Container wastewater treatment plants (WWTPs) are designed according to worksheet ATV-A 126 based on standards ČN 756402 and ČSN 756401, taking into account the regulation for combined WWTPs ATV-H-254.

The external dimensions of the container tanks correspond to the ISO standard for containers with a height of 3.0 m. The tanks of the container WWTPs are made from 5 mm thick steel sheet of quality ST 37.2 with corrosion protection, or alternatively from polypropylene construction elements, which are concreted on-site with structural concrete for static reasons.

Upon request, the tanks of the container WWTPs can be equipped with a light cover made of plastic or fiberglass laminate.

The advantages of container WWTPs (compared to traditional wastewater treatment plant construction) are primarily their low cost, flexibility, and the possibility to increase capacity in stages, while enabling rapid commissioning of the entire plant — i.e., connection to the incoming sewer and discharge of treated water. Standard commissioning is carried out within one calendar week. Another significant advantage is the very simple construction preparation, which consists only of the construction of a concrete foundation slab on which the container is placed using lifting equipment.

All container WWTPs are pre-assembled and test-operated at the factory. The customer can carry out a technical acceptance. Afterwards, the container WWTP is disassembled to allow transport via normal container transport routes to the destination site. For transport purposes, parts exceeding the container tank outline are dismantled and stored inside the container tank. The internal equipment of the container WWTP is designed as a modular system, which is assembled and installed according to specific requirements for each project.

Basic description of the container wastewater treatment plant:

At the inlet, before the biological stage, mechanical pretreatment is included, consisting of a bar screen or sieve, grease trap, and grit trap. The activation stage is equipped with a flooded loop fixed-bed bioreactor with integrated fine-bubble aeration by membrane hoses, operating based on a combined technology of fixed biofilm carrier and activated sludge in suspension. The settling tank is designed as a lamella separator and, together with the activation stage, is integrated into one container tank.

The machinery room is either integrated directly into the container WWTP tank or, upon request, can be provided as a separate lockable 10- or 20-foot living container. Besides blowers, it can house the electrical switchboard, sanitary facilities, and possibly a spare parts storage.

The control of the container WWTP is either manual or automatic. In automatic mode, the aeration of the activation stage is controlled either by an oxygen electrode or a timer. The switchboard is equipped with individual fault signals, which are combined into a summary fault report. Upon request, the system can also be equipped with a modem output or other communication links to a remote monitoring location (e.g., municipal office, reception, security gate, etc.).

If needed (as an upgrade), the outlet from the container WWTP can be equipped with a microsieve drum filter or chlorine disinfection, or UV radiation (e.g., for the requirement to use pretreated water as utility water or for irrigation of green areas).

The piping layout of the container WWTP is determined according to the technological scheme after verification and approval on site.

Basic size range of container wastewater treatment plants:

In plastic (PP) containers for concreting: 100 PE to 800 PE
In steel containers: 250 PE to 5000 PE

Scheme of the WWTP:

Container

Since 2015, container production has been included in the manufacturing range for the purpose of outfitting with technological equipment according to customer requirements. Containers are primarily intended for the installation of various types of machinery, with the outfitted container forming an independent functional unit within the given technological system. Containers can be delivered fully equipped, empty, or with preparations for outfitting at the customer’s location.

Basic description of the container

The robust supporting structure made of profiled steel is usually manufactured from steel grade 11 according to ČSN standards and is coated with a multilayer protective paint. The container cladding consists of insulated sandwich panels. Containers, or even assemblies of multiple containers, can be stationary or adapted for handling and transportation using standard transport means. Characteristic features of the containers include:

• Robust construction
• Easily replaceable wall panels
• Optimal sound and thermal insulation
• Equipment customized according to individual customer requirements

Container equipment

Containers are manufactured individually according to specific requirements specified in the order. Delivered container equipment includes, among others:

• Corner castings, pockets for forklifts, and lifting eyes for cranes
• Prepared installations for electrical wiring, heating, and ventilation (HVAC)
• Color finish according to customer requirements
• Lockable entrance to the container
• Structural adaptation of the container to installed equipment