ECOLOGICAL TREATMENT THROUGH
SUBSURFACE ARTIFICIAL WETLANDS

OPERATING PRINCIPLE

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Artificial wetlands are natural treatment systems formed by lagoons or shallow channels, filled with gravel and sand, where aquatic vegetation is planted. In these systems, decontamination procedures take place through the interaction that occurs between water, filtering fillers, microorganisms and vegetation.

CHARACTERISTICS


In wetlands with subsurface flow, there is groundwater circulation through a granular medium in contact with the roots and rhizomes of the plants. The depth of the sheet of water is usually between 0.3 and 0.9 m. The biofilm that grows adhered to the granular medium and to the roots and rhizomes of the plants plays a fundamental role in the processes of water decontamination.


Subsurface wetlands are classified, based on the direction of water
circulation, in horizontal or vertical wetlands.

SUBSURFACE HORIZONTAL FLOW WETLAND

In this type of systems the water circulates horizontally through the granular medium and the rhizomes and roots of the plants. The depth of the water is between 0.3 and 0.9 m. They are characterized by functioning permanently flooded (water is found between 0.05 and 0.1m below the surface) and with loads of around 6 g BOD/m2/day.

SUBSURFACE VERTICAL FLOW WETLAND

This type of wetland was developed as an alternative to horizontal wetlands in order to produce nitrified effluents. Generally vertical systems are combined with horizontal systems so that the nitrification and denitrification processes take place progressively, thus eliminating nitrogen. Water circulation is of vertical type and takes place by pulses, so that the granular medium is not permanently flooded. The depth of the granular medium is between 0.5 and 0.8 and they operate with loads of around 20 g BOD/m2 per day.

Vertical systems have a greater capacity of treatment than the horizontal ones (they require less surface to treat a certain organic load). On the other hand, they are more susceptible to aggradation.

BENEFITS

Subsurface Wetlands are ecological
wastewater treatment systems.

  • LOW OPERATING COSTS
  • SIMPLE OPERATION AND MAINTENANCE
  • DOES NOT REQUIRE CHEMICAL REAGENTS
  • LOW SLUDGE PRODUCTION
  • SIMPLE CONSTRUCTION

APPLICATIONS

Applications for this type
of wastewater treatment plants:

  • URBAN CENTRES, UP TO 10,000 INHABITANTS
  • HOTELS, RESORTS AND OTHER TOURIST FACILITIES
  • SMALL AGRO-FOOD INDUSTRIES

BIDATEK ECOLOGICAL SOLUTIONS

BIDATEK offers engineering services for the
design of treatment plants equipped with both:

  • Vertical flow planted wetland.
  • Horizontal flow planted wetland.
Bidatek provides construction services for these treatment systems. As an expert company in water treatment though natural systems, we offer a specialized service for:
  • Implementation of the wetland vessels, land or gabion excavation.
  • Installation of different waterproofing solutions for wetlands, from HDPE, PVC or EPDM sheet and polypropylene or polyester geotextiles.
  • Placement of drainage fillings, gravels with different grain size, plastic cells, slags, etc.
  • Installation of air ventilation elements.
  • Installation of water input and distribution network.
  • Installation of water regulation and evacuation network.
Bidatek also carries out the commissioning and operators training of this type of facilities.
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Wetland vessel
implemented in gabions

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Installation of HDPE sheet

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Wetland vessel implemented in concrete
and use of draining plastic cells.

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Treatment of industrial water.

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OTHER NATURAL TECHNOLOGIES FOR
WATER TREATMENT:

  • Lagooning anaerobic and/or facultative plants
  • Lagooning facultative and maturation plants
  • Vermifilters