More efficient and sustainable water treatment for cooling systems
Operating costs are also rising for industrial cooling systems and regulations are becoming stricter. Sustainable innovations in the water treatment of evaporative cooling systems are in demand. By replacing 100 per cent of chemical biocides with natural microorganisms, industrial companies can benefit from economic and ecological advantages.
A new process using natural microorganisms reduces the operating costs of cooling systems and improves water quality.
Micropollutants such as industrial chemicals, cleaning agents or surfactants are increasingly found in dissolved form as water pollutants in the aquatic environment. Wastewater treatment plants, for example, are therefore faced with the major challenge of efficiently removing these micropollutants using suitable processes in order to fulfil the requirements of nature and society as well as the German Drinking Water Ordinance (TrinkwV). This task is made more difficult by the fact that the chemicals used by industry have a long half-life. This is over a year for some biocides, for example. As a result, water quality and biodiversity are permanently impaired and damaged.
Even if the purification performance of wastewater treatment plants is generally good, there is currently no practical and economical method for removing anthropogenic trace substances such as biocides to a sufficient extent for the subsequent production of drinking water. As a result, further removal of trace substances in wastewater treatment plants by means of a fourth purification stage is being demanded and publicly discussed. This is a challenging task that can only be partially realised technologically by means of ozonisation, oxidation processes and the combined use of reverse osmosis and nanofiltration. These methods are not only very complex in terms of process management, but are also usually associated with very high costs for wastewater treatment plants.
New process easy to implement
The principle of ‘prevention is better than cure’ applies particularly to such complex tasks as safeguarding drinking water quality and biodiversity. This imperative can be achieved with the following three rules: Firstly, the use of environmental pollutants of any kind in industrial processes must be avoided to a greater extent in future and replaced with environmentally friendly alternatives. Secondly, the existing minimisation requirement for the use of biocides should be applied and enforced more consistently. And thirdly, petroleum-based inhibitors should be replaced by ecological substitutes based on renewable raw materials that are completely biodegradable.
The company Blue Activity is breaking new ground in industrial water treatment with an innovative and sustainable approach. The cleantech start-up is replacing biocides with natural microorganisms and phosphates with biodegradable biopolymer-based inhibitors, which will completely eliminate micro-pollutants that are very difficult to eliminate in future.
The new, natural water treatment is easy for operators of evaporative cooling systems to implement during operation in accordance with the 42nd BImSchV.
Industrial companies have an ‘all-round carefree package’ at their disposal: On the one hand, this includes the natural microorganisms used as operating materials. On the other hand, online monitoring including biofilm and scaling/deposition sensors, online corrosion and fill level measurement. Online monitoring enables 24/7 monitoring and visualises all relevant KPIs in real time via a dashboard. This makes it easy to optimise the driving style and intervene quickly if necessary. The offer is rounded off by a needs-based on-site service by competent employees.
During the service visits, a Legionella rapid test is also carried out to check the microbial parameters and hygiene safety. The rapid test makes it possible to provide an indication of the legionella bacteria (serogroups 1, 2 – 14) present in the cooling water directly on site. The reproducible result is available after just 25 minutes.
Big savings with improved water quality
Under the motto: ‘With nature instead of against nature’, the subsequent water quality can be sustainably improved. In addition, the need for make-up water can be significantly reduced by replacing 100 per cent of classic biocides with natural-based microorganisms.
The water savings in evaporative cooling systems (VDKA) result, among other things, from the significantly improved heat transfer compared to the use of biocides. This leads to an overall increase in the efficiency (cooling capacity) of the evaporative cooling system, as biofilms are continuously minimised by the microorganisms.
As a result, the overall balance of the evaporative cooling system improves thermodynamically in terms of energy transfer. This helps to conserve natural resources and protect water while improving water quality at the same time.
Further water savings can be achieved by sensibly increasing the thickening rate depending on the input water quality.
The successful substitution of hazardous substances with biocides as well as additives for corrosion protection and petroleum-based hardness stabilisation results in a circular use of water. Compared to conventional, commercially available additives, the concentration of phosphates in these innovative inhibitors is reduced by around 80 %. The result: a significant reduction in pollutant loads in waste water.
Industrial companies can therefore reduce water consumption by up to 52 % and sustainably improve wastewater quality. Against the backdrop of constantly increasing water scarcity, this is of great added value for people and society alike.
More efficient and sustainable water treatment for cooling systems makes a practicable, economical and ecological contribution to meeting the environmental challenges of our time.
Improving CSRD sustainability indicators
Legislation in the form of the Hazardous Substances Ordinance (GefStoffV) has long advocated the prudent and reduced use of hazardous substances in the operation of evaporative cooling systems. This is a thoroughly positive approach, but one that can still be optimised. Complete substitution of hazardous substances would be a much better and more sustainable solution in terms of climate change and water protection.
With innovative cooling water conditioning including sustainable system cleaning, the operator not only fulfils several sustainability goals of the United Nations (‘SDGs’), but also demonstrably improves its environmental and energy indicators. The approach is particularly beneficial for larger and listed companies, which have to collect various key figures and data as part of the European Sustainability Reporting Directive (CSRD). This is because the new European Sustainability Reporting Standards (ESRS) developed as part of the CSRD can be significantly improved by this solution for the specific standards water/biodiversity (E3-4) and climate change (E1).
The concept based on microbiology not only enables industrial companies to significantly reduce their operating costs, but also to directly benefit from the fulfilment of the very demanding obligations within the framework of European sustainability reporting.
Next task: reducing sewage sludge
The new process also improves the downstream sewage treatment processes. The functional, food-safe and genetically non-modified microorganisms added to the water as a biocide substitute reduce the carbon load in the wastewater, among other things. This improves the quality of the wastewater and facilitates the downstream treatment processes.
In a further step, Blue Activity is currently working on a sustainable solution to reduce sewage sludge by adding special microorganisms. This is because sewage sludge currently amounts to almost two million tonnes of dry matter per year in Germany alone. Around 80 % of the sewage sludge is utilised thermally. Incineration results in avoidable CO2 emissions. New ways are therefore needed to enable agricultural businesses to safely reuse the sewage sludge – which contains high levels of phosphorus, among other things – in the form of fertiliser. This is because phosphorus is not only a limited raw material, but also an important nutrient for flora and fauna. If circular processing were to succeed, the mineral fertiliser would no longer have to be imported in future to meet the growing demand.
Author: Lars Havighorst, CEO, Blue Activity
