Station for sewage sludge 15 m3/h
In the accompanying FLOWCHART schematically treatment plant designed for a production of glazes and colors, the design flow is 15 m3 / h.
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| EOutline treatment system of industrial wastewater for 15 m3/h |
Line of physical-chemical treatment: lamellar settler
The waste water is pumped from a raft of accumulation, where it is recommended to install a homogenization system (A 1.0.2.) To prevent settling of heavier particles in the interior thereof. In this pond, install a submersible pump (P 1.0.0.) To deliver the wastewater to the system of coagulation-flocculation. This pump is driven by a float level control (B 1.0.1.) When the level exceeds that determined raft, and stops when the level of the pond is minimal.
The physico-chemical treatment system consists of a coagulation / flocculation. Addition of reagents the following order: adding a product to adjust the pH, a coagulant and a flocculant. For this system has to foresee three metering pumps for addition of coagulant (P 2.2.1.), Flocculent (P 2.1.1.) And pH control (P 2.3.1.). Moreover it has to have a system for preparing the floculate, consisting of a tank (2.1.) and stirrer (M 2.1.0.) To facilitate dissolution and homogenization of the reagent.
A digital controller of pH (2.4.) Controls the addition of sodium hydroxide, in order to maintain the pH to facilitate the coagulation-flocculation and to avoid degradation of the machines after reuse water.
Coagulation was carried out in a settling chamber designed for this purpose with rapid stirring. The flocculation is also performed in the settler in a chamber larger than the coagulation and with slow stirring by a gearmotor.
The lamellar clarifiers (2.0.) Are constructed of stainless steel AISI 304, electro-welded oxicortados and on standardized perfilerías reinforcements also made in AISI 304. For a system debug 15m3 / h, has an internal volume greater than 20 m3. The lamellae are square or hexagonal geometry is to reduce turbulence and facilitate sedimentation. With this type of lamellae, the lamellar surface is m2/m3 16,388, with a hydraulic diameter of 35.
The treated water (purified) is fed by gravity into a water receiving tank for reuse or to a tertiary process, eg, an ion exchange.
The decanter has a timer valve for removing sludge and subsequent conduction line sludge treatment.
Line treatment of sludge: sludge thickener and filter press
In a filter press sludge dewatering is achieved to reduce significantly the percentage of moisture in the dewatered sludge (cakes), to a large extent by reducing the amount of waste to be managed.
A pneumatic pump (P 4.0.1.) Drives the sludge to sludge thickener (4.0.), Which concentrates, increasing the quantity of solids. This silo is designed to concentrate thickener and sludge accumulate for later filtering in the filter press. For a cleaning system 15 m3 / h, the silo thickener must have a capacity of 9 m3 and a height of 6.9 m. In the raised portion of the silo thickener and overflow water is recirculated to the raft of accumulation. This silo thickener is made of stainless steel AISI 304.
A tire pressure group (P 4.0.2.) Feeds the filter press by the silo timed purges sludge thickener. The cakes produced in the filter press (5.0.) Fall into a container to be managed and filtered water from the pond is recycled to the homogenization of wastewater.
 | Line treatment of wastewater purification system for a lamellar flow of 15m3 / h. It consists of the coagulation and flocculation chambers, lamellar clarifier, dosing pumps coagulant and flocculant tank agitation for proper preparation. It also has a pH control for the proper dosage of soda, as is a control parameter. This system is a compact system debugging, as the raft of homogenization is buried beneath the lamellar sewage. |
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 | Line treatment of sludge: sludge thickener and filter press. Silo consists of a sludge thickener or compactor about 7 meters high, its output below pneumatic pump and a filter press. The filter press consists of 19 plates chamber with dimensions of 800 x 800 mm. |
Sewage sludge station 350 m3/h
In the attached FLOWCHART schematically represents the system of sewage treatment for a flow of 350 m3/h.
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| Outline treatment system of industrial wastewater to 350 m3 / h |
Line of physical-chemical treatment: Settling circular sludge scavenger
The waste water is pumped from a raft accumulation buried in the system is installed a homogenization to prevent settling of heavier particles in the interior thereof. In this pond, install a submersible pump that supplies water to the system residual coagulation / flocculation. This pump is driven by a float level control when the level exceeds that determined raft, and stops when the level of the pond is minimal.
The physico-chemical treatment system consists of a coagulation / flocculation. Addition of reagents the following order: adding a product to adjust the pH, a coagulant and a flocculant. For this system has to foresee three metering pumps for addition of coagulant and flocculant pH control. Moreover it has to have a system for preparing the floculate, consisting of a tank and a stirrer to facilitate dissolution and homogenization of the reagent.
A digital controller of pH (2.4.) Controls the addition of sodium hydroxide, in order to maintain the pH to facilitate the coagulation / flocculation and to avoid degradation of the machines after reuse water.
Coagulation was carried out in a settling chamber designed for this purpose with rapid stirring, regulated by an inverter. The flocculation is also performed in the settler in a chamber larger than the coagulation and with slow stirring by a gearmotor.
The decanter designed for this flow has a diameter of 11.75 m and a surface area of ??110 m2. It consists of a semi-flat-bottomed cylindrical tank which is equipped with a scraper on the inside (bottom also scavenger lladamas), arranged so that made a complete sweep of the sludge, leading to the center where they are extracted.
The raw water and coagulated and flocculated are sent to the central bell, which separates the liquid from the mud. By means of a peripheral overflow, water-free solids, the tank overflow of treated water for reuse.
