Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

    We have a manual that explains all the features 

Current refinement(s):

Records 1 - 20 / 453

  • help
  • print

    Print search results

  • export
    A maximum of 250 titles can be exported. Please, refine your queryYou can also select and export up to 30 titles via your marked list.
  • alert
    We will mail you new results for this query: keywords==afvalwaterbehandeling
Check title to add to marked list
Removal of pharmaceutically active compounds in constructed wetlands: mechanisms and application
He, Yujie - \ 2017
University. Promotor(en): Huub Rijnaarts, co-promotor(en): Alette Langenhoff; Nora Sutton. - Wageningen : Wageningen University - ISBN 9789463436328 - 290
artificial wetlands - drugs - waste water treatment - biodegradation - helofytenfilters - geneesmiddelen - afvalwaterbehandeling - biodegradatie

A constructed wetland (CW) is an integrated and enhanced version of natural ecosystem for fate and transport of pharmaceutically active compounds (PhAC). This thesis demonstrates removal mechanisms of PhACs in CWs and their application as post-treatment processes to eliminate PhACs from wastewater effluent. Four main subjects were investigated in this thesis: 1) mechanisms of PhAC removal in individual processes in CWs, including photodegradation, sorption, biodegradation, and phytoremediation and their interactions; 2) effect of important environmental factors (i.e. dissolved organic matter, redox conditions) on the removal processes; 3) enhancement of photodegradation and biodegradation capacity in CWs; 4) fate and distribution of PhACs in CWs by using chemical and toxicological analytical tools.

AQUAFARM van zuiveren naar oogsten
Verdonschot, P.F.M. - \ 2017
Aquafarm NL
afvalwater - waterzuivering - industriële grondstoffen - biobased economy - afvalwaterbehandeling - aquacultuur - biomassa productie - waste water - water treatment - feedstocks - waste water treatment - aquaculture - biomass production
Aquafarm ziet afvalwater als basis voor het produceren van hoogwaardige bouwstoffen, waarmee tegelijkertijd het water gezuiverd wordt.
Mobiele waterzuivering glastuinbouw
Ruijven, Jim van; Os, Erik van; Vermeulen, Peter - \ 2017
Bleiswijk : Wageningen University & Research, BU Glastuinbouw (Rapport GTB 1424) - 54
kassen - glastuinbouw - afvalwaterbehandeling - afvalwater - waterverontreiniging - afvoer - zuiveren - waterzuivering - oppervlaktewater - oppervlaktewaterkwaliteit - gewasbescherming - pesticiden - substraten - cultuur zonder grond - mobiele uitrusting - greenhouses - greenhouse horticulture - waste water treatment - waste water - water pollution - discharge - purification - water treatment - surface water - surface water quality - plant protection - pesticides - substrates - soilless culture - mobile equipment
Application of a mobile unit for discharge water purification is one of four options to apply to the purification obligation per 1-1-2018. Depending on the amount of discharge, future water strategy and investment options, mobile purification can be an interesting option. The amount of discharge water varies with crop, irrigation strategy and quality of the irrigation water and is between 122 and 3.340 m3/ha/year for surveyed companies. About 65% of greenhouse companies discharges
From harmful to useful algae
Blaas, Harry - \ 2017
University. Promotor(en): Carolien Kroeze. - Wageningen : Wageningen University - ISBN 9789463430357 - 117
algae - algae culture - adverse effects - nitrogen - phosphorus - rivers - eutrophication - waste water treatment - europe - algen - algenteelt - nadelige gevolgen - stikstof - fosfor - rivieren - eutrofiëring - afvalwaterbehandeling - europa

Eutrophication of coastal waters is a worldwide phenomenon. This study focuses on eutrophication in the coastal waters of Europe. Eutrophication is mainly a result of the increased transport of nutrients from watersheds by rivers to the coastal waters. Nutrient losses from watersheds are generally from agriculture, sewage, atmospheric deposition and from natural sources. In case of an overload of nutrients in the coastal waters, algal blooms may develop which increase the risk of hypoxia, fish mortality, and loss of biodiversity.

Algae can also be useful. They are increasingly considered an interesting product. For instance, micro-algae can be grow on land to produce proteins, lipids and fatty acids. Some studies indicate that micro-algae can be an important feedstock in the future for, for instance, the production of biodiesel. Moreover, macro-algae can be produced in seawater in sea farms. Macro-algae can be edible, or be used as a feedstock. By yielding macro-algae, nutrients are removed from the water, reducing coastal eutrophication.

The objective of this study is to analyse past and future trends in nutrient export by rivers to European seas with a focus on the role of algae. Three types of algae will be distinguished: (1) harmful algal blooms in coastal seas, (2) cultivation of micro-algae on land for the production of proteins, lipids and fatty acids, and (3) cultivation of multi cellular algae in seaweed farms for human consumption or other products.

To meet the objective the following research questions are addressed:

RQ1 To what extent do N and P loads exceed levels that minimize the risk of harmful algal blooms, and what are the relative shares of sources of N and P in rivers of the European Union?

RQ2 What are the potential consequences of large-scale land-based production of biodiesel from cultivated micro-algae in Europe for coastal eutrophication?

RQ3 Would it possible to cultivate and process micro-algae in a factory, and what is the environmental performance?

RQ4 To what extent can seaweed farming in combination with nutrient management in agriculture and waste water treatment reduce the potential for coastal eutrophication?

