@article{BienerSasseArnoldetal.1999,
  author    = {Biener, Ernst and Sasse, T. and Arnold, J. and Woltering, S.},
  title     = {New treatment of harbour sludge in Bremen and Bremerhaven / E. Biener ; T. Sasse ; J. Arnold ; S. Woltering ; N. Binder},
  series = {Characterisation and treatment of sediments : Antwerpen, Belgium, September 15 - 17, 1999 ; [preceded by 12th International Harbour Congress] ; proceedings / CATS 4. Ed.: G. De Schutter. Organized by: Technologisch Instituut, Koninklijke Vlaamse Ingenieursvereniging},
  journal   = {Characterisation and treatment of sediments : Antwerpen, Belgium, September 15 - 17, 1999 ; [preceded by 12th International Harbour Congress] ; proceedings / CATS 4. Ed.: G. De Schutter. Organized by: Technologisch Instituut, Koninklijke Vlaamse Ingenieursvereniging},
  publisher = {Technolog. Inst.},
  address   = {Anvers},
  isbn      = {9076019118},
  pages     = {115 -- 122},
  year      = {1999},
  language  = {en}
}
@article{Bung2013,
  author    = {Bung, Daniel B.},
  title     = {Non-intrusive detection of air-water surface roughness in self-aerated chute flows},
  series = {Journal of hydraulic research},
  volume    = {Vol. 51},
  journal   = {Journal of hydraulic research},
  number    = {Iss. 3},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {1814-2079 (E-Journal); 0022-1686 (Print)},
  pages     = {322 -- 329},
  year      = {2013},
  language  = {en}
}
@article{ValeroVitiGualtieri2019,
  author    = {Valero, Daniel and Viti, Nicolo and Gualtieri, Carlo},
  title     = {Numerical Simulation of Hydraulic Jumps. Part 1: Experimental Data for Modelling Performance Assessment},
  series = {Water},
  volume    = {11},
  journal   = {Water},
  number    = {1},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2073-4441},
  doi       = {10.3390/w11010036},
  pages     = {Art. Nr. 36},
  year      = {2019},
  language  = {en}
}
@article{VitiValeroGualtieri2019,
  author    = {Viti, Nicolo and Valero, Daniel and Gualtieri, Carlo},
  title     = {Numerical Simulation of Hydraulic Jumps. Part 2: Recent Results and Future Outlook},
  series = {Water},
  volume    = {11},
  journal   = {Water},
  number    = {1},
  issn      = {2073-4441},
  doi       = {10.3390/w11010028},
  pages     = {Art. Nr. 28},
  year      = {2019},
  language  = {en}
}
@article{ZhangValeroBungetal.2018,
  author    = {Zhang, G. and Valero, Daniel and Bung, Daniel B. and Chanson, H.},
  title     = {On the estimation of free-surface turbulence using ultrasonic sensors},
  series = {Flow Measurement and Instrumentation},
  volume    = {60},
  journal   = {Flow Measurement and Instrumentation},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0955-5986},
  doi       = {10.1016/j.flowmeasinst.2018.02.009},
  pages     = {171 -- 184},
  year      = {2018},
  abstract  = {Accurate determination of free-surface dynamics has attracted much research attention during the past decade and has important applications in many environmental and water related areas. In this study, the free-surface dynamics in several turbulent flows commonly found in nature were investigated using a synchronised setup consisting of an ultrasonic sensor and a high-speed video camera. Basic sensor capabilities were examined in dry conditions to allow for a better characterisation of the present sensor model. The ultrasonic sensor was found to adequately reproduce free-surface dynamics up to the second order, especially in two-dimensional scenarios with the most energetic modes in the low frequency range. The sensor frequency response was satisfactory in the sub-20 Hz band, and its signal quality may be further improved by low-pass filtering prior to digitisation. The application of the USS to characterise entrapped air in high-velocity flows is also discussed.},
  language  = {en}
}
@article{CheenakulaPaulsenOttetal.2023,
  author    = {Cheenakula, Dheeraja and Paulsen, Svea and Ott, Fabian and Gr{\"o}mping, Markus},
  title     = {Operational window of a deammonifying sludge for mainstream application in a municipal wastewater treatment plant},
  series = {Water and Environment Journal},
  journal   = {Water and Environment Journal},
