Technology

Dissolved air flotation

Flotation is the most effective method of removing contaminants such as fats, suspensions, oil-derived substances and other undissolved substances found in industrial wastewater. The separation of these contaminants takes place in chemical processes using coagulants and flocculants (polymers). After separation, separation takes place using a water-air mixture in the flotation chamber. The resulting sludge is discharged outside the system and possibly dewatered before being disposed of, e.g. in a biogas plant.

Technology

Mechanical pretreatment

Most industrial wastewater streams contain solids that must be removed before wastewater reaches the treatment plant equipment. Removal of solids is necessary to protect pumps, mixers, sensors and other system components from blocking or even damage. In EMI installations, we use two stages of mechanical pre-treatment: coarse and fine. Coarse pre-treatment removes the largest elements, with a cross-section above 20 mm, and is carried out at the inlet to the first pumping station, before wastewater comes into contact with any pump. Coarse separation devices include vertical screens, basket screens and step/hook screens. The purpose of fine mechanical pre-treatment is to further remove solids, with their cross-section dropping below 3 mm, most often to 1 mm, although in some cases it is appropriate to use even smaller cross-sections (up to 0.25 mm). At this stage, rundown and rotary screens are used. The latter type of screen is used in a system with external or internal inflow. Mechanical pre-treatment involves very low costs, mainly resulting from the consumption of water rinsing the screens. No reagents are used, and energy consumption is minimal. Mechanically pre-treated wastewater is suitable for further treatment by physico-chemical and biological means.

Technology

Equalization

Wastewater in industrial plants is generated in many places and in many processes. As a result, its quantity and composition fluctuate significantly during the day and sometimes many days. Adjusting the treatment process to rapidly changing wastewater would be inefficient and uneconomical. Therefore, in industrial installations we use equalization tanks of appropriate size and equipment. We select the size based on data from the plant, industry knowledge and our own experience. The equipment of equalization tanks may include pumps, mixers, aeration systems, neutralization systems, by-passes and additional interceptor tanks and many other elements carefully selected to meet the requirements of individual cases.

Technology

Neutralization

Ensuring the appropriate pH value in sewage is very important for two reasons. Firstly, each receiver (sewage system, environment) requires that the sewage directed to it has a pH within a predetermined range. Secondly, the sewage pretreatment and purification processes themselves require ensuring their appropriate pH. Emi offers a wide range of solutions, from simple systems with one measurement and dosing of one neutralizing agent to complex, multi-stage systems requiring the use of specific neutralizing agents. pH correction can take place at many levels, stages and in one of two modes: flow (online) or batch.

Technology

Container solutions

EMI has developed modular container systems in a marine version and designed to be connected into larger systems. The containers we offer have been designed from the ground up to operate in the harsh conditions of industrial sewage treatment plants. The interiors are lined with 100% stainless steel, have heating, ventilation, health and safety devices and individually configured technological equipment. The use of container construction allows for the shortest possible project implementation time. The entire installation is prefabricated in the EMI production plant and is delivered ready for start-up immediately after connection on site (in some cases preparatory works are required, such as tanks and underground networks, ground hardening, etc.). EMI's offer also includes tanks in containers that can perform averaging, storage and even become biological reactors.