E. coli transport in soil columns: implications for reuse of treated wastewater in irrigation

2006 ◽  
Vol 54 (11-12) ◽  
pp. 175-182 ◽  
Author(s):  
E. Smith ◽  
S. Hegazy
Keyword(s):  
Groundwater Resources ◽  
Soil Column ◽  
Management Plan ◽  
Treated Wastewater ◽  
Soil Columns ◽  
E Coli ◽  
The Matrix ◽  
The Impact ◽  
Reuse Of Treated Wastewater ◽  
Vital Element

Reuse of treated wastewater in irrigation is gaining recognition as a vital element in the water resources management plan of developing countries, especially those situated in arid and semi-arid regions. An understanding of the transport of residual pollutants from treated wastewater, such as bacteria, in soil as a result of irrigation is critical to assessing health risks and the possible contamination of limited groundwater resources. In this work, retention of E. coli is evaluated for a soil that is irrigated by treated wastewater for growth of non-food crops near Egypt's Red Sea coast. In particular, the effects of soil organic fraction (SOF) and hydraulic loading rate (HLR) were investigated in laboratory soil columns. The matrix of experiments included three HLRs and three SOFs. The retention of bacteria by adsorption was observed at HLRs of 5 and 13 cm/h, with the magnitude of the adsorption increasing proportionally to the SOF. The impact of SOF was greater for the lower HLR. At the lowest HLR investigated (5 cm/h), filtration was also observed for the two higher SOFs (0.674 and 2.04 per cent). At a high HLR (66 cm/h) simulating flood irrigation, retention of bacteria was minimal regardless of the SOF. Since the bacterial solution is applied to a dry soil column to simulate field conditions, E. coli breakthrough after two pore volumes of throughput (vs. one) provided a meaningful comparison of bacterial retention as a function of HLR and SOF.

Modelling E. coli transport in soil columns: simulation of wastewater reuse in agriculture

2008 ◽  
Vol 57 (7) ◽  
pp. 1123-1129 ◽  
Author(s):  
Edward Smith ◽  
Aimen Badawy
Keyword(s):  
Agricultural Soils ◽  
Chemical Properties ◽  
Breakthrough Curves ◽  
Transport Processes ◽  
Treated Wastewater ◽  
Reclaimed Wastewater ◽  
Soil Columns ◽  
Local Conditions ◽  
E Coli ◽  
The Impact

Transport of E. coli bacteria was investigated in laboratory soil columns for three Egyptian agricultural soils, with aim toward determining a set of site specific criteria for safe and sustainable use of treated wastewater in irrigation in Egypt. In particular, the impacts of varying soil type and hydraulic loading rate (HLR) on E. coli effluent breakthrough curves were examined in the laboratory and simulated using the CXTFIT package to solve a one-dimensional mass transport equation that included advection, dispersion, adsorption, and straining/filtration. The attempt was made to measure the coefficients associated with each mass transfer process from independent experiments. The HLR used in irrigation was found to exert considerable influence on the impact of transport processes on E. coli breakthrough. At low HLRs, adsorption and straining/filtration are significant in addition to advection and dispersion. However, at high HLRs approaching flood irrigation, E. coli is essentially unaffected by reaction processes, with breakthrough a function of advection and dispersion only. Estimating Kdvia independent batch experiments did not provide a suitable description of adsorption of E. coli in soil columns. To ensure safe and sustainable reuse of reclaimed wastewater in irrigation, guidelines should account for physical and chemical properties of the soil and other local conditions that may impact residual contaminant transport.

scholarly journals Modelling soil water content variations under drought stress on soil column cropped with winter wheat

2014 ◽  
Vol 62 (4) ◽  
pp. 269-276 ◽  
Author(s):  
Szilveszter Csorba ◽  
Andrea Raveloson ◽  
Eszter Tóth ◽  
Viliam Nagy ◽  
Csilla Farkas
Keyword(s):  
Climate Change ◽  
Drought Stress ◽  
Winter Wheat ◽  
Soil Water ◽  
Soil Column ◽  
Time Variability ◽  
Efficiency Coefficient ◽  
Soil Columns ◽  
Swap Model ◽  
The Impact

Abstract Mathematical models are effective tools for evaluating the impact of predicted climate change on agricultural production, but it is difficult to test their applicability to future weather conditions. We applied the SWAP model to assess its applicability to climate conditions, differing from those, for which the model was developed. We used a database obtained from a winter wheat drought stress experiment. Winter wheat was grown in six soil columns, three having optimal water supply (NS), while three were kept under drought-stressed conditions (S). The SWAP model was successfully calibrated against measured values of potential evapotranspiration (PET), potential evaporation (PE) and total amount of water (TSW) in the soil columns. The Nash-Sutcliffe model efficiency coefficient (N-S) for TWS for the stressed columns was 0.92. For the NS treatment, we applied temporally variable soil hydraulic properties because of soil consolidation caused by regular irrigation. This approach improved the N-S values for the wetting-drying cycle from -1.77 to 0.54. We concluded that the model could be used for assessing the effects of climate change on soil water regime. Our results indicate that soil water balance studies should put more focus on the time variability of structuredependent soil properties.

