Phosphorus Paper

Prévia do material em texto

Armour College of Engineering 
Illinois Institute of Technology 
 
 
 
 
 
 
 
 
 
 
 
Selection of Phosphorus Removal and Recovery 
Processes for Brazil 
ENGR 498 – 102: Nutrient Control and Recovery 
 
 
 
 
 
 
 
 
 
 
 
Luiz N. Caracas Neto 
Layan S. Gomes 
Natalia A. Killer 
Henrique L. Ribeiro 
Peterson R. Marques 
 
Dr. Thomas E. Wilson 
 
 
Chicago, IL 2016 
 
 
2 
 
Table of Contents 
 
Abstract ........................................................................................................................................... 3 
1. Background ............................................................................................................................ 4 
1.1 Phosphorus Impact and Recovery Importance ...................................................................... 5 
1.2 Phosphorus Legislation ....................................................................................................... 6 
1.3 Phosphorus Removal ........................................................................................................... 7 
1.4 Brazilian Status ................................................................................................................... 7 
2. Objective ..................................................................................................................................... 8 
3. Methods....................................................................................................................................... 8 
4. Results ......................................................................................................................................... 9 
4.1 Chemical Phosphorus Removal ............................................................................................ 9 
4.1.1 Phosphorus Removal with Calcium ............................................................................. 10 
4.1.2 Phosphorus Removal with Aluminum and Iron ........................................................... 11 
4.1.3 Chemical addition at multiple points ............................................................................ 12 
4.1.4 Sludge handling and phosphorus bioavailability .......................................................... 12 
4.2 Biological Phosphorus Removal ......................................................................................... 13 
4.3 Combining phosphorus and nitrogen removal .................................................................... 14 
4.4 Phosphorus Recovery .......................................................................................................... 15 
4.3.1 Crystallization ............................................................................................................... 15 
4.3.2 Struvite Recovery ......................................................................................................... 16 
5. Conclusion ................................................................................................................................ 17 
Acknowledgements ....................................................................................................................... 18 
References ..................................................................................................................................... 19 
Tables ............................................................................................................................................ 21 
Figures........................................................................................................................................... 22 
Appendix ....................................................................................................................................... 27 
 
 
 
 
 
 
 
 
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Abstract 
Phosphorus is a main pollutant that can be found in wastewater. Treatment plants often 
reduce phosphorus levels to avoid eutrophication, which is the ecosystem's response to the 
addition of artificial or natural nutrients in a waterbody. This paper aims to review technologies 
and processes utilized to remove and recovery phosphorus from the wastewater and, then, 
suggest some that are possible to be applied to Brazilian plants. The two main methods found to 
reduce levels of phosphorus are chemical precipitation and enhanced biological removal. The 
chemical precipitation is a reliable method and relatively simple. The biological phosphorus 
removal is more complex, needs extra carbon source, but requires less chemical storage and 
chemical sludge disposal. Also, the biological removal makes possible to recover phosphorus in 
the form of struvite. 
 
 
 
 
 
 
 
 
 
 
 
4 
 
1. Background 
In the environment, phosphorus can be found incorporated to particles or be present as 
dissolved inorganic (DIP) and organic phosphorus (DOP) (WEF MOP, 2010). Inorganic 
phosphorus exists in various orthophosphate forms, such as H3PO4, H2PO4
-
 , H2PO4
2-
, and PO4
3-
) 
(Sawyer et al., 1994). The usual forms of phosphorus found in aquatic solutions include 
orthophosphate, polyphosphate, and organic phosphate (Metcalf & Eddy, 2003). 
Taking into consideration the phosphorus life cycle, phosphorus moves primarily between 
the Earth’s crust and the aquatic dissolved, particulate (including biota), and the sedimentary 
cycle (WEF MOP, 2010). Since phosphorus is one of the most abundant element in the planet, 
and apatite is the most abundant phosphate mineral in the Earth’s crust, the delivery of 
phosphorus to rivers depends mostly on the geology of the watershed and the type of rocks being 
weathered in the vicinity (WET MOP, 2010). 
Both nitrogen and phosphorus, along with carbon, are essential nutrients for growth. 
When discharged to the aquatic environment, these nutrients can lead to the uncontrolled growth 
of aquatic life, and also, when discharged in excessive amounts on land, they can contaminate 
the groundwater (Metcalf & Eddy, 2003). Phosphorus can enter freshwaters through several 
process, these processes include drainage from agricultural land, excreta from livestock, 
municipal and industrial effluents, atmospheric deposition and diffuse urban drainage (Lee et al., 
1978). Phosphorus inputs from point sources, such as municipal sewage effluents, are more 
amenable to control than those from non-point sources (Yeoman et al, 1987). 
Therefore, to account for nutrient removal, in special phosphorus removal, from the 
wastewater before discharging it is essential to contribute to the loading control of phosphorus to 
water sources. 
 
