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Efficient design of trickle irrigation system depends on the shape and volume of wetted soil, which are affected by many factors. Among these factors are water application rate, soil profile type, initial soil moisture, and continuous or intermittent water application. The aim of this research is to study the effect of intermittent water application on the wetting pattern and soil moisture distribution for homogeneous and layered soils under trickle source. Thirty experiments were conducted to monitor the advance of the wetting front in the soil profiles. Measurements of soil moisture content were also made at selected locations to evaluate the moisture distribution in soil. A rectangular box with inside dimensions of 147 cm*90 cm*5 cm was used to build the soil profile. One of the faces of the box is transparent. Two different soils were used; a sandy loam and a silty clay loam. The soils were air dried, sieved, and packed inside the box in accordance with their apparent densities which have been measured in the field. Four types of soil profiles were built; the first was sandy loam soil, the second was silty clay loam soil, the third was (silty clay loam/ sandy loam) layered soil, and the fourth was (sandy loam/ silty clay loam) layered soil. Three water application rates were used for each soil profile. Three continuous or intermittent applications were used; continuous applications, equally intermittent applications (120 minutes ON with 120 minutes OFF), and different intermittent applications ([1]20 minutes ON with 240 minutes OFF). In addition, several cylindrical infiltration tests were conducted to describe some characteristics of each soil. Empirical relations to predict each of vertical (under trickle source) and horizontal (at soil surface) wetting front advance were found in this study. Empirical relations to predict the percentage of applied water volume in horizontal strips as a function of soil depth and in vertical strips as a function of horizontal distance from the trickle emitter were also found. The study showed that the wetted soil volume increases as either the water application rate increases, or the intermittent application ratio increases. Also, it showed that the ratio of horizontal advance to vertical advance of wetting front increases as either the water application rate increases, or the intermittent application ratio decreases. The study demonstrated that the accumulated ratio of water application volume at a certain soil depth from trickle source increases as the intermittent application ratio decreases. Also, it demonstrated that the accumulated ratio of water application volume at a certain horizontal distance from trickle source decreases as the intermittent application ratio decreases.

PurposeAccurate values for infiltration rate are important to reliably estimate heat losses from buildings. Infiltration rate is rarely measured directly, and instead is usually estimated using algorithms or data from fan pressurisation tests. However, there is growing evidence that the commonly used methods for estimating infiltration rate are inaccurate in UK dwellings. Furthermore, most prior research was conducted during the winter season or relies on single measurements in each dwelling. Infiltration rates also affect the likelihood and severity of summertime overheating. The purpose of this work is to measure infiltration rates in summer, to compare this to different infiltration estimation methods, and to quantify the differences.Design/methodology/approachFifteen whole house tracer gas tests were undertaken in the same test house during spring and summer to measure the whole building infiltration rate. Eleven infiltration estimation methods were used to predict infiltration rate, and these were compared to the measured values. Most, but not all, infiltration estimation methods relied on data from fan pressurisation (blower door) tests. A further four tracer gas tests were also done with trickle vents open to allow for comment on indoor air quality, but not compared to infiltration estimation methods.FindingsThe eleven estimation methods predicted infiltration rates between 64 and 208% higher than measured. The ASHRAE Enhanced derived infiltration rate (0.41 ach) was closest to the measured value of 0.25 ach, but still significantly different. The infiltration rate predicted by the “divide-by-20” rule of thumb, which is commonly used in the UK, was second furthest from the measured value at 0.73 ach. Indoor air quality is likely to be unsatisfactory in summer when windows are closed, even if trickle vents are open.Practical implicationsThe findings have implications for those using dynamic thermal modelling to predict summertime overheating who, in the absence of a directly measured value for infiltration rate (i.e. by tracer gas), currently commonly use infiltration estimation methods such as the “divide-by-20” rule. Therefore, infiltration may be overestimated resulting in overheating risk and indoor air quality being incorrectly predicted.Originality/valueDirect measurement of air infiltration rate is rare, especially multiple tests in a single home. Past measurements have invariably focused on the winter heating season. This work is original in that the tracer gas technique used to measure infiltration rate many times in a single dwelling during the summer. This work is also original in that it quantifies both the infiltration rate and its variability, and compares these to values produced by eleven infiltration estimation methods.

As an important form of reactors for gas/liquid/solid catalytic reaction, trickle bed reactors (TBRs) are widely applied in petroleum industry, biochemical, fine chemical and pharmaceutical industries because of their flexibility, simplicity of operation and high throughput. However, TBRs also show inefficient production and hot pots caused by non-uniform fluid distribution and incomplete wetting of the catalyst, which limit their further application in chemical industry. Also, process intensification in TBRs is necessary as the decrease in quality of processed crude oil, caused by increased exploitation depths, and more restrictive environmental regulations and emission standards for industry, caused by increased environment protection consciousness. In recent years, lots of strategies for process intensification in TBRs have been proposed to improve reaction performance to meet the current and future demands of chemical industry from the environmental and economic perspective. This article summarizes the recent progress in techniques for intensifying gas/liquid/solid reaction in TBRs and application of intensified TBRs in petroleum industry.

Reducing the water loss sources, i.e. soil evaporation and weeds presence, is an essential act for keeping well soil moisture to crop growth, especially under drought conditions. Therefore, two–yea...

Over the past several years GSK has been developing the capability to perform continuous hydrogenations within trickle bed reactors. Motivation to develop this technology stems from the ability of ...

Biological methanation of renewable H2 and CO2 has been projected to have considerable potential in future energy systems by coupling power and gas energy infrastructures. A suitable technology to facilitate the biological methanation is the ex-situ trickle bed reactor in which a methanogenic biofilm produces CH4 from H2 and CO2. Biofilm irrigation constitutes a critical element for reactor control and has previously been shown to both enhance and decrease reactor performances. In this study, an improvement in the H2 conversion rate of 53% was demonstrated when increasing the interval between sprinklings from 1 to 7 days. The results demonstrate a minimal requirement for nutrient supply to support biological activity and underline that carrier irrigation not only impairs H2 conversion at short-term due to increases in the mass transfer resistance, but also induces longer-term effects on process performance. Three potential mechanisms underlying the physicochemical and biological effects imposed by carrier irrigation are discussed.

