DAUZUC

DAUZUC , based on the inventions of "Septic tank with self-draining", and "Device for Increasing the Efficiency of Constructed Wetlands"   eliminates these components, without : additional investment costs ,  electricity consumption and exploitation costs.

DESCRIPTION

The device is composed of naturally ventilated tanks, with filtering and dispersing  pipes, communicating with the surface of the soil through air absortion pipes, through which air is absorbed due to the natural smoke effect, and through the air outlet pipes through which air is evacued . The filtering and dispersing  pipes has, on the underside of the circumference, rectangular slots interrupted at the base by a  drainage channel. Above the filtering and dispersing  pipes there is a waste water pipe with a discharge on them. The equipment is placed in a CW with a gravel bed, covered with a geo textile membrane filter, placed under a layer of vegetal soil. All components are placed in a pool made of PVC or PE foil. The process is continuous and consists of:

Mechanical treatment in tank:

         When the waste water falls in the tank , on the filtering and dispersing  pipes, because of the Coanda effect, the liquid  flows to the slots, where a large part of the gray water and also the liquid fraction of the black water penetrates and  flowing on the drainage channel, in the CW. In the tank are retained until liquefaction or dissolution in liquid due the turbulence created at the fall of wastewater, only large solids, sand, grease.

Biological treatment   in tank:

         In the tank, the anaerobic digestion of biodegradable materials alternates with aerobic digestion, depending on the variation of the waste water flow and the build up of the CW. Aeration is achieved by the air circulation between the absorption pipe and the outlet pipe , but also due to the disorder created by the wastewater in the fall and by the influx of water entering the tank from the wet area built through filtering and dispersing  pipes. This influx also enriches the content of aerobic microorganisms with those in the wet built area.  In the tank occurs and the anaerobic phase and denitrification for the elimination of the gaseous nitrogen on the outlet air pipes, after the nitrification in the built-up wet zone and the anoxic phase of phosphorus removal.

          In  CW  :

The aerobic digestion of the biodegradable materials takes place by the stationary bio-media existing in the soil and in the gravel bed which, due to the variable flow of the waste water and the variations in level and absorption in the multilayer CW, is submerged alternately aerated at each exceedance offiltering and dispersing  pipes level by the water inside the tank and the outlet in CW and its withdrawal due to soil absorption. Aeration inside the gravel layer and in the soil is enhanced by both convection caused by the water infiltration motion through the granular medium and by air diffusion from the surface to the granular material layer by absorption into porous media. Ammonium nitrification (biological oxidation) also occurs due to chemical autotrophic bacteria but also to the decomposition at its base, by aerobic microorganisms when dissolved oxygen consumes oxidized nitrogen instead of oxygen, and by anaerobic microorganisms. They convert nitrites and nitrates into gas as nitrogen (N2). Due to organic soil loading and permanent aeration, phosphorus removal is also taking place.

          CW also purifies the waters through two filtration processes, namely:

         - superficial filtration of the treated water, whereby medium-sized solid suspensions are removed by retention in the pores of the gravel bed until the effluent is portion wise dissolved. Since the solid suspensions retained are of both mineral and biological origin, it results that by the superficial filtration process the suspended materials and a significnificant part of the organic load of the treated water are eliminated;

       - the final filtration of treated water, whereby the solid suspensions are almost entirely removed from the water overflow of the geotextile membrane level which only allows the passage of clean water.

Bio-degradation and disintegration of organic compounds and filtration is continued by the aerobic microorganisms in the vegetal soil, which are also activated by the absorbed air.

The purification performance obtained is as follows:

            - CBO5 reductions of 90% -98% (less than 25mg / l), CCO (less than 120mg / l), and solid SS suspensions (below 30mg / l)

             - complete virtual nitrification;

             - denitrification 70-80%

             - phosphorus reduction 60-70%

             - partial elimination of faecal bacteria (reductions of 1,000 times the number of faecal bacteria for every 1 m of granule layer thickness).

Purified water is finally absorbed into the upper layers of soil and eliminated by evapotranspiration (ET) sweating and use for plants irrigation at the root. By sterilizing water can also be used for surface irrigation.

Increasing the coefficient of ET by remodeling the natural soil

ET is a complex process of water vapor transformation through a series of physical processes (evaporation in the liquid phase and sublimation in the case of snow and ice) and biological (perspiration). Water transformation into vapors occurs at the surface of the field, in the field (at low depths) and in the vegetation cover (natural or cultivated).

Evaporation can affect all forms of liquid water: • meteoric water in the atmosphere, retained by the vegetation cover and fallen water on the surface of the ground; • groundwater in the soil profile, the capillary area and even the shallow groundwater aquifers. The evaporation process consists in "detaching" the molecules from the surface of the water or the wet ground under the action of solar radiation and their passage into the state of vapor that returns to the atmosphere. In all cases, the evaporation rate is influenced by: the evaporating power of the atmosphere, the type of the evaporating surface, and the ability to supply the evaporation.

The evaporating power of the atmosphere refers to its state in the vicinity of the evaporating surface and its ability to cause evaporation. Factors that determine evaporating power are: atmospheric saturation deficiency, air and water temperature, barometric pressure, water chemistry, altitude, and so on. The evaporating wetlands are studied in terms of water availability and their ability to supply evaporation. In this respect, in hydro geological research it is interesting to evaporate to the surface of a land lacking vegetation, as well as in conditions of different humidity states: • soil (soil) saturated with water; • unsaturated land; • For aquifer at low depth.

If the land is saturated with water, the evaporation rate is equal to that of a free water surface. Apart from the physical characteristics of the land (porosity, granulation, saturation), evaporation at the surface of a vegetation-free land also depends on the depth of the groundwater aquifer.

