مراحل معالجة الصرف الصناعى والصحى

Wastewater Treatment Applications

by

general.dr

bahaa badr

technolab el-bahaa group

Primary treatment
Inlet pumping station
Biological treatment
Tertiary treatment
Chemical treatment
Sludge treatment

Primary treatment

Overview

Screening station

Raw wastewater has a high content of large materials, such as toilet paper, textiles, napkins, as well as plastic bags, pieces of wood. Such materials must be removed as the first part of the treatment process, not least to prevent clogging and possible malfunction of mechanical equipment at the wastewater treatment plant.

The screening station is therefore the first step in the mechanical treatment of wastewater.

Effective washing of the detained material will reduce the amount of disposal significantly and prevent odour problems.

we offers pump and control solutions for the effective backwash of the screens, ensuring reliable operation of your screening station.

our Hydro MPC range of multistage pressure boosting systems means you can manage your pressure zones with ease, and together with our range of level sensor accessories will ensure effective washing of the entire screening station.

Sand, grit and grease removal

Once wastewater has been screened for the removal of large materials, mechanical treatment’s next step is the removal of grit and grease. Removing these prior to commencing biological treatment of wastewater is essential for ensuring the smooth operation of the wastewater treatment plant.

The usual solution is an aerated grit and grease chamber, where aeration operates continuously to keep organic matter in suspension while grit and grease is removed through sedimentation and floatation.

If sand and grit are not removed and continue to the primary clarifier or even further in the plant, a significant increase of clogging and wear on equipment could result.

Removal of grit requires robust and durable pumps.
our ranges of SE/SL and S pumps with vortex impellers are specifically designed for durable use with heavy sewage flows and can be installed dry or submerged.

They offer the reliability you need to ensure safe operation.

Diffuser systems from Grundfos offer fine or coarse bubble diffusers for large air flows for the separation processes of the grit and grease removal.

Equalisation tank

The equalisation tank is where excess wastewater can be stored during heavy rain. Equalisation tanks can be an effective way of cost-optimising the wastewater treatment plant as this allows for the construction of smaller tanks for treatment and ensures a steady hydraulic load through the plant.

we offers a range of pumping and control solutions as well as mixers and cleaning equipment that together ensure reliable and automatic operation of the stormwater tank.

Once the hydraulic load is reduced and capacity is available, you can get wastewater moving again with perfect efficiency.

Stormwater tanks can be built to almost any size and shape. The inlet and outlet can be managed by gravity, by a pump system or a combination of both, depending on hydraulic conditions in the system.

we has the pumps to cope with these heavy demands.

our ranges of SE/SL, S and KPL/KWM pumps are specifically designed for durable use with heavy flows and can be installed dry or submerged.

our range of level sensor accessories ensures that your pumps system can control possible fluctuations in demand for performance.

This ensures the optimum delivery of wastewater to and from the equalisation tank.

Efficient mixing and cleaning of equalisation tanks is essential to minimise operation costs avoid odour problems.

our range of RainJets is especially designed for this purpose, offering a robust construction and easy service and maintenance.

The RainJets can work either alone or together with the robust and durable AMD mixer.

Control and monitoring systems increase the potential for improving both efficiency and reliability.

Primary clarification

Following mechanical treatment, the purpose of primary clarification is to reduce the organic load prior to biological treatment.

Simply by letting particles settle by gravity, a significant part of organic impurities in wastewater can be removed, and this is a cost-effective way to reduce the size and cost of biological treatment.

It is important to create optimal conditions for settling under primary clarification, and therefore the flow conditions and water velocities are designed to favour sedimentation.

The settled matter resulting from primary clarification is referred to as primary sludge, which is then pumped from the primary clarifiers to sludge treatment.

The ranges of SE/SL and S pumps with vortex impellers are specifically designed for durable use with heavy sewage flows and can be installed dry or submerged.