Unlike other micro-irrigation facilities like a drip, trickle, and sprinklers that emits water at regularly spaced intervals with predefined discharges, porous rubber pipes (soaker hose) has openings of variable sizes that become unevenly spaced with uneven distribution. The latter makes discharge to be variant along its lateral. Shorter sections are used under laboratory column experiments of soil wetting pattern studies and for this reason, laboratory experiments were conducted to evaluate the extent of emission rates variability on short sections of commercial Irrigation Soaker Hose, 16 mm diameter. Three sections of 10 cm length pipes were randomly selected from 15 no's cuts from different parts of the twenty meters length pipe bundle and used to investigate the extent of variability on emission rates characteristics under six different operating pressures. The result was achieved by collecting and measuring water emitted through the pipe sections at pre-determined pressures. The various discharges, coefficient of variation, and pressure-discharge curves of the section of the pipe then determined from the data. The result shows somewhat similar trends on the increase for water collected with an increase in pressures; however, when statistically compared, the discharges among the pipe sections vary. The values of Coefficient of Variation (CV) are less than 10 % as the values CV range from 0.92 % to 5.82 %, which is within a good category, according to ASAE Standard EP405.1 of 0-10%. The findings indicate that, despite variations among the investigated sections, it can use any part as a representative unit in the soil column experiments with reasonable accuracy.

Correctly applied rock dust can dilute, inert, and mitigate the explosive potential of float coal dust. Trickle dusters are one element of a comprehensive system to help prevent coal dust explosions in underground coal mines. Trickle dusters supply rock dust to inert fine float coal dust in areas where it is commonly deposited, such as the longwall tailgate returns, return airways, pillaring areas, and downwind of belt transfers. Dust deposition studies show that the effectiveness of trickle dusters depends on several key factors. Using multiple orifices, rock dust should be released near the mine roof in the direction of the airflow in order to spread the cloud cross the entry. The rock duster should have a mechanism to break up rock dust agglomerates as they leave the rock duster. The particle size distribution of the limestone rock dust and its airborne concentration should be proportional to the airborne size distribution and concentration of coal dust passing by the trickle duster. Specifically, rock dusts having a greater proportion of

Nutrient supply to the coastal euphotic zone is critical in sustaining the productivity of ecosystems and provides an important feedback on the carbon cycle via stimulating the biological pump. The supply of coastal nutrients is typically thought to be dominated by terrestrial inputs and upwelling of deep ocean waters. Marine-terminating glaciers can provide nutrients via both mechanisms but the relative importance of each is dependent on complex physical–biogeochemical processes ranging from those in the glacier drainage system to the ice–ocean interface. Constraining these glacial nutrient supply processes in a remote part of the Canadian Arctic Archipelago (CAA) is the focus of a new study by Williams et al. (2021, https://doi.org/10.1029/2021JG006289). Their findings advance our understanding of the role glaciers play in polar nutrient cycling by highlighting significant shallow meltwater pumping of macronutrient-replete marine waters by CAA marine-terminating glaciers into the euphotic zone.

Background Commercial vegetable production in the United States of America (USA) often relies on foliar insecticide sprays for managing key insect pests. However, foliar applications of insecticides have a number of drawbacks to the health of consumers, farmworkers, and the environment. Drip chemigation is the application of pesticides to the soil through trickle (drip) irrigation systems, and can overcome a number of the drawbacks typical of foliar insecticide applications. Results We conducted a two-year study in five commercial fields of staked tomatoes in western North Carolina to compare the efficacy, economics, and environmental impact of drip chemigation versus foliar sprays. Drip chemigation significantly reduced insecticide inputs, utilized more selective and environmentally compatible insecticides, and reduced the time lost to reentry intervals, while maintaining comparable efficacy and economic returns. Conclusions Drip chemigation was an effective tool for managing key insect pests, provided a broad range of human and environmental health benefits, and will likely become increasingly cost effective in the future as insecticide patents expire and more insecticide options become available. This article is protected by copyright. All rights reserved.

Biotrickling filters are one of the most effective methods of air bio-purification, this bioremediation process if of high efficiency in pollution reduction. It is an eco-friendly process and economically viable. The technology of biotrickling filters includes Compact Trickle Bed Bioreactors (CTBB), which are currently used in an increasingly wide range. The aim of this work will be an objective assessment of the implementation potential of the CTBB technology to various industries, including the municipal sector. The paper briefly discusses the characteristics and operating parameters of biotrickling filters, a review of their applications as an effective method of VOC and odor removal including sources of their emissions, as well as the characteristics of CTBB and implementation possibilities to various industries. It was concluded that CTBB are promising solution for the future, as it combines the high degradation efficiency of a wide range of pollutants with cost-effectiveness and ecology. According to the analyzed data and results, this technology can be successfully used to remove VOCs and odors from various industries.

Gas–liquid distributors form an integral part of an industrial packed bed reactor, esp. trickle bed reactors used for hydrodesulphurization of liquid fuels. Among several process parameters that influence performance of trickle bed reactors, gas–liquid distributors are of foremost importance. In the present work, we have developed a computational model based on Eulerian two-fluid approach to simulate the gas–liquid flow in widely–varying flow regimes encountered in a distributor unit. The predictions are validated using the liquid distribution measured using high-speed imaging, morphology of gas–liquid flow measured using in–house developed voidage probes, and pressure drop measurements. Owing to the difference in the inherent nature of flow through the standard chimney and standard bubble cap distributors, the liquid discharge pattern, uniformity and symmetry of flow streams, and pressure drop across the distributor were found to be significantly different from each other. Further, the addition of liquid dispersion plates to the outlet of the main distributor unit not only resulted in improved liquid discharge pattern and wider coverage span, but also in a highly dispersed stream. Lastly, the application of the above study and the presented methodology was demonstrated for predicting the gas–liquid distribution through industrial trays, using standard bubble cap and chimney trays.

Agricultural wastewater is a major source of herbicides, which pose environmental and health concerns owing to their substantial use and poor elimination rate in conventional wastewater treatment plants. White-rot fungi are versatile in degrading xenobiotics; however, the key problem encountered with their application in actual scenarios is competition with indigenous microorganisms, mainly bacteria. To address this barrier, two different strategies were implemented in the present study. One strategy was to set up a trickle bed with Trametes versicolor immobilized on pine wood, and another strategy was to employ a T. versicolor-pelleted, fluidized-bed reactor to remove diuron and bentazon from actual wastewater under non-sterile conditions. The residence time in the trickle bed was estimated using three methodologies. With 10 batches of a 3-day cycle operation, although the trickle-bed reactor possessed a shorter contact time (8.5 h per cycle) and lower laccase activity compared with those of the fluidized-bed reactor, it demonstrated a higher removal yield and lower bacterial counts. In addition, the utilization of pine wood as a carrier obviously reduced the cost since no additional nutrients were required. Hence, after evaluating all advantages and limitations of both bioreactors, for the purpose of treating over the long term and scaling up, a trickle-bed reactor is the preferred choice., This work has been supported by the Spanish Ministry of Economy and Competitiveness State Research Agency (CTM2016-75587-C2-1-R) and co-financed by the European Union through the European Regional Development Fund (ERDF). This work was partly supported by the Generalitat de Catalunya (Consolidate Research Group 2017-SGR-0014). K. Hu acknowledges the financial support from Chinese Scholarship Council.