When the piezometric level of the groundwater aquifer is at a low depth, the evaporation reaches maximum values, determined by the evaporating power of the atmosphere, because the supply of the evaporating surface is made continuously by the ascending capillary movement of the aquifer water.

Through experiences can determine the depth from which evaporation becomes insignificant, this being the critical depth under which no salts are added to the soil profile.

The evaporation process also depends on the humidity gradient distribution as well as on the water-vapor mass diffusion component. Evaporation in the ground ceases when the hygroscopic humidity is reached is in equilibrium with that of the atmosphere and can not be eliminated by evaporation.

Transpiration  is the physiological process of transforming groundwater (mainly from the soil profile) into vapors (through vegetation) that return to the atmosphere. It is influenced by both physical factors (atmospheric evaporation, meteorological factors, soil humidity) and physiological factors (plant species, age or stage of vegetation, development of the root system and leaves, rooting depth). Plants, through their roots, can absorb water from the soil up to depths of 0.30 to 1.50 m for crops, but up to 10 m for trees. Research has shown that root systems can grow to the upper limit of the capillary area generated by the groundwater aquifer. Some root systems can reach a total length of 100m and even 1000m, thus contributing to a significant increase in the amount of sweat water.

Remodeling results for DAUZUC:

1. Obtaining a stagnant water regime by placing in waterproofed pools with PVC or PE membrane or foil.

Stagnant hydronic regime occurs naturally in clayey soils (wetlands) in wetlands, under relief conditions ons (flat surfaces, depressions, slope bases) and favoring excessive water stagnation in their upper part (sometimes even to the surface) not affecting the groundwater canvas.

2. Increase in soil gas content to 60%

The gaseous component of the natural soil is the air (gas + water vapor) in its pores. It holds between 15 and 35% of the soil volume depending on the humidity. Air is indispensable in the soil, controlling seed germination, plant growth, microorganism activity and most physical and chemical processes. The balanced bonding between the solid, liquid and gaseous phases gives the soil optimal fertility conditions. Air can be present in the soil in several states: - free → affects most of the soil and is in capillary pores and (especially) uncapillary; circulates through the ground and exchanges with the atmosphere; - captive → has a very low influence, is in isolated pores and does not flow through the soil; does not exchange atmospheric air; - adsorbed → is bound to the surface of the mineral particles; - dissolved → dissolved gases in soil water; does not influence aeration.

DAUZUC achieves the absorption of additional air through the absorption and oulet pipes  through the natural smoke effect, a doubling of the gaseous component of the soil.

Once the drainage is completed, the large pores of the soil are filled with both water and air, while small pores are still full of water. Gradually, the water stored in the soil is taken up by the roots of the plants or evaporates from the surface of the soil into the atmosphere. Without additional water intake the soil will gradually dry out. Soil contains a very small amount of water (hygroscopic and film water), which is more strongly bound, with a force (over 20 atmospheres), which exceeds that of plant suction (less than 20 atmospheres). Natural soil incorporates less tightly bonded water and capillary water. The available water capacity depends to a large extent on the texture and soil structure. DAUZUC by using a gravel layer of 75% deep granulation adds to this capacity, the volume of the gap between stones, which represents over 40% of the gravel volume.

DAUZUC obtains by soil remodeling, but also due to the heat intake of spilled wastewater and exothermic biological processes of soil microorganisms, evapotranspiration values ​of 6 mm / day (average annual). The irrigation is carried out according to the requirements related to water analysis indicators for irrigation of non-food crops.

Wastewater supply is made by free fall, while mixing, filtration is ensured by natural mechanical processes such as: "Coanda effect", kinetic energy of sewerage, turbine flow of liquids in cylindrical bodies.

· The suplimentary aeration is done through natural ventilation using the natural smoke effect. Similar to the processes in the mecano biological treatment plants, the addition of oxygen in solution favors the multiplication of aerobic bacteria and the consumption of nutrients. Their population is much larger and more diversified and efficient. This process encourages the conversion of nitrogen into nitrites and nitrates, remove phosphorus compounds from the liquid. During this stage, the sludge formed by the bacteria and products of their digestion is let down. Aerobic microorganisms continue to multiply in the upper part until the dissolved oxygen is consumed. At the bottom, due to the permanent fluid layer, anaerobic microorganisms develop. Many of these and some of the aerobic ones that use oxidized nitrogen, instead of oxygen, convert nitrites and nitrates into gas as nitrogen .

· Stabilization takes place in the gravel bed and has the effect of temporarily fixing the solids in suspension to digestion.

The effluent is absorbed by the vegetal soil layer and then by the naturally occurring plants on it.

BENEFITS:

1. lNO ENERGY
2. lNO CHEMICALS
3. lNO SERVICE
4. lNO INSTALATION  FOR TREATED WATER DISCHARGE
5. lNO TEHNICAL SURVEILANCE
6. lLESS INVESTMENT AND EXPLOITATION COSTS OVER 80% THAN MECHANICAL AND BIOLOGICAL TREATMENT PLANTS AND 30% LOWER THAN OTHER CW
7. lTHE VALUE OF WASTEWATER COLLECTION WORKS DECREASES SIGNIFICANTLY

CW for the consumed water of 6 EQUIVALENT INHABITANT(IE) ( through evapotranspiration  and water reuse for irrigation at the root of non-food vegetation   during the vegetation period ) it is necessary to have an area of ​15 sm and 2,5 sm /IE for the built wet area and 10 sm / IE  of the irrigated surface at the root.

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