Nutrient recovery from waste streams through struvite formation
(2015)- Abstract
- Eutrophication or the nutrient enrichment of water bodies, typically by nitrogen and phosphorus has adversely
affected the aquatic life and the quality of water. Governments have been forced to take actions in order to reduce
the release of these nutrients into the environment.
To date the main global effort has been to remove such nutrients at source. However, with an increase in awareness
of the importance of phosphorus as a non-renewable resource, more studies are being carried out to find methods to
prevent loss of phosphorus and to recover it instead. The struvite crystallization process has been shown to be a
promising technology to efficiently recover phosphorus from point... (More) - Eutrophication or the nutrient enrichment of water bodies, typically by nitrogen and phosphorus has adversely
affected the aquatic life and the quality of water. Governments have been forced to take actions in order to reduce
the release of these nutrients into the environment.
To date the main global effort has been to remove such nutrients at source. However, with an increase in awareness
of the importance of phosphorus as a non-renewable resource, more studies are being carried out to find methods to
prevent loss of phosphorus and to recover it instead. The struvite crystallization process has been shown to be a
promising technology to efficiently recover phosphorus from point sources such as municipal, agricultural and
industrial wastewater.
The work throughout this thesis deals with the use of the struvite crystallization process as a mean to recover
nitrogen and phosphorus from waste streams. To prevent the formation of struvite fine crystals, which are difficult to
harvest; aggregation of struvite crystals was promoted using a fluidized bed reactor. Further analysis of the
precipitates using X-ray diffraction proved that these precipitated aggregates were in fact struvite. In cases where
crystal aggregation cannot be performed, it has been suggested that harvesting of struvite fine crystals can be
improved by the addition of coagulants and coagulating aids such as chitosan and bentonite, which have been shown
to be efficient in increasing the setting velocity of the crystals. Furthermore, struvite crystals were formulated into
granules to create a product with a higher commercial value. The quality of this product as a fertilizer was
investigated in terms of its physical and chemical properties. Finally, the use of struvite crystallization followed by a
struvite recycling process to recover nutrients from urine was investigated. Using this process, it was possible to
recover 90% of both nitrogen and phosphorus from urine. (Less) - Abstract (Swedish)
- Popular Abstract in English
These days we hear a lot about sustainability and most of us try to live in a more
sustainable way. We use less water and energy, we sort our household waste and we
prefer to consume products that are produced with less negative human impact.
However, when it comes to our own excreta we definitely think of it as waste. And we
are glad enough that wastewater treatment systems are there to take care of it! But the
question is: how sustainable are our wastewater treatment systems?
Today’s wastewater treatment systems are mainly built on the concept of removing
substances that can be harmful to humans and the environment. The problem... (More) - Popular Abstract in English
These days we hear a lot about sustainability and most of us try to live in a more
sustainable way. We use less water and energy, we sort our household waste and we
prefer to consume products that are produced with less negative human impact.
However, when it comes to our own excreta we definitely think of it as waste. And we
are glad enough that wastewater treatment systems are there to take care of it! But the
question is: how sustainable are our wastewater treatment systems?
Today’s wastewater treatment systems are mainly built on the concept of removing
substances that can be harmful to humans and the environment. The problem still
remains; we are left with substances that we do not really know how to dispose of.
However, considering the principles of sustainability recovering and reusing resources
is a far superior approach than removing them.
One good example of this is today’s unsustainable phosphorus flow; from its starting
point in mining to its end point in discharging it to the environment. Phosphorus,
which is mainly used as a fertilizer, is obtained by mining of phosphorus rock and
deterioration of land is its obvious consequence. A lot of this phosphorus ends up on
our plate and eventually in our excreta. But from this point on, this valuable element
becomes waste. Phosphorus is a non-renewable resource and with its ever-increasing
consumption, it is predicted to be depleted within 50 to 100 years.
The goal of this thesis is to capture and reuse the phosphorus lost in our wastewater.