Municipal solid waste classification is a major livelihood project, while the classified materials are deficiently utilized, especially the inert waste. In this study, a composite biological trickle reactor, packed with foam concrete, waste textile, animal bone and aged refuse, was developed for the treatment of mature landfill leachate, and the function of reaction factors were investigated systematically. Results indicated that under the optimum conditions with mixed filler, temperature of 30 °C, hydraulic loading of 40 L/(m3·d), and aeration rate of 1.8 L/(h·L), the average removal rates of chemical oxygen demand, total nitrogen, ammonia nitrogen and total phosphorus were 85.02%, 76.00%, 99.90% and 96.83%. The reactor presented well buffering performance after 100 days operation, with a slightly accumulation of organic and nitrogen substances. Biological analysis showed that the main phyla in all fillers were Actinobacteria and Proteobacteria. The microbial diversity and richness of waste textile were inferior to those of animal bone, aged refuse and foam concrete. In the operation system, the alternate aerobic–anoxic–anaerobic environment was structured, and the contaminants removal was due to the comprehensive function of adsorption, promotional biotreatment and chemical precipitation. All the results demonstrated that this novel trickle reactor was an excellent choice for leachate treatment because of the low cost and superior efficiency.

The results of studies conducted by Ekoinwentyka sp. z o.o. concerning the possibility of using a trickle-bed bioreactor for reducing of volatile organic compounds (VOCs) emitted by PKN ORLEN S.A. wastewater treatment plant were presented and discussed. During the one-month trial, inlet and outlet concentrations of VOCs, H2S and NH3 were analysed and the efficiency of bio-purification process was determined on their basis. The obtained results confirmed the effectiveness of the applied technology under the given conditions, simultaneously demonstrating the validity of conducting further technological analysis to derive the design assumptions of the bioreactor on the industrial scale.

A biofilm developed on polyurethane packing in a trickle bed bioreactor was used to effectively remove formaldehyde from contaminated air. Formaldehyde removal depended on the retention time of the gas in the bed as well as on the gas-liquid mass transfer coefficient. Both retention time and the mass transfer coefficient depended on the gas flow rate. At 25±1°C and pH 7, a 99% removal of formaldehyde from air with an initial contamination level of 450 mg L -1 was achieved at a hydraulic retention time of 132 s. The degradation rate was likely limited by oxygen mass transfer. The bioreactor could be operated stably over the pH range of 5 to 7 at 25±1°C. Formaldehyde removal in the bioreactor was mathematically modeled to facilitate design and scale up. The model was shown to agree well with the experimental data. Trickle bed bioreactors offer a potentially viable option for cleaning air streams contaminated with formaldehyde.

This research was carried out to study the effect of plants on the wetted area for two soil types in Iraq and predict an equation to determine the wetted radius and depth for two different soil types cultivated with different types of plants, the wetting patterns for the soils were predicted at every thirty minute for a total irrigation time equal to 3 hr. Five defferent discharges of emitter and five initial volumetric soil moisture contents were used ranged between field capacity and wilting point were utilized to simulate the wetting patterns. The simulation of the water flow from a single point emitter was completed by utilized HYDRUS-2D/3D software, version 2.05. Two methods were used in developing equations to predict the domains of the wetting pattern. The principal strategy manages each soil independently and includes plotting, fitting, and communicating relevant connections for wetted zone and profundity, maximum error did not exceed 31.2%, modeling efficiency did not less 0.95, and root mean square error did not surpass 1.43 cm. The second strategy additionally treated each soil independently yet used electronic programming that uses different relapse methods for wetted territory and profundity, the maximum error did not exceed 15.64 %, modeling efficiency did not less 0.98, and root mean square error did not surpass 1.18 cm. a field test was directed to quantify the wetted radius to check the outcome acquired by the software HYDRUS-2D, contrast the estimation and the reproduced by the software. The after effects of the conditions to express the wetted radius and depth regarding the time of water system, producer release, and initial soil moisture content were general and can be utilized with great precision.

Biomethane constitutes an important biofuel for the transition towards a biobased circular economy with a sustainable energy sector. An environmentally friendly pathway for its production is through the gasification of 2nd generation biomass that generates syngas (H2, CO, and CO2), followed by syngas biomethanation. A novel design thermophilic trickle bed bioreactor was successfully tested at semi-pilot scale. It was operated continuously performing biomethanation of an artificial syngas mixture (45% H2, 20% CO, 25% CO2 and 10% N2). Its effectiveness was compared to a primitive design lab scale trickle bed reactor with a 28 times lower bed volume under identical operating conditions. At an empty bed residence time of 0.6 h, the novel semi-pilot scale trickle bed reactor converted 100% and 98% of the influent H2 and CO, respectively and produced CH4 at a rate of 10.6 ± 0.2 mmol·lbed−1·h−1, whereas the lab scale reactor converted 89% of the H2 and 73% of the CO and achieved a CH4 productivity of 8.5 mmol·lbed−1·h−1. The maximum CH4 productivity achieved in the semi-pilot scale reactor was 17.6 ± 0.6 mmol·lbed−1·h−1 at an empty bed residence time of 0.33 h with a 99.2 ± 0.1% product selectivity. Furthermore, the semi-pilot scale reactor was connected in series with a fluidized bed gasifier fed with wood pellets to assess the biomethanation potential of the system when supplied with real syngas. The obtained results showed no process inhibition in the semi-pilot scale reactor, which accomplished 100% H2 conversion efficiency and 92.4 ± 0.6% CO conversion efficiency at an empty bed residence time of 0.6 h.