 
5 
 
1.1 Phosphorus Impact and Recovery Importance 
As mentioned previously, one of the limiting nutrient in most freshwater lakes, reservoirs 
and rivers is phosphorus, and inputs of this element from anthropogenic sources accelerate the 
process of eutrophication, which normally proceeds slowly in the natural ageing of lakes 
(Yeoman et al, 1987). 
According to Yeoman et al (1987), as a consequence of the reduced economic value of 
phosphorus limited eutrophic water bodies, considerable attention has been given to them. In an 
attempt to improve the water quality of the North American Great Lakes, the United States and 
Canada, via the 1978 Great Lakes Water Quality Agreement, stipulated that the effluents from 
400 municipal treatment plants discharging to the lakes should contain a maximum of l.0 mg/L 
of phosphorus in the upper lakes and 0.5 mg/L phosphorus in the lower lakes (Yeoman et al, 
1987). Also according to Yeoman et al (1987),another example is the United Kingdom, where, 
in order to try to control the eutrophication of the River Ant and Barton Broad in the Norfolk 
Broads, the Anglian Water Authority decided to reduce phosphorus concentrations in the 
effluents of sewage treatment works. 
However, phosphorus is not just the villain. It is an essential element for human nutrition, 
playing multiple roles in the human body, including the development of bones and teeth (Doyle, 
2015). Moreover, phosphorus is presented in fertilizer applied to crops or lawns, enabling 
healthy growth. Without it, the basic cells of plants and animals, and life itself, would not exist 
(Doyle, 2015). 
As indicated by Doyle (2015), typically, phosphorus is found in phosphate-containing 
minerals that are mined, in other words, it is a limited and non-renewable resource. The annual 
demand is rising quickly and yet, once used, phosphorus is difficult to reclaim (Doyle, 2015). 
 
 
6 
 
Technologies for removal and recovery of phosphorus from wastewater have advanced 
considerably in recent years. The use of renewable sources offers the immediate advantage of 
avoiding the environmental impacts associated with primary production from phosphate rock and 
also to provide a continuous phosphorus supply (Morse et al, 1998). 
 1.2 Phosphorus Legislation 
The Environmental Protection Agency (EPA), in 1998, outlined a Numeric Nutrient 
Strategy to describe the approach that it would follow to develop nutrient information and work 
with the states and tribes to adopt numeric nutrient criteria (EPA, 2016). EPA (2016) defines the 
Numeric Nutrient Criteria as a tool for protecting and restoring a waterbody's designated uses 
related to nitrogen and phosphorus pollution. These criteria make possible to monitor a 
waterbody for attaining its designated uses, to facilitate formulation of NPDES discharge 
permits, and simplify development of total maximum daily loads (TMDLs) for restoring waters 
not attaining their designated uses (EPA, 2016). 
In 2008, EPA published "State Adoption of Numeric Nutrient Standards 1998–2008", a 
document that was the first national report on progress made by the states in adopting numeric 
nutrient water quality standards (WQS). 
In 2013, EPA developed an interactive website to show each state progress on developing 
its Numeric Nutrient Criteria. The site features maps and tables showing development of 
nitrogen and phosphorus criteria from 1998 projected through 2019. It also includes each state's 
existing numeric criteria and development plans (EPA, 2016). Figure 1 shows how this 
interactive website looks like, revealing the states that already present any type of nutrient 
criteria. 
 