These questions are answered through model analyses. The Global NEWS (Nutrient Export from WaterSheds) model simulates river export of nutrients as function of human activities on land. It includes more than 6000 rivers worldwide. It can be used to quantify nutrient flows from land to sea for the years 1970, 2000, 2030 and 2050. For future years four scenarios have been implemented. One of these scenarios is named Global Orchestration and mostly used as a reference in this thesis. This scenario assumes a globalised world, with a reactive approach towards environmental problems. The model was released in 2010, has been validated for the years 1970 and 2000. The nutrients considered in the model are nitrogen (N) and phosphorus (P). In this thesis Global NEWS is used to calculate transport of nutrients to the coastal waters of Europe. The model uses ICEP (Indicator for Coastal Eutrophication Potential) values at the river mouths as an indicator for potentially harmful effects of nutrient enrichment. These ICEP values reflect the ratio of nitrogen and phosphorus to silica in coastal seas. A positive ICEP value indicates that nitrogen or phosphorus levels are too high, favouring conditions for potentially harmful algae to bloom.

In chapter 2 Global NEWS is used to calculate the transport of nutrients and ICEP values for 48 European rivers for the years 2000 and 2050. The model calculates a positive ICEP for 38 rivers in the year 2000, and for 34 rivers in the year 2050. This indicates that current policies are not so effective in reducing the river transport of nutrients. For polluted rivers the anthropogenic sources of the nutrients are investigated. For most rivers the dominant polluting sources are agriculture or sewage. The results indicate that a basin-specific policy is needed to reduce the risks of coastal eutrophication.

In chapter 3 the focus is on useful algae: micro-algae cultivation on land for, for instance, biodiesel production. The consequences of large-scale production of biodiesel on nutrient export by rivers to the European coastal waters are investigated. A scenario is developed assuming that a production of 0.4 billion m3 diesel from cultivated micro-algae. The cultivation is assumed to be in the open air, for instance in ponds or in closed tube systems. Such production levels would need a land surface area as large as Portugal. The Global NEWS model is used to calculate the amount of waste water from micro-algae production that will be transported to the coastal waters in this scenario. The results indicate that large-scale cultivation of micro-algae on land can become a source of nutrient pollution in rivers. In the scenario with large-scale micro-algae cultivation the future transport of nitrogen and phosphorus is considerably higher than in the reference scenario. To ensure sustainable production of biodiesel from micro-algae it is important to develop cultivation systems with low nutrient losses to the environment.

Chapter 4 presents a design of a factory for the cultivation and processing of micro-algae in an environmentally sound way. The factory does not use fossil fuels and applies maximum recycling of water and nutrients. In this factory it is possible to produce lipids, carbohydrates, proteins and minerals. The factory can be built on any piece of land, so there is no need to use arable land. The factory is independent of weather and climate. Energy can be delivered by wind mills. In this chapter an example of producing diesel in the factory is shown. In the 12 stories factory with a cultivation area of 1 hectare, 810 ton micro-algae can be cultivated per year. This is enough for the production of 386 ton diesel per year.

Chapter 5 focuses on mitigation of eutrophication in European coastal waters. A scenario is presented assuming different types of measures. The scenario first assumes that nutrient use efficiencies in agriculture are higher than today, and that waste water treatment in sewage systems is improved. In addition, it assumes that all excess N and P in coastal waters is harvested in seaweed farms producing edible macro-algae. In our scenario for 2050 there is seaweed farming in the coastal waters of 34 rivers mouths in Europe .NEWS The areas needed to ensure that ICEP values remain below 0 (low potential for coastal eutrophication) range between 0 and 952 km2 per river mouth.

This thesis shows that algae can be both harmful and useful. River export of nutrients can lead to coastal eutrophication increasing the risks of harmful algal blooms. On the other hand, micro-algae can be produced without environmental harm on land, and macro-algae can be useful in reducing pollution levels in coastal seas. This thesis could serve as a basis for environmental policies to stimulate the production of these useful algae. The methods to mitigate algal blooms and to use algae in a sustainable way in this thesis are also useful for other parts of the world.

