What is a plastic septic tank, which one to choose

This is a plastic container where all sewage waste water is collected for their processing. It is used in case of absence or impracticality of connection to the centralized sewerage. The site eurolos.ru presents a variety of plastic septic tanks. 

The principle of operation is similar for most types of treatment facilities: first, the effluent is settled, then it is biologically treated by anaerobic or aerobic bacteria.

In a simple device, purification takes place in 2 stages: decomposition of heavy components and secondary waste treatment, followed by removal of the purified liquid to the outside – usually to a drainage system with a ventilation outlet (for further purification).

What materials are septic tanks made of?

Plastic septic tanks are made from polyethylene, polypropylene, fiberglass.

The most budgetary material – low-pressure polyethylene. Rotational molding allows you to get seamless septic tanks. This ensures their tightness, which is especially in demand in areas with a high level of groundwater (GWL).

Unfortunately, the production method does not allow obtaining at least approximately the same wall thicknesses – they can vary by half (8-17 mm). In addition, ethylene itself is not very durable, so it is reinforced: with stiffeners along the body and internal partitions. The formed chambers are connected by overflows.

Pros polyethylene septic tanks:

• resistant to aggressive environments, rusting, silting of the walls, to the characteristics of the soil;
• solidity, seamlessness;
• large operating temperature range: -50+70⁰C.

Cons:

• low-pressure polyethylene is not particularly strong, it requires reinforcement.

Polypropylene septic tanks – they turn out to be stronger and tougher, although they are also inexpensive. Polypropylene sheets are extrusion welded, which allows you to make a variety of protruding elements on the body that enhance rigidity.

Polypropylene compared to polyethylene:

• withstands temperatures up to +140⁰C, not subject to temperature deformations;
• more solid and durable.

In general, it is considered an intermediate material in terms of performance between polyethylene and fiberglass.

Fiberglass septic tanks are considered relatively expensive. Made of composite material, they already withstand ground pressure at a depth of 3 meters, where they are preferred to be mounted.

Pros:

• resistant to any aggressive environment;
• easy;
• anti-corrosion and durable (up to 50 years).

Cons:

• fragility;
• not the strongest of plastics, in practice polypropylene is stronger than fiberglass.

Advantages and disadvantages of plastic septic tanks

The following advantages of plastic septic tanks can be noted:

• ease of maintenance and operation;
• complete tightness (unlike concrete rings, bricks and other “folk” sewage options)
• compactness and light weight;
• safety for the environment, the absence of specific odors;
• can be installed anywhere;
• durability and corrosion resistance.

Cons (mainly for simple septic tanks):

• lower strength – in comparison with concrete, but this is fully compensated by competently carried out installation by specialists;
• reliable anchoring is necessary – a light hull without water can be squeezed out by groundwater or soil when it swells.

Types of plastic wastewater treatment plant

For clarity, we will consider them for different degrees of purification using the example of Evrolos plastic septic tanks, as the most advanced treatment facilities for country houses with permanent and seasonal residence:

aeration plant Eurolos Pro

aeration plant Eurolos Pro — high degree of wastewater treatment (98%). It is achieved through biological wastewater treatment – complex devices with compressors, aerators and airlifts.

Case material – monolithic sheet polypropylene. Purified water can be discharged either to a drainage ditch or to the ground surface.

Eurolos PRO is a modern innovative development adapted to conditions. It is based on the technology used in urban wastewater treatment plants, but adapted for the end user. Jet aeration of effluents using ejector technology.

Differs in the following qualities:

• strength – the cylindrical shape of the hull allows you to withstand significantly greater soil compression (in comparison with rectangular ones) with the same material consumption;
• reliability – increased by the lack of automation in technology;
• compactness – due to intensive cleaning methods;
• stability – microorganisms on an inert carrier make it possible to withstand the discharge of prohibited toxic substances into the septic tank, plus increase the degree of purification;
• maintainability – most of the key elements are easy to find in hardware stores.

Conclusion: Such installations are for country houses, small hotels / hotels, villages.

Local wastewater treatment plant

Local wastewater treatment plant — Eurolos Bio (purification up to 92-97%).

This is a pumping autonomous sewage system, consisting of 3 compartments. Material – polypropylene. The station includes: pump, ejector, biofilter.

During operation, mechanical and biological cleaning is carried out. Effluent circulates in the compartments, repeatedly passing through the biofilter in the bioreactor with plastic loading. The cycle repeats every hour.

In case of a power outage for 2 days, the station operates in normal mode, then it switches to the non-volatile septic tank mode. Those. maintenance is required every 2 years according to the passport, but it depends on the intensity of operation.

Conclusion: a universal option for permanent and seasonal living in suburban areas and cottage villages.

Overflow anaerobic non-volatile septic tank Eurolos Eco

Overflow anaerobic non-volatile septic tank Eurolos Eco (cleaning up to 60-70%).

Case material – monolithic sheet polypropylene. It consists of 3 compartments where triple cleaning takes place: mechanical, biological and final settling. Purified water must then be supplied to the drainage for post-treatment (filtration field or drainage well). A non-volatile septic tank is only suitable for installation on sandy soils with low GWL.

Conclusion: for non-permanent residence. For example, when visiting the dacha only on weekends.

Deep biological treatment station Eurolos Primer

Deep biological treatment station Eurolos Primer – for areas with high groundwater levels, as well as weakly absorbent soil types: loam, peat, etc. Compressor aeration unit with two aerotanks. Wastewater treatment reaches 99%.

Under conditions of high GWL, the installation of treatment facilities is very difficult, as is the removal of treated water. This led to a change in the layout of the device in order to reduce the depth of the pit pulled out under it. The increase in length has led to an increase in productivity.

The full cycle of mechanical and biological cleaning is eight-stage:

1. Mechanical.

2-3. Biological: in aerobic and anaerobic conditions.

4. Silt separation.
5. Post-treatment aerobic.
6. Fixation of spent biofilm.
7. Disinfection and discharge of purified water.
8. Sediment stabilization (anaerobic).

Conclusion: for a site with an increased level of groundwater, for a swampy area.

Which plastic septic tank to choose for a summer residence or a private house

First of all, when choosing, the operating conditions, free area, groundwater level and the desired degree of cleaning are taken into account. And you should also focus on cleaning performance, the expected load.

Eurolos BIO is applicable almost everywhere, as a universal station – both for a house with permanent residence and for a seasonal dacha. If they live extremely rarely in the country, then you can choose Eurolos ECO, but on condition that the GWL is low and the soil absorbs moisture well. For swampy areas or in quicksand, only Eurolos Grunt is suitable with the use of formwork during installation.