Chemicals and poly-electrolytes can be added to increase efficiency and improve sludge settling, helping remove up to 80% of the suspended matter.

we can supply complete dosing pumps systems for large or small volumes and based on different technologies for precipitation and flocculation and pH adjustment, and PLC-controlled, fully automatic systems to handle preparation and the reliable dosing of organic coagulants or poly-electrolytes.

wecan supply the specialist expertise to help meet your performance objectives, from the initial identification of needs, to the selection, installation, operation, and maintenance of the pumping and dosing solution.

we commissioning agreements ensure correct installation and service agreements cover all eventualities, from routine maintenance to spare parts.

Inlet pumping stations

Overview

The wastewater entering at a wastewater treatment plant’s inlet pumping station contains all substances that have entered the sewer system.

This is not only what we flush down the toilet, but also industrial effluents, wastewater from hotels, hospitals and restaurants, and substances drawn directly into the sewer system through manholes.
we has the pumps to cope with these heavy demands.

The ranges of SE/SL, S, and KWM pumps are specifically designed for durable use and heavy sewage flows and can be installed dry or submerged.

If the design of the pump sump does not prevent sedimentation, the Grundfos range of robust AMD mixers ensure full mixing and thereby ensure trouble-free operation and prevent odours.

The inlet pumping station involves great fluctuations in demand for performance.

With multiple inlet pumps installed, adding external variable speed drives (Grundfos CUE) will equalize the hydraulic load to the wastewater treatment plant.

Computational Fluid Dynamics (CFD) simulations at the design phase helps ensure the optimum delivery of wastewater through the inlet pumping station for mechanical treatment by visualising hydraulic conditions at the pumping station.

Control and monitoring systems increase the potential for improving both efficiency and reliability.

In addition to variable speed drives, Grundfos supplies motor protection (MP204) to monitor motor conditions, ensuring optimal operation.

we can supply the specialist expertise to help meet your performance objectives, from the initial identification of needs, to the selection, installation, operation, and maintenance of the pumping solution.

we commissioning agreements ensure correct installation and service agreements cover all eventualities, from routine maintenance to spare parts.

Biological treatment

biological treatment

Overview

Biological treatment is the most commonly used method for additional treatment of wastewater to remove high amounts of organic matter and nutrients following mechanical treatment and is one of the largest and most expensive elements at a wastewater treatment plant.

The activated sludge process that is most common in biological treatment utilises the growth of specific floc-forming bacteria that live suspended in the wastewater.

To create optimal conditions for the bacteria, a certain retention time for wastewater and sludge is necessary for the biological processes to take place.

During biological treatment, bacteria circulate between different process zones which provide them with specific living conditions.

The different zones use aerobic, anoxic and anaerobic conditions utilising different biological processes for the removal of organic matter and nutrients, such as Nitrogen and Phosphorous.

For circulation of wastewater between these zones the SRP recirculation pumps keep vast flows at low head moving reliably.

To avoid settling of the bacterial flocs AFG flowmakers offer an optimum, energy-efficient solution for mixing in big tanks, creating a bulk-flow with an almost uniform flow-velocity and limited risk of dead zones.

For aeration of wastewater during biological treatment Grundfos offers fixed or retractable systems of fine bubble diffusers for efficient oxygen transfer.

The self-aspirating AeroJet is made from stainless steel and is also available for aeration of wastewater, which handles both mixing and aeration.

Where tank design doesn’t allow the use of flowmakers, Grundfos AMD and AMG mixers offer a robust design with corrosion resistant materials, easy service and maintenance, and trouble-free operation in difficult environments.

Recirculation of sludge from the secondary clarifier to the aerobic tank is a key process of the activated sludge process.

This can be reliably handled with the ranges of SE/SL, S, and KPL/KWM pumps, which are specifically designed for durable use and flow management, and can be installed dry or submerged.

Variable speed drives ( CUE) can be added, depending on the specific control strategy at the treatment plant.

we can supply complete dosing pump systems for large or small volumes, based on different technologies.

These pumps can be used for pH adjustment in the process tank and for substrate dosing, for example to keep biological phosphorous removal and de-nitrification running.

Secondary clarification

Following biological treatment, the treated water must be separated from the activated sludge, which is done in the secondary clarifiers.

