122 research outputs found
Isotopic Fingerprints of Organic Pollutants: Quantifying Sources and Sinks of Organic Pollutants with Isotope Analysis from Aquifer to Catchment Scale
No full textStuijfzand, P.J. [Promotor]Breukelen, B.M. [Copromotor]van Meerveld, H.J. [Copromotor
Addressing quality issues during potable water ASR: Optimizing Aquifer Storage Recovery through hydrogeochemical analysis of a pilot project, column tests and modeling
No full textStuijfzand, P.J. [Promotor]Breukelen, B.M. van [Copromotor
Impacts of Shallow Geothermal Energy on Groundwater Quality: A Hydrochemical and geomicrobial study of the effects of ground source heat pumps and aquifer thermal energy storage
No full textStuijfzand, P.J. [Promotor]Breukelen, B.M. van [Copromotor
Groundwater Quality in Curaçao: A hydrochemical multi-annual assessment (1977-2021) of a Caribbean island
No full textFor this thesis a hydrochemical groundwater survey was carried out on the Caribbean island of Curaçao in 2020 as part of the NWO SEALINK project. In order to be well-adapted against anthropogenic and natural pressures, Curaçao needs representative data, yet thorough hydrochemical datasets were only sparsely collected in the wet seasons of 1977 and 1992. The aim of this thesis was to determine the current chemical state of the groundwater and analyze for long-term pollution trends with an extended database spanning four decades, also including data that was collected in another fieldwork campaign in 2021.NWO SEALINKCivil Engineering | Environmental Engineerin
Peeking inside the black-box: A model-based interpretation of multi-elemental isotope date of chlorinated ethenes in heterogeneous aquifer systems
No full textSanitary Engineerin
Removal of plant pathogenic bacteria during agricultural managed aquifer recharge to produce irrigation water and protect plant health
No full textFresh water is an essential resource for life. Yet, overexploitation of water resources, rainfall shortages, and a decrease in water quality by pollution increase water scarcity worldwide. Since agricultural production consumes about 70% of the available fresh water resources, it is particularly vulnerable for water scarcity. Therefore, this research investigated agricultural aquifer storage, transfer and recovery (ASTR) as nature-based solution to store fresh water in the subsurface from where it can be reused for irrigation. The source water used for infiltration may carry plant pathogens that have to be removed during the storage. Otherwise, the recovered water poses a threat to crop production if pathogens are still present in the irrigation water. Consequently, an understanding of pathogen die-off and removal under relevant conditions found in aquifers is required to predict changes in water quality and protect plant health. In my research, I focussed on the removal of three plant pathogenic bacteria during ASTR: Ralstonia solanacearum and the Soft Rot Pectobacteriaceae, Dickeya solani and Pectobacterium carotovorum. They affect a broad variety of crops with hosts ranging from potato to flower bulbs, both being important cash crops worldwide and particularly in the Netherlands.An ASTR pilot site located in North Holland was investigated where tile drainage water (TDW) is collected from a 10 ha agricultural field and infiltrated into a sandy, anoxic, and originally brackish aquifer. The TDW can mix with surface water where the selected pathogens are regularly detected. ASTR uses separated wells for infiltration and abstraction of the recharged water. This creates a soil passage and forces the water to flow through the porous medium (sand layers) of the aquifer. Water microcosms and column experiments were used to simulate the aquifer processes in the laboratory and analysed pathogen removal during ASTR. The results showed that the die-off in the water phase depends on the residence time and ranged between 1.3 to 2.7 log10 after 10 or 60 days for R. solanacearum, respectively. A subpopulation of the bacteria persisted for a prolonged time at low concentrations which may pose a risk if the water is recovered too early. However, the soil passage within the aquifer proved to be highly effective in removing the bacteria by attachment (18 log10 after 1 m). Together with results of dose-response experiments where I studied the effect of contaminated irrigation water on potato plants, all results were ultimately combined in a quantitative microbial risk assessment (QMRA). QMRA is a useful (water) management tool to evaluate the treatment steps of water reclamation technologies and support decision-making processes. As a result of this PhD work, ASTR can be considered a natural treatment system to remove bacterial plant pathogens and provide safe irrigation water
Improving water efficiency and crop yield on a sugarcane plantation in Xinavane, Mozambique: An analysis of irrigation practices, yield variability and the potential of a decision support system
No full textThis report contains the findings of a multidisciplinary project in Mozambique which ran from mid-November 2018 to mid-January 2019. This study is part of the IWACA-TECH project, which is an abbreviation for “Improved Water efficiency Control based on remote sensing TECHnologies. The goal is to increase water efficiency and crop yield without increasing the consumptive use of water, using remote sensing and Model Predictive Control (MPC). The structural water scarcity in the region points out the relevance of the IWACATECH project and with that this study. The research, carried out by students of Delft University of Technology, is of importance for both the company Tongaat Hulett and all inhabitants who are direct or indirect dependent on the water of the Incomati river. The study area on the plantation in Xinavane copes not only with inefficient irrigation water use but also suffers a sugarcane yield decline in recent years ??. Therefore, the overall aim of this report is to improve water efficiency and crop yield within Tongaat Hulett. To achieve this from a multidisciplinary perspective several research questions have been formulated. Although they all contribute to the overall aim, they do so from different angles and in varying degrees. Therefore, to