Environmental flows are an integral component for the conservation and management of rivers, flood plains and other wetlands in the Murray–Darling Basin. Under the Basin Plan, environmental water is managed by the Commonwealth Environmental Water Office (CEWO) and the states. We assessed CEWO environmental flows (2014–15 to 2018–19), compared our findings with expected outcomes for vegetation in the Basin-wide Environmental Watering Strategy (EWS) and interviewed water managers about the efficacy of environmental watering. Some 21% of CEWO water was delivered as flood events, to 9 of 19 river valleys, inundating 7% of wetland area in those valleys annually and 0.8% of major Basin wetlands. A consistent pattern was the watering of many small wetlands on the South Australian Murray with small volumes (median area 43ha, volume 125ML). Just 12% of the area of river red gum subject to EWS expected outcomes was flooded, and half these events were likely suboptimal to achieve ecological benefits. Wetlands have not received the water they need and vegetation outcomes cannot be met by completion of the Plan in 2024. Rules that constrain flooding of private land must be relaxed if the Plan is to achieve its statutory requirement of wetland conservation.

Sensitivity to low rhizosphere soil aeration may change over time and therefore plant response may also depend on different growth stages of a crop. This study quantified effects of soil aeration during 5 different periods, on growth and yield of trickle-irrigated potted single tomato plants. Irrigation levels were 0.6 to 0.7 (low level) or 0.7 to 0.8 (high level) of total water holding capacity of the pots. Soil was aerated by injecting 2.5 l of air into each pot through the drip tubing immediately after irrigation. Fresh fruit yield, above ground plant dry weight, plant height, and leaf area index response to these treatments were measured. For all these 4 response variables, means of post-infiltration aeration between 58 to 85 days after sowing were 13.4, 43.5, 13.7, and 37.7% higher than those for the non-aerated pots, respectively. The results indicated that: post-infiltration soil aeration can positively impact the yield and growth of sub-surface trickle-irrigated potted tomato plants; positive effects on plant growth can be obtained with aeration during the whole growth period or with aeration for partial periods; positive growth effects of partial periods of aeration appears to persist and result in yield benefit.

This research was carried out at steep slope area planted with trees in different elevation terraces. The experiments were conducted at the experimental site at the Chabahar Free Zone. One major disadvantage of trickle systems is the tendency for emitters to clog. A trickle irrigation system was installed in a 50 m long and 20 m wide plot. The hydraulic performance of emitters was based on water flow, uniformity coefficient, application efficiency, and water losses through deep percolation. The flow volumes along the lateral length were fairly consistent and the variation was diminutive under both types suggesting uniform distribution of water. The difference in elevation between upper and lower terraces at the area of study was about 50 m irrigated by drip irrigation system. The system of irrigation has a problem in distribution uniformity of water resulted from initial filling of the pipes and drainage of water after stopping irrigation. Therefore, the lowest terrace receives the highest while the upper terrace receives the lowest amount of water. The problem of a lateral pipe with equally emitters and uniform supply of water is investigated. The flow volumes along the lateral length were fairly consistent and the variation was diminutive under both types suggesting uniform distribution of water. The system achieved rationally high DU, CU, Ea. The CU values for randomly selected laterals with smooth emitters averaged to 81.7% and spiral emitters averaged to 87.4%. The DU values averaged to 75.4% for smooth and averaged to 81% for spiral emitters. The overall Ea achieved were 82.7% and 89.4% for smooth and spiral emitters, respectively. The higher values of CU, DU, and Ea with spiral emitters as compared to smooth emitters suggest that they performed better and could be preferred to achieve uniform water distribution. Water movement below the emission point was more pronounced in the vertical. In most cases, the wetting front followed an axially symmetric pattern. The water laterally moved to about 0.35 m while it moved to a 0.56 m depth. The root zone for many short rooted crops is located in this range hence the percolation losses would practically be negligible under such situations.

The study presents the preliminary results of research with the aim to test a Compact Trickle-Bed Bioreactor (CTBB) to the biopurification of air from VOC’s mixtures (ethyl alcohol, dimethyl sulphide, styrene). The experiments were performed using a 45 dm3 semi-industrial scale bioreactor in which gas and liquid phases flowed co-currently in downward direction through a bed made up of polyethylene rings. The bioreactor was inoculated with a co-culture of microorganisms including bacterial strains found in the wastewater and adopted to chosen pollutants. The gas-flowrate was 4.0 m3/h and VOC concentration in the gas phase was changed from 40 to 255 ppm. In the whole period of research the efficiency of pollutant removal was in the range 92-99%. The lowest result of efficiency was achieved in the 2nd day of research as a response of the highest concentration of VOC. Possible consequences of a violent pollutant overload and the time required for regenerating the microorganisms and returning to the stable process conditions were also investigated. An increase of VOC concentration to 220-255 ppm did not significantly influence the deterioration of process efficiency. After the period of adaptation of microorganism to the process condition and immobilization of microflora on the packing material, the experimental set-up has been working reliably for 21 days.

This study quantifies the natural ventilation rate in single-sided natural ventilation with a trickle ventilator, inserted in a window frame or a shutter box. The seasonal characteristics of natural ventilation in actual residential conditions were examined by long-term field measurements in a multi-residential building during spring and summer seasons. The wind velocities and pressure differences between indoors and outdoors in the summer season, which are the driving forces of natural ventilation, were relatively lower compared to the spring season. The turbulence intensity was greater in summer when the outdoor wind velocity was lower. During this study about 90% of the outdoor wind velocity was less than 2.5 m/s, and the wind speed and wind direction constantly fluctuated. The ventilation rate of the trickle ventilator was quantified by four methods: the tracer gas method, inlet air velocity-based, pressure difference-based, and reference wind velocity-based. The tracer gas method was considered the reference to which the other three methods were compared. The calculation method based on the indoor/outdoor pressure difference, which is widely used for calculating the natural ventilation rate, failed in this case to capture the actual natural ventilation rate; only 63% of the ventilation rate quantified by the tracer gas method could be explained by this method. In addition, the reference wind velocity-based quantification showed the worst agreement, with an error rate around 54%. The inlet air velocity-based quantification of the ventilation rate showed the best agreement with the results of the tracer gas method in the trickle ventilator.