The activated sludge is slightly heavier than water and separation is achieved by letting the sludge flocs settle by gravity, which is aided by design of the clarifier to ensure low turbulence and velocity.

The ranges of SE/SL or S pumps with a vortex impeller can handle a dry matter concentration of up to 5% for the return pumping of sludge.

Variable speed drives ( CUE) can be added, dependent on the specific control strategy at the treatment plant.

The majority of the settled sludge is then returned to the process tank to be utilised one more time, and an amount equal to the daily production is pumped to sludge treatment.

Recirculation of sludge ensures that a certain sludge age is attained which accounts for its ability to clean the wastewater effectively.

Chemicals and poly-electrolytes can be added, to induce coagulation and improve sludge settling.

we can supply complete dosing pumps systems for large or small volumes and based on different technologies for precipitation and flocculation and PLC-controlled, fully automatic systems to handle preparation and the reliable dosing of organic coagulants or poly-electrolytes.

Grundfos has the specialist expertise to help meet your performance objectives, from the initial identification of needs, to the selection, installation, operation, and maintenance of the solution for your process tank.

Computational Fluid Dynamics (CFD) simulations can be used to optimise the total hydraulic solution for aeration and mixing.

we commissioning agreements ensure correct installation and service agreements cover all eventualities, from routine maintenance to spare parts.

موضوع: tertiary treatment السبت مارس 10, 2012 10:23 am

tertiary treatment

Discharging purified wastewater to a sensitive area or using it for irrigation requires tertiary treatment such as filtration and/or disinfection, in what is called the polishing phase for waste water.

we can supply pump systems for the varying demands of this stage of wastewater treatment.

Sand filters are the most commonly used technology but other technologies such as drum filters and membranes can also be used for filtration.

Whatever the filter technology applied, reliable flow and pressure must be maintained by the pumps system for both feeding and backwashing the filters.

Particulate matters are retained in the filter through straining, adhesion and interception.

The retained matter will increase the pressure loss in the filter and has to be removed either continuously or when the pressure drop reaches a given limit.

Centrifugal pump systems available in a range of flow capacities and for dry or submerged installation ensure the correct feeding of the filters.

The Hydro MPC range of multistage pressure boosting systems means sufficient pressure for backwashing is available.

Following filtration, the water can be disinfected before discharge.

we can supply complete dosing systems for large or small volumes and based on different disinfection technologies.

our disinfection systems can be tailored to your needs and dosing requirements.

Disinfection is used in the treatment of wastewater to substantially reduce the number of microorganisms and thereby increase effluent quality.

Used today in most wastewater treatment plants, chemical treatment is highly effective for the job at hand.

With a range of electronic accessories we offers a complete control of your dosing and disinfection processes can be seamlessly integrated into your system.

we has the specialist knowledge to do this and can tailor a dosing station utilising chemicals as either concentrates or ready-to-use solutions, according to your requirements, the relevant safety procedures, chemical storage, and your existing system.

Traditionally, chlorine compounds are the most widely used method for chemical disinfection of wastewater.

we can advise and supply disinfection solutions using chlorine compounds such as chlorine gas (Cl2), sodium hypochlorite (NaOCl), and chlorine dioxide (ClO2).

Control and monitoring systems increase the potential for improving both efficiency and reliability.

we can supply the specialist expertise to help meet your performance objectives, from the initial identification of needs, to the selection, installation, operation, and maintenance of the pumping solution and dosing system.

we commissioning agreements ensure correct installation and service agreements cover all eventualities, from routine maintenance to spare parts.

Chemical treatment

is an aspect of the entire treatment of wastewater and is used in most wastewater treatment plants to increase effluent quality and ensure optimal living conditions for bacteria.

The selection of the chemical methods used depends on the effluent requirements and mainly includes chemical precipitation for the removal of phosphorous and for pH regulation.

Other uses include adding an external carbon source, if availability of carbon is a limiting factor for the biological conversion of nitrate to nitrogen.

Because of the harsh nature of many of the chemicals used, a dosing station must be designed according to the specific chemicals.

