Machine Production

SDG depuration designs and manufactures, at its seat in Italy, every machineries needed for water depuration plants.

SDG depuration has its own internal workshop, fully equipped with the best machineries and the most sophisticated equipment, here occur the assembly, tests and the first trial too.

SDG depuration the company applies to the entire production cycle precise protocols.

SDG depuration invests continuously in research, technologies and innovation. So it offers to its own custom only the best of technology and efficiency in water treatment.

Water is a precious good we all have to take care of.

SDG depuration is aware of this responsibility and it applies the best available technology to its equipment and machineries, it uses the best quality components, and it realizes its plants and structures of stainless steel.

The technicians, whole staff and the collaborators of SDG depuration, are always up to date on innovations and on improvements of this sector. Years after years, they spend all their energy for the benefit of their customers and with the aim of always provided the best product, most effective and most efficient.

SDG depuration realizes its plants using the best technology and components, with high quality standard (Italian, German and American) both to provide a quality product but also to provide a prompt maintenance when it is needed.

The continuous research, tests, lab analysis and the tests that are carried out on the ground in over forty years of activity in the world, allow to obtain machineries and plants that always forefront are.

It can be said, not without a pit of pride, that the plants of SDG s.r.l., are designed and manufactured completely in Italy by technicians and skilled workers with great experience and professionalism, which work with great passion for the exclusive benefit of the customer.

The customer, that requests the design and the realization of a SDG’s water treatment plant, a demanding customer is. He requests technologically advanced equipment and products , sophisticated and efficient machineries but economical in management.

The SDG’s customer requests extremely high quality, safety and environment respect standard. He pay close attention at the initial investment and the successive operating, management and maintenance costs.

SDG depuration researches the quality and cost of the plant for all its years of operation and flexibility of use.

The demanding customer find on SDG an ideal and flexible partner, ready to interpret needs and be able to find and propose the most technical and economic solution.

The water treatment plants of SDG are provided “keys in hand” working and ready to go into production. They are characterized by simplicity in use, with some control panels that are easy to use.

Through its technical staff SDG depuration transfers to users the knowhow needed for a correct use of plants, carrying out an accurate training on place.

This formative-training allows the buyer to be assured of proper management and the ideal operating of the plants because its staff has had a live professional training directly from SDG’s technicians.


17 Item(s)

  • Air diffusion system

    The aeration basin receives the waste water from the equalization tank, as well as a mass of recycled biological micro-organisms from the subsequent sedimentation basin (activated sludge). Air or oxygen is pumped into the basin via blowers at the bottom of the tank to maintain aerobic conditions and the influent, oxygen and activated sludge are thoroughly agitated.
    Bacteria and other micro-organisms decompose the organic matter converting it into more stable forms of biomass (activated sludge).  
    Hence , a good air diffusion system becomes a must for the optimal performance of your Wastewater Treatment Plant.
    Sdg Depurazione pays therefore a lot of attention in choosing air blowers and diffusers.
    Blowers are volumetric, with rotating roots and able to deliver, according to the models , from 300 up to 2400 mc/h , with 5 meters water head into tank .
    Soundproof boxes are delivered upon Customer requirement.
    Air diffusers , with an EPDM rubber plate, feature a thick membrane which make them rugged and dependable : with averages air flows between 5 and 7 Nmc/h ,the percentage of oxygen transferred into water varies between 18 and 20 % ; moreover , thanks to a special limiting ring , the airflow can be as high as 10 Nmc/h.
    Other basic criteria which drive the designing of our air diffusion systems are :
    - tank dimensions and shape
    - tank net surface and depth
    - kind of circulation
    - kind of air distribution
    Air diffusers life span is normally between two and five years and it is possible substituting the
    membrane only , thus recovering supporting plate and its locknut.


  • Belt filter press

    Belt presses are essentially composed of two moving  belts guided by a series of rollers. The sludge is spread out  on the top belt and channeled back and forth by plastic blades to allow most of the water to drain through the belts (meshed nets). The sludge is then dropped onto the lower belt and sandwiched between the upper belt as it moves through a series of rollers, which squeezes out even more water. The sludge cake is then scraped off the belt and falls by gravity into a suitable container.

    Sdg Depurazione belt presses feature a frame entirely in Stainless Steel and synthetic plastic belts , for a long life and easy replacement.