  number    = {Early View},
  publisher = {Wiley},
  address   = {Chichester},
  issn      = {1747-6593},
  doi       = {10.1111/wej.12898},
  pages     = {1 -- 12},
  year      = {2023},
  abstract  = {The present work aimed to study the mainstream feasibility of the deammonifying sludge of side stream of municipal wastewater treatment plant (MWWTP) in Kaster, Germany. For this purpose, the deammonifying sludge available at the side stream was investigated for nitrogen (N) removal with respect to the operational factors temperature (15-30°C), pH value (6.0-8.0) and chemical oxygen demand (COD)/N ratio (≤1.5-6.0). The highest and lowest N-removal rates of 0.13 and 0.045 kg/(m³ d) are achieved at 30 and 15°C, respectively. Different conditions of pH and COD/N ratios in the SBRs of Partial nitritation/anammox (PN/A) significantly influenced both the metabolic processes and associated N-removal rates. The scientific insights gained from the current work signifies the possibility of mainstream PN/A at WWTPs. The current study forms a solid basis of operational window for the upcoming semi-technical trails to be conducted prior to the full-scale mainstream PN/A at WWTP Kaster and WWTPs globally.},
  language  = {en}
}
@article{BungValero2016,
  author    = {Bung, Daniel B. and Valero, Daniel},
  title     = {Optical flow estimation in aerated flows},
  series = {Journal of Hydraulic Research},
  volume    = {54},
  journal   = {Journal of Hydraulic Research},
  number    = {5},
  publisher = {Taylor \& Francis},
  address   = {London},
  doi       = {10.1080/00221686.2016.1173600},
  pages     = {575 -- 580},
  year      = {2016},
  abstract  = {Optical flow estimation is known from Computer Vision where it is used to determine obstacle movements through a sequence of images following an assumption of brightness conservation. This paper presents the first study on application of the optical flow method to aerated stepped spillway flows. For this purpose, the flow is captured with a high-speed camera and illuminated with a synchronized LED light source. The flow velocities, obtained using a basic Horn-Schunck method for estimation of the optical flow coupled with an image pyramid multi-resolution approach for image filtering, compare well with data from intrusive conductivity probe measurements. Application of the Horn-Schunck method yields densely populated flow field data sets with velocity information for every pixel. It is found that the image pyramid approach has the most significant effect on the accuracy compared to other image processing techniques. However, the final results show some dependency on the pixel intensity distribution, with better accuracy found for grey values between 100 and 150.},
  language  = {en}
}
@article{HoettgesRitterbachEls1987,
  author    = {H{\"o}ttges, J{\"o}rg and Ritterbach, E. and Els, H.},
  title     = {Optical Improvement of LDV-Measurement in Pipe Flow / Ritterbach, E.; J. H{\"o}ttges; H. Els},
  series = {Laser anemometry : advances and applications; proceedings of the 2. International Conference, Strathclyde, Scotland, 21st to 23rd September 1987 / ed. by John Turner ... UK LDA Users Group},
  journal   = {Laser anemometry : advances and applications; proceedings of the 2. International Conference, Strathclyde, Scotland, 21st to 23rd September 1987 / ed. by John Turner ... UK LDA Users Group},
  publisher = {Springer},
  address   = {Berlin [u.a.]},
  isbn      = {3540187561},
  pages     = {VII, 601 S : Ill., graph. Darst.},
  year      = {1987},
  language  = {en}
}
@article{vonHaefenKrautwaldStolleetal.2022,
  author    = {von H{\"a}fen, Hajo and Krautwald, Clemens and Stolle, Jacob and Bung, Daniel Bernhard and Goseberg, Nils},
  title     = {Overland flow of broken solitary waves over a two-dimensional coastal plane},
  series = {Coastal Engineering},
  volume    = {175},
  journal   = {Coastal Engineering},
  number    = {August},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1872-7379},
  doi       = {10.1016/j.coastaleng.2022.104125},
  pages     = {14 Seiten},
  year      = {2022},