This is done with regard to the relevant safety procedures as well as to the design of chemical storage, dosing pumps, mixers and piping.

we has the specialist knowledge to do this and can tailor a dosing station utilising chemicals as concentrates, ready-to-use solutions or dry chemicals, according to your requirements, the relevant safety procedures, chemical storage, and your existing system.

we can supply the specialist expertise to help meet your performance objectives, from the initial identification of needs, to the selection, installation, operation, and maintenance of the pumping solution and dosing system.

we commissioning agreements ensure correct installation and service agreements cover all eventualities, from routine maintenance to spare parts.

موضوع: معالجة المخلفات السبت مارس 10, 2012 10:45 am

sludge treatment

Sludge is a bi-product from treatment of wastewater at any traditional wastewater treatment plant, and while treated water can be discharged to the receiving waters according to the requirements in the discharge permit, handling sludge treatment is more complicated.

Generally, final disposal will be utilisation as fertiliser on farmland, deposition at waste disposal sites, or incineration onsite or at an external partner, often as part of energy generation.

Sludge pumping requires equipment that can keep viscous media moving – without becoming clogged.

Primary sludge needs to be pumped from the primary clarifiers to the sludge treatment, and the sludge pumping station requires careful selection of the pumps, depending on the sludge content and flow.

Centrifugal pumps like the ranges of SE/SL or S pumps with vortex impellers are often used and are designed for durable use in difficult environments.

For sludge pumping, dry installed pumps are preferred as this allows frequent inspection and easy maintenance.

Control and monitoring systems increase the potential for improving both efficiency and reliability.

we supplies external variable speed drives (Grundfos CUE), motor protection (MP204) to monitor motor conditions, ensuring optimal operation.

Sludge thickening/dewatering

The main purpose of sludge thickening/dewatering is to minimise the volume of the sludge, thereby reducing the required size and capacity of subsequent treatment processes and equipment.

Furthermore, a decrease in water content reduces energy consumption for heating the sludge in the digester.

The efficiency of the dewatering depends on the type of equipment and sludge quality.

we can supply PLC-controlled, fully automatic systems to handle preparation and the reliable dosing of organic coagulants or poly-electrolytes.

we has the specialist knowledge to do this and can tailor a dosing station utilising chemicals as concentrates, ready-to-use solutions or dry chemicals, according to your requirements.

Sludge can be dewatered directly from a concentration tank or sludge storage tank.

Usually, sludge is thickened by gravitation in a sludge concentration tank or by mechanical dewatering in simple dewatering units, and quite simply involves removal of water from the sludge.

Poly-electrolytes can be added to enhance formation of large sludge-flocs.

Removing the water is handled with the ranges of SE/SL and S pumps, which are specifically designed for durable use and flow management, and can be installed dry or submerged.

The tanks can be equipped with a low-speed AMG mixer in order to secure a homogeneous sludge concentration.

our mixers offer a robust design with corrosion resistant materials, easy service and maintenance, and trouble-free operation in difficult environments.

Sludge digestion

Sludge is often treated using a variety of digestion techniques, the purpose of which is to reduce the amount of organic matter and the number of disease-causing microorganisms present in the solids.

Today, digesters are relatively easy to operate, and despite the relatively high temperatures required in the sludge digestion process, a retention time of 25 to 30 days is required.

A low-speed AMG mixer can be used in this process.

Due to biological degradation of organic material, biogas will be produced in the system. The biogas can be utilised in a Combined Heat and Power (CHP) system, where it produces heat and electricity.

For large wastewater treatment plants, anaerobic digestion is the most widespread method for sludge treatment.

Anaerobic digestion results in a further degradation of the sludge under anaerobic conditions, reducing the total organic content of the sludge by up to 40 to 60%.

After digestion, a final dewatering will take place.

The dewatered sludge has to be disposed of in a secure way, for example by incineration for energy generation.

we can supply the specialist expertise to help meet your performance objectives, from the initial identification of needs, to the selection, installation, operation, and maintenance of the pumping solution.

we commissioning agreements ensure correct installation and service agreements cover all eventualities, from routine maintenance to spare parts.