L C Rietveld

Delft University of Technology, Delft, South Holland, Netherlands

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Publications (105)175.51 Total impact

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    Yasmina Bennani, Peter Appel, Luuk C. Rietveld
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    ABSTRACT: This paper presents an outline of the effects of photoelectrocatalytic operating parameters in a batch reactor on the kinetics of photo(electro) catalytic (PEC) oxidation, using phenol as a model compound. Process parameters and electrode configuration were varied to examine which mechanism becomes dominant under which conditions. The parameters studied were: the effect of the TiO2 layer thickness, agitation, different light intensities (UV300–400), and the initial concentration of phenol in an aqueous solution as encountered in practice.
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    ABSTRACT: Alkalizing amines such as cyclohexylamine and dimethylamine have great potential for protecting steam-water cycles against corrosion, but their thermal stability is limited and anionic decomposition products are a concern due to increased corrosion risk. In this study morpholine, ethanolamine, cyclohexylamine, dimethylamine and 3-methoxypropylamine were exposed to 500, 530 and 560 ˚C at 9.5, 13.5 and 17.5 MPa to investigate the influence of temperature and pressure on amine thermolysis kinetics. The surface:volume ratio of the reactor tube was 0.4 mm-1, close to the value of superheater tubes in steam-water cycles. All amines thermolyzed by first order kinetics, with the exception of dimethylamine. The Arrhenius constants Ea, ln(A) and Va were obtained from the experimental data for all investigated amines. The influence of pressure on thermolysis kinetics was less pronounced than in previous studies and was different for each amine. Dimethylamine did not degrade below 20 and 10% at 500 and 530 ˚C respectively, in spite of longer retention times being applied, suggesting synthesis may occur. Limited practical data showed some promise for the applicability of the model to steam-water cycles. More plant data is necessary to fully validate the model. In all cases, thermolysis of the amines led to the formation of between 150 and 600 ppb organic acid anions. In most cases the concentrations increased linearly with increasing degradation percentage. Acetate and formate were found as major degradation products, with some propionate and traces of glycolate. Cationic degradation products were ammonia and some amines, meaning that the complete thermolysis of an amine does not necessarily lead to acidic conditions.
    Industrial & Engineering Chemistry Research 02/2015; DOI:10.1021/ie504849v · 2.24 Impact Factor
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    ABSTRACT: Forward osmosis (FO) processes, due to internal concentration polarisation, are limited with regards to flux. Improved flux performance will allow FO to compete with fluxes achieved by hydraulically driven membrane processes. Pressure assisted osmosis (PAO) is proposed to enhance FO performance, by adding hydraulic pressure (0.1-0.8 bar) on the feed side. An FO mass transport model (active layer to feed side orientation) incorporating pressure was developed to describe the fluxes in PAO. Continuous and discontinuous PAO operations on laboratory scale were proposed and evaluated using draw solutions equivalent to 24 bar osmotic pressure. The fluxes increased with increasing hydraulic feed pressures for all PAO experiments, including activated sludge feeds, owing to the increased driving force and membrane deformation. Discontinuous PAO was found to have an adverse effect on the salt fluxes, due to the subsequent pressure release. This study emphasizes the benefits of PAO for use in innovative membrane systems, while illustrating the importance of developing more rigid membranes and better support designs.
    Journal of Membrane Science 02/2015; 476:182-193. DOI:10.1016/j.memsci.2014.11.022 · 4.91 Impact Factor
  • Urban Water Journal 12/2014; DOI:10.1080/1573062X.2014.938762 · 0.91 Impact Factor
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    ABSTRACT: Soil deformation is believed to play a crucial role in the onset of failures in the underground infrastructure. This article describes a method to generate a replacement-prioritisation map for underground drinking water pipe networks using ground movement data. A segment of the distribution network of a Dutch drinking water company was selected as the study area. Failure registration data comprising 868 failures registered over 40 months and geographical network data were obtained from the water utility. Ground movement was estimated using radar satellite data. Two types of analyses were performed: cell and pixel based. For the cell-based analysis, asbestos cement (AC) pipes exhibited the highest failure rates. Older AC pipes were also shown to fail more often, whereas failure rates for PVC were the lowest. For the pixel-based analysis, ground movement was demonstrated to play a role in the failure of all materials combined. Therefore, a replacement-prioritisation map for AC was generated which combined ground movement data and pipe-age data. This method can be a beneficial resource for network managers for maintenance and continuous monitoring.
    Structure and Infrastructure Engineering 12/2014; DOI:10.1080/15732479.2014.938660 · 0.95 Impact Factor