For this purpose, magnesium is added to a process that, together with phosphorus
and nitrogen, forms a crystal compound called struvite. Struvite can be separated
from wastewater and can be used as a high-quality fertilizer. Currently, there are only
a few full-scale struvite crystallization processes in use around the world. Several
technical and economical limitations hinder wide application of this process. One of
the main objectives of this study was to improve the process by either coagulation or
aggregation of struvite crystals. It was also possible to efficiently capture both nitrogen
and phosphorus from urine. This is an important finding for better use of potential
future decentralized sanitation systems.
The work throughout this thesis is a step towards a more sustainable waste
management. It is an effort to further highlight the notion that “waste is a valuable
resource”. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4936528
- author
- Latifian, Maryam LU
- supervisor
-
- Jing Liu LU
- Olle Holst LU
- opponent
-
- Professor Gustafsson, Jon Petter, SLU, Uppsala
- organization
- publishing date
- 2015
- type
- Thesis
- publication status
- published
- subject
- keywords
- struvite, nutrient, phosphorus, nitrogen, wastewater treatment, anaerobic digestion, urine
- defense location
- Kemicentrum Lecture Hall B, Getingevägen 60, Lund University, Faculty of Engineering, (LTH)
- defense date
- 2015-02-12 10:30:00
- ISBN
- 978-91-7422-383-5
- language
- English
- LU publication?
- yes
- id
- ebf95620-b938-4d3d-8a81-7f4501d1f7e0 (old id 4936528)
- date added to LUP
- 2016-04-04 13:21:44
- date last changed
- 2018-11-21 21:13:29
@phdthesis{ebf95620-b938-4d3d-8a81-7f4501d1f7e0,
abstract = {{Eutrophication or the nutrient enrichment of water bodies, typically by nitrogen and phosphorus has adversely<br/><br>
affected the aquatic life and the quality of water. Governments have been forced to take actions in order to reduce<br/><br>
the release of these nutrients into the environment.<br/><br>
To date the main global effort has been to remove such nutrients at source. However, with an increase in awareness<br/><br>
of the importance of phosphorus as a non-renewable resource, more studies are being carried out to find methods to<br/><br>
prevent loss of phosphorus and to recover it instead. The struvite crystallization process has been shown to be a<br/><br>
promising technology to efficiently recover phosphorus from point sources such as municipal, agricultural and<br/><br>
industrial wastewater.<br/><br>
The work throughout this thesis deals with the use of the struvite crystallization process as a mean to recover<br/><br>
nitrogen and phosphorus from waste streams. To prevent the formation of struvite fine crystals, which are difficult to<br/><br>
harvest; aggregation of struvite crystals was promoted using a fluidized bed reactor. Further analysis of the<br/><br>
precipitates using X-ray diffraction proved that these precipitated aggregates were in fact struvite. In cases where<br/><br>
crystal aggregation cannot be performed, it has been suggested that harvesting of struvite fine crystals can be<br/><br>
improved by the addition of coagulants and coagulating aids such as chitosan and bentonite, which have been shown<br/><br>
to be efficient in increasing the setting velocity of the crystals. Furthermore, struvite crystals were formulated into<br/><br>
granules to create a product with a higher commercial value. The quality of this product as a fertilizer was<br/><br>
investigated in terms of its physical and chemical properties. Finally, the use of struvite crystallization followed by a<br/><br>
struvite recycling process to recover nutrients from urine was investigated. Using this process, it was possible to<br/><br>
recover 90% of both nitrogen and phosphorus from urine.}},
author = {{Latifian, Maryam}},
isbn = {{978-91-7422-383-5}},
keywords = {{struvite; nutrient; phosphorus; nitrogen; wastewater treatment; anaerobic digestion; urine}},
language = {{eng}},
school = {{Lund University}},
title = {{Nutrient recovery from waste streams through struvite formation}},
url = {{https://lup.lub.lu.se/search/files/6101216/4936628.pdf}},
year = {{2015}},
}