nir-vana innovation network

The German SME is active in the fields of development, application and sale of specialty chemicals and processes for treatment and disposal of industrial wastewater. Main areas of application are industrial wastewater containing emulsified oil and heavy metals.

The problem:
Used water-mixable cooling lubricant emulsions (o/w-emulsions) contain approx. 3 - 5% or more emulsified oil. The majority consists of water and the rest of various inorganic and organic chemicals, which give the o/w-emulsion the required effect and stability – but unfortunately also the very high COD (chemical oxygen demand). Used o/w-emulsions must be disposed of expensively. In order to keep disposal costs low, the oil and possible heavy metals must be removed and the water should be reprocessed in an environmentally sound manner and returned to the natural water cycle. In practice, chemical-physical operations with polymers, ultrafiltration and evaporation are carried out with high investment and operating costs. In many countries, however, combustion and treatment with acid at higher temperatures are still used - with all the disadvantages.

State of the art:
The SME and many customers prepare the used water-mixable o/w-emulsions according to the state of the art as follows: The emulsions are split in water and oil at ambient temperature in a stirring container as the 1st process stage with a polymer of the SME. After the natural flotation, the water and the liquid oil phase is separated. The oil phase goes to controlled, separate disposal. The separated, usually still slightly oily water is after-treated and clarified in a further stirring container as the 2nd process stage with a heavy metal precipitation agent. This produces a thin sludge that sediments. Finally, the clear water and after that the thin sludge is separated via a belt filter or a filter press. The solid sludge goes to controlled, separate disposal.

The new solution:
The more environmentally friendly and economical solution in just one stirring container or in a fully automatic flotation plant is the 1-stage process with the SME’s innovative demulsifier: They recently split and clear the used o/w-emulsion with their demulsifier and their heavy metal precipitation agent, which not only brings heavy metals such as copper and zinc far below required limit values, but also reduces rests of pollutants such as cyanide, nitrate and nitrite and other anions and is not toxic to fish. It can ideally be dosed in a controlled manner with a paper reagent. After the natural (or an artificial) flotation they separate the clear water and the oil phase containing heavy metals. Only the heavy metal-containing oil phase goes to controlled, separate disposal.

Reuse of the clear water.
The clear water from both processes with a hydrocarbon (HC) residual content mostly below < 20 mg/l has the quality of a permeate from an ultrafiltration. The SME recommends this clear water not to be fed to osmosis or evaporation due to the high COD, but better to lead to aerobic biology. In the latter case, the clear water is first pre-treated in a classical industrial aerobic biology and then fed to a municipal wastewater treatment plant. A strictly controlled very low-dose disposal of the clear water directly into a municipal wastewater treatment plant is often possible.

The SME looks for a cooperation under a commercial agreement with technical assistance with a company (e.g. a plant manufacturer) generating used o/w-emulsions that have to be disposed of and that is interested in applying the SME’s new 1-stage process and demulsifier. As the range of o/w emulsions to be treated is often very broad the SME will further adapt demulsifier and process to the special requirements of their partner.
The SME would also be open to distribution agreements with partners specialized in industrial wastewater chemicals. They would also adapt the product/processes to requirements of the distributor’s clients.

Advantages & innovations

The advantages of the 1-stage process are: • the treatment time is less than half • the disposal costs are much lower, as only the oil phase is disposed of • heavy metal precipitation and demulsification are combined and this results in a lower salination of the water while heavy metals, nitrate and nitrite and other anions are significantly reduced • this does not require complex plant technology and is therefore particularly suitable as a simple batch process or better in an existing flotation plant for small and medium-sized enterprises.

Stage of development

Already on the market

Partner sought

Type of partner sought: The SME is looking for partners from industry such as plant builders of industrial wastewater treatment plants or manufacturers of water-mixable cooling lubricants. Distributors of industrial wastewater treatment chemicals might also be possible partners, Tasks to be performed by the partner sought: The partner should integrate the demulgator and 1-stage process of the SME into their wastewater treatment processes. The partner shall deliver samples of untreated waste water to SMEs when product and process adjustments or further developments are required. In case of a distribution agreement, the partner should include the demulgator of the SME in their sales program. In the frame of such a distribution agreement the SME would also adapt the product or processes to specific requirements of the distributor’s clients.