What does Pao stand for?
Periacetabular Osteotomy: An Overview 1 Introduction. Periacetabular osteotomy (PAO) is a surgical treatment for hip dysplasia resulting... 2 Diagnosis and Presurgical Imaging. In addition to a thorough physical exam and patient history,... 3 Treatment. At HSS, many patients with more mild forms of hip dysplasia undergo a trial...
What are the different methods of phosphorous removal?
While chemical and biological phosphorous treatments are the two main techniques for removing phosphorus from domestic and industrial wastewater, many variations and combinations have been used. The following is intended to provide a basic overview of basic phosphorous removal processes.
Can a Pao be done with a hip arthroscopy?
Hip arthroscopy may also be performed along with a PAO in selected patients (for example, to repair a damaged labrum). Throughout the surgery, X-ray guidance is used and the nerves and muscles that surround and support the hip joint are carefully protected.
When is a Pao indicated in the treatment of acetabulum dysplasia?
If non-operative measures are not successful in patients with mild dysplasia, a PAO may be considered for patients who have reached skeletal maturity with a malalignment of the acetabulum but do not have advanced osteoarthritis.
How is phosphate removed from wastewater treatment?
Phosphorus removal from wastewater can be achieved either through chemical removal, advanced biological treatment or a combination of both. The chemical removal of phosphorus involves the addition of calcium, iron and aluminium salts to achieve phosphorus precipitation by various mechanisms which are discussed.
How does chemical phosphorus removal work?
Chemical treatment for phosphorus removal involves the addition of metal salts to react with soluble phosphate to form solid precipitates that are removed by solids separation processes including clarification and filtration.
How does biological phosphorus removal work?
The basic principle of biological phosphorus removal is to expose bacteria to alternating anaerobic and aerobic conditions to promote “luxury uptake” of phosphorus. Under anoxic to anaerobic conditions, phosphorus accumulating organisms (PAO) have the ability to take in organic substrate.
How much amount of phosphorus is removed by secondary treatment?
Therefore, primary and secondary wastewater treatment can removes about 20-30% of phosphorus, and phosphorus content in pre-treated water is high above standard regulated limits.
How much amount of phosphorus is removed by secondary treatment in mg L?
1-2 mg/lHow much amount of phosphorus is removed by secondary treatment? Explanation: Normally secondary treatment can only remove 1-2 mg/l, so a large excess of phosphorous is discharged in the final effluent, causing eutrophication in surface waters.
Why is there an aeration tank in secondary treatment?
The activated sludge process is the most common option in secondary treatment. Aeration in an activated sludge process is based on pumping air into a tank, which promotes the microbial growth in the wastewater. The microbes feed on the organic material, forming flocks which can easily settle out.
How do you remove phosphorus from your body?
Here are seven methods to help control high levels of phosphorus:Reduce the amount of phosphorus you eat. ... Take phosphorus binders. ... Take vitamin D. ... Take a calcimimetic medicine. ... Stay on dialysis the entire time. ... Start an exercise program approved by a doctor. ... Get an operation to remove some of the parathyroid glands.
How does biological nutrient removal work?
Biological nutrient removal (BNR) removes total nitrogen (TN) and total phosphorus (TP) from wastewater through the use of microorganisms under different environmental conditions in the treatment process (Metcalf and Eddy, 2003).
What are mainly responsible for biological removal of phosphorus?
Activated sludge systems are designed and operated globally to remove phosphorus microbiologically, a process called enhanced biological phosphorus removal (EBPR).
Do water treatment plants remove phosphates?
Most wastewater treatment plants (WWTPs) use two strategies to remove phosphorus: chemical phosphorus removal (CPR) and biological phosphorus removal (BPR). Chemical phosphorus removal typically involves precipitating influent phosphorus with an iron or aluminum salt.
How does alum remove phosphorus?
Aluminum sulfate, called alum, when added to lake water removes phosphates through precipitation, forming a heavier than water particulate known as a floc. This floc then settles to the lake bottom to create a barrier that retards sediment phosphorus release.
How is nitrate and phosphate removed from wastewater?
Phosphate and nitrate pollutants can be removed by chemical precipitation, biological treatment, membrane processes, electrolytic treatment, ion-exchange and adsorption process to remove these pollutants from water sources effectively.
What will dissolve phosphorus?
Chemical precipitation is used to remove the inorganic forms of phosphate by the addition of a coagulant and a mixing of wastewater and coagulant. The multivalent metal ions most commonly used are calcium, aluminium and iron.
How is phosphorus removed from lake water?