 
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 1.3 Phosphorus Removal 
Conventional biological wastewater treatment does not remove phosphorus effectively 
enough to achieve nowadays aims. This way, along the years, new processes and technologies 
needed to be developed. 
Phosphorus removal from wastewater can be achieved either through chemical removal, 
advanced biological treatment or a combination of both. All alternatives have advantages and 
disadvantages that need to be evaluated before being implemented. This paper will discuss 
better the alternatives in the Results section. 
1.4 Brazilian Status 
Brazil is a country with an impressive water availability. 12% of all world freshwater is 
located in Brazilian lands (ANA, 2013). However, for a country with several hydric resources, it 
does not have good programs and a solid legislation to protect them and ensure their good 
quality. As can be seen in Figure 2, almost half of the Brazilian urban water bodies are classified 
as in bad or terrible condition and, according to the Brazilian federal water agency (ANA), one 
of the mainly sources of pollution to be blamed is the wastewater discharges. Figures 3 and 4 
reflects the trophic state of the waterbodies in Brazil, revealing that eutrophication is presented in 
great part of its water resources. 
Around 47.5% of all domestic wastewater produced in Brazil is collected and just 14% of 
it is treated (ANA, 2013). This numbers are even more worrisome when pointed out that, of this 
14% treated, just 60% undergoes secondary and/or tertiary (10%) treatment, while 40% only 
have preliminary or primary treatment (ANA, 2013). These figures show how Brazilian 
sanitation infrastructures are deficient and the urgent need of improvement. 
 
 
8 
 
 Between 2001 and 2010, the Brazilian federal govern invested almost $15 billion in 
sanitary programs and pollution control of water bodies (ANA, 2013). With the help of this 
programs, new wastewater treatment facilities are being built around the country, with the 
promise of improving Brazilian water quality. 
Under these circumstances, this paper focuses in analyzing and then proposing some 
technologies and processes to remove nutrients that could be incorporated to the already existing 
plants in Brazil and also to the new plants being built. 
2. Objective 
This paper discusses phosphorus control and recovery processes from the wastewater. 
Moreover, it aims to analyze and suggest methods and alternatives that could be incorporated to 
the already existing plants in Brazil and also to the new plants being built. 
3. Methods 
The research, in which this paper was based, combined lectures taught by Dr. Thomas E. 
Wilson, environmental engineer, consultant and specialist in Nutrient Control and Removal; site 
visits to Stickney WRP
1
 and John E. Egan WRP; case studies based on American plants that 
have innovative nutrient removal and recovery technologies, such as the Denver Metro 
Wastewater Reclamation District, Hampton Roads Sanitation District, New York City 
Department of Environmental Protection, District of Columbia Water and Sewer Authority, 
Tahoe-Truckee Sanitation Agency, and Noman M. Cole Jr. Pollution Control Plant; contact to 
professionals from on-site plants, and also an extended gather of information for nutrients, 
regulations and types of processes from literature review. 
 
1
 Pictures took during site visits can be seen in the Appendix Section. 
 
 
9 
 
4. Results 
As mentioned before, there are different ways to remove phosphorus from wastewater. In 
this section, all the methods studied will be discussed. 
The removal of phosphorus from wastewater involves the incorporation of phosphate into 
suspended solids and then subsequent removal of those solids (Metcalf & Eddy, 2003). 
According to WEF MOP (2011), the phosphorus can be removed by sedimentation, filtration, or 
some other solids removal process, or it can be concentrated into a side-stream using membrane 
ion separation treatments, such as reverse osmosis. 
The main processes of phosphorus removal are chemical and biological. Figure 5 shows 
the different types of the two processes of phosphorus removal. 
4.1 Chemical Phosphorus Removal 
Phosphorus removal by chemical addition is very attractive for its simplicity of operation 
and ease of implementation. However, it can cause increased sludge production and additional 
operation and maintenance costs. Chemicals are added to the wastewater at a well-mixed 
location, followed by flocculation and solids removal by sedimentation, filtration, membrane 
separation, or similar processes (WEF MOP, 2011). 
The chemical reactions favor phosphorus partitioning from the aqueous phase to the solid 
phase, and will produce low residual phosphorus levels. Phosphorus levels less than 0.1 mg P/L 
can consistently be achieved with chemical addition at well-designed filtration facilities. Lower 
concentrations can be achievedwith optimal chemical application and complete solids removal 
(WEF MOP, 2011). 
 