Groen proceswater: zuivering brouwerijprocesafvalwater met microalgen
Dijk, W. van; Weide, R.Y. van der; Kroon, A. - \ 2016
Lelystad : ACRRES - Wageningen UR (PPO 721) - 42 p.
brouwerij-industrie - brouwerijafvalwater - afvalwater - afvalwaterbehandeling - waterzuivering - algen - biomassa - biomassa productie - afvoerwater - flotatie - algenteelt - brewing industry - brewery effluent - waste water - waste water treatment - water treatment - algae - biomass - biomass production - effluents - flotation - algae culture
In 2012 is het project Groen Proceswater gestart. Hierin worden de mogelijkheden van zuivering van brouwerijprocesafvalwater met behulp van microalgen onderzocht. Dit is gedaan in een samenwerkingsverband van Heineken Nederland BV, Algae Food & Fuel en WUR-ACRRES. De resultaten behaald in 2012 en 2013 zijn beschreven in afzonderlijke rapporten. In dit rapport zijn de resultaten van 2014 en 2015 beschreven. In 2014 is onderzocht of een voorbehandeling van het proceswater via cavitatie-flotatie het zuiveringsresultaat kan verbeteren en in 2015 of de energie-input van de LEDbelichting kan worden verminderd door te flashen (afwisselende licht-donker periodes op microseconde tijdschaal). Verder is in 2015 en 2016 via een literatuurstudie gekeken naar de verwaarding van de geproduceerde algenbiomassa en zijn de conclusies van het gehele project samengevat.
Onderzoek Waterkringloopsluiting Tulpenbroeierij : overzicht huidige en toekomstige technieken om waterkringloopsluiting mogelijk te maken
Os, E.A. van; Feenstra, L. ; Ruijven, J. van; Stijger, C.C.M.M. ; Koeman-Stein, N. ; Appelman, W. - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1394) - 38
tulpen - forceren van planten - glastuinbouw - kasgewassen - afvalwaterbehandeling - afvalwater - recirculatiesystemen - drainagewater - pathogenen - pathogeen eliminatie - gewasbescherming - voedingsstoffen - fenolen - tulips - forcing - greenhouse horticulture - greenhouse crops - waste water treatment - waste water - recirculating systems - drainage water - pathogens - pathogen elimination - plant protection - nutrients - phenols
Closing of the water cycle is required in the forcing of tulips. For growers it is important to know if and how they can eliminate pathogens at an adequate way and which equipment is most suitable to break down plant protection products from waste water. Now participating growers have various equipment for full or partly disinfection. It is recommended to start with good pre-filtration methods to eliminate pathogens which can be fully achieved with UV and ozone, while products such as hydrogen peroxide with additives or chlorite products can be used for an after-effect in the pipe work. Phenolic compounds, released by the roots, can be eliminated with oxidising methods. However efficacy has not been investigated. Purification of discharge water, before entering the waste ditch, will be obliged. New, certified, equipment will come on the market soon. Reuse of discharge water, after pre-fi ltration and disinfection, is also an option.
Evaluatie zuiveringstechniek voor verwijdering gewasbeschermingsmiddelen III
Ruijven, J.P.M. van; Beerling, E.A.M. ; Staaij, M. van der; Os, E.A. van - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1414) - 30
afvalwaterbehandeling - waterzuivering - afvalwater - waterverontreiniging - glastuinbouw - kassen - cultuur zonder grond - gewasbescherming - pesticiden - ozon - verwijdering - filtratie - technieken - waste water treatment - water treatment - waste water - water pollution - greenhouse horticulture - greenhouses - soilless culture - plant protection - pesticides - ozone - removal - filtration - techniques
Dutch greenhouse horticulture has to treat all discharged water from soilless cultivations for the removal of plant protection products, to meet the new Dutch Directive Hoofdlijnenakkoord (2015). Building on previous research, (1) the life span of activated carbon filters, (2) the effect of increasing concentrations of plant protection products on the removal efficacy of ozone and the removal efficacy of (3) multimedia filtration and (4) ultrasonic water treatment have been investigated. It turned out to be difficult to design an active carbon based water treatment system capable of durable treatment of greenhouse discharge water: organic and mineral material in the water blocked the pores, thereby clogging the filter system and causing leakage by pressure build-up. Activated carbon filtration (granular activated carbon, 48 min contact time, 50 μm prefiltration with sand filter) achieved a removal efficacy of >95% for up to 430 bed volumes treated. Combination with advanced oxidation improved the removal efficacy, but the removal time of the filter could not be determined due to leakage. The removal efficacy of ozone oxidation remained >98%, even at increased concentrations (factor 10 and 100) of plant protection products in the untreated water. The multimedia filter removed 75% of the plant protection products by adsorption, biological breakdown within the filter was not determined. Treatment of the water with ultrasonic waves hardly had any effect (maximum 30% efficacy) on the breakdown.
Biobased chemicals from polyhydroxybutyrate
Spekreijse, Jurjen - \ 2016
University. Promotor(en): Johan Sanders, co-promotor(en): Elinor Scott; Harry Bitter. - Wageningen : Wageningen University - ISBN 9789462578630 - 148
bioprocess engineering - biopolymers - waste water treatment - polyhydroxyalkanoates - acrylics - propylene - biomass conversion - biobased chemistry - biobased economy - bioproceskunde - biopolymeren - afvalwaterbehandeling - polyhydroxyalkanoaten - acrylaten - propyleen - biomassaconversie - chemie op basis van biologische grondstoffen

Currently, most chemicals and materials are obtained from fossil resources. After use, these chemicals and materials are converted to CO2. As discussed in chapter 1, this causes a build-up of CO2 in the atmosphere, the main driving force of global warming. In order to reach a sustainable system, biomass could be used as a resource for chemicals and materials instead. A biorefinery approach, where all parts of biomass are used to its full potential is essential. Taking this into consideration, wastewater streams of current biobased processes could be an excellent source for chemicals and materials. However, wastewater is often dilute and heterogeneous of nature. To overcome these challenges, wastewater rich in carbon can be processed by microorganisms to obtain a biodegradable polyester, polyhydroxyalkanoate (PHA). However, the mechanical properties of this polymer make it unsuitable as polymeric material. Moreover, processing of PHA is challenging. To circumvent these issues, we propose a conversion of the inferior PHA to methyl acrylate and propylene (Figure 7.1) which can be used in current processing infrastructure. PHA rich cells are obtained from the purification of wastewater. The PHA obtained can be purified and converted to MC (Figure 7.1, chapter 2) or the PHA rich cells can be used directly (Figure 7.1, chapter 3). For the second step, the conversion of methyl crotonate (MC) to methyl acrylate and propylene, the catalyst was immobilised (Figure 7.1, chapter 4). The current state of ethenolysis reaction on biomass was reviewed (Figure 7.1, chapter 5). The conversion of PHA to methyl acrylate and propylene enables the use of carbon from wastewater streams without the disadvantages related to the direct use of PHA.

In chapter 2, the first step of the conversion of PHA to methyl acrylate and propylene was investigated. Since PHA obtained from wastewater exists mostly as polyhydroxybutyrate (PHB), this was chosen as a starting material for our studies. It was shown that PHB could be converted to MC using methanol at 200 °C.. MC has the advantage of being immiscible with water, which aids its separation. In chapter 2, the pathway of the reaction was clarified, which was subsequently used to optimise the conditions of this conversion. The conversion of PHB to MC proceeds via a thermolysis to crotonic acid (CA), which is followed by an esterification to MC. The formation of CA is the rate determining step below 18 bar, where above 18 bar this changes to the esterification to MC. A selectivity of 60% to MC is obtained with a full conversion of PHB with 18 bar being the optimal pressure for the conversion.