scholarly journals Effect of Urban Wastewater Discharge on the Abundance of Antibiotic Resistance Genes and Antibiotic-Resistant Escherichia coli in Two Italian Rivers

2020 ◽  
Vol 17 (18) ◽  
pp. 6813 ◽  
Author(s):  
Fabrizio Pantanella ◽  
Itziar Lekunberri ◽  
Antonella Gagliardi ◽  
Giuseppe Venuto ◽  
Alexandre Sànchez-Melsió ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Treated Wastewater ◽  
Flow Volume ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Absolute Concentrations ◽  
The Impact

Background: Wastewater treatment plants (WWTPs) are microbial factories aimed to reduce the amount of nutrients and pathogenic microorganisms in the treated wastewater before its discharge into the environment. We studied the impact of urban WWTP effluents on the abundance of antibiotic resistance genes (ARGs) and antibiotic-resistant Escherichia coli (AR-E. coli) in the last stretch of two rivers (Arrone and Tiber) in Central Italy that differ in size and flow volume. Methods: Water samples were collected in three seasons upstream and downstream of the WWTP, at the WWTP outlet, and at sea sites near the river mouth, and analyzed for the abundance of ARGs by qPCR and AR-E. coli using cultivation followed by disk diffusion assays. Results: For all studied genes (16S rRNA, intI1, sul1, ermB, blaTEM, tetW and qnrS), absolute concentrations were significantly higher in the Tiber than in the Arrone at all sampling sites, despite their collection date, but the prevalence of target ARGs within bacterial communities in both rivers was similar. The absolute concentrations of most ARGs were also generally higher in the WWTP effluent with median levels between log 4 and log 6 copies per ml but did not show differences along the studied stretches of rivers. Statistically significant site effect was found for E. coli phenotypic resistance to tetracycline and ciprofloxacin in the Arrone but not in the Tiber. Conclusions: In both rivers, diffuse or point pollution sources other than the studied WWTP effluents may account for the observed resistance pattern, although the Arrone appears as more sensitive to the wastewater impact considering its lower flow volume.

scholarly journals The sustainable use of groundwater resources concerning further climate change scenarios in Ulaanbaatar City Area, Mongolia

2021 ◽  
Author(s):  
Dorjsuren Dechinlkhundev ◽  
Munkhtsetseg Zorigt ◽  
Ijiltsetseg Dorjsuren
Keyword(s):  
Climate Change ◽  
Groundwater Resources ◽  
Sustainable Use ◽  
Management Plan ◽  
Climate Change Scenarios ◽  
Assess Climate Change ◽  
Future Potential ◽  
Change Impact ◽  
The Impact ◽  
The City

Abstract To estimate groundwater resources under changing climate is one of the important issues for Ulaanbaatar City in the Tuul river basin of Mongolia. The main water supply is provided from groundwater and demand has been increasing due to the rapid growth of population and economic development. There have not been any complete studies to assess climate change impact on groundwater resources for Ulaanbaatar city. Therefore, in this study we proposed to estimate future potential resources of the groundwater from the main wellfields in the city using the AnAqSim (Analytic Aquifer Simulator) model. The model calibration was performed on 10 wellfields during the reference period from 1960 to 2015. Based on the reliable calibration results for the natural conditions, the impact of climate change on groundwater resources was assessed to use the projected HadCM3 scenario for the periods 2046–2065 and 2080–2099. The results of the study contribute to a water management plan for the city to recommend seasonal abstraction.

scholarly journals Assessment of Groundwater Salinization and Soil Degradation in Abdally Farms, Kuwait

2004 ◽  
Vol 9 (1) ◽  
pp. 17 ◽  
Author(s):  
M. AI-Rashed ◽  
M. Al-Senafy
Keyword(s):  
Fresh Water ◽  
Soil Salinity ◽  
Soil Degradation ◽  
Groundwater Resources ◽  
Treated Wastewater ◽  
Physical Parameters ◽  
Water And Soil Samples ◽  
Kuwait Group ◽  
Semi Arid Region ◽  
The Impact

Kuwait is a part of the arid and semi arid region, where irrigation is necessary for any realistic agricultural activities. There are no surface fresh water resources in Kuwait. Fresh water is provided from desalination of seawater. However, this water is used mainly for potable purposes. A total of 100,000 cubic meters of brackish groundwater is annually produced from the Kuwait Group and Dammam Formation aquifers. This water is mainly used for mixing at 5-10% with distilled water and for irrigation of specific crops. The aim of this study was to assess the impact of brackish groundwater irrigation on groundwater and soil. A total of 161 water and soil samples from 25 selected farms were collected and analyzed for chemical and physical parameters It was concluded that soil salinity was directly proportional to that of groundwater and a high increase in soil salinity was recognized since the establishment of the farms in Abdally. That was mainly related to the mismanagement of groundwater resources, which causes soil degradation in addition to the losses and inefficiency in water usage. It is recommended to use tertiary treated wastewater for irrigation activities in order to have a wider range of crops to be grown and to prevent the deterioration in both soil and groundwater resources.  