 
10 
 
The chemical precipitation of phosphorus is brought about by the addition of the salts of 
multivalent metal ions that form precipitates of sparingly soluble phosphates. The most used 
multivalent metal ions are calcium, aluminum and iron. In addition of alum and calcium, 
polymers also have been used as flocculant aids (Metcalf & Eddy, 2003). 
In Figure 6, it is shown where the chemicals can be added, they may be implemented 
individually or also combined and in Table 1, the advantages and disadvantages are presented 
being related to where the chemicals are added. 
4.1.1 Phosphorus Removal with Calcium 
As indicated by Metcalf & Eddy (2003), usually calcium is added in the form of lime 
Ca(OH)2, when lime is added to water it reacts with the bicarbonate alkalinity to precipitate 
CaCO3. As the wastewater has its pH increased beyond about 10, the calcium ions in excess will 
react with the phosphate and precipitate hydroxylapatite Ca10(PO4)6(OH)2, as shown in the 
following equation. 
 Equation 1 
The quantity of lime required does not depend on the amount of phosphate present, it 
depends on the alkalinity of the wastewater. The quantity required is about 1.5 times the total 
alkalinity expressed as CaCO3. When lime is used in the raw wastewater or in the secondary 
effluent, pH adjustment is usually required before subsequent steps or disposal and so carbon 
dioxed CO2 is used to lower the pH value (Metcalf & Eddy, 2003). 
 
 
11 
 
4.1.2 Phosphorus Removal with Aluminum and Iron 
As mentioned by WEF MOP (2011), the chemical reaction of phosphorus with aluminum 
and ferric salts in a liquid environment is very complex. Under the conditions in a wastewater 
treatment plant the classic model of a metal reacting with a phosphate to produce a metal-
phosphate precipitant (AlPO4 or FePO4) does not occur. Several fundamental reactions occur 
simultaneously. 
According to WEF MOP (2011), the complex metal hydroxides/phosphate chemistry 
makes it really difficult to predict the net chemical reactions and their results. First, the formation 
of hydroxy-metal complex does not dependent only on the chemical dose and factors such as pH 
and temperature, but it also depends on mixing intensity, age of the precipitant, and other factors. 
The dose must therefore often be determined from practical experience for a given 
application. Second, a significant amount of sludge is produced by the reactions (approximately 
2.9 mg solids/mg Al for alum and 1.9 mg solids/mg Fe for ferric) that must be processed through 
dewatering and disposal. Third, a significant amount of alkalinity is consumed during the 
reactions (approximately 5.8 mg as CaCO /mg Al and 2.7 mg as CaCO /mg Fe) (WEF MOP, 
2011). 
In conclusion, WEF MOP (2011), also affirms it is clear that successful chemical 
phosphorus removal requires an efficient solids removal process and often includes filtration to 
achieve low phosphorus concentrations. Due high quantities of chemical sludge, sedimentation 
commonly is added to reduce the solids loading onto the filters. Chemical clarification processes 
such as contact clarifiers or sludge blanket clarifiers have been used successfully in chemical 
phosphorus removal schemes. 
 