Leave a wide strip of deep-rooted plants along shoreland. Instead of planting and mowing turf grass along lakes and streams, plant wildflowers, ornamental grasses, shrubs, or trees. These plants absorb and filter runoff that contains nutrients and soil, as well as providing habitat for wildlife.
How does alum remove phosphorus?
Aluminum sulfate, called alum, when added to lake water removes phosphates through precipitation, forming a heavier than water particulate known as a floc. This floc then settles to the lake bottom to create a barrier that retards sediment phosphorus release.
How is phosphate removed from drinking water?
Reverse Osmosis is one of the most common and effective methods used for treatment and removal of Phosphates in drinking water. A whole-house reverse osmosis system pushes water through a membrane with tiny pores. The membrane removes several contaminants, including Phosphate, while allowing water to pass through.
How long do you have to be hospitalized for PAO?
At HSS, patients who undergo PAO are hospitalized for 2 to 4 days. Physical therapy and instructions on weight-bearing guidelines are initiated before discharge, and crutches must be used for 6 to 8 weeks. Most individuals return to school or work after three months and can resume athletics between 6 to 12 months.
What is periacetabular osteotomy?
What is a periacetabular osteotomy? A periacetabular osteotomy (PAO) is a surgical treatment for hip dysplasia that is caused by a deformity in the acetabulum, the curved portion of the pelvis that forms the socket of the hip joint. Symptoms of this condition – which may be present from birth, but may only become evident in adolescence ...
How to treat hip dysplasia?
At HSS, many patients with more mild forms of hip dysplasia undergo a trial of nonsurgical treatment with steroid injections and physical therapy. When this approach is successful, the patient is followed with a series of MRIs in order to make sure that there is no progression of damage in the joint. For patients with long histories of symptoms or more severe forms of dysplasia, operative correction is usually recommended at the outset, as long as the extent of hip joint arthritis is not too advanced or severe.
Can you have a PAO with osteoarthritis?
Surgical treatment. If non-operative measures are not successful in patients with mild dysplasia, a PAO may be considered for patients who have reached skeletal maturity with a malalignment of the acetabulum but do not have advanced osteoarthritis. It is not uncommon to recommend a PAO in patients with mild forms of dysplasia when other surgeries ...
Can a PAO be performed with a hip arthroscopy?
Hip arthroscopy may also be performed along with a PAO in selected patients (for example, to repair a damaged labrum). Throughout the surgery, X-ray guidance is used and the nerves and muscles that surround and support the hip joint are carefully protected.
When is operative correction recommended for hip joint arthritis?
For patients with long histories of symptoms or more severe forms of dysplasia, operative correction is usually recommended at the outset, as long as the extent of hip joint arthritis is not too advanced or severe.
Can you have a PAO with dysplasia?
It is not uncommon to recommend a PAO in patients with mild forms of dysplasia when other surgeries have failed , such as a hip arthroscopy, which may repair the labrum but does not correct the underlying dysplasia. The decision to proceed to PAO surgery must take into account the patient’s age and lifestyle.
What are the processes of phosphate removal?
The main phosphate removal processes are (see picture below): 1 Treatment of raw/primary wastewater 2 Treatment of final effluent of biological plants (postprecipitation) 3 Treatment contemporary to the secondary biologic reaction (co-precipitation).
How is phosphate removal achieved?
Phosphate removal is currently achieved largely by chemical precipitation , which is expensive and causes an increase of sludge volume by up to 40%. An alternative is the biological phosphate removal (BPR).
How is phosphorous removed from wastewater?
In the biological removal of phosphorous, the phosphorous in the influent wastewater is incorporated into cell biomass, which is subsequently removed from the process as a result of sludge wasting. The reactor configuration provides the P accumulating organisms (PAO) with a competitive advantage over other bacteria. So PAO are encouraged to grow and consume phosphorous. The reactor configuration in comprised of an anaerobic tank and an activated sludge activated tank. The retention time in the anaerobic tank is about 0.50 to 1.00 hours and its contents are mixed to provide contact with the return activated sludge and influent wastewater.
How is the amount of phosphorous removed by biological storage estimated?
The amount of phosphorous removed by biological storage can be estimated from the amount of bsCOD that is available in the wastewater influent. Better performance for BPR systems is achieved when bsCOD acetate is available at a steady rate.
What is the name of the compound that is added to wastewater to remove SS?
it is usually added in the form of lime Ca (OH) 2. It reacts with the natural alkalinity in the wastewater to produce calcium carbonate, which is primarily responsible for enhancing SS removal.