  abstract  = {Landslides, rock falls or related subaerial and subaqueous mass slides can generate devastating impulse waves in adjacent waterbodies. Such waves can occur in lakes and fjords, or due to glacier calving in bays or at steep ocean coastlines. Infrastructure and residential houses along coastlines of those waterbodies are often situated on low elevation terrain, and are potentially at risk from inundation. Impulse waves, running up a uniform slope and generating an overland flow over an initially dry adjacent horizontal plane, represent a frequently found scenario, which needs to be better understood for disaster planning and mitigation. This study presents a novel set of large-scale flume test focusing on solitary waves propagating over a 1:14.5 slope and breaking onto a horizontal section. Examining the characteristics of overland flow, this study gives, for the first time, insight into the fundamental process of overland flow of a broken solitary wave: its shape and celerity, as well as its momentum when wave breaking has taken place beforehand.},
  language  = {en}
}
@article{ValeroSchalkoFriedrichetal.2021,
  author    = {Valero, Daniel and Schalko, Isabella and Friedrich, Heide and Abad, Jorge D. and Bung, Daniel B. and Donchyts, Gennadii and Felder, Stefan and Ferreira, Rui M. L. and Hohermuth, Benjamin and Kramer, Matthias and Li, Danxun and Mendes, Luis and Moreno-Rodenas, Antonio and Nones, Michael and Paron, Paolo and Ruiz-Villanueva, Virginia and Wang, Ruo-Qian and Franca, Mario J.},
  title     = {Pathways towards democratization of hydro-environment observations and data},
  series = {Iahr White Paper Series},
  journal   = {Iahr White Paper Series},
  number    = {1},
  publisher = {International Association for Hydro-Environment Engineering and Research (IAHR)},
  pages     = {1 -- 9},
  year      = {2021},
  language  = {en}
}
@article{BayonValeroGarciaBartualetal.2016,
  author    = {Bayon, Arnau and Valero, Daniel and Garcia-Bartual, Rafael and Vall{\´e}s-Mor{\´a}n, Francisco Jos{\´e} and L{\´o}pez-Jim{\´e}nez, P. Amparo},
  title     = {Performance assessment of OpenFOAM and FLOW-3D in the numerical modeling of a low Reynolds number hydraulic jump},
  series = {Environmental Modelling \& Software},
  volume    = {80},
  journal   = {Environmental Modelling \& Software},
  publisher = {Elsevier},
  address   = {Amsterdam},
  isbn      = {1364-8152},
  doi       = {10.1016/j.envsoft.2016.02.018},
  pages     = {322 -- 335},
  year      = {2016},
  abstract  = {A comparative performance analysis of the CFD platforms OpenFOAM and FLOW-3D is presented, focusing on a 3D swirling turbulent flow: a steady hydraulic jump at low Reynolds number. Turbulence is treated using RANS approach RNG k-ε. A Volume Of Fluid (VOF) method is used to track the air-water interface, consequently aeration is modeled using an Eulerian-Eulerian approach. Structured meshes of cubic elements are used to discretize the channel geometry. The numerical model accuracy is assessed comparing representative hydraulic jump variables (sequent depth ratio, roller length, mean velocity profiles, velocity decay or free surface profile) to experimental data. The model results are also compared to previous studies to broaden the result validation. Both codes reproduced the phenomenon under study concurring with experimental data, although special care must be taken when swirling flows occur. Both models can be used to reproduce the hydraulic performance of energy dissipation structures at low Reynolds numbers.},
  language  = {en}
}
@article{BienerSasseBoekers1999,
  author    = {Biener, Ernst and Sasse, T. and B{\"o}kers, H.},
  title     = {Preliminary or final capping of sanitary landfills? : Technical and economical aspects},
  series = {Sardinia 99 : proceedings / Seventh International Waste Management and Landfill Symposium, [4 - 8 October 1999, S. Margherita di Pula, Cagliari, Sardinia, Italy]. Ed.: Thomas H. Christensen. - Bd. 3 : Barriers, waste mechanics and landfill design},
  journal   = {Sardinia 99 : proceedings / Seventh International Waste Management and Landfill Symposium, [4 - 8 October 1999, S. Margherita di Pula, Cagliari, Sardinia, Italy]. Ed.: Thomas H. Christensen. - Bd. 3 : Barriers, waste mechanics and landfill design},