The pattern of distribution of the two-phase gas-liquid flow in the inlet pipeline and the effect of the input conditions on the distribution of the flow in the upper part on the trickle bed reactor was investigated by CFD. The multiphase Euler-Euler VOF (Volume Of Fluid) model was used. The analysis of the distribution of the two-phase flow in a trickle bed reactor was carried out using the inlet diffuser and the tray with chimney distributors. Two different cases of input diffusers, which are used in industry, were investigated. The first type is designed to eliminate the influence of the dynamic pressure of a two-phase jet from the inlet pipeline by placing several grids under the reactor inlet. The second type completely mixes the two-phase flow from the inlet pipeline, but does not eliminate the intense axial two-phase flow. Studies have shown that the choice of design of the inlet diffuser affects the distribution of the liquid phase in the distribution tray, distorting the curvature of the surface of the liquid layer to a different extent and drying various chimneys. This leads to a decrease in the quality of the distribution of the liquid phase to the underlying catalyst bed for both the studied types of the inlet diffuser. Consequently, the selection of the inlet diffuser is an important part of the design and creation of trickle bed reactors for hydrotreating processes.

Considering the relevance of the reduction or replacement of fresh water supplies for irrigation, to mitigate the use of agricultural fertilizers and to improve sustainability, this study aimed to evaluate water and nutritional efficiency of treated sewage in cowpea plots. The experiment was conducted in the city of Tianguá-CE, on land belonging to the Water and Sewage Treatment Company of Ceará. It used a randomized block design for the arrangement of split plots. The plots contained two water sources (treated sewage and well water). The subplots contained four irrigation levels based on potential evapotranspiration (50%, 75%, 100%, and 125% of ETc) and the sub-subplots contained four nitrogen, phosphorous, and potassium (NPK) levels (0%, 33%, 66%, and 99% of the nutritional recommendations for cowpea cultivation). The yield variables, number of pods per plant, bean numbers per pod, and bean production, were improved with increased irrigation, regardless of the water source. Examining NPK levels in particular, yields differed depending on the water source. The use of treated domestic wastewater for bean irrigation can replace up to 100% of commercial fertilizers. RESUMO Objetivou-se com o presente trabalho quantificar os componentes de produtividade da cultura do feijão submetida a diferentes lâminas de irrigação com água de poço e esgoto doméstico tratado em solo com diferentes níveis de adubação NPK. O experimento foi conduzido em Tianguá - CE, na área da Estação de Tratamento de Esgoto da Companhia de Água e Esgoto do Ceará. Foi utilizado o delineamento em blocos casualizados, em parcelas subsubdivididas 2 x 4 x 4, referente à duas fontes hídricas (efluente de esgoto doméstico tratado e água de poço amazonas) nas parcelas, quatro lâminas de irrigação baseadas na evapotranspiração potencial (50, 75, 100 e 125% da ETc) nas subparcelas e nas subsubparcelas quatro níveis de NPK (0, 33, 66 e 99%) da recomendação nutricional para a cultura. As variáveis analisadas, número de vagens por planta, números de grãos por vagem e produtividade de grãos aumentaram em função do incremento da lâmina de irrigação, independente da fonte hídrica. Quanto ao tratamento níveis de NPK, os resultados produtivos divergiram em função da fonte hídrica. O uso do efluente esgoto doméstico tratado na irrigação do feijoeiro pode substituir até 100% dos fertilizantes comerciais.

Historical data from thirteen monitored and controlled process variables (PVs) is used to build a Partial Least Square (PLS) model to estimate the content of methylacetylene and propadiene (MAPD) on the product of a propene production plant in Brazil. A technique called Variable Importance in Projection (VIP) is used to select the important PVs and the performances of the PLS-VIP models for two trickle bed reactors are compared with the performance of the PLS models for the same beds. An F test did not provide evidence for significant difference between the PLS and the PLS-VIP models in neither bed. The coefficient of determination of both PLS-VIP models were above 0.80 (0.81 and 0.87), an acceptable value given the industrial nature of the data. The developed models show are adequate for implementation as empirical models for virtual analysers that can estimate the content of MAPD contaminants in case on-line analysers fail to provide such.

The response of wine grapes to irrigation systems was investigated in a Cabernet Sauvignon/140 Ru vineyard in sandy loam soil in Sicily during a two-year study. Two different drip irrigation systems were evaluated: one surface drip and two subsurface drip irrigation systems, with the trickle line located at different distances from vine trunks. Vegetative and quantitative parameters, must quality and root distribution were compared among irrigation treatments. During the two study years, irrigation of grapevines via a subsurface drip system resulted in greater water use efficiency without affecting must composition. Establishing the trickle line near the trunk positively influenced trunk growth and total root contact while establishing the trickle line 1.20 m from the trunk increased yield. Dry mass partitioning was modified in subsurface irrigation treatments in favour of reproductive organs. We conclude that subsurface drip irrigation under the trunk can be successfully used under water deficit irrigation management, even in sandy loam soil and in the hot climate conditions of the Mediterranean vineyard. Some aspects of management deserve further investigation and further studies may better define the optimum conditions for the successful utilization of the SDI 120 irrigation strategy.

The need to reduce carbon emissions and fuel poverty has led to increased building envelope air tightness, intended to reduce uncontrolled ventilation heat losses. Ventilation strategies in dwellings still allow the use of trickle ventilators in window frames for background ventilation. The extent to which this results in “healthy” Indoor Air Quality (IAQ) in recently constructed dwellings was a concern of regulators in Scotland. This paper describes research to explore this. First a review of literature was conducted, then data on occupant interactions with ventilation provisions (windows, doors, trickle vents) gathered through an interview-based survey of 200 recently constructed dwellings, and measurements made on a sample of 40 of these. The main measured parameter discussed here is CO2 concentration. It was concluded after the literature review that 1000 ppm absolute was a reasonable threshold to use for “adequate” ventilation. The occupant survey found that there was very little occupant interaction with the trickle ventilators e.g., in bedrooms 63% were always closed, 28% always open, and in only 9% of cases occupants intervened to make occasional adjustments. In the measured dwellings average bedroom CO2 levels of 1520 ppm during occupied (night time) hours were observed. Where windows were open the average bedroom CO2 levels were 972 ppm. With windows closed, the combination of “trickle ventilators open plus doors open” gave an average of 1021 ppm. “Trickle ventilators open” gave an average of 1571 ppm. All other combinations gave averages of 1550 to 2000 ppm. Ventilation rates and air change rates were estimated from measured CO2 levels, for all dwellings calculated ventilation rate was less than 8 L/s/p, in 42% of cases calculated air change rate was less than 0.5 ach. It was concluded that trickle ventilation as installed and used is ineffective in meeting desired ventilation rates, evidenced by high CO2 levels reported across the sampled dwellings. Potential implications of the results are discussed.