Spatiotemporal effects of wastewater ponds from a geoenvironmental perspective in the Kharga region, Egypt

2019 ◽  
Vol 44 (3) ◽  
pp. 376-397 ◽  
Author(s):  
Mahmoud H Darwish ◽  
Wael F Galal
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Groundwater Resources ◽  
Management Plan ◽  
Water Levels ◽  
Environmental Data ◽  
Gis And Remote Sensing ◽  
Comprehensive Management ◽  
Surrounding Areas ◽  
The Impact

One of the major geoenvironmental problems in the Kharga region arises from the haphazard exploitation of groundwater resources and sewage dumping, which have resulted in wastewater accumulation in the form of ponds. The impact of the spatial expansion of wastewater ponds in Kharga and the surrounding area has been so pervasive that ponds have become a source of environmental degradation. These ponds are distributed throughout the area, but the major lakes are located in the eastern and southeastern provinces. The water levels of these ponds are rising at a remarkable rate, especially in the winter, when there is no evaporation and rainfall can lead to overflows that flow towards cities, villages and farmlands. As a result of untreated sewage inflows, all the low surrounding spaces are at high risk of being influenced by these ponds. The objectives of this study were to evaluate the spatiotemporal threats posed by wastewater ponds and develop a conceptual model to estimate the geoenvironmental impacts on the surrounding areas. GIS and remote sensing were used to process all available geological, topographical, hydrogeological, hydrological, land use and environmental data. The pond expansion trend was estimated from Landsat time series from 1984 to 2018, and the results indicated that the wastewater bodies continuously increased and the land cover percentage decreased. The encroachment of wastewater ponds has resulted in extensive land cover disturbances in recent years, and land use change has affected nearly 2.5% of the region. The complexity of the problems associated with wastewater ponds in the Kharga district requires a comprehensive management plan that is effective in not only maintaining the stability of the ponds but also in improving the sociocultural and economic conditions around the ponds. Specifically, the wastewater drainage and accumulation system should be managed according to the surrounding functional context.

Impact Strength, Flexural Modulus and Wear Rate of PMMA Composites Reinforced by Eggshell Powders

2020 ◽  
Vol 38 (7A) ◽  
pp. 960-966
Author(s):  
Aseel M. Abdullah ◽  
Hussein Jaber ◽  
Hanaa A. Al-Kaisy
Keyword(s):  
Impact Strength ◽  
Wear Rate ◽  
Flexural Modulus ◽  
Matrix Material ◽  
Weight Fraction ◽  
Pure Pmma ◽  
Calcination Process ◽  
The Matrix ◽  
The Impact ◽  
Interface Bond

In the present study, the impact strength, flexural modulus, and wear rate of poly methyl methacrylate (PMMA) with eggshell powder (ESP) composites have been investigated. The PMMA used as a matrix material reinforced with ESP at two different states (including untreated eggshell powder (UTESP) and treated eggshell powder (TESP)). Both UTESP and TESP were mixed with PMMA at different weight fractions ranged from (1-5) wt.%. The results revealed that the mechanical properties of the PMMA/ESP composites were enhanced steadily with increasing eggshell contents. The samples with 5 wt.% of UTESP and TESP additions give the maximum values of impact strength, about twice the value of the pure PMMA sample. The calcination process of eggshells powders gives better properties of the PMMA samples compared with the UTESP at the same weight fraction due to improvements in the interface bond between the matrix and particles. The wear characteristics of the PMMA composites decrease by about 57% with increases the weight fraction of TESP up to 5 wt.%. The flexural modulus values are slightly enhanced by increasing of the ESP contents in the PMMA composites.

Impact of changing rainfall conditions on surface and groundwater resources in an experimental watershed in Greece

2013 ◽  
Vol 12 (2) ◽  
pp. 119-125
Keyword(s):  
Groundwater Resources ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Winter Rainfall ◽  
Rainfall Depth ◽  
Rainfall Volume ◽  
The Mean ◽  
Groundwater Reserves ◽  
The Impact

The present study concerns the impact of a change in the rainfall regime on surface and groundwater resources in an experimental watershed. The research is conducted in a gauged mountainous watershed (15.18 km2) that is located on the eastern side of Penteli Mountain, in the prefecture of Attica, Greece and the study period concerns the years from 2003 to 2008. The decrease in the annual rainfall depth during the last two hydrological years 2006-2007, 2007-2008 is 10% and 35%, respectively, in relation to the average of the previous years. In addition, the monthly distribution of rainfall is characterized by a distinct decrease in winter rainfall volume. The field measurements show that this change in rainfall conditions has a direct impact on the surface runoff of the watershed, as well as on the groundwater reserves. The mean annual runoff in the last two hydrological years has decreased by 56% and 75% in relation to the average of the previous years. Moreover, the groundwater level follows a declining trend and has dropped significantly in the last two years.

Impact of Raw Materials and Processing Techniques on The Microbiological Quality of Egyptian Domiati Cheese

2020 ◽  
Keyword(s):  
Raw Materials ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Plate Count ◽  
E Coli ◽  
Fresh Cheese ◽  
Processing Techniques ◽  
The Impact ◽  
Total Yeast

Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.

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