Using membranes to separate sludge ensures higher quality treated water free from suspended solids. Membranes can retain activated sludge at high concentrations (MLSS), resulting in more efficient BOD and nitrogen removal (higher solids retention time).
Full Answer
What is a package wastewater treatment plant?
Package plants are pre-manufactured treatmentfacilities used to treat wastewater in smallcommunities or on individual properties.Accordingto manufacturers, package plants can bedesigned to treat flows as low as 0.002 MGD or ashighas 0.5 MGD,although they more commonlytreatflows between 0.01 and 0.25 MGD (Metcalfand Eddy, 1991).
What happens during the settling phase of a wastewater treatment plant?
Some aeration may occur during this phase. Then, in the react phase, the basin is aerated, allowing oxidation and nitrification to occur. During the settling phase, aeration and mixing are suspended and the solids are allowed to settle. The treated wastewater is then discharged from the basin in the decant phase.
How much flow can be treated in a package plant?
According to manufacturers, package plants can be designed to treat flows as low as 0.002 MGD or as high as 0.5 MGD, although they more commonly treat flows between 0.01 and 0.25 MGD (Metcalf and Eddy, 1991).
What are the tertiary processes in wastewater treatment?
The tertiary processes form a group of operations pursued at the end of the wastewater treatment to achieve particular objectives. Wilson (1981) puts several different operations in this category: solids removal, disinfecting and nutrient removal.
How do you remove solids from wastewater?
Sedimentation processes are very effective in removing suspended solids in industrial wastewater. Clarifiers, either rectangular or circular, are most commonly used in the application of sedimentation in wastewater treatment facilities.
What happens to the solids in wastewater treatment plant?
The process occurs when a wastewater treatment plant is operating properly. Most solids in the wastewater will be removed at the plant, while the water is discharged as effluent to the receiving waters. These solids, or sludge, must be stabilized and reduced in volume before they can be reused or disposed of.
What steps are involved in solids treatment?
Treatment StepsStep 1: Screening and Pumping. ... Step 2: Grit Removal. ... Step 3: Primary Settling. ... Step 4: Aeration / Activated Sludge. ... Step 5: Secondary Settling. ... Step 6: Filtration. ... Step 7: Disinfection. ... Step 8: Oxygen Uptake.
What are other options for dealing with solids sludge )?
There are various options for treating sludge including stabilization, thickening, dewatering, drying, and incineration. The costs for treating sludge and removing sludge from wastewater are roughly the same. Typically a polymer chemical is used for the volume reduction process known as dewatering.
What is done with the solid waste that is accumulated during preliminary treatment?
The incoming wastewater is passed through the bars or screens and periodically the accumulated material is removed. The racks or screens may be cleaned either manually or by means of automatically operated rakes. The solids removed by these units can be disposed of by burial or incineration.
How do you reduce sludge production in wastewater treatment?
The new wastewater treatment processes including SANI®, high-rate activated sludge coupled autotrophic nitrogen removal and anaerobic membrane bioreactor coupled autotrophic nitrogen removal also have a great potential to reduce sludge production.
What are the 7 steps in wastewater treatment?
The Wastewater Treatment ProcessStage One — Bar Screening. ... Stage Two — Screening. ... Stage Three — Primary Clarifier. ... Stage Four — Aeration. ... Stage Five — Secondary Clarifier. ... Stage Six — Chlorination (Disinfection) ... Stage Seven — Water Analysis & Testing. ... Stage Eight — Effluent Disposal.
What are the 3 stages of wastewater treatment?
There are three main stages of the wastewater treatment process, aptly known as primary, secondary and tertiary water treatment. In some applications, more advanced treatment is required, known as quaternary water treatment.
What are the 4 stages of wastewater treatment?
4-Step Wastewater Sludge Treatment ProcessStep 1 – Sludge Thickening. The first step in the sewage sludge treatment plan is called thickening. ... Step 2 – Sludge Digestion. After amassing all the solids from the sewage sludge begins the sludge digestion process. ... Step 3 – Dewatering. ... Step 4 – Disposal.
How do I control my SVI?
Raising the amount of MLSS (reducing waste rates) changes the density of the floc, creating a heavier sludge particle. The more dense the particle, the more likely it will settle faster. The higher milligram per liter MLSS reduces the SVI result.
What is the best method for a wastewater treatment plant?
Chemical. Chlorine is the chemical most often used in treating sewage and other types of wastewater. The process is called chlorination. This is the most effective means of destroying a variety of viruses and bacteria.
Which of the following methods is used for stabilization of the sludge?
Explanation: The sludge is stabilized by anaerobic digestion. Lime conditioning and aerobic digestion are the other methods in order to bring about stabilization. The sludge is stabilized before it is subjected to conditioning.
What is the wastewater generated from pulping and bleaching processes?
The wastewater generated from commonly used pulping and bleaching processes is high in color, BOD/COD, chlorinated organic, and solids.
