled.
We are currently designing a major project for the demin water supply and condensate water treatment of a petrochemical plant. Ion exchanger, reverse osmosis and electrode ionisation plants are used to ensure the water quality required. The plant technology is designed for 350 m³/h of demin water and 560 m³/h of condensate water.
Our clients come from the manufacturing, chemical and petrochemical, as well as the food and beverage industry worldwide.

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