Microorganisms produce PHA within their cells, which poses challenges to the downstream processing of PHA as the material has to be isolated from within the cells and dried. The isolation and drying of PHB is costly and is responsible for a large part of the production costs of PHA. In order to reduce the costs of PHA for the production of biobased chemicals, the conversion of PHA to MC was tested using whole cells. In chapter 3, PHA rich cells were directly converted to MC using the optimised conditions found in chapter 2. The influence of fermentation salts, water and the presence of valerate monomers in the PHA were studied. It was found that the valerate monomers have no influence on the conversion. Fermentation salts do influence the conversion depending on the salt. Magnesium hydroxide catalyses the conversion of PHB to MC, where magnesium sulphate catalyses the formation of methyl 3-hydroxybutyrate as side product. The reaction tolerates up to 20% water, which means that the drying step in the downstream processing of PHA can be significantly reduced.

The second step of the conversion of PHA to methyl acrylate and propylene involves an ethenolysis, a cross metathesis of MC with ethylene. This ethenolysis reaction requires a homogeneous catalyst. One of the most active catalysts for this conversion is the ruthenium based Hovey-Grubbs 2nd generation. However, the required high loading of this catalyst makes it an expensive part of the conversion. In order to enable reusing of the catalyst, immobilisation of the Hovey-Grubbs catalyst was investigated in chapter 4. The catalyst was immobilised inside a metal organic framework (MOF). For this purpose MIL-101-NH2(Al) was used for its large cavities connected by small openings. This allows the catalyst to reside inside the cavities, while the small openings prevent it from leaching out. The catalyst was successfully immobilised using a mechanochemical approach. This method can be applied on other catalysts as well, which was shown by the immobilisation of Zhan catalyst. Both immobilised catalysts show metathesis activity for multiple reaction cycles. It was found that the MOF, MIL-101-NH2(Al), partially undergoes a structural change to form MIL-53-NH2(Al). When MIL-53-NH2(Al) was used as starting MOF the catalyst was trapped but inactive. It was concluded that when starting from MIL-101-NH2(Al), the catalyst trapped in the parts of the material that was converted to MIL-53-NH2(Al) are catalytically inactive.

To investigate the current state of the art of the use of ethenolysis on biomass, a literature review was performed in chapter 5. The results of the ethenolysis of methyl oleate (MO) were compared in order to investigate the most important parameters. It was found that the purity of the ethylene feed has the biggest influence on the turn over numbers (TONs) and that a higher purity ethylene has shown a larger impact on the ethenolysis of MO than the development of novel catalysts. When electron poor substrates are used, the highest TONs are obtained with the less stable Hoveyda-Grubbs 2nd generation. However, no studies were performed on the influence of ethylene purity on these reactions and higher TONs may be achieved using a higher purity ethylene.

In chapter 6, the results and conclusions of the thesis are summarised. The implications of these findings are discussed and suggestions for further research within the field are given.

Recirculatie bij snij-amaryllis (Hippeastrum) in drie teeltjaren (2013-2015) : Behoud plantgezondheid en voorkomen groeiremming bij hergebruik drainwater
Kromwijk, J.A.M. ; Burg, R. van der; Nijs, L. ; Overkleeft, J. ; Eveleens-Clark, B.A. ; Blok, C. ; Os, E.A. van; Baar, P.H. van; Grootscholten, M. ; Woets, F. - \ 2016
Bleiswijk : Wageningen UR Glastuinbouw (Rapport GTB 1398) - 88 p.
amaryllis - glastuinbouw - kasgewassen - kasproeven - teelt onder bescherming - emissie - hergebruik van water - afvalwaterbehandeling - afvalwater - recirculatiesystemen - lycorine - stikstof - voedingsstoffen - kunstmeststoffen - greenhouse horticulture - greenhouse crops - greenhouse experiments - protected cultivation - emission - water reuse - waste water treatment - waste water - recirculating systems - nitrogen - nutrients - fertilizers
In the Netherlands most crops grown in greenhouses reuse drain water. However, in the cultivation of amaryllis
cut flowers (Hippeastrum) little drainage water is being reused so far because of strong suspicions of inhibitory
substances in the drainage water. To reduce the emission of nutrients to the environment an experiment was
started on request of the amaryllis growers. In a greenhouse experiment drainage water of amaryllis was treated
with advanced oxidation and reused. This was compared with the reuse of drainage water treated with an UV
disinfector and a control treatment without the reuse of drainage water. In three years of cultivation, there was
no difference in production and no adverse effects were seen in crop growth. This research was funded by the
Dutch amaryllis growers, the ‘Topsector Tuinbouw en Uitgangsmaterialen’, the Product Board for Horticulture, the
project ‘Samenwerken aan Vaardigheden’ and Koppert.
Sanitation planning in developing countries : added value of resource recovery
Kerstens, S.M. - \ 2016
University. Promotor(en): Grietje Zeeman, co-promotor(en): Ingo Leusbrock. - Wageningen : Wageningen University - ISBN 9789462576889 - 316 p.
sanitation - developing countries - recovery - urban planning - waste water treatment - waste treatment - waste management - environmental technology - volksgezondheidsbevordering - ontwikkelingslanden - terugwinning - stedelijke planning - afvalwaterbehandeling - afvalverwerking - afvalbeheer - milieutechnologie

Sanitation planning in developing countries: Added value of resource recovery

Worldwide 2.5 billion people lack access to sanitation. This impacts human live, the environment and represents a loss of valuable resources that can be regained from wastewater. This study shows that resource recovery can be a potential driver to accelerate sanitation. A new sanitation decision framework for policy makers was created and tested in Indonesia.