This paper is part two of a broader investigation into pre-cooling the air that enters natural draft dry cooling towers. Evaporative cooling of air is to some extent different from evaporative cooling of water. Two trickle media (Trickle125 and Trickle100) originally designed for evaporative cooling of water were studied in an open-circuit wind tunnel for evaporative cooling of air. Three medium thicknesses (200, 300 and 450 mm) and two water flow rates (10 and 5 l/min per m2 horizontally exposed surface area) were used in the tests. The air velocities ranged from 0.5 to 3.0 m/s. The cooling efficiency and the pressure drop of the two media were curve fitted to yield a set of correlations. The pressure drop ranges for Trickle125 and Trickle100 were 0.7–50 Pa and 0.6–41.6 Pa, respectively. The cooling efficiencies of Trickle125 and Trickle100 fell within 15.7–55.1% and 11–44.4%, respectively. Generally, media with large effective surfaces provide high cooling efficiencies and high pressure drops; there is a trade-off between cooling efficiency and pressure drop when selecting a particular medium for a specific application. The water entrainment off the media was detected with water-sensitive papers, and both media had severe water entrainment at large air velocities.

A field study was conducted in 2013 and 2014 to evaluate the effect of air-injection into the irrigation stream in subsurface trickle irrigation on the productivity of potato. The growth characteristics, yield and water use efficiency (WUE) of potatoes grown in a sandy clay loam soil with subsurface trickle irrigation with an air-injection treatment were compared with those of potatoes grown under a conventional trickle and subsurface trickle irrigation as a control. The yield was 27.11% and 17.8% greater, in the air injection treatment comparing with non-aerated treatments trickle irrigation (DI) and subsurface trickle irrigation (SDI) respectively, for the first season, while it was greater by 38.2% and 7.66% than DI and SDI, respectively, for the second season. The WUE was 46.41% and 30.52% greater, in the air injection treatment comparing with non-aerated treatments (DI) and (SDI) respectively, for the first season, while it was greater by 61.78% and 19.33% than DI and SDI, respectively, for the second season. The plant height was 14.7% and 6.07% greater, in the air injection treatment than in the control (DI) and (SDI) respectively, for the first season, while it was greater by 14.13% and 9.7% than in the control for the second season. The shoot fresh weight per plantwas 14.8% and 4.61% greater, aerated treatment than in DI and SDI respectively, for the first season, while it was greater by 37.6% and 1.94% for the second season. Data from this study indicate that potato yield can be improved under SDI if the drip water is aerated.

Laboratory rainfall simulation experiments using a small artificial olive tree are used to show that the fraction of rain falling at a constant intensity that becomes stemflow rises from 9% at 2.5 mm/h to 36.1% at 35 mm/h. Natural rainfall events commonly exhibit wide fluctuations of intensity. Simulated rainfall events each having a mean intensity of 10 mm/h, but containing short intensity peaks of 20 to 100 mm/h at varying intra-event positions, were used to explore the effect of varying intensity profiles. Results demonstrate that changes in rainfall event profile are associated with wide variation in stemflow flux, stemflow volume and stemflow fraction. When applied to an initially dry plant, rainfall events with a late intensity peak yielded an average peak stemflow flux up to 188% larger than events of contrasting profile, such as early peak events. The increase was smaller, up to 141%, when rain was applied to plants that were already partially wet, but was again found in events with a late intensity peak. Moreover, such events yielded a peak stemflow flux up to approximately seven times larger than comparable events of uniform intensity. Likewise, changing event profile with no change in rainfall depth was associated with a maximum stemflow fraction that was 31% larger than theminimum stemflow fraction, and a maximum stemflow volume that was nearly 37% larger than the minimum stemflow volume. These results suggest that rainfall event profile exerts a significant effect on all of the studied stemflow parameters. It is hypothesized that this is a consequence of the way in which intensity profile affects the rate of wetting-up of trickle pathways on the plant, and variation in the time taken for these pathways to become fully connected. Event profile must therefore be considered along with plant architecture in seeking to understand stemflow. Copyright © 2014 John Wiley & Sons, Ltd.

Increasing shares of energy production originating from fluctuating renewable sources require measures that are able to balance power production for a stable electricity grid. H 2 /CO 2 biomethanation is a suitable approach to convert fluctuating excess renewable energy into the storable substitute natural gas. This study investigated the rapid load change capability of an anaerobic thermophilic trickle bed reactor while maintaining a high methane content. The return to full load (62.1 m 3 H2 /m 3 trickle bed /d) after a 30-min operational off-cycle was possible almost immediately, while 24-h interruptions required a 60-min stepwise load increase. To accelerate this delayed microbial conversion activity, non-steady state substrate gas conversion can be controlled via substrate and product gas flow rates, allowing to reactivate the entire microbial community and produce high quality product gas. Reactor design might be further improved to avoid short-circuiting and use the entire trickle bed gas phase as high quality gas buffer during initial load increases.

This paper presents the first experimental study of how rainfall intensity and event profile affects stemflow behaviour on the rigid branches and stems of leafless, woody plants. Constant intensity rainfall simulation experiments showed that stemflow fraction rises with intensity. Varying intensity experiments showed that the stemflow fraction and stemflow flux vary with the rainfall event intensity profile and peak intensity. Stemflow fraction tends to be larger when intensity peaks occur early in the rainfall event, and variable intensity events exhibited peak stemflow fluxes >3 times those seen in constant intensity events. Moreover, experiments in which incident drop energy was reduced by a mesh screen suspended above the test plant commonly showed increases of >100% (and exceeding 300% under particular intensity profiles) in stemflow fraction, depth and peak stemflow flux. The results suggest that the development of trickle pathways along woody branches is facilitated by rain of moderate intensity and that splash dislodgement of attached water progressively reduces the adhesion of drops during intense rainfall. Thus, in plants with extensive woody branches, it is not merely rainfall intensity that determines stemflow fraction but the temporal variations in rainfall intensity. This offers a new explanation for increased stemflow production when trees are leafless, than when foliage is present, in terms of the reduced intensity peaks during rain in the dormant season. Copyright © 2013 John Wiley & Sons, Ltd.

In this paper, different technologies of distributors for trickle bed reactors were compared, in terms of intrinsic performance of distribution and resistance to tray unlevelness. γ-ray tomography has first been used, in a large column unit, to visualize gas–liquid distribution just below several tray technologies. Results obtained show a better distribution performance under multiaperture chimney trays, in comparison with gas-lift and bubble cap systems. Then, a specific cold mock-up was designed in order to mimic tray tilt between two tray elements. Sensitivities to tray unlevelness of both gas-lift and multiaperture systems are comparable, far better than the one for the bubble cap system. Multiaperture chimneys have indeed excellent behavior at nominal conditions, while gas-lift technology is interesting for its ability to behave similarly over a large flow range. Considering those results, some guidelines are finally given for the choice of the distribution technology.