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    ABSTRACT: Ultrasound, closed-circuit television (CCTV) and Panoramo® are capable of inspecting drinking water pipes and joints of any pipe material. The three tools were tested for their accuracy and reproducibility for gap width sizing in double-socket push-fit joints. The tests were performed at laboratory scale (PVC pipes and joints) in the field (asbestos cement pipes and joints) and in three full-scale tests (PVC) inside pipes used to supply drinking water. In the laboratory tests both accuracy and reproducibility were evaluated. In the field and full-scale tests only reproducibility of the tools was tested. CCTV proved to be the most accurate and reproducible for the application. This straightforward approach is considered to be a surrogate measure for joint's condition.
    Urban Water Journal 11/2014; 11(8). DOI:10.1080/1573062X.2013.806562 · 0.91 Impact Factor
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    ABSTRACT: Algae organic matter (AOM), including intracellular organic matter (IOM) and extracellular organic matter (EOM), are major membrane foulants in the treatment of algae-polluted water. In this study, the effects of EOM and IOM (at dissolved organic concentrations of 8 mg/L) on the fouling of a polyethersulfone ultrafiltration (UF) membrane were investigated using a dead-end down-flow UF unit. Changes in the membrane pore geometry and the interaction energy between the membrane and foulants were analyzed based on the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory. The data (relative standard deviation within 10%) showed that UF was able to retain 57% and 46% of IOM and EOM respectively, while the corresponding membrane fluxes rapidly reduced to 28% and 33% of their respective initial values after a specific filtration volume of only 3.75 mL/cm2. The fouling model implied that cake formation was the major mechanism. Specifically, IOM foulant had a much greater free energy of cohesion (-59.08 mJ/m2) than EOM foulant (3.2 mJ/m2), leading to the formation of a compacted cake layer on the membrane surface. In contrast, small molecules of hydrophobic EOM tended to be adsorbed into the membrane pores, leading to significant reduction of the pore size and membrane flux. Therefore, the overall fouling rates caused by EOM and IOM were comparable when both of the above mentioned mechanisms were considered.
    Environmental Science & Technology 11/2014; DOI:10.1021/es5035365 · 5.48 Impact Factor
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    ABSTRACT: The draw solution is the driving force of the forward osmosis (FO) process; however, the solute loss of the draw solute to the feed side is a general, financial limitation for most applications. The anthropogenic amino acid ethylenediaminetetraacetic acid (EDTA) was investigated as a draw solution for FO. At concentrations of approximately 1.0 osmol/kg, EDTA demonstrated comparable water fluxes (Jv = 5.29 L/m(2) h) to the commonly used salt, NaCl (Jv = 4.86 L/m(2) h), and both produced better water fluxes than glucose (Jv = 3.46 L/m(2) h). EDTA showed the lowest solute loss with Js (reverse solute loss or solute leakage) = 0.54 g/m(2) h. The molecular weight, degree of ionisation and charge of EDTA played a major role in this efficiency and EDTA was therefore well rejected by the membrane, showing a low Js/Jv ratio of 0.10 g/L. Owing to the low solute loss of EDTA and its resistance to biodegradation, this compound has the potential to be used as a draw solute for FO during long periods without requiring much replenishment.
    Water Science & Technology 11/2014; 70(10):1677-82. DOI:10.2166/wst.2014.424 · 1.21 Impact Factor
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    M.F. Mohd Amin, S.G.J. Heijman, L.C. Rietveld
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    ABSTRACT: The appearance of pharmaceuticals in wastewater has become a significant concern to both the water treatment industry as well as consumers. The availability of advanced treatment methods has optimized the removal of these compounds present in wastewater sources. The latest development in polymers as flocculants and combining it with other treatment helps to reduce the quantities of these pharmaceuticals in the final wastewater effluent. This paper gives an insight on the potential usage of polymer flocculants and its combination with particles, organic substances and conventional adsorbents towards removing pharmaceutical compounds from wastewater. Polymer flocculants alone will have a limited ability in pharmaceuticals removal. The flocculation process combination with adsorption on natural components and particles is always necessary. Interaction of polymers with adsorbents in the wastewater could also play an important role in their removal by polymer flocculants due to its proven implementation. An understanding of the changes in processes and mechanisms involving the polymers is essential for achieving effective removal rate. Combination of polymer flocculants with conventional adsorbents such as carbon and clays during the treatment process could lead to a new effective and economic approach in removal of the pharmaceutical compound.
    10/2014; 3(1):1-10. DOI:10.1080/21622515.2014.966784
  • World Water Congress IWA; 09/2014
  • Water Practice & Technology 08/2014; 9(2):264. DOI:10.2166/wpt.2014.030