    Our FPN belt presses feature also an exclusive system for sludge /polyelectrolyte mixing , thanks to a special reaction tank provided with a variable speed mixer:such in a way the optimal reaction between the chemical product and sludge isassured. This in turn means a sludge that drains more easily , a low chemicalconsumption and high percentages of dried matter , up to 30 % , even if thenormal values stay between 18 and 25 %.

    The filtering clothes washing is achieved thanks to a multi- stage , high pressure pump ; the machine is provide by a control panel installed on a side of the press.

  • Centrifuges

    The centrifuge is a machinery that possesses the value of versatility, in fact, with the exception of abrasives, it can be used with every type of mud considered problematic for filter press and tape press, such as sludge rich in fat and substances that would go to clog the filter cloths. The centrifugation process consists in separating water from sludge through applying a centrifugal force. The sludge to be dehydrated is fed in to a structure composed mainly of a rotating drum and a internal auger. The applied centrifugal force causes the heavier particles, or rather sludge flakes, to lie on the outer part (thickened mud), while it causes the water to stay in the middle (centered). The internal auger with its rotation drag the thickened mud down to convey it in a special duct, while the water is extracted from a centered discharge duct. Two types of centrifuges are available depending on the configuration: - in co-current, where thickened mud and water are extracted from the same extremity of the centrifuge; - countercurrent, where the auger rotates in the opposite direction, dragging the sludge to the other end of the centrifuge against the central channel water.

  • Dinamic sand removal

    Dinamic sand removal

    For some productive typologies ( see for example textile industry ) a certain concern is about the presence ( more or less massive ) of abrasive powders coming from pumice stone used into process.

    To avoid that equalization tank gets filled with sands and, above all, an early wearing of all electro-mechanical components installed into the plant ( impellers, valves, screens etc.) , Sdg Depurazione offers its own sanding removal system.

    The process takes place thanks to the slow rotation of a shaft moved by a central gearmotor ; the shaft is provided with two scrapers which maintain all the liquid contained into the tank in a gentle stirring , while the sloped bottom of the tank helps the settling itself.

    The process is enhanced also by the particular structure of the upper part ( the so- called baffle cylinder ).

    Fundamental components of the unit are :

    Baffle cylinder , in Stainless Steel AISI 304

    Central shaft with scrapers driven by a gearmotor

    Thomson profile-shaped gate in Stainless Steel AISI 304

    The thickened sands are taken out of the tank by a proper pump periodically.

    They can be sent either into draining bags or directly into sludge stabilization  tank to be disposed of.

    The water, from which most of the sand has been taken away, flows then into equalization tank.

  • Dosers And Preparators

    To increase their performance, some treatments, for example the flotation and the sludge dehydration, they may require the addition of a polyelectrolyte. This product has to be prepared without lumps and with the correct concentration. Powder dispensers and preparators of SDG depuration are needed to prepare the polyelectrolyte in an optimal and completely autonomous way thanks to level probes and security systems. The supporting structure is entirely made of AISI 304 stainless steel. The three-helix mixing system is able to ensure effective dissolving even by high polymer concentration, which can be a liquid or powder product. The maximum volume of measurable polymer is 1500 l/h and the dosage is carried out via a programmable dosing machine.

    The models currently in production are the three-tanks DPP 1800 for large capacities and the two-tanks DPP 1800.



    N° agitatori

    Kw agitatori

    Kw coclea

    Portata max

    DPP 1800




    1500 l/h

    DPP 1000




    1000 l/h

  • Dynamic Stretchers

    The excess sludge coming from biological oxidation hasn’t got the characteristics necessary to be sent directly to dehydration: in fact, to be treated in a filter press or in a tape press it is necessary to dry at least 2%, instead the excess sludge has a degree of dryness between 0,8% and 1,5%. Before de dehydration, it must undergo a pretreatment to reduce the amount of water inside it.

    About this SDG depuration propose the dynamic stretcher. Inside a sloped bottom tanks, a shaft mounted on a gearmotor rotates slowly, keeping the fluid volume moving slightly. The mechanical arms break the sludge flakes releasing gas and water inside. The movement takes place in such a way as to allow the stratification of mud, which is easily removed from the bottom, results more dense and homogeneous.