This work validates the appropriate application of chemical reaction engineering principles in the successful design of a full-scale industrial trickle bed reactor for a proprietary hydrogenation reaction over a palladium catalyst. After identifying an effective catalyst formulation in a continuous laboratory scale trickle bed reactor, the project team used the same small-scale reactor to generate kinetic data for scale-up. The scale factor from the laboratory to the final design was about 3 × 106. The development effort identified and resolved three important problems: (1) incomplete catalyst wetting of the small catalyst bed, even though the catalyst was diluted with inert fines; (2) lower than economically attractive catalyst productivity; and (3) catalyst deactivation.

The hydraulic characteristics of three irrigation systems (trickle, subsurface and sprinkler irrigation) were investigated in terms of required pressure and flow characteristics of emitters, leaky pipes and sprinklers. Added to that, the pump power required for operating the used irrigation systems was also estimated. The performances of the used irrigation systems in terms of application efficiency, coefficient of uniformity, flow rate variation and irrigation system efficiency were experimentally determined under conditions of sandy soil. The experimental results reveal the following: - The required pump pressure to operate the trickle, subsurface and sprinkler irrigation systems must not be less than 2.9, 2.9 and 4.3 bar, so as to pump water from the emitters, lucky pipe and sprinkler at pressure of 1.3, 1.3 and 2.4 bar. - The required pump power to operate the trickle, subsurface and sprinkler irrigation systems must be not more than 32.6 kW instead of the already used pump in the experimented area (44.1 kW) that will be saved power with percentage of 26%. - The exponent x value of emitters was 0.77 meaning that the flow rate through emitters is between a laminar and turbulent. - Values of application efficiency and emission uniformity for subsurface irrigation system were much higher than trickle irrigation system. - Sprinkler irrigation system recorded higher flow rate variation comparing with trickle and subsurface irrigation systems.

After a 40-year drought, the first trickle of new drugs is emerging from the tuberculosis pipeline. They are a welcome addition to a field that has labored with old, inefficient treatments and the ...

A numerical model for liquid mal-distribution in randomly trickle bed reactors has been investigated and the results are compared with the experimental data. A CFD model based on the three-phase Eulerian approach is developed and a two-fluid model is utilized to perform the inter-phase momentum exchanges. Furthermore, radial distribution of the bed porosity is considered adjacent to the reactor wall. Two different types of liquid inlet distributors have been used in order to study the accuracy of the CFD model. To validate the CFD model, the simulation results are compared with the experimental data and the results from the porous media concept in which the permeability model has been applied to implement the inter-phase momentum exchange. Experimental results have been obtained on an industrial trilobe catalyst under a trickling flow regime in a pilot scale reactor setup. Co-current liquid and gas streams have entered to the reactor through a mono or multi orifice distributor. Results of the developed CFD model have found more accurate than that of the porous media concept when compared with the experimental data.

Designing drip irrigation systems involve selection of an appropriate combination of emitter discharge rate and spacing between emitters for any given set of soil, crop, and climatic conditions, as well as understanding the wetted zone pattern around the emitter. The exact shape of the wetted volume and moisture distribution will depend on many factors, including soil hydraulic characteristics, initial conditions, emitter discharge rate, application frequency, root characteristics, evaporation, and transpiration. Multi-dimensional nature of water flow, plant uptake and high frequency of water application increase the complexity in modelling soil moisture dynamics from trickle irrigation. Researchers used analytical methods, semi-analytical methods and numerical methods to Richards’ equation using certain boundary conditions to model the infiltration from point source irrigation for use in design, install, and manage of drip irrigation systems due to their merits over direct measurements. Others developed models based on Green-Ampt equation, empirical models using regression techniques/dimensional analysis techniques/moment approach techniques/artificial neural networks on this topic to describe infiltration from a point/line sources. A review on these models developed under each category is presented in this study. Other knowledge gaps identified include (a) effect of variations in initial moisture content and packing conditions, (b) precision in observing the wetting front and soil–water content, (c) validity of soil surface boundary conditions, (d) effect of crop root architecture and its withdrawal pattern for different input parameters, (e) effects of gravitational gradients, (f) stratification in the soils, and (g) impact of soil hysteresis. The review promotes better understanding of the soil water dynamics under point source trickle emitters and helps to identify topics for more emphasis in future modelling activity.

Two successive growing seasons of sunflower production were conducted at Yashaa village Al-Intlaq, West Delta, Egypt during 2009 and 2010 for evaluating either soil moisture distribution patterns or sunflower yieldunder pulse irrigation technique. The split plot design with 4 replicates was used to achieve the study objectives, main plots were frequency treatments (daily "D1", every 2 days "D2" and every 3 days "D3") and subplots as times events were pulse (P) (10 min on 10 min off) and continuous (C) irrigation treatments.Results indicated that the average amount of water was 3033.31 m3/fed for both treatments. Also there were no significant differences between the two irrigation techniques and the three irrigation period on saving applied water. The pulse trickle irrigation gave a good distribution of moisture content within the root zone, especially with irrigation every two days (D2) before and after irrigation during the different stages of plant growth. The pulsing trickle irrigation had the highest yield, and yield components. Also the lowest performance was obtained by the continuous treatment. The trend obtained indicates that every 2 days trickle irrigation might improve yields and yield components. The results revealed that the water use efficiency increased as the irrigation frequency increased from D1 to D2 with percent of 12.3 % thendecline for D3 with percent of 27.0 %. The results indicate that the application of pulsed irrigation led to improve the water storage efficiency in the effective root zone compared to the continuous irrigation,although the continuous irrigation led to improvement of efficiency in the depths away from the root zone and horizontal distances not far to the emitter. The results refer that there is no significant differences between daily irrigation D1 and irrigation every two days D2 but water storage efficiency, significantly decreased with irrigation every three days D3 under both pulsed trickle irrigation and continuous irrigation.