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    ABSTRACT: Reverse osmosis (RO) systems for secondary effluent water reuse frequently encounter severe biofouling due to the high nutrient concentration in the RO feed water. Deployment of negatively charged tight ceramic ultrafiltration (UF) may restrict biofouling in RO by phosphate limitation, since the tight ceramic UF can reject dissolved phosphate by electrostatic interactions. However, the organic matter and cations can potentially impact phosphate rejection by tight ceramic UF. In this study, the effects of organic matter and Ca2+ on phosphate rejection by the 3 kDa tight ceramic UF membrane were investigated, using synthetic water containing natural organic matter (NOM) and effluent organic matter (EfOM), as well as secondary effluent water. Phosphate rejection was found to be linearly correlated to the zeta potential of the organics in the membrane feed water when the membrane was fouled by NOM. Furthermore, the EfOM-fouled membrane yielded higher phosphate rejection than the membrane fouled by the NOM due to additional adsorption of phosphate by the biopolymers. A preferential phosphate rejection was observed during effluent water filtration by the 3 kDa tight ceramic UF membrane.
    Separation and Purification Technology 08/2014; 132:289–294. DOI:10.1016/j.seppur.2014.05.024 · 3.07 Impact Factor
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    Advanced Materials Research 08/2014; 1024:11-14. DOI:10.4028/www.scientific.net/AMR.1024.11
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    ABSTRACT: The draw solution is the driving force in forward osmosis (FO) processes. The reverse solute leakage of the draw solution is however a major constraint due to cost and energy requirements when reconcentrating the solutes subsequent to the FO process. Several zwitterions as draw solutions (π≈24 bar and 7 bar) were systematically investigated to enhance the FO performance and minimise the solute loss. The highly soluble zwitterions: glycine, l-proline and glycine betaine demonstrated comparable water fluxes to NaCl (~5 L/m2 h), but with significantly lower solute loss (Js: 2.13±0.54 g/m2 h; 1.37±0.09 g/m2 h, 0.96±0.4 g/m2 h respectively and JsNaCl: 3.26±0.53 g/m2 h), which is advantageous for cost reduction. The physico-chemical properties, charge and size played a dominant role in the flux efficiencies. The Js/Jv ratios decreased with (i) a decrease in hydrophobicity and (ii) an increase in size. The FO mass transfer model verified the experimental investigations of the solute transport through the membrane.
    Journal of Membrane Science 06/2014; 460:82–90. DOI:10.1016/j.memsci.2014.02.032 · 4.91 Impact Factor
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    ABSTRACT: Amines show great potential for protecting steam-water cycles against corrosion, but their thermal stability is limited and acidic decomposition products are a concern due to increased corrosion risk. In this study, morpholine (hydro)thermolysis is simulated at boiler (352 °C, 17.5 MPa) and superheater (490 °C, 17.5 MPa) conditions with an experimental stainless steel flow reactor. Thermolysis under superheater conditions was more rapid than hydrothermolysis under boiler conditions. Organic acid anion decomposition products increased linearly over time, while the thermal decomposition of morpholine followed first order kinetics. Further experiments under superheater conditions were performed at 470, 490 and 510 °C, with pressures of 9.5, 13.5, and 17.5 MPa. With the kinetic rate constants for morpholine thermolysis in dry steam derived empirically, the activation energy of the decomposition reaction was 160.0 (±2.0) kJ/mol, the pre-exponential factor was e21.7 (±0.66) s–1, and the activation volume was 896 (±36) cm3/mol. This led to a model capable of predicting the observed pressure and temperature dependent thermolysis of morpholine under the investigated conditions. Care must be taken when using the model results to calculate morpholine stability in the SWC, because wall effects during (hydro)thermolysis require further investigation.
    Industrial & Engineering Chemistry Research 05/2014; 53(19):8012–8017. DOI:10.1021/ie500756v · 2.24 Impact Factor
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    ABSTRACT: To efficiently adsorb micropollutants from surface water and groundwater by activated carbon, the concurrent natural organic matter (NOM) was removed by anionic exchange resin (AER) to reduce the adsorption competition. The studied AER showed a great affinity to the NOM fractions ‘humic substances’ and ‘building blocks’ measured by liquid chromatography with organic carbon detection. The overlapping adsorption isotherms of target compounds (atrazine and caffeine) in the presence of raw water and AER-treated water reflected an irrelevance of AER-removed NOM to site competition. Instead, it was likely the hydrophobic low molecular organics, refractory to AER treatment, competed with the target compounds. Microporous carbon, which contains higher amounts of small and secondary micropores, tended to have less site competition, and a lower dosage was required to achieve 90% removal of the target compounds. During fixed adsorber filtration, however, AER pretreatment slightly prolonged the breakthrough of most of the investigated micropollutants. This could be attributed to less pore blockage due to the lower contents of ‘humic substances’ and ‘building blocks’ in the background water.
    Separation and Purification Technology 05/2014; 129. DOI:10.1016/j.seppur.2014.03.019 · 3.07 Impact Factor