How much phosphorus is discharged from a water treatment?
Normally secondary treatment can only remove 1-2 mg/l, so a large excess of phosphorous is discharged in the final effluent, causing eutrophication in surface waters. New legislation requires a maximum concentration of P discharges into sensitive water of 2 mg/l.
What is the process of removing phosphorus from wastewater?
The removal of phosphorous from wastewater involves the incorporation of phosphate into TSS and the subsequent removal from these solids. Phosphorous can be incorporated into either biological solids (e.g. micro organisms) or chemical precipitates.
What is secondary treatment?
The secondary treatment is designed to remove soluble organics from the wastewater. Secondary treatment consists of a biological process and secondary settling is designed to substantially degrade the biological content of the sewage such as are derived from human waste, food waste, soaps and detergent.
How is dissolved carbonaceous organic matter removed from wastewater?
The removal of dissolved and suspended carbonaceous BOD and the stabilization of organic matter found in wastewater is accomplished using a v ariety of microorganisms, principally bacteria. Microorganisms are used to oxidize the dissolved and suspended carbonaceous organic matter into simple end products and additional biomass. This is achieved by providing the favourable environment to microorganisms with food, DO, pH, temperature etc. The organic solids present in the wastewater serve as food for the aerobic microorganisms. The only thing to be provided is the DO, which is essential for the respiration of the aerobic organisms. In the biological treatment processes the DO is supplied either through natural means or by mechanical means by agitation.
How is DO supplied in biological treatment?
In the biological treatment processes the DO is supplied either through natural means or by mechanical means by agitation. Anaerobic organisms can multiply in the absence of DO and do the decomposition, but the end products are undesirable fowl smelling gases like H 2 S, CH, etc.
What is attached growth bio treatment?
In attached growth biological treatment systems the biomass is attached. Trickling filters and biological towers are examples of systems that contain biomass adsorbed to rocks or plastic. Wastewater is sprayed over the top of the rocks or plastic and allowed to trickle down and over the attached biomass, which removes materials from the waste through sorption and biodegradation. A related type of attached-growth system is the rotating biological contactor, where biomass is attached to a series of thin, plastic wheels that rotate the biomass in and out of the wastewater. This coating of microorganisms is able to trap and consume B.O.D. and ammonia in the wastewater.
Clinical significance
Society and culture
- In the healthy hip, the upper end of the femur (thigh bone) meets the acetabulum in the pelvis, and the two fit together like a ball and socket, in which the ball (the femoral head moves freely in the hip socket.[Figure 1.]
Causes
- For some people, hip dysplasia results when the acetabulum does not develop fully, making it too shallow or otherwise misaligned to adequately contain and support the femoral head. Owing to this misalignment, over time the cartilage and labrum (a soft tissue rim made of fibrous cartilage, which lines the hip socket) can end up bearing the brunt of forces that should be distributed thro…
Treatment
- Hip dysplasia occurs more frequently in women than in men, explains Ernest L. Sink, Associate Attending Orthopedic Surgeon and Co-Director, Center for Hip Preservation, Hospital for Special Surgery (HSS). Treatment for hip dysplasia ranges from symptomatic relief to surgical correction. In older patients (age 50 and above) with advanced osteoarthritis, total hip replacement may eve…
Diagnosis
- In addition to a thorough physical exam and patient history, orthopedists use X-rays, magnetic resonance imaging (MRI) and, in some cases, three-dimensional CT images to confirm a diagnosis of hip dysplasia. The highly sophisticated MRI techniques available at HSS are particularly helpful in providing images that show a clear distinction between bone and cartilage…
Safety
- Throughout the surgery, X-ray guidance is used and the nerves and muscles that surround and support the hip joint are carefully protected.
Introduction
- Periacetabular osteotomy was first developed under the direction of Reinhold Ganz, MD, professor emeritus at the University of Bern in Switzerland. Although the procedure has become more widely used around the world, the HSS Center for Hip Preservation is one of a limited number of centers in the United States where a high volume of these procedures are performed.
Results
- In appropriately screened patients who have not developed significant hip joint arthritis, PAOs yield very good results, even up to 20-25 years after the procedure.[1] Performed by an experienced orthopedic surgeon, PAO has a good safety profile and produces predictable results, says Dr. Sink. If you are considering undergoing a PAO, its important to go to a center where the …
Selected publications
- 1. Steppacher SD, Tannast M, Ganz R, Siebenrock KA. Mean 20-year followup of Bernese periacetabular osteotomy. Clin Orthop Relat Res. 2008; 466:1633-1644