How is water lost to the atmosphere?
The majority of water is lost to the atmosphere as evaporative losses. A smaller amount of water (< 1 percent) also leaves as water in the solids residuals (as moisture in the solids.) The remainder is treated through the wastewater treatment system and discharged to the receiving water body.
How much sediment can be removed from a sedimentation tank?
Efficiently designed sedimentation tanks, in conjunction with DAF and filtration, can remove 80 to 85 percent of the suspended solids and from 30 to 40 percent of the overall BOD load. Figure 2 shows the typical block flow diagram for primary treatment.
How much water does pulp and paper use?
The pulp and paper industry is one of the heaviest users of water in the US, using almost 15,000 gallons of water per ton of finished product. With water used in nearly every step of the production process, the large volumes of wastewater and residual sludge waste present treatment, discharge and disposal issues.
What is Kraft pulping?
Kraft pulping is usually carried out in the presence of alkaline media such as sodium hydroxide and sodium sulfide. The sulfide process, an acidic pulping process, is carried out in the presence of sulphurous acid and bisulfide ions. The production of white paper involves additional bleaching processes in conjunction with pulping processes.
What is the main source of water used in milling?
The main sources of water for manufacturing operations include: surface water; ground water; purchased water; and rain.
Why should source segregation of process streams, along with end-of-pipe treatment technologies, be evaluated in detail?
Source segregation of process streams, along with end-of-pipe treatment technologies, should be evaluated in detail to optimize overall water consumption. Advanced technologies should be used in lieu of conventional treatment technologies to minimize water loss and provide high quality water that can be recycled and reused within a mill.
What happens if a company discharges industrial wastewater?
If your company discharges industrial wastewater, you must ensure that you treat it as needed before it enters the sewer system or otherwise leaves the facility. Properly operating a wastewater treatment plant in accordance with regulations includes many requirements.
When a new process is brought online, must you be involved in the early planning stages to determine what waste,?
When a new process is brought online, you must be involved in the early planning stages to determine what waste, if any, will contribute to your wastewater discharge. You should review the material data sheets for any products used in the new process and even run some sample analyses on the waste to confirm whether it poses any discharge compliance concerns.
What is industrial wastewater?
Industrial wastewater is a by-product of industrial processes, and is separate from domestic sources of wastewater. It includes runoff and leachate from areas that receive pollutants associated with industrial or commercial storage, handling, or processing facilities.
What is an oxidation ditch?
Oxidation ditches are suitable for facilities thatrequire nutrient removal, have limitations due to thenature of the site, or want a biological system thatsaves energy with limited use of chemicals unlessrequired for further treatment. Oxidation ditchtechnology can be used to treat any type ofwastewater that is responsive to aerobicdegradation. In addition, systems can be designedfor denitrification and phosphorous removal.
What is sequencing batch reactor?
sequencing batch reactor (SBR) is a variation ofthe activated sludge process. As a fill and draw orbatch process, all biological treatment phases occurin a single tank. This differs from the conventionalflow through activated sludge process in that SBRsdo not require separate tanks for aeration andsedimentation (Kappe, 1999). SBR systems containeither two or more reactor tanks that are operated inparallel, or one equalization tank and one reactortank. The type of tank used depends on thewastewater flow characteristics (e.g. high or lowvolume). While this setup allows the system toaccommodate continuous influent flow, it does notprovide for disinfection or holding for aeratedsludge.
What is extended aeration?
The extended aeration process is one modificationof the activated sludge process which providesbiological treatment for the removal ofbiodegradable organic wastes under aerobicconditions. Air may be supplied by mechanical ordiffused aeration to provide the oxygen required tosustain the aerobic biological process. Mixing mustbe provided by aeration or mechanical means tomaintain the microbial organisms in contact withthe dissolved organics. In addition, the pH must becontrolled to optimize the biological process andessential nutrients must be present to facilitatebiological growth and the continuation of biologicaldegradation.
What are the components of an oxidation ditch?
Key components of a typical oxidation ditchinclude a screening device, an influent distributor(with some systems), a basin or channel, aerationdevices (mechanical aerators, jet mixers, ordiffusers, depending on the manufacturer), asettling tank or final clarifier (with some systems),and an RAS system (with some systems).Typically , the basin and the clarifier areindividually sized to meet the specific requirementsof each facility. These components are often builtto share a common wall in order to reduce costs andsave space (Lakeside, 1999).Concrete tanks are typically used when installingpackage plant oxidation ditches. This results inlower maintenance costs as concrete tanks do notrequire periodic repainting or sand blasting.Fabricated steel or a combination of steel andconcrete can also be used for construction,depending on site conditions (Lakeside, 1999).
What is a package plant?