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    ABSTRACT: Research in the field of Forward Osmosis (FO) membrane technology has grown significantly over the last 10 years, but its application in the scope of wastewater treatment has been slower. Drinking water is becoming an increasingly marginal resource. Substituting drinking water for alternate water sources, specifically for use in industrial processes, may alleviate the global water stress. FO has the potential to sustainably treat wastewater sources and produce high quality water. FO relies on the osmotic pressure difference across the membrane to extract clean water from the feed, however the FO step is still mostly perceived as a "pre-treatment" process. To prompt FO-wastewater feasibility, the focus lies with new membrane developments, draw solutions to enhance wastewater treatment and energy recovery, and operating conditions. Optimisation of these parameters are essential to mitigate fouling, decrease concentration polarisation and increase FO performance; issues all closely related to one another. This review attempts to define the steps still required for FO to reach full-scale potential in wastewater treatment and water reclamation by discussing current novelties, bottlenecks and future perspectives of FO technology in the wastewater sector.
    Water Research 04/2014; 58C:179-197. DOI:10.1016/j.watres.2014.03.045 · 5.32 Impact Factor
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    ABSTRACT: Organic carbon breaks down in boilers by hydrothermolysis, leading to the formation of organic acid anions, which are suspected to cause corrosion of steam–water cycle components. Prediction of the identity and quantity of these anions, based on feedwater organic carbon concentrations, has not been attempted, making it hard to establish a well-founded organic carbon guideline. By using a batch-reactor and flow reactor, the influence of temperature (276–352 °C), retention time (1–25 min), concentration (150–2400 ppb) and an oxygen scavenger (carbohydrazide) on organic acid anion formation from organic carbon was investigated. By comparing this to data gathered at a case-study site, the validity of setups was tested as well. The flow reactor provided results more representative for steam–water cycles than the batch reactor. It was found that lower heating rates give more organic acid anions as degradation products of organic carbon, both in quantity and species variety. The thermal stability of the organic acid anions is key. As boiler temperature increases, acetate becomes the dominant degradation product, due to its thermal stability. Shorter retention times lead to more variety and quantity of organic acid anions, due to a lack of time for the thermally less stable ones to degrade. Reducing conditions (or the absence of oxygen) increase the thermal stability of organic acid anions. As the feedwater organic carbon concentration decreases, there are relatively more organic acid anions formed.
    Applied Thermal Engineering 04/2014; 65(s 1–2):194–200. DOI:10.1016/j.applthermaleng.2014.01.019 · 2.62 Impact Factor
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    ABSTRACT: One of the main advantages of controlled struvite formation in digested sludge is an improvement in dewaterability of the digested sludge, which eventually leads to lower volumes of dewatered sludge that need to be transported. The effects of the control parameters for struvite formation, magnesium concentration and pH, on digested sludge dewaterability were investigated and are discussed in relation to the efficiency of struvite formation. Laboratory experiments with digested activated sludge were performed in a 20 L batch reactor. CO2 was stripped from the digested sludge using a bubble aerator and magnesium chloride was added to induce struvite formation. The dewaterability of the sludge was determined by gravity filtration tests. In the experiments, either the pH or the molar magnesium to phosphate ratio (Mg:PO4) was varied. The results confirm improved sludge dewaterability after struvite formation. Magnesium to phosphate ratios above 1.0 mol/mol did not further improve dewaterability. The addition of magnesium did not prevent the need for polymer addition for sludge dewatering. An increase in pH led to a deterioration in dewaterability. The best dewaterability results were found at the lowest pH value (pH = 7.0), while stirring the sludge instead of using the bubble aerator. At these settings, an orthophosphate removal of around 80% was achieved.
    Environmental Technology 03/2014; 35(5-8):549-55. DOI:10.1080/09593330.2013.837081 · 1.20 Impact Factor
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    ABSTRACT: In order to evaluate the feasibility of installing decentralised installations for wastewater reuse in cities, information about flows at specific spots of a sewer is needed. However, measuring intermittent flows in partially filled conduits is a technical task which is sometimes difficult to accomplish. This paper describes a method to model intermittent discharges in small sewers by linking a stochastic model for wastewater discharge to a hydraulic model to predict the attenuation of the discharges and its impact on the arrival time to a defined spot. The method was validated in a case study. The model estimated adequately the wastewater discharges on working days.
    Water Science & Technology 03/2014; 69(5):1059-66. DOI:10.2166/wst.2014.010 · 1.21 Impact Factor

Publication Stats

434 Citations
175.51 Total Impact Points

Institutions

  • 2002–2015
    • Delft University of Technology
      • • Department of Water management
      • • Sanitary Engineering
      • • Faculty of Civil Engineering and Geosciences (CEG)
      Delft, South Holland, Netherlands
  • 2014
    • Tongji University
      Shanghai, Shanghai Shi, China
  • 2011
    • KWR Watercycle Research Institute
      Nieuwegen, Utrecht, Netherlands