Search results for "subsurface"
showing 10 items of 41 documents
Novel method and instruments for the optimal techno-economic sizing of borehole heat exchangers
2021
El test de respuesta térmica (TRT) es ampliamente utilizado como método estándar para caracterizar las propiedades térmicas del terreno adyacente a un intercambiador de calor enterrado (BHE). Los métodos tradicionales para interpretar los resultados aplican soluciones analíticas o numéricas asumiendo que el terreno es infinito, homogéneo e isotrópico. Sin embargo, en realidad el subsuelo presenta generalmente una estructura estratificada y heterogénea, y por lo tanto las propiedades térmicas pueden variar sustancialmente con la profundidad. En este sentido y con la intención de resolver las limitaciones del TRT estándar, la presente tesis doctoral se centra en el desarrollo de métodos e ins…
Effects of plant species in a horizontal subsurface flow constructedwetland – phytoremediation of treated urban wastewater withCyperus alternifolius …
2013
Abstract Plant species carry out a series of important biological, chemical and physical processes within a constructed wetland wastewater treatment system and make a significant contribution to wastewater purification. This paper compares two emergent macrophytes – Cyperus alternifolius L. and Typha latifolia L. – planted separately in a pilot horizontal subsurface flow system for the phytoremediation of treated urban wastewater in the West of Sicily (Italy). The total surface area of the three units within the pilot system was 99 m 2 . Six subunits were planted with two species and three subunits were left unplanted as the control. The main aim of the study was to demonstrate that, under …
Moroccan Climate in the Present and Future: Combined View from Observational Data and Regional Climate Scenarios
2008
The impact of climate change on water availability in the Middle East and the Upper Jordan catchment (UJC) is investigated by dynamic downscaling of ECHAM4 time slices and subsequent hydrological modelling. Two time slices (1961–90 and 2070–99) of the global climate scenario B2 of ECHAM4 were dynamically downscaled with the meteorological model MM5 in two nesting steps of 54 km and 18 km resolution. The meteorological fields were used to drive a physically based hydrological model, computing in detail the surface and subsurface water flow and water balance of the UJC.
Treatment of Combined Dairy and Domestic Wastewater with Constructed Wetland System in Sicily (Italy). Pollutant Removal Efficiency and Effect of Veg…
2021
Dairy wastewater (DWW) contains large amounts of mineral and organic compounds, which can accumulate in soil and water causing serious environmental pollution. A constructed wetland (CW) is a sustainable technology for the treatment of DWW in small-medium sized farms. This paper reports a two-year study on the performance of a pilot-scale horizontal subsurface flow system for DWW treatment in Sicily (Italy). The CW system covered a total surface area of 100 m2 and treated approximately 6 m3 per day of wastewater produced by a small dairy farm, subsequent to biological treatment. Removal efficiency (RE) of the system was calculated. The biomass production of two emergent macrophytes was dete…
Management of irrigation water and nutrient demands of tomato (Lycopersicon esculentum Mill.) using urban treated wastewater from a pilot-scale horiz…
2017
The reuse of treated wastewater (TWW) in crop irrigation is an advanced and rational approach to water resource management in agriculture. Results would seem to demonstrate that it could be an extremely important tool in the reduction of freshwater (FW) consumption in agriculture, at the same time helping to increase crop yields through the transfer of nutrients required for crop growth. In arid and semi-arid areas of the Mediterranean, constructed wetlands can play a key role in the treatment and reuse of wastewater due to their multifunctional nature. The aim of this study was to manage water and nutrient requirements of tomato (Lycopersicon esculentum Mill.) using TWW from a pilot-scale …
The use of constructed wetlands for the treatment of agro-industrial wastewater – A case study in a dairy-cattle farm in Sicily (Italy)
2017
Wastewaters generated by agro-industrial operations often represent an unsustainable cost for farms due to high wastewater-treatment management costs. The wastewater produced by dairies, wineries or oil mills may vary in quantity and in quality depending on the time of the year, making the use of a conventional treatment system less efficient and more costly. Constructed wetland systems (CWs) provide low-cost technology and an efficient solution in the treatment of a number of wastewaters from agriculture. They are simple to build, have low maintenance costs and are sustainable compared to conventional treatment methods. This paper shows a case study that was carried out on a dairy-cattle f…
Growth of Arundo donax L. and Cyperus alternifolius L. in a horizontal subsurface flow constructed wetland using pre-treated urban wastewater - a cas…
2013
Constructed wetland systems for wastewater treatment represent an excellent opportunity for the recovery of water resources in those areas subject to prolonged periods of water shortage. This paper presents a study of the efficiency of a pilot horizontal subsurface flow system using pre-treated urban wastewater from a small town in the West of Sicily. The pilot system had a total surface area of 100 m2 with two units. Unit A was planted with Arundo donax L. and unit B with Cyperus alternifolius L. The HLR was 10 cm d-1. The main objectives of research were to evaluate the growth and biomass yield of two macrophytes and determine the removal efficiency of physical-chemical and microbiologica…
A Comprehensive Model for Hydraulic Analysis and Wetting Patterns Simulation under Subsurface Drip Laterals
2022
In the absence of suitable specialized models to simulate the soil wetting patterns in subsurface drip irrigation systems considering the hydraulic conditions along the laterals, a new model was developed and named a “comprehensive model” in this study. This model couples the subsurface drip irrigation lateral characteristics with the soil hydraulic properties and utilizes the Hydrus-3D software as a complementary section of the model to simulate the wetting front beneath the lateral. To evaluate the model, three 16 mm drip-line pipes of 62 m length with 20, 40, and 50 cm spacing emitters and 2 to 5 L/h discharge were buried at 0.2 m depth in a soil box containing clay loamy soil. Then, the…
Application of EMI and FDR Sensors to Assess the Fraction of Transpirable Soil Water over an Olive Grove
2018
Accurate soil water status measurements across spatial and temporal scales are still a challenging task, specifically at intermediate spatial (0.1–10 ha) and temporal (minutes to days) scales. Consequently, a gap in knowledge limits our understanding of the reliability of the spatial measurements and its practical applicability in agricultural water management. This paper compares the cumulative EM38 (Geonics Ltd., Mississauga, ON, Canada) response collected by placing the sensor above ground with the corresponding soil water content obtained by integrating the values measured with an FDR (frequency domain reflectometry) sensor. In two field areas, characterized by different soil clay conte…
Assessing HYDRUS-2D model to simulate water content and salt accumulation in a soil irrigated with a subsurface drip system: Application in a semiari…
2015
In this paper, the suitability of HYDRUS-2D model to predict the average soil water content in the root zone of potato crop irrigated with subsurface drip irrigation plant, is initially assessed on the basis of a field study. Then, the model is tested to predict the salt distribution around a buried emitter, when two different water qualities (i.e. electrical conductivity of 1.0 dS m-1 and 4.0 dS m-1), are used during the growing season (treatments T1 and T2). Finally, the soil volume in which salts accumulates, as well as the effects on crop yield is recognized for both the considered treatments.The results evidenced that predicted values of average soil water content in the root zone were…