increase the readability of the report, the research questions have been divided into three sections: (1) Irrigation Practices, (2) Field Assessment on Yield Variability and (3) Decision Support System. Fieldwork was conducted over a five week period in order to gather data. Groundwater levels were measured, water quality of irrigation, ground- and precipitation water samples was analysed and soil moisture content was measured. This led to further research of soil types and quality. Soil profiles along the edges of both fields were made revealing a shallow aquifer in the bad-performing field. Irrigation water quality seems to form no hazard, but ground water quality analyses revealed significantly high electrical conductivity levels and a high sodium adsorption ratio in areas without growth. These findings, combined with an analysis of the digital elevation map and socio-technical data revealed that evaporation of irrigation water seems to be a large contributor to the impaired crop growth. When excess water cannot run off, puddles are formed. When these puddles evaporate, salts can be taken up by the soil once the thickened irrigation water infiltrates. This process is strengthened by the clay soil layer and the shallow aquifer, which prevent water from infiltrating deeper into the ground. Results concerning remote sensing prove the relationship between soil moisture content and precipitation for meteo-station XNA-20. Combining spatial and temporal variability of soil moisture content with remote sensing can play an essential role in managing irrigation practices. For the decision support system, and in specific the controller part of the system, measurements have been done. It can be concluded that storage area and delay times can be considered insignificant, and that canals do not have to be modelled. This makes the controller significantly easier and thus more time and effort can be spend on other aspects of the controller.MP27
Modelling Iron Floc Filtration Through Porous Media Filters
No full textAdditional master thesisAdditional thesisWater Managemen
Biodegradation-driven Landfill Settlement Modelling
No full textEternal aftercare for landfills is the standard in Dutch waste management policy after a law came into effect in 1996, meaning eternal waste management from potentially hazardous substances. A prescription of this policy is the application of watertight barriers on top of the wastebody. The policy also prescribes the renewal of the packing materials every 75 years. The wastebody is dried out, and the degradation has stopped so the wastebody does not change. The 'dry tomb' stays hazardous, thus eternal aftercare is implied.The project 'introductie Duurzaam Stortbeheer (iDS) aims to create aftercare with an ending, or finite aftercare. It is looking for possibilities to stabilise the landfill mass, i.e. to eliminate the threat of pollutants by treating the wastebodies.The goal of the CURE project is to develop fundamental insight into landfill processes in order to research the feasibility of wastebody stabilisation. To predict behaviour of landfills, and to monitor the processes, as much information as possible needs to be gathered through measurements. These consist of measurement of gas concentration and production rates together with the variation in leachate quality and volumes, as well as many more. This research, as part of the CURE project, presents the applicability of settlement as and addition to these measurements.The main goal of waste body stabilisation is to actively reduce the amount of organic matter in a landfill. Uncontrolled landfills produce considerable methane emissions as well as high concentrations of nitrogen and heavy metals in the leachate, leading to groundwater hazards in the environment.McDougall (2007) introduced the fundamental conceptual model upon which this research is based. This model is not publicly available, so one of the goals of this research is to provide a fundamental conceptual model. The relation between degradation and settlement has been studied and implemented in a 1D model which allows for hydrological systems, oxygen penetration, degradation and cell strain. The outcome is a relation between mechanics, biochemistry and hydrology. A few assumptions and simplifications were made to make the model versatile and adjustible, but also easy to read. For instance, the model uses oxygen as absolute limiting factor in degradation, neglecting all processes concerning anaerobic degradation. The model also assumes that at the beginning of the simulation, each cell has the same composition, because there is no conclusive data about the distribution of waste types. The model has been created in one dimension, thereby neglecting all multi-dimensional processes and limitations. In the final scenario, the main limitation to degradation is the availability of dissolved oxygen. As irrigation provides infiltration of 5 mm water per day with 10 mg dissolved oxygen per liter, the daily reduction of oxygen demand is 50 mg. The total modelled oxygen demand of the landfill is over 9600 kg, which concludes that a different tactic needs to happen in order to stabilise the wastebody. To increase the degradation rate, more oxygen needs to be applied. An approximation of the effect of applying a partial vacuum above the water table in the landfill to attract air from the environment is modelled, giving the oxygen more transfer area into unsaturated water. An increase by a factor 10^{4} is applied to the effect of oxygen on organic matter to model this enhanced irrigation system. The results are modeled over 100 years, after which approximately 26.17% of the degradation has happened. This shows that aerobic degradation over a wastebody takes too long with conventional degradation, and the unsaturated voids might help the process.The model shows credible results for an unspecified landfill with deterministic parameters. Settlement has been brought in relation to a simplified form of biodegradation. The need for further research, with a spatial fluctuation of these parameters and detailed multidimensional water flow is needed to predict landfill behaviour in more detail. \pagebreakGeo-Engineerin
- …