    ID 2000

    ID 3000

    ID 4000

    ID 5000

    ID 6000

    ID 7000

    ID 8000

    Raggio braccio mobile mm








    Potenza kW

    Da 0,75 a 2,0


  • Filterpress

    Dehydratation by pressure filtration is achieved by a filter press  made up  of a series of vertical plates inside a rigid structure.


  • Flat table

    The flat table device is used in sludge dehydration and uses the principle of gravity drain allowing to concentrate up to ten times the content of suspended solids contained in wastewater.
    It can also be used as a pre-thickener combined with other dehydration methods when you wish to increase the flow rates and the percentage of requested dry.
    The flat tables produced by Sdg Depurazione are made of stainless steel and are complete with all devices (reactor, plows, cloth washing system, etc..) in order to ensure the proper  operation of the equipment.

  • Flotation unit

    Clarification by flotation can be used  alternatively to clarification by gravity

    Dissolved air flotation is a  method  for separating and removing  suspended solids from liquid, based on changes in the solubility of gas as pressure varies.

    Air is dissolved under pressure in a clean liquid, usually recycled effluent from the Daf unit, and injected into the  raw fees stream.  Upon entering the DAF unit, the air pressure is  released and combined with the liquid, which becomes supersaturated with micron.sized air bubbles.

    Suspended materials attach to the anionically-charged, micron-sized air bubbles producing a lower specific gravity for the agglomerate less than that of water, thus effectively raising the suspended particles to the liquid surface, forming a floating sludge layer that is removed by skimmers. Heavier solids settle to the bottom of the tank and are raked to a sludge pocket for removal. Clear subnatant liquid  is withdrawn under the tank baffle and over the weir for disposal  or re-use.

  • Membrane filtration

    Sdg Depurazione is able to supply, according to which extent the removal has to be pushed, microfiltration, nano-filtration and reverse osmosis plants.

    Membrane filtration is a pressure-driven technology able to separate molecules of different size, ranging from some microns to few nanometers. This kind of treatment splits the incoming flow into a fraction free from the unwanted pollutants (salts, paint pigments, oil emulsions etc.) called "permeate" and another one, enriched with all these contaminats called "concentrate".

  • Microscreening

    Micro-screening, when used, is installed after the initial screening of large debris. It serves to the remove smaller solids still present in the influent.

    Drum-type rotating screens are used. All drum screens are made entirely in Stainless steel.


    MODELLI GRT 600 GRT 800 GRT 1000
    Diametro tamburo mm 600 800 1000
    Portata mc/h 20-30 30-40 40-60
    Potenza motoriduttore kW 0,75 0,75 0,75
  • Ozone

    Ozone is one of the most powerful known Oxidants. It’s capabilities have been recognized for over 100 years and it is used extensively in the purification of water throughout the world.  Several installations if cooling towers with ozone provided the following benefits :

    ·         Reduction or elimination of chemicals needed Bacteria/virus elimination/prevention;

    .     Organic built-up elimination/prevention;

    ·         Reduction  biofilm (inorganic pollutant for legionary’s feed);

    ·         Elimination of  scale and improvement of energetic yield;

    ·     A small quantity of this effective biocide reduces by about 40% to 80% the renewal, usually necessary to compensate the increase of suspended solids;

    ·         Reduction of  maintenance;

    ·         Reduction of chemicals handling such as chlorine,  sulphuric acid, bactericide, galvanized compounds;

    ·         Towers ‘ dilution water   doesn’t contain either chlorate and organic elements  or salt, and no risk for waste water treatment plants;

    ·         Ozone is a natural disinfectant and decomposes  as oxygen with no residual, a solution for the sustainable development.

    Energetic yield for a better operation of heat exchangers, compressors‘ consumption reduction by abut 30% (in kW/kg of air) by air temperature lowering from 20 to 30°C.

    With a good application, ozone for disinfection is 3000 times  more efficacious  than chlorine and with a larger spectrum.

    In galvanic and non exchangers, water treatment with ozone  reduces corrosion rate if compared to disinfection solutions with chlorine or its derivatives. The biofilm elimination, important corrosion source, allows a superficial micro-oxidation.

  • Peripheral traction bridges

    Settling tanks, whose diameter is more than 5 meters and normally made in concrete, are provided with a peripheral traction bridge to recollect the settled sludge.