The variety of advantages and disadvantages of sanitation interventions complicates the sanitation planning process. Conventional sanitation systems consume energy, chemicals and land or produce a sludge that requires disposal, whereas a range of opportunities exists that enables valorization of resources from our “waste”. To support policy makers in planning sanitation that considers sustainability dimensions (social, environment and economy), a new sanitation framework was developed. This framework resolves trade-offs of sanitation alternatives across spatial and temporal scales in three steps. First, it identifies feasible wastewater and solid waste systems in relation to the type of residential area. Secondly, the anticipated population development, current access and formulated targets are an input to generate the number of required systems, their location and associated implementation costs. The required systems are visualized in geographical maps, while budgets are allocated to responsible implementing institutions. Thirdly, the potential demand from “back-end users” of sanitation products, such as agriculture for compost and phosphorus, aquaculture for produced duckweed and industries for recovered plastic and paper, to substitute conventionally produced materials is determined. These three steps are then combined to quantitatively evaluate the (1) environmental impact, (2) operational costs and benefits, and (3) the potential of selected sanitation alternatives to close material cycles. A case study of the Citarum River was performed in which (monetized) benefits such as health, welfare and revenues from the sale of recovered resources were compared with the costs of different (conventional and resource recovery) sanitation systems. The study showed that the economic Benefit to Cost Ratio (BCR) of resource recovery technologies is bigger than BCR of conventional (low cost) technologies, while improving the water quality. It thus shows that resource recovery is a potential driver to accelerate sanitation development. The framework was illustrated using Indonesia as an example, but its application can benefit the quality of millions of lives worldwide.

Bio-filtration of helminth eggs and coliforms from municipal sewage for agricultural reuse in Peru
Yaya Beas, R.E. - \ 2016
University. Promotor(en): Grietje Zeeman; Jules van Lier; Katarzyna Kujawa. - Wageningen : Wageningen University - ISBN 9789461734945 - 187 p.
waste water treatment - waste water treatment plants - anaerobic treatment - helminth ova - anaerobic conditions - filtration - public health - afvalwaterbehandeling - afvalwaterbehandelingsinstallaties - anaërobe behandeling - wormeneitjes - anaërobe omstandigheden - filtratie - volksgezondheid

Where fresh water resources are scarce, treated wastewater becomes an attractive alternative for agricultural irrigation. However, the presence of large amounts of pathogens, even in treated wastewater, constraints its productive use, which is aggravated when sanitation and public health are poor. Among pathogenic indicators, helminth eggs are one of the most persistent microorganisms in treated effluents that may survive for several months in the irrigated fields. Application of upflow anaerobic sludge blanket (UASB) reactors could contribute to decrease the pathogenic content in wastewater due to physical and biological interactions with the anaerobic sludge bed, such as filtration and entrapment. In this thesis, the potential of the anaerobic sludge bed to particularly remove helminth eggs, was investigated in four phases. In the first phase, a temperature of 4° C was fixed in the UASB reactors in order to reduce the biological activity of the sludge. Hence, the anaerobic sludge filtration capacity at different upflow velocities was studied. This phase of the research was performed in two experiments. The first one using latex beads, simulating helminth eggs, and the second one using real helminth eggs, predominating in Peruvian wastewater. First experimental results show that increasing the upflow velocity led to a decrease in the removal efficiency of latex beads. At the lowest upflow velocity of 0.3 m·h−1, 100% removal of latex beads was reached. At an upflow velocity higher than 1 m·h−1, the removal efficiency dropped under 90 %. The degree of stabilisation of the sludge nor the sludge bed volume did not have a significant effect. Second experiment's results show that with upflow velocities below 1.5 m·h−1 real helminth eggs removal is greater than 70 %. Simultaneously tested, total and faecal coliforms removal was less than 83 %. The most common helminth eggs species found in the studied wastewater were Ascaris lumbricoides, Trichuris spp. and Strongyloides spp. The second phase was performed using two lab-scale UASB reactors at average ambient temperatures between 16.7 °C and 28.5 °C in the city of Lima (Peru). Ascaris suum eggs originating from infected pigs were selected as model organisms, considering their similarity, in terms of size and morphology, with Ascaris lumbricoides, a human pathogen. The sludge filtration capacity was determined, applying upflow velocities between 0.09 and 0.68 m·h−1. Average helminth eggs removals varied between 26 and 93 %, depending on upflow velocity and sludge bed height. 93 % removal was achieved when applying an upflow velocity of 0.09 m·h−1 and a sludge bed height reaching 19-25 % of the total reactor height. The third phase was conducted to test the effect of lower operational temperatures in the UASB reactor on the pathogen removal from domestic wastewater. Thus, a lab scale UASB reactor in the city of Puno (Peru), treating wastewater with temperatures varying between 11.3 and 14.3 °C for a period of 22 weeks after the start-up of the reactor, was used. Upflow velocities varied between 0.12 and 0.41 m·h−1. Results confirmed outcomes of the first phase of this research concerning helminth eggs removal, and consequently show that the sludge bed filtration capacity varied between 89 and 95 %. Faecal coliform removal varied between 0.9 and 2.1 log10 and E. coli removal between 0.8 and 1.6 log10. In general, removal efficiencies regarding helminth eggs and faecal coliforms, are not sufficient to comply with reuse standards. Finally, the capacity of Down Flow Hanging Sponge (DHS) reactors for removing faecal coliforms from domestic UASB reactor effluent for agricultural reuse in developing countries was investigated. Applied reactors were the cube type DHS (G1) without recirculation, the cube type DHS (G1) with recirculation and the curtain type DHS (G2). Results reveal an average faecal coliform removal of 4.74, 3.42 and 1.25 log10 respectively. These results comply with categories A, B and C of WHO (1989) standards, correspondingly. Therefore, treatment trains consisting of UASB-DHS reactors can possibly be applied when agricultural reuse is contemplated.