Package plants are pre-manufactured treatmentfacilities used to treat wastewater in smallcommunities or on individual properties .Accordingto manufacturers, package plants can bedesigned to treat flows as low as 0.002 MGD or ashighas 0.5 MGD,although they more commonlytreatflows between 0.01 and 0.25 MGD (Metcalfand Eddy, 1991).
Where are package treatment plants used?
They are most often used inremote locations such as trailer parks, highway restareas, and rural areas.
Where is the Aldie Wastewater Treatment Plant located?
The Aldie Wastewater Treatment Plant, located inAldie , Virginia, is an extended aeration facilitywhich treats an average of 0.0031 MGD with adesign flow of 0.015 MGD. This technology waschosen because it would allow the area to meetpermit requirements while minimizing land use.The plant consists of an influent chamber whichdirects the flow to two parallel aeration basins,parallel clarifiers, and a UV disinfection system.
1. Solids Prevention in Collection Systems
The most logical way to reduce wastewater solids is to prevent them from entering the collection system. This is easier said than done, but it doesn’t hurt to try.
2. Establishing a Headworks
Establishing a headworks comes in at number 2 on our list in our “5 Ways to Reduce Wastewater Solids” article.
4. Mechanical Dredging
As we move to the 4th item in our “5 Ways to Reduce Wastewater Solids” article, we now come to Mechanical Dredging.
5. Solids Wasting
As we round out our “5 Ways to Reduce Wastewater Solids” article, we have come to the last item. Solids in mechanical activated sludge plants are handled within the system design.
Closing Thoughts
The items on the list that can help reduce solids in any type of treatment facility include prevention through education and screening, installing a headworks, and solids bioaugmentation. Mechanical dredging and solids wasting practices are specific to lagoon systems and activated sludge processes.
How to reduce electricity consumption in wastewater treatment plant?
You could optimize aeration by upgrading the blowers and air distribution system components with variable frequency drives and installing dissolved oxygen control systems, which can decrease the blowers’ electricity consumption. If you have aging blowers, consider replacing them with a single high-efficiency turbo blower, which has a wide range of operation and can be controlled based on dissolved oxygen. Do you have an aging diffuser system? If so, replacing the diffuser grid with new fine-pore or ultra-fine-pore diffusers will improve oxygen transfer efficiency and reduce the amount of air needed for treatment.
How much energy does a wastewater treatment plant use?
Solids handling processes use over 20% of the energy at a wastewater treatment facility, and pumping and disposing of solids requires energy every step of the way. Options to save money and energy are abundant, from minimizing transported water and solids to utilizing biogas for producing electricity and heating water, also known as co-generation.
What is SCADA in a plant?
Supervisory Control and Data Acquisition (SCADA) can provide real-time data on the treatment processes in your plant. SCADA can automate the operation of your plant or allow the operator to control the plant remotely. The system can monitor equipment and alert the operator of emerging issues. When properly planned and integrated, the SCADA system can provide operators with the desired amount of hands-on versus hands-free control, freeing operators to perform other duties. Continuous monitoring and trending of various processes and equipment can reveal periods when energy usage can be reduced or peak energy loads can be shaved.
What is the best opportunity to turn brown into green?
One such opportunity offering excellent potential is your wastewater treatment plant (WWTP) - turning brown into green.
How much energy does a large facility use?
Operating a large facility consumes a significant amount of energy (averaging 9.3% ) through lighting, heating, and cooling the enclosed spaces. If you have old T-12 fluorescent lighting fixtures in your plants, consider updating them to new high-efficiency T-8 fixtures, which will result in savings. In addition to energy savings, rebates are often available for these types of improvements.
Why are pump stations important?
A significant portion of a utility’s energy usage is attributed to one or more pump stations used in virtually every community’s collection system. Older pumps were typically designed to operate at a single speed and on/off cycling. Today’s pump/motor/drive combinations are more efficient over a wider range of flows. Upgrading older pumps can produce long-lasting operation and maintenance savings. Inexpensive and more reliable variable frequency drives can also be used to match pump speeds to flow rates, further reducing energy needs.
Is chlorine dechlorination expensive?
Chlorine and dechlorination chemicals are expensive and energy-intensive to manufacture and transport. Energy usage of UV disinfection systems is minimal, and the decommissioning of hazardous chlorine disinfection systems is a major safety benefit. 6. Update Lighting and HVAC Systems.
What Does the Wastewater Treatment Industry Do?
The industry's primary aim is to remove as much of the suspended solids (effluent) as possible from used water before returning the water to the environment. Wastewater treatment plants can treat water up to different qualities or degrees in order to satisfy various industry-specific requirements.
Why Treat Wastewater?
Wastewater treatment is done to promote human and environmental health. Untreated wastewater can carry diseases, disrupt wildlife habitats, and expose humans, animals, and plant life to toxins, pollutants, excessive nutrients, and other harmful substances. Decaying organic matter also uses up dissolved oxygen found in water, and therefore can deprive fish and other aquatic lifeforms of the oxygen they need to survive.