 
 
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4.1.3 Chemical addition at multiple points 
 Addition of mineral salts at multiple locations in the treatment plant it is an efficient and 
cost-effective means of chemical addition for phosphorus removal (EPA, 1987). Some 
advantages of this approach can be the overall reduction in chemical dosages to achieve an 
effluent phosphorus objective and increased operational flexibility (EPA, 1987). Moreover, in 
design of new facilities, multiple chemical addition points are recommended to allow the 
optimization of the chemical feed system to achieve the most economical, environmental and 
feasible solution (EPA, 1987). 
4.1.4 Sludge handling and phosphorus bioavailability 
 The sludge generated from use of chemicals for phosphorus precipitation is important to 
be considerate (EPA, 1987). Although chemical addition is easily implemented, there are 
impacts on thickening, stabilization, dewatering, and disposal operations of sludge (EPA, 1987). 
This is caused because of both the additional mass and volume of sludge generated as well as the 
effects on thickening and dewatering characteristics (EPA, 1987). 
One disposal solution for these materials is application to agricultural land partly closing 
the loop in the soil-plant-food P cycle (Richards & Johnston, 2001). The P in these materials is, 
however, not water soluble and there could be a reluctance by farmers to use them until more is 
known about their value as a source of P for crop production (Richards & Johnston, 2001). 
 Plants usually can only uptake the phosphorus they need by roots in simple ionic forms 
(H2PO4
- 
and HPO4
2-
) from the soil solution (Richards & Johnston, 2001). Thus the value of any 
soil amendment intended to supply P depends on its ability to release P in these ionic forms to 
the soil solution (Richards & Johnston, 2001). 
 
 
13 
 
Taking this into consideration, it is possible to affirm, even if the phosphorus contained in 
sludge is much less readily soluble than the phosphorus contained in artificial fertilizer, sludge is 
generally a good phosphorus fertilizer (Bresters et al, 1997). The phosphorus accessibility in 
sludge depends on the treatment of the sludge. Per examples, for iron phosphates from P 
precipitation using Fe, the plant availability of the P may depend on the degree of hydration and 
perhaps the extent of ageing and slow transformations of the iron phosphate (Richards & 
Johnston, 2001). 
4.2 Biological Phosphorus Removal 
According to WEF MOP (apud Greenburg et al. (1955), 2011), in the 1950s it was 
proposed that activated sludge could take up phosphate at a level beyond its normal microbial 
growth requirements. In 1959, it was reported batch experiments in which soluble phosphorus 
concentrations could be reduced to below 1 mg/L following vigorous aeration (WEF MOP, 
2011). In 1965, Levin and Shapiro were the first to report EBPR (Enhanced Biological 
Phosphorus Removal), in an activated-sludge plant in Washington, D.C., but it was the work in 
the United States and South Africa that clearly demonstrated that EBPR can occur (WEF MOP, 
2011). Since the demonstration was clear, great progress has been made in understanding the 
fundamentals of EBPR process, especially with the advanced tools of modern microbiology and 
biotechnology. 
As discussed in Metcalf & Eddy (2003), the common element in EBPR implementations 
is the presence of an anaerobic tank (nitrate and oxygen are absent) prior to the aeration tank, as 
show in Figure 7. Under these conditions a group of heterotrophic bacteria, called PAO 
(Polyphosphate-Accumulating Organisms), are selectively enriched in the bacterial community 
 
 
14 
 
within the activated sludge. These bacteria accumulate large quantities of polyphosphate within 
their cells and the removal of phosphorus is said to be enhanced (Metcalf & Eddy, 2003). 
In Figure 8, the 3 more commonly used processes are shown, and they are Phoredox; 
A
2
O; UCT – University of Cape Town (Metcalf & Eddy, 2003). As indicated by Metcalf & Eddy 
(2013), the main characteristic of Phoredox process, is that nitrification does not occur, the 
initiation of nitrification is prevented by the use of low operating SRTs (Solids Retention Time). 
In the A
2
O process, the RAS (Return Activated Sludge) recycle is directed to the anaerobiczone. 
In the UCT process, the RAS is directed to an anoxic zone. 
The PhoStrip
TM
 process is a combination of biological and chemical processes. A portion 
of RAS is diverted to an anaerobic stripping tank where phosphorus is released in solution 
(Figure 9). So supernatant is precipitated with lime and the biomass is returned to the aeration 
tank. 
4.3 Combining phosphorus and nitrogen removal 
 As mentioned in Hearley (2013), nitrogen and phosphorus removal can be integrated by 
the addition of an anaerobic reactor ahead of the primary anoxic reactor. The modified 
Bardenpho process consists of the anaerobic, anoxic, aerobic, anoxic, and aeration zones in 
sequence with an internal recycle from the aerobic to first anoxic zone, as seen in Figure 10. 
In the anaerobic zone an environment free of pure and oxidized oxygen will be provided, 
resulting in the growth of PAOs (phosphorus accumulating organisms) for EBPR (enhanced 
biological phosphorus removal) (Hearley, 2013). Under anaerobic conditions, the PAOs take up 
VFAs (volatile fatty acids), primarily acetic and propionic acids, and release phosphorus, which 
is then taken up in subsequent aeration zones and removed from the system in the waste 
activated sludge (WAS). The first anoxic zone functions as the main denitrification zone. 
 
