Land containerized wastewater treatment plant Crystall-BIO-K
Crystall BIO-K is meant for domestic or similar industrial wastewater biological treatment. The technology is based on the method of extended aeration, which allows to simplify plant operation and, consequently, minimize operating costs. The entire complex of units is made in land containerized design that allows to locate the units on sites with difficult geological and hydrogeological conditions.
For maximum effect and in accordance with requirements to treated wastewater composition, it is recommended to discharge treated water to subsurface discharge or filtration trenches.
|Capacity||from 5 to 100 m3/day|
|Treatment efficiency||SS (Suspended Solids) - 98-99%
BOD 5 (Biological Oxygen Demand) - 95-99%
COD (Chemical Oxygen Demand) - 80-95%
The plant is designed for treatment of domestic wastewater from autonomous facilities with treated wastewater discharge to water bodies or subsurface discharge.The complex includes the units of mechanical, chemical and natural biological treatment, as well as of sludge digestion. If treated wastewater is discharged into fishery water bodies, the technological scheme is complemented with secondary and tertiary treatment systems. The technological scheme considers the features of wastewater composition and inflow mode, the possible operation level of the units. They are manufactured individually according to Customer’s specifications with regard to their capacity, terrain relief, hydrogeological, geological and other conditions.
Technological scheme of the plant Crystall-BIO-K
Taking into account high concentration of organic pollutants, hourly, daily and seasonal nonuniformity of their income, the following units are included in the technological scheme:
Mechanical treatment is performed by means of mechanical rake or step screens, or sieve filters for detention of large mechanical impurities. Tangential sand catchers are used for sand detention. In some cases, integrated plants of mechanical treatment can be used for place saving.
Equalizing tank (equalizing tank-predenitrifier) is meant for equalizing of incoming sewage flow rate and balanced loading of the basic units. If intensification of biological treatment is needed, it can be used as a predenitrifier supplying circulating sludge directly to the equalizing tank. Depending on local conditions, the equalizing tank can be manufactured as a free-standing unit, or included in the complex of the basic units of the containerized plant.
Aerotank of extended aeration (total oxidation) is meant for complete biological treatment of wastewater. Its distinctive feature is that wastewater treatment and activated sludge mineralization take place in the aeration zone simultaneously, what significantly reduces its growth. Surplus activated sludge is periodically (once every 2-4 months) pumped from the secondary clarifier into the septic tank. In the aerotank of extended aeration (here wastewater should be stored for not less than 24 hours), according to BOD5, organic pollutants are reduced up to 20-25 mg/liter, ammonia nitrogen is reduced by 30-50%.
The technological process in the aerotank is provided by aeration by means of air blowers and constant recirculation of activated sludge from the secondary clarifier. Relative air rate is 30-35 m3/m3 of wastewater.
The aerotank operates at variable concentration of activated sludge (2-6 g/liter); the average value is 3-4 g/liter. When sludge concentration increases up to 6-7 g/liter, surplus sludge is pumped to the septic tank.
For the period of possible prolonged stoppage of wastewater income (for more than 2 days), aerotank operation is transferred to the recirculation mode, at which the part of the activated sludge is supplied to the septic tank. In this case, the products of sludge decomposition in the form of volatile fatty acids (VFA) that are a good substrate for life support of activated sludge biocenosis, come from the septic tank to the aerotank.
Secondary clarifier is meant for separation of activated sludge from treated water and flow formation of circulating activated sludge.
Clarified water is collected in a water collecting tray and discharged from the clarifier, and sludge in the form of circulating activated sludge is continuously pumped by a submersible pump into the aerotank. There is the possibility to supply a part of sludge to the septic tank (for surplus sludge densification).
At normal operation of the secondary clarifier, suspended solids, which concentration does not exceed 25-30 mg/liter, are discharged to subsurface discharge, filtration trenches and sand-gravel filters.
The choice of such type of units depends on their capacity, hydrological conditions of their location, terrain relief, etc.
Tertiary treatment is used if it is necessary to provide wastewater suitable for discharge into fishery water bodies. Bio-filters with immobilizing bed Bio-Yozh and mechanical filters can be used to bring wastewater to the required composition.
Structure of the plant Crystall-BIO-K
In order to minimize general construction works and reduce construction time, the basic units are manufactured as container units of full factory readiness. One plant can consist of several container units of shipping dimensions, which are put together on a common foundation base on site.