  publisher = {CISA, Environmental Sanitary Engineering Centre},
  address   = {Cagliari},
  pages     = {287 -- 294},
  year      = {1999},
  language  = {en}
}
@article{BienerSasseKonertz1993,
  author    = {Biener, Ernst and Sasse, T. and Konertz, K.},
  title     = {Preparation of mineral sealing materials for landfills by different processing technologies / Sasse, T. ; Biener, E. ; Konertz, K.},
  series = {Sardinia 93 : Fourth International Landfill Symposium "Barrier systems, environmental aspects, upgrading and remediation, siting, monofills, effects of waste pretreatment, landfilling in developing countries" ; 11 - 15 October 1993, S. Margherita di Pula (Cagliari), Sardinia, Italy ; proceedings / coord. by Thomas H. Christensen ... - Bd. 1},
  journal   = {Sardinia 93 : Fourth International Landfill Symposium "Barrier systems, environmental aspects, upgrading and remediation, siting, monofills, effects of waste pretreatment, landfilling in developing countries" ; 11 - 15 October 1993, S. Margherita di Pula (Cagliari), Sardinia, Italy ; proceedings / coord. by Thomas H. Christensen ... - Bd. 1},
  publisher = {CISA, Environmental Sanitary Engineering Centre},
  address   = {Cagliari},
  pages     = {275 -- 283},
  year      = {1993},
  language  = {en}
}
@article{GosslaSato1998,
  author    = {Gossla, Ulrich and Sato, R.},
  title     = {Present production circumstances of aggregate in Germany / Sato, R.; Gossla, U.},
  series = {Cement \& Concrete (1998)},
  journal   = {Cement \& Concrete (1998)},
  pages     = {146 -- 153},
  year      = {1998},
  language  = {en}
}
@article{HoettgesArnoldRouve1992,
  author    = {H{\"o}ttges, J{\"o}rg and Arnold, Uwe and Rouv{\´e}, Gerhard},
  title     = {Profiles of Mixing Coefficient in Compound Open Channel},
  series = {Flow modeling and turbulence measurements : [... a collection of lectures and papers presented at the Fourth International Symposium on Refined Flow Modelling and Turbulence Measurements held in Wuhan, People's Republic of China, on September 20-23, 1990]},
  journal   = {Flow modeling and turbulence measurements : [... a collection of lectures and papers presented at the Fourth International Symposium on Refined Flow Modelling and Turbulence Measurements held in Wuhan, People's Republic of China, on September 20-23, 1990]},
  publisher = {Hemisphere Publ. Corp.},
  address   = {Washington, DC [u.a.]},
  isbn      = {1-56032-209-8},
  pages     = {XVII, 773 S. : graph. Darst.},
  year      = {1992},
  language  = {en}
}
@article{Hoettges2017,
  author    = {H{\"o}ttges, J{\"o}rg},
  title     = {QKan - Management of drainage system data with QGIS},
  series = {Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings},
  volume    = {17},
  journal   = {Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings},
  number    = {Article 13},
  pages     = {95 -- 100},
  year      = {2017},
  language  = {en}
}
@article{BienerSasse1993,
  author    = {Biener, Ernst and Sasse, T.},
  title     = {Quality improvements in the construction of multilayer covers},
  series = {G{\´e}ologie et confinement des d{\´e}chets toxiques : actes du symposium international, 8 - 11 juin 1993 / GEOCONFINE 93, Montpellier, France. R{\´e}d. Marcel Arnould},
  journal   = {G{\´e}ologie et confinement des d{\´e}chets toxiques : actes du symposium international, 8 - 11 juin 1993 / GEOCONFINE 93, Montpellier, France. R{\´e}d. Marcel Arnould},
  publisher = {Balkema},
  address   = {Rotterdam [u.a.]},
  isbn      = {90-5410-330-2},
  pages     = {309 -- 312},
  year      = {1993},
  language  = {en}
}
@article{BungValero2018,
  author    = {Bung, Daniel B. and Valero, Daniel},
  title     = {Re-aeration on stepped spillways with special consideration of entrained and entrapped air},
  series = {Geosciences},
  volume    = {8},
  journal   = {Geosciences},
  number    = {9},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2076-3263},
  pages     = {Article number 333},
  year      = {2018},