New wastewater treatment concepts towards energy saving and resource recovery
Khiewwijit, R. - \ 2016
University. Promotor(en): Huub Rijnaarts, co-promotor(en): Karel Keesman; Hardy Temmink. - Wageningen : Wageningen University - ISBN 9789462576407 - 148 p.
waste water treatment - energy saving - recovery - municipal wastewater - nutrients - volatile fatty acids - afvalwaterbehandeling - energiebesparing - terugwinning - stedelijk afvalwater - voedingsstoffen - vluchtige vetzuren
At present, conventional activated sludge (CAS) systems are widely applied to treat municipal wastewater. The main advantages of CAS systems are that they are robust and generally produce an effluent quality that meets the discharge guidelines. However, CAS systems cannot be considered sustainable because they consume large amounts of energy (mainly for aeration and sludge treatment), have a high CO2 emission and do no recover a potential resource of water, energy and nutrients nitrogen (N) and phosphorus (P). Therefore, in this thesis new municipal wastewater treatment concepts that combine treatment with recovery of valuable resources and can save considerable amounts of energy were investigated by modelling and experiments.

Quantitative numerical results showed that the feasibility of two novel wastewater treatment configurations, including combined bioflocculation and anaerobic digestion but with different nutrient removal technologies, i.e. (cold) partial nitritation/Anammox or microalgae treatment, is location dependent. Using Dutch municipal wastewater and climate conditions, the configuration with cold partial nitritation/Anammox is the most promising wastewater treatment concept, because it can: 1) treat wastewater year round; 2) produce an effluent at a quality that meets the discharge guidelines; 3) reduce CO2 emission by 35% compared to the CAS system; 4) achieve a net energy yield up to 0.24 kWh per m3 of wastewater compared to a negative net energy yield of -0.08 kWh per m3 of wastewater for the CAS system; and 5) recover 80% of the sewage P. Additionally, the feasibility of the two configurations was investigated for 16 locations around the globe. The results quantitatively support the pre-assumption that the configuration with (cold) partial nitritation/Anammox is applicable in tropical regions and some locations in temperate regions. The configuration with microalgae treatment is only applicable the whole year round in tropical regions that are close to the equator line. The results also showed that the configuration employing microalgae treatment has an advantage over the configuration employing partial nitritation/Anammox with respect to consumption of aeration energy and recovery of nutrients, but not with respect to area requirements. For a tropical climate country like Thailand, the net energy yield of both configurations is at least a factor 10 higher than the CAS system, while CO2 emission is at least 22% lower.

In CAS systems energy recovery from wastewater is accomplished by anaerobic digestion of the organic solids in primary and secondary sludge into methane. However, volatile fatty acids (VFA), which are intermediate digestion products, may be preferred over methane, because VFA can be used as starting compounds for a wide range of higher value products. In this thesis the experimental results showed that a combined process with bioflocculation, using a high-loaded membrane bioreactor (HL-MBR) to concentrate sewage organic matter, and anaerobic fermentation, using a sequencing batch reactor to produce VFA is technologically feasible. An HL-MBR operated at a hydraulic retention time (HRT) of 1 hour and a sludge retention time (SRT) of 1 day resulted in very good performance, because as high as 75.5% of the sewage COD (chemical oxygen demand) was diverted to the concentrate and only 7.5% was mineralized into CO2. It was also found that 90% of the sewage NH4-N and PO4-P were conserved in the HL-MBR permeate, which can be reused as irrigation water as it is free from solids and pathogens.

