**4.2 Container sewage wastewater treatment plant (CSWTP)—leachate treatment plant in reverse osmosis technology**

Container sewage wastewater treatment plant (CSWTP) with a capacity of 30 m3 /d includes system called a single-stage membrane process ensuring obtaining the leachate parameters enabling them to be safely transported to the municipal sewage treatment plant. The treatment plant operates on the basis of the reverse osmosis process (e.g., **Figure 6**), the essence of which consists in passing the leachate from the storage site through a semipermeable membrane under the influence of the pressure set on the inlet side of the effluent.

Membrane separation is a purely physical separation; separated components do not undergo any chemical or biological transformation. The applied solution is a pilot solution for cooperation with the existing pretreatment plant in order to increase the cleaning effects. The effect of the treatment plant is to obtain purified leachate (permeate) and leachate residue (concentrate).

The sewage treatment plant works in a continuous system and cleanses the effluents from the ZRO2 reservoir, i.e., from quarters 9 to 12. The treatment plant will be controlled by means of a computer program and will work in an automatic system. The computer will monitor, through systematic conductivity measurement, the quality of treated leachate discharged into the environment. If the conductivity

**Figure 6.**  *The treatment plant based on the reverse osmosis process (source: [18]).* 

rises above the programmed value, the installation will automatically stop, and a cleaning program for filters or modules will start.

Sewage plant is located in a paved square for turning vehicles. Container of treatment plant with dimensions of 12.2 × 2.5 m is set on a separate foundation.

The container is made of steel construction with a layer casing made of trapezoid sheet metal from the outside and a polypropylene plate from the inside of the container. The addition between the layers is a mineral wool insulation layer. Tight floor is made of chemically resistant material. The container has mechanical ventilation.