Wetting pattern can be obtained by either direct measurement of soil wetting in field, which is site specific, or by simulation using some models. Use of numerical or analytical flow models for design purpose is considered cumbersome and impractical in many situations. Therefore, present study was undertaken to develop a model for wetting pattern under trickle source in sandy soil of Nirjuli, Arunachal Pradesh. In the present study, the drip irrigation system was operated to record observed wetting front advance (vertical and horizontal) of emitters with flow rates of 2, 4 and 10 l h−1. A fixed quantity of 4 l of water was applied to the bare dry soil kept in a container of perspex sheet (1 m × 1 m × 0.9 m). The wetting front advance was observed just after irrigation and its subsequent redistribution after 1, 2, 4, 6, 9, 12, 15, 18, 24 and 48 h respectively after irrigation. Using Buckingham π theorem, a semi-empirical model was developed to simulate the wetting front pattern under trickle point source at the end of irrigation. Performance of the model just after irrigation was evaluated by comparing estimated values against observed values using F test, t test, ME and RMSE values. The redistribution of the wetting front geometry with respect to elapsed time was modelled with regression analysis using four models viz. linear, logarithmic, exponential and power. Power function was found to be the best fit for horizontal wetting front (W) as well as vertical wetting front advance (Z) based on the highest R 2 value.

The air quality of indoor spaces is the most significant parameter in providing a healthy living environment. Low indoor air quality (IAQ) leads to Sick Building Syndrome—one of the major reasons for labor loss in office buildings. The fundamental measure to ensure indoor air quality is ventilation, which includes two basic types: mechanical ventilation and natural ventilation. Natural ventilation is an exchange of stale indoor air with fresh outdoor air by means of a pressure difference due to wind and/or stack effect. Trickle Vents, known also as background ventilators, are natural ventilation devices which can be integrated into façades or window systems as an alternative to operable vents, specifically in high-rise buildings. The major design criteria of Trickle Vents are ventilation capacity, controllability, actuation, thermal insulation, air permeability, water tightness, climatic adaptation, security, and acoustic attenuation. Other important parameters in Trickle Vents design are positioning, equivalent area, and control strategy. This paper aims to review all these aspects, particularly with reference to building regulations and commercial products. Furthermore, simulation, experimental, monitoring, and survey studies of Trickle Vents are also discussed. This literature review is presented from the perspective of performance parameters, control strategies, positioning, etc., with an aim to provide a comprehensive overview of such technology.

Wetted soil shape under trickle irrigation is an important parameter in irrigation scheduling and design in agricultural farms. Irrigation water should not be beyond crop root zone to avoid deep percolation. Moreover, irrigation water applied should adequate crop water use in irrigation interval. The purpose of this work is to figure out the suitable shape of wetted soil based on soil type, flow rate, and crop water use. A field experiment was conducted in sand, silt and clay soils under trickle source with varying flow rates as 2, 4, 8, 16, and 24 liter/h. Squash, corn, and grape crops were selected to represent different root zones for irrigation scheduling. Field results showed that horizontal and vertical water movements were related to both emitter flow rate and soil intake rates. Suitable flow rate and irrigation interval were found for selected soil and crop types. Soil moisture content was contoured directly after irrigation and soil-water redistribution. Optimal flow rates were 2 and 4 liter/h in clay soil, 8 and 16 liter/h in loam, 16 and 24 liter/h in sand. Adjusted method was recommended to calculate irrigation interval by revising wetted root zone volume, taking into account different soil, crops, crop stages, and seasons.

This study was conducted at Wadi El-Natron area, season (2008-2009), to evaluate the influence of three irrigation systems (Bubbler, Micro-sprinkler and Trickle) on Jatropha production. Also, this work includes different water management techniques, (quantities 60%, 80% and 100% from ETo and irrigation interval of 2 and 4 days). The objective of the present work is to implement some of these intervals and water deficits in computing actual evapotranspiration of Jatropha under desert conditions, to maximize the seeds oil content production of Jatropha under different irrigation systems to save water .The results are as follows: Highest seeds yield production (302.40 kg/fed), was obtained under bubbler irrigation system at 100% applied irrigation water and 2 days intervals, comparing with micro-sprinkler and trickle irrigation systems (238.48 kg/fed) and (204.80kg/fed), respectively. Maximum crude Jatropha oil content “CJO” (%) (29.33%) was obtained under trickle irrigation system at 60% applied irrigation water and 4 days intervals, comparing with micro-sprinkler and bubbler systems (24.2%) and (23.21%), respectively. lowest actual evapotranspiration “ETa” for (initial, development, mid-season, and late-season) growth stages of value were (50.50, 326.37, 671.79 and 142.34) respectively and 1191mm for all-season, were obtained under trickle irrigation system at 60% applied irrigation water with 2 days intervals . Water use efficiency under bubbler irrigation system at 80% applied water quantity and 2 day intervals (0.18 kg/m3) was highest than different treatments.

The aim of this work was to compare the performance of sprinkler and subsurface trickle irrigation systems under treated sewage water increase of landscape conditions. Field experiments were conducted at Residential and Industrial Wastewater Treatment System located in the National Monitoring in Delta Barrage (El-Qanater), Cairo Egypt. Hybrid Bermuda grass was cultivated in two separate experimental locations; one was irrigated by treated sewage water and the other with Nile water. At each location three irrigation systems has been tested, which note (1) sprinkler irrigation system :a) rotary sprinkler heads and: b) spray sprinkler heads (2) subsurface trickle irrigation laterals with long path emitters and (3) irrigation with leaky pipes. Results indicated that, applying treated sewage water by subsurface trickle laterals was more safely used due to the lowest concentration of heavy metals in soil profile. The highest value of the volumetric soil moisture content (0.152 m3 of water / m3 of soil) was recorded by subsurface trickle irrigation system with long path emitters when the treated sewage water is applied. Also, using subsurface trickle systems saved about 11 % of total seasonal water applied comparing with sprinkler systems.

An artificial neural network (ANN) technology is presented as an alternative to physical-based modeling of subsurface water distribution from trickle emitters. Three options are explored to prepare input–output functional relations from a database created using a numerical model (HYDRUS-2D). From the database the feasibility and advantages of the three alternative options are evaluated: water-content at defined coordinates, moment analysis describing the shape of the plume, and coordinates of individual water-content contours. The best option is determined in a way by the application objectives, but results suggest that prediction using moment analyses is probably the most versatile and robust and gives an adequate picture of the subsurface distribution. Of the other two options, the direct determination of the individual water contours was subjectively judged to be more successful than predicting the water content at given coordinates, at least in terms of describing the subsurface distribution. The results can be used to estimate subsurface water distribution for essentially any soil properties, initial conditions or flow rates for trickle sources.