During anaerobic fermentation of the HL-MBR concentrate at an SRT of 5 days, 35°C and without pH control, methane production was inhibited, but incomplete solids degradation mainly limited the VFA production as only 15% of the sewage COD was converted to VFA. Thus, the VFA yield needed to be increased. It was hypothesized that high pH (pH 8–10) fermentation combined with a long SRT, allowing for sufficient solubilization of solids and colloidal COD, can improve the VFA yield. In the current study, it was found that application of a pH shock of 9 in the first 3.5 hours of a sequencing batch cycle followed by a pH uncontrolled phase for 7 days gave the highest VFA yield of 440 mg VFA-COD/g VSS and this was equivalent to 26% of the sewage COD. This yield was much higher than at fermentation without pH control or at a constant pH between 8 and 10. The high yield in the pH 9 shock fermentation could be explained by: 1) a reduction of methanogenic activity; or 2) a high degree of solids degradation; or 3) an enhanced protein hydrolysis and fermentation. This study also demonstrated that the VFA yield can still be further optimized by fine-tuning pH levels and longer operation, possibly with fermentative microorganisms adapted to a high pH that are commonly found in nature. This would further increase VFA yield to 33% of the sewage COD.
Aquatische biomassa, het verwaarden van waterige reststromen op lokaal niveau : Technisch deelrapport 1: Verkenning van de mogelijkheden van reststromen en aquatische biomassa
Huurman, Sander ; Weide, R.Y. van der - \ 2015
Lelystad : PPO AGV (Rapport / PPO-AGV 650) - 54 p.
afvalwateraquacultuur - aquatische biomassa - biomassa productie - afvalwaterbehandeling - haalbaarheidsstudies - reststromen - biobased economy - wastewater aquaculture - aquatic biomass - biomass production - waste water treatment - feasibility studies - residual streams
Het verwaarden van lokaal geproduceerde waterige reststromen door middel van aquatische biomassa is onderdeel van de PPS Kleinschalige bioraffinage (WP5). In dit deelrapport is een overzicht van een aantal in Nederland aanwezige waterige reststromen weergegeven. Een aantal van deze reststromen is ingezet in een microalgen well-plaat screeningtest om de biomassa ontwikkeling op deze stromen te onderzoeken. Op het vlak van het gebruik van aquatische biomassa zijn er een aantal samenvattingen van rapporten en literatuurstukken opgenomen in dit rapport. Ook is er een overzicht van de verschillende soorten aquatische biomassa en de mogelijke toepassing van deze biomassa op reststromen weergegeven. Als voorbeeld is de productie van verschillende soorten biomassa op effluent van een RWZI is gebruikt om een mogelijke verwaarding van componenten uit de biomassa weer te geven. De hoofdconclusie uit dit rapport is dat in Nederland op lokaal niveau diverse reststromen met uiteenlopende samenstellingen en volumes voorkomen. De inzet van aquatische biomassa om reststromen te ontdoen van nutriënten en afvalstoffen kan succesvol toegepast worden. Dit wordt vaak ‘effluent polishing’ genoemd. Het daadwerkelijk verwaarden van aquatisch biomassa gekweekt op reststromen is nog beperkt succesvol.
Alg groeit goed op plas en poep van NIOO
Sikkema, A. ; Lamers, P.P. - \ 2015
Resource: weekblad voor Wageningen UR 10 (2015)8. - ISSN 1874-3625
afvalwater - afvalwaterbehandeling - nieuwe sanitatie - biobased economy - algen - chlorella sorokiniana - organische meststoffen - algenteelt - waste water - waste water treatment - new sanitation - algae - organic fertilizers - algae culture
Chlorella sorokiniana reinigt geconcentreerd wc-water. Resultaat: schoon water én meststof
A Downflow Hanging Sponge (DHS) reactor for faecal coliform removal from an Upflow Anaerobic Sludge Bed (UASB) effluent
Yaya Beas, R.E. ; Kujawa-Roeleveld, K. ; Lier, J.B. van; Zeeman, G. - \ 2015
Water Science and Technology 72 (2015)11. - ISSN 0273-1223 - p. 2034 - 2044.
faecal coliforms - biochemical oxygen demand - chemical oxygen demand - waste water - waste water treatment - anaerobic treatment - waste water treatment plants - fecale coliformen - biochemisch zuurstofverbruik - chemisch zuurstofverbruik - afvalwater - afvalwaterbehandeling - anaërobe behandeling - afvalwaterbehandelingsinstallaties
This research was conducted to study the faecal coliforms removal capacity of Downflow Hanging Sponge (DHS) reactors as a post-treatment for an Upflow Anaerobic Sludge Blanket (UASB) reactor. Three long-term continuous lab-scale DHS reactors i.e. a reactor with cube type sponges without recirculation, a similar one with recirculation and a reactor with curtain type sponges. The porosities of the applied medium were 91%, 87% and 47% respectively. The organic loading rates were 0.86 kgCOD m-3 d-1, 0.53 kgCOD m-3 d-1 and 0.24 kgCOD m-3 d-1 correspondingly at hydraulic loading rates of 1.92 m3 m-2 d-1, 2.97 m3 m-2 d-1 and 1.32 m3 m-2 d-1, respectively. The corresponding averages for faecal coliform removal were 99.997%, 99.919% and 92.121% respectively. The WHO (1989) standards, in terms of faecal coliform content for unrestricted irrigation (Category A), was achieved with the effluent of the cube type DHS (G1) without recirculation. Restricted irrigation, category B and C is assigned to the effluent of the cube type with recirculation and the curtain type, respectively. Particularly for organic compounds, the effluent of evaluated DHS reactors complies with USEPA standards for irrigation of so called non-food crops like pasture for milking animals, fodder, fibre, and seed crops.
Closing Domestic Nutrient Cycles Using Microalgae
Vasconcelos Fernandes, T. ; Shresthat, R. ; Suit, Y. ; Papini, G. ; Zeeman, G. ; Vet, L.E.M. ; Wijffels, R.H. ; Lamers, P.P. - \ 2015
Environmental Science and Technology 49 (2015)20. - ISSN 0013-936X - p. 12450 - 12456.
algen - afvalwater - afvalwaterbehandeling - stikstof - fosfor - biomassa productie - proefopzet - nieuwe sanitatie - algae - waste water - waste water treatment - nitrogen - phosphorus - biomass production - experimental design - new sanitation
This study demonstrates that microalgae can effectively recover all P and N from anaerobically treated black water (toilet wastewater). Thus, enabling the removal of nutrients from the black water and the generation of a valuable algae product in one step. Screening experiments with green microalgae and cyanobacteria showed that all tested green microalgae species successfully grew on anaerobically treated black water. In a subsequent controlled experiment in flat-panel photobioreactors, Chlorella sorokiniana was able to remove 100% of the phosphorus and nitrogen from the medium. Phosphorus was depleted within 4 days while nitrogen took 12 days to reach depletion. The phosphorus and nitrogen removal rates during the initial linear growth phase were 17 and 122 mg·L–1·d–1, respectively. After this initial phase, the phosphorus was depleted. The nitrogen removal rate continued to decrease in the second phase, resulting in an overall removal rate of 80 mg·L–1·d–1. The biomass concentration at the end of the experiment was 11.5 g·L–1, with a P content of approximately 1% and a N content of 7.6%. This high algal biomass concentration, together with a relatively short P recovery time, is a promising finding for future post-treatment of black water while gaining valuable algal biomass for further application.
Bio-induced solid selenium for recovery from water
Hageman, S.P.W. - \ 2015
University. Promotor(en): Cees Buisman, co-promotor(en): Renata van der Weijden; Fons Stams. - Wageningen : Wageningen University - ISBN 9789462575103 - 156
selenium - waste water - waste water treatment - recovery - toxicity - bioreactors - afvalwater - afvalwaterbehandeling - terugwinning - toxiciteit - bioreactoren

Selenium in the form of selenate or selenite in wastewater needs to be removed due to its potential toxicity in the environment. Also, selenium is a valuable element that is used in several industries and current selenium resources are likely to be exhausted in less than 50 years. Waste streams containing selenium can therefore be used as a source of selenium. This requires conversion of the selenium in wastewater into a form that can be recovered. Biologically induced selenate reduction to recoverable selenium has the advantage that it uses the selective reduction capacities of biomass and a renewable electron donor.