 
15 
 
Aerobic zones provide the detention time and oxygen transfer required for oxidation of the 
influent organic compounds, nitrification, and phosphorus uptake (Stone at al, 2015). 
Observations of phosphorus removal in the late 1960s and early 1970s pointed that in all 
plug-flow plants that removed phosphorus, release of phosphorus was observed at the influent 
end, and then when nitrification took place, the phosphorus removal was reduced (Barnard et al, 
2011). Nitrates in the anaerobic zone can be used by other heterotrophs to oxidize VFA and to 
inhibit the fermentation of readily bio-degradable COD to VFA (Barnard et al, 2011). It would 
appear that in nitrifying plants without denitrification zones, it is necessary for the sludge to 
settle into a sludge blanket where the oxidation-reduction potential could be low enough and 
where no nitrates are present, to ensure fermentation in spite of the nitrates in the influent 
(Barnard et al, 2011). An example can be seen in Figure 11, while there were some nitrates in the 
mixed liquor of the second anoxic zone, there was no mixing in the fermentation zone, which 
allowed the development of a thick sludge blanket where fermentation can take place (Barnard et 
al, 2011). However, in some plants, phosphorus removal was observed even with a low 
concentration of VFA in the influent, this would require some in-basin fermentation (Barnard et 
al, 2011). 
4.4 Phosphorus Recovery 
The main processes of phosphorus recovery are the crystallization and the struvite 
recovery, some examples of each are listed below. 
4.3.1 Crystallization 
Crystallization is a process that allows formation of salt pellets utilizing forced 
precipitation of calcium phosphates by the addition of crystallization adjuvants in a specially 
 
 
16 
 
designed fluidized-bed reactor. Crystallization is favored by sand or anthracite, with strict control 
of precipitation conditions by addition of sodium hydroxide or lime. When applied to 
concentrated solutions (>100 mg P/L) the resulting high crystallization rate provides short 
retention time and relatively small reactors (WEF MOP, 2011). 
4.3.1.1 Crystalactor Process 
The Crystalactor process, developed by DHV Water BV, Netherlands (1998), is an 
example of crystallization processes. In the Netherlands this technology is used in several full-
scale installations (WEF MOP, 2011). 
4.3.2 Struvite Recovery 
Researchers identified the process of struvite formation using magnesium addition with 
pH adjustment. Commercialization of these technologies are ongoing. The technologies can be as 
simple as chemical dosing, contact, clarification, and solids handling (WEF MOP, 2011). 
4.3.2.1 Ostara Technology 
As mentioned in WEF MOP (2011), one of the newer struvite recovery technologies is 
Ostara™. This technology uses magnesium chloride and caustic followed by granule formation. 
The technology is based on controlled chemical precipitation in a fluidized bed reactor that 
recovers struvite in the form of pure crystalline pellets. 
4.3.2.2 Phosnix Process 
According to WEF MOP (2011), the Phosnix process, developed by Unitika Ltd, Japan, 
is based on an air agitated column reactor with complementary chemicals dosing equipment (i.e., 
Mg(OH) or MgCl and NaOH for pH control to 8.5–9.5) ensuring fast nucleation and growth of 
 
 
17 
 
struvite pellets, offering removal efficiencies of more than 90%. The process is used in some 
full-scale installations in Japan, where recovered struvite is sold. 
 