These teams are characterized by their robustness, large area and high sedimentation and consequently obtain high density sludge with a minimum consumption of flocculant.
Sludge treatment line: filter press
Due to compaction of the sludge undergoing the treated water, and depending on the characteristics of the incoming water purification in these systems is not necessary to install a silo sludge thickener. A tire pressure group feeds the filter press by timed purges sludge thickener. For a flow of 350 m3 / h, are designed with a press filter 40 of cam plates, with a size of 1000 x 1000 mm each.
The cakes produced by a filter press fall into a container for subsequent management. The water from the filtration is recycled to the raft homogenization of waste water.
 | Circular clarifier operation. In the center of the image settler dons the hood is introduced coagulated and flocculated water, and is also the overflow channel through which separates the decanted water (purified). |
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 | Aerial installation of a purification system comprising two circular clarifiers where the system is scavengers sludge (square blades). |
Characterization of effluents
Optimized depending on what is found the system for treatment of waste water, purified water present the removal of contaminants in a more or less effective. For systems with optimal performance is achieved elimination of:
- Heavy metals: 92 - 97 %
- Suspended solids: 90 - 95 %
Reuse of treated watewater
The quality of the wastewater collected will define the uses that it can be made. In the circuit in which the purification system is part of the circuit itself requires further purges aimed at controlling salinity in appropriate values, water is continuously reused.
The treated wastewater from conventional industrial processes, often used in housekeeping: cleaning floors, cleaning of equipment or tanks, ....
The final destination of such treated water will be the authorized management or disposal. To pour the wastewater must comply with relevant legislation and have discharge permit issued by the competent body vary depending on the point of discharge.
| Pour Point | Competent body |
| Sewerage | Owner sewage drainage network. City council |
| Public water catchment | Basin Confederation |
| Sea | Ministry of Environment |
| Direct discharge to the WWTP | WWTP Owner |
Physical processes in physical-chemical treatment of wastewater
Sedimentation
Subsequent to the treatments pH adjusting chemicals, coagulation and flocculation is performed by sedimentation or decantation. Is to reduce the sedimentation velocity of the fluid, increasing the passage area, favoring the fall by gravity from the heavier particles (particles coagulated and flocculated later). There are basically three types of sedimentation depending on the geometry of the settler. Sedimentadotes are rectangular, circular and sedimentadotes sedimentadotes lamellar. Besides the circular sedimentadotes are divided into two subtypes, circular conical settlers and settlers scavenger circular background. We will see each of them. - Rectangular settler: Usually have a system of blades at the bottom of the decanter for sludge collection. Today the system remains in use, since the rectangular geometry favors accumulation of sludge in the corners.
- Circular sedimentator: The water inlet is usually performed through the center of the decanter, the output of the clarified water is evacuated by a weir at the top perimeter of the decanter, and removal of sludge is effected by the lower central part of the decanter. Circular settler are divided into two subsets according to the method of extracting sludge.
Settlers circular cone: Also known as scrubbers conical. Possess two parts or body essentially the cylinder and cone. In the cylinder is effected in the cone decantation and the accumulation of sludge. To favor removal of sludge cone should be designed with a minimum slope environment to 55-60%.
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| Circular conical settler |
Sweeping circular clarifiers sludge: Also known as thickeners. Are used in industries with high flow rates in excess of 100 m3 / h approximately. The sludges are extracted by the conical bottom of the decanter through a system of rotating scrapers. In the ceramics industry commonly used in plants for cutting, grinding and polishing, since high flow rates are generated suspended solids.
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| Circular clarifier bottom scavenger | Circular clarifier sludge scavenger |
- Lamellar settler: Also known as sewage lamellar or lamellar settler. The lamellar clarifiers are most currently used in the industry with low flow rates, to approximately 100 m3 / h, depending on the space provided on the premises and the concentration of suspended solids from wastewater.
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| Lamellar settler or decanter |
The lamellar sedimentation is based on the application of physical laws incorporated in the generation of laminar regimes in fluids, increasing the settling velocity of the particle to descend the turbulent regime. Besides the lamellae are inclined in order to increase the contact surface between the lamella and the fluid anticipating the fall of the particle. The settling velocity depends on the type of lamella, square, hexagonal or tubular, and the pitch distance.
Lamellar decanters accelerate the precipitation of settleable solids with respect to traditional systems decanting, thus achieving a saving of space around 30-50%.
Sludge treatment process generated by physical-chemial process
The sludge generated as a result of treatment processes carried out physico-chemical waste water must be separated from industrial effluents and managed properly. Treatment facilities wastewater have a suitable devices to achieve the discharge of the sludge.
The sludge produced by the companies can can take different actions:
- Companies without compacting device / drier sludge: the sludge can accumulate on a raft enabled for at purpose until the volume justifies the move by truck Cuba for its management.
- Businesses with compactor device / dehydrator own: the udge generated passes to a thickener (compactor) that manages to increase the content of suspended solids (the density increases) and said structure is fed from a suitable dehydration system, allowing manipulating said sludge dry.
The primary compaction system is a cone sludge thickener, which, like the sedimentadires circular conical, has two part body and the cylinder or cone. The sludge enters the top and be compacted by gravity. There is a separate water extraction by the top and a drain that goes to the dryer by the bottom.
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| Sludge silo compactor prior to a filter press |
There are various sludge dewatering systems: filter presses, belt filters, centrifuges, .. In a filter press sludge dewatering is achieved to reduce significantly the percentage of moisture in the dewatered sludge (cakes), to a large extent by reducing the amount of waste to be managed.
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| Filter press for sludge treatment |