To improve the recoverability of selenium the conversion of selenate to selenite was seen as an interesting opportunity. Selenite is more reactive than selenate and can be removed in a second step. As described in Chapter 2, it proved possible to convert selenate to mainly selenite at a low electron donor concentration.

Another method which is reviewed in this thesis is direct biological reduction of selenate to elemental selenium. After reduction the solids can be removed by a liquid solid separation process. Previously amorphous selenium particles were produced, which hampered recovery. In this research it is demonstrated that at a higher temperature, around 40 - 50°C, and at a higher pH, around pH 8 - 9, a more hexagonal selenium structure can be produced (Chapter 3). Crystalline acicular selenium particles of different sizes were thus obtained. This implies that selenium particles formation can be controlled and that selenium particles can grow. Large selenium particles make the separation process economic.

To grow larger selenium particles, a long-term experiment was performed at 50°C (Chapter 4). The reduction rate was poor, but selenium acicular particles were produced. These particles were also detected as clusters. These clusters open up new recovery opportunities. With Eerbeek sludge the optimal conditions for selenate conversion are around pH=7 and 30°C. To enlarge the selenium particles it is strongly recommended to use a different sludge since the optimal conditions with Eerbeek sludge do not match the conditions needed for acicular particle formation.

When selenate is converted to selenite, the selenite can be precipitated by sulphide to form selenium sulphide. Emmtec sludge was used to reduce the sulphur compounds to sulphide, leaving selenium as the sole remaining element. This process was performed at T=30°C and a pH between 6 and 7. The selenium thus recovered had a crystalline hexagonal structure (revealed by x-ray diffraction) and the particles were as large as 125µm3.

Future research on the two routes that are explored in this thesis can give insights into selenium reduction mechanisms and the formation of large selenium particles. The recoverability of biological selenium particles has also been improved (as discussed in this thesis). In conclusion, this thesis has resulted in a new, bio-selective, renewable selenium recovery method via selenium sulphide.

Pathogen removal using saturated sand colums supplemented with hydrochar
Chung, J.W. - \ 2015
University. Promotor(en): Piet Lens, co-promotor(en): J.W. Foppen. - Leiden : CRC Press/Balkema - ISBN 9789462574977 - 156
drinkwater - afvalwaterbehandeling - biochar - biomassaconversie - pyrolyse - micro-organismen - gezondheidsgevaren - volksgezondheid - drinking water - waste water treatment - biomass conversion - pyrolysis - microorganisms - health hazards - public health
Towards spatially smart abatement of human pharmaceuticals in surface waters: defining impact of sewage treatment plants on susceptible functions
Gils, J.A.G. ; Coppens, L.J.C. ; Laak, T.L. ter; Raterman, B.W. ; Wezel, A.P. van - \ 2015
Water Research 81 (2015). - ISSN 0043-1354 - p. 356 - 365.
afvalwaterbehandeling - waterzuivering - geneesmiddelen - oppervlaktewater - inventarisaties - nederland - waste water treatment - water treatment - drugs - surface water - inventories - netherlands - personal care products - endocrine disrupting compounds - organic persistent pollutants - health-risk assessment - municipal waste-water - aquatic environment - drinking-water - climate-change - transformation products - continental-scale
For human pharmaceuticals, sewage treatment plants (STPs) are a major point of entry to surface waters. The receiving waters provide vital functions. Modeling the impact of STPs on susceptible functions of the surface water system allows for a spatially smart implementation of abatement options at, or in the service area of, STPs. This study was performed on a nation-wide scale for the Netherlands. Point source emissions included were 345 Dutch STPs and nine rivers from neighboring countries. The Dutch surface waters were represented by 2511 surface water units. Modeling was performed for two extreme discharge conditions. Monitoring data of 7 locations along the rivers Rhine and Meuse fall mostly within the range of modeled concentrations. Half of the abstracted volumes of raw water for drinking water production, and a quarter of the Natura 2000 areas (European Union nature protection areas) hosted by the surface waters, are influenced by STPs at low discharge. The vast majority of the total impact of all Dutch STPs during both discharge conditions can be attributed to only 19% of the STPs with regard to the drinking water function, and to 39% of the STPs with regard to the Natura 2000 function. Attributing water treatment technologies to STPs as one of the possible measures to improve water quality and protect susceptible functions can be done in a spatially smart and cost-effective way, using consumption-based detailed hydrological and water quality modeling.
Bacterial battery chargers
Versluis, K. ; Heijne, A. ter - \ 2015
Mugmedia
stedelijk afvalwater - afvalwaterbehandeling - elektriciteit - elektronen - bacteriën - bio-energie - biobased economy - biotechnologie - waterzuivering - municipal wastewater - waste water treatment - electricity - electrons - bacteria - bioenergy - biotechnology - water treatment
Annemiek ter Heijne investigates a new method to produce electricity from waste water. She uses bacteria as battery chargers.
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

 
Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.