    This bridge is made up of a strong , AISI 304 stainless steel framework of girders. It is pivoted on a bearing mounted on the central supporting column and is leant against the tank edge on a dragging trolley.

    The dragging trolley is provided by a gear motor and rubber wheels leaning on the tank edge , which becomes the rolling track for the trolley itself.

    The linear speed of the bridge on the track is around 1 m/min. On the bridge girder are anchored the steel deflection cylinder , the bottom scraper featuring a continuous , logarithmic curve – shaped profile and scrapers profiled in special rubber , as well as a skimming blade with a compensator tip to discharge  the floating solids into the relevant scum box.

    On the outer circumference of the tank are located the Thomson – profiled spillway rim to discharge the clarified waters and a fixed, scum stopping blade to hold back the floating substances.

    The galvanized walking grate is fitted up with side parapets.

  • Reverse osmosis and ultrafiltration

    Sdg Depurazione supplies reverse osmosis systems according the its customers specific requirements in terms of final quality of water discharge

    Ultra-filtration is a analagous process that takes place with equipment similar to that used for reverse osmosis.  In both applications are used particular membranes , able to split the incoming flow into a concentrated rejected fraction and a pure , salts-free re-usable water.

    Reverse osmosis significantly reduces salts, most other inorganic material present in the water, and some organic compounds. 

  • Sand and carbon filtration

    The most common filters are filled with granular media such as sand/anthracite .
    Filters are completely enclosed to use the line water pressure to push the influent through the media.
    Sdg Depurazione offers a wide range of filters of different types and dimensions. Some of them are made entirely of Stainless Steel and can be operated  either manually or automatically.
    Sand filtration foresees using quartz sand , highly hard , whose granules dimensions can vary between 0.7 and 8 mm ; widely used filtration on beds with different granules size.
    Filtered water is virtually suspended solids-free.
    Sdg Depurazione filters have diameters up to 2000 mm , height up to 3500 mm and flows up to 50 mc/h; they are provided with a counter washing system.
    With the same Stainless Steel vessels , downstream sand filtration itself , the GACadsorption technology can be used. Activated Carbons can be either from mineral or vegetal raw matter.

    Thanks to their huge inner surface, one can stop several pollutants that you could not get rid of in other alternative ways, such as surfactants, dyeing molecules and many other organic compounds.

  • Screening

    Screening is a mechanical operation which allows the removal of solid matter contained into water to be treated.

    It is a pre–treatment which takes away pollutant solids whose dimensions exceed a certain size . It is the first step in a wastewater treatment process able to remove trash and debris carried by the water, such as wooden pieces, rags,paper, leaves and similar.

    Sdg Depurazione offers a large range of screens , The commonest ones are the rotating brush type ( GSR models ),, located into the duct which carries the waste to the plant , suitable for low and medium depths , and the inclined plane type ( GCV models ) , which allow the displacement of the screened solids and fit to be installed into deeper reinforced concrete canals , as well as where a hydraulic uplift is foreseen.

    The installation of such machines depends on operating working conditions of the Client and takes into account kind of matter to be removed , water speed , maximum and minimum flow and so on.

    All models are entirely manufactured in AISI 304 and /or AISI 316 Stainless steel. 

    More precisely , GSR models are thought to be installed in reinforced concrete ducts but, upon request , are available in a different arrangement for external installations , featuring a stainless steel tank.

    The screen slots can be rectangular ( mm 2 x 20 ) or circular ( diameter 5 mm ).

    On the other hand GCV screens are fit to be positioned into deeper reinforced concrete canals and are provided with a cleaning system ( brush or water sprays system ) and come with a screen whose slots are rectangular ( mm 2 x 20 ) or circular ( diameter 5 mm ).

  • Uv Light Disinfestation

    With an appropriate doses of UV rays, they shows an efficient bactericidal and virucidal power.Using an appropriate gap of radiation, the UV rays are able to sink in the cellulose wall: into the microorganisms, the radiation inhibits the cell replication and as a result it causes its die. In this way, it is possible to purify the waters from the bacteria and microorganisms. The UV rays don’t cause problems of overdose and they don’t alter the water organoleptically, but they only act on exposed bacteria and not those nested in microscopic organic particles, therefore this treatment must be preceded by a filtration.

17 Item(s)