 
5. Conclusion 
The chemical removal would be a good option to Brazil, since it doesn’t demand high 
capital costs. This process has less costs, because it is not necessary to build new reactors to do 
it, only the infrastructure to add chemicals such as Aluminum and Iron, to the conventional 
treatment. The biological removal, in comparison, produces slightly less sludge and has a lower 
operational costs, since you don’t need to buy the chemicals. It consists of promoting two zones, 
one anaerobic, where the microorganisms will release some phosphorus and one aerobic zone, in 
which these microorganisms will now uptake more phosphorus than they released in the previous 
step. This would be a good option for plants that already have activated sludge processes that can 
be upgraded to include anaerobic zones. Also the biological removal makes possible to have 
phosphorus recovery in the form of struvite. Struvite is a little crystal formed with the 
combination of phosphorus and magnesium that can be sold as fertilizer, this way you can 
generate some profit from the phosphorus removal. 
In conclusion, when applied to Brazil, even the biological removal with recovery of 
phosphorus seems a good possibility, the chemical removal is the only one being currently used 
in Brazilian plants, what makes us believe that for now the chemical treatment is more feasible to 
our reality. However, in the future, we understand that this can easily change with more plants 
being implemented and more investments being made by our government, and when this 
 
 
18 
 
happens, the biological removal can spread all over the country as a primary source to remove 
and recovery phosphorus. 
 
 
 
Acknowledgements 
 
We would like to express special thanks of gratitude to our professor Dr. Thomas E. 
Wilson who gave us the opportunity to do this wonderful research on Nutrients Control & 
Recovery. We also would like to thank our sponsors, Coordination for the Improvement of 
Higher Education Personnel (CAPES), which through the Brazilian federal government program 
Science without Borders, with partnership of the Institute of International Education (IIE), 
provided all arrangements to pay our tuition, room, board, health insurance, visa sponsorship, 
round trip transportation and monthly stipend. 
A special thanks to Dan VanderSchuur from the H.F Curren AWT Plant at the city of 
Tampa, Dr. Chris Wilson from the District Hampton Roads Sanitation District, Keith Mahoney 
from the New York City Department of Environmental Protection, Christine DeBarbadillo from 
the District of Columbia Water and Sewer Authority (DC Water) and Jay Parker from the Tahoe-
Truckee Sanitation Agency for the contribution on the study cases of several water reclamation 
plants around US. 
In addition, we thank Dr. Catherine A. O'Connor andthe other employees of the Greater 
Chicago Metropolitan Reclamation District (GCMRD), who guided us during the site visits to 
Egan and Stickney WRPs and shared their knowledge with us. 
 
 
19 
 
Finally, we thanks to the Illinois Institute of Technology for this summer research 
experience and academic training opportunity at the amazing city of Chicago. 
 
 
 
 
References 
Agência Nacional de Águas - ANA (2013). Panorama da Qualidade das Águas Superficiais do 
Brasil 2012. Brazil. 
Barnard, J.; Houweling, D.; Steichen, M. (2011). Fermentation of Mixed Liquor for Removal and 
Recovery Phosphorus. Proceedings of the Water Environment Federation, Nutrient 
Recovery and Management 2011, pp. 1-17(17). 
Bresters et al. (1997). Sludge Treatment and Disposal: Management Approaches and 
Experiences. Environmental Issues Series. No. 7. 
Doyle, K. (2015). A model approach for sustainable phosphorus recovery from wastewater. 
Accessed in: https://www.agronomy.org/science-news/model-approach-sustainable-
phosphorus-recovery-wastewater. 
Environmental Protection Agency – EPA (1987). Design Manual: Phosphorus Removal. 
EPA/625/1-87/001. September, 1987. 
Environmental Protection Agency – EPA (2016). Nutrient Pollution Policy and Data. Accessed 
in: https://www.epa.gov/nutrient-policy-data. 
Hartley, K. (2013). Tuning Biological Nutrient Removal Plants. 1 st ed., IWA Publishing, New 
York, NY. 
 