  abstract  = {As with most high-velocity free-surface flows, stepped spillway flows become self-aerated when the drop height exceeds a critical value. Due to the step-induced macro-roughness, the flow field becomes more turbulent than on a similar smooth-invert chute. For this reason, cascades are oftentimes used as re-aeration structures in wastewater treatment. However, for stepped spillways as flood release structures downstream of deoxygenated reservoirs, gas transfer is also of crucial significance to meet ecological requirements. Prediction of mass transfer velocities becomes challenging, as the flow regime differs from typical previously studied flow conditions. In this paper, detailed air-water flow measurements are conducted on stepped spillway models with different geometry, with the aim to estimate the specific air-water interface. Re-aeration performances are determined by applying the absorption method. In contrast to earlier studies, the aerated water body is considered a continuous mixture up to a level where 75\% air concentration is reached. Above this level, a homogenous surface wave field is considered, which is found to significantly affect the total air-water interface available for mass transfer. Geometrical characteristics of these surface waves are obtained from high-speed camera investigations. The results show that both the mean air concentration and the mean flow velocity have influence on the mass transfer. Finally, an empirical relationship for the mass transfer on stepped spillway models is proposed.},
  language  = {en}
}
@article{ValeroBung2018,
  author    = {Valero, Daniel and Bung, Daniel B.},
  title     = {Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment},
  series = {International Journal of Multiphase Flow},
  volume    = {100},
  journal   = {International Journal of Multiphase Flow},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0301-9322},
  doi       = {10.1016/j.ijmultiphaseflow.2017.12.011},
  pages     = {127 -- 142},
  year      = {2018},
  abstract  = {A new formulation for the prediction of free surface dynamics related to the turbulence occurring nearby is proposed. This formulation, altogether with a breakup criterion, can be used to compute the inception of self-aeration in high velocity flows like those occurring in hydraulic structures. Assuming a simple perturbation geometry, a kinematic and a non-linear momentum-based dynamic equation are formulated and forces acting on a control volume are approximated. Limiting steepness is proposed as an adequate breakup criterion. Role of the velocity fluctuations normal to the free surface is shown to be the main turbulence quantity related to self-aeration and the role of the scales contained in the turbulence spectrum are depicted. Surface tension force is integrated accounting for large displacements by using differential geometry for the curvature estimation. Gravity and pressure effects are also contemplated in the proposed formulation. The obtained equations can be numerically integrated for each wavelength, hence resulting in different growth rates and allowing computation of the free surface roughness wavelength distribution. Application to a prototype scale spillway (at the Aviemore dam) revealed that most unstable wavelength was close to the Taylor lengthscale. Amplitude distributions have been also obtained observing different scaling for perturbations stabilized by gravity or surface tension. The proposed theoretical framework represents a new conceptualization of self-aeration which explains the characteristic rough surface at the non-aerated region as well as other previous experimental observations which remained unresolved for several decades.},
  language  = {en}
}
@article{Biener1985,
  author    = {Biener, Ernst},
  title     = {Rehabilitation of old gravity dams},
  series = {[Transactions] : proceedings of fifteenth international congress on large dams ; 24 - 28 Juin 1985, Lausanne, Suisse = Quinzieme Congres International des Grands Barrages. - Bd. 4},
  journal   = {[Transactions] : proceedings of fifteenth international congress on large dams ; 24 - 28 Juin 1985, Lausanne, Suisse = Quinzieme Congres International des Grands Barrages. - Bd. 4},
  publisher = {Intern. Commission on Large Dams},
  address   = {Paris},
  pages     = {Q 59, R.2, S. 21 -- 23},
  year      = {1985},
  language  = {en}
}