 
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Lee, G. E, Rast, W. & Jones, R. A. (1978). Eutrophication of water bodies: Insights for an age-
old problem. Environ. Sci. Technol., 12, 900-8. 
Metcalf & Eddy. Inc. (2003). Wastewater Engineering Treatment Disposal Reuse. 4th edition. 
New York, McGraw - Hill Book, 1815p. 
Morse, J. K.; Brett, S. W.; Guy, J. A.; Lester, J. N. (1998). Review: Phosphorus removal and 
recovery technologies. Science of the Total Environment, Volume 212, Issue 1, 5 March 
1998, Pages 69–81. 
Richards, I. R.; Johnston, A. E. (2001). The effectiveness of different precipitated phosphates as 
 resources of phosphorus for plants. Report on work undertaken for CEEP, EFMA 
(European Fertilizer Manufacturers Association), Anglian Water UK, Thames Water 
UK and Berlin Wasser Betriebe. 
Sawyer, C. N.; McCarty, P. L.; Parkin, G. F. (1994). Chemistry for Environmental Engineering. 
4
th
 ed., McGraw-Hill, Inc., New York, NY. 
Stone, E., Walker, S., Reardon, R., and Pretorius, C. (2015). Nutrient Removal Remedies: 
Troubleshooting BNR Processes Requires a Holistic Review. WE&T Water Environment 
and Technology. Volume 27, Number 4, pp: 42. 
Water Environment Federation - WEF (2011). Nutrient Removal, WEF MOP 34. Water 
Resources and Environmental Engineering Series. 1st edition. 
Yeoman, S; Stephenson, T; Lester, J. N; and Perry R. (1988). The Removal of Phosphorus 
during Wastewater Treatment: A Review. Environmental Pollution 49 (1988) 183-233. 
 
 
 
21 
 
Tables 
 
Table 1 – Advantages and disadvantages of chemical addition in different sections (WEF MOP, 
2011) 
 
 
 
22 
 
Figures 
 
Figure 1 – Current States with Total Nitrogen and Total Phosphorus Criteria (EPA website, 
2016). 
 
 
23 
 
 
Figure 2 – Water quality of urban water bodies in Brazil (ANA, 2013). 
 
 
Figure 3 - Trophic State of lotic Brazilian environments (ANA, 2013). 
 
 
Figure 4- Trophic State of lentic Brazilian environments (ANA, 2013). 
 
 
24 
 
 
Figure 5 - Typical phosphorus removal processes (WEF MOP, 2011). 
 
 
Figure 6 - Typical wastewater treatment scheme. The arrows indicate the usual situations, where 
the chemicals added. (WEF MOP, 2011) 
 
 
25 
 
 
Figure 7 – EBPR Schematic (Made by the authors). 
 
 
Figure 8 – Typical mainstream biological phosphorus-removal processes; a) Phoredox; b) A2O; 
c) UCT – University of Cape Town. (Metcalf & Eddy, 2003). 
 
 
26 
 
 
Figure 9 – PhoStrip process (Metcalf & Eddy, 2003). 
 
Figure 10 – Modified Bardenpho process (WEF MOP, 2011). 
 
Figure 11 - Original Bardenpho pilot plan 
 
 
27 
 
Appendix 
 
Section A – Members’ contribution 
Major contributors: 
- Natalia A. Killer - Background section, final review and paper formatting. 
- Henrique L. Ribeiro - Abstract, objectives, methods, conclusion and acknowledgements. 
- Luiz N. Caracas Neto - Results Section. 
Secondary contributors: 
- All 5 members helped to gather information to elaborate our two posters and our two 
papers during the eight weeks of academic training experience. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
28 
 
Section B – Site visit pictures: Stickney Water Reclamation Plant 
This section contains some pictures took during our site visit to Stickney WRP in June, 2016. 
 
Picture 1 – Anoxic, Anaerobic and Aerobic zones in the mixing tanks. 
 
Picture 2 – Secondary clarifier. 
 
 
29 
 
 
Picture 3 – Phosphorus recovery room: Pearl reactor and Crystal Green bags. 
 
 
Picture 4 – Sludge handling: Centrifuges.