Water quality dependence on the depth of the vadose zone in SAT-simulated soil columns

2005 ◽  
Vol 5 (1) ◽  
pp. 17-24 ◽  
Author(s):  
W. Cha ◽  
H. Choi ◽  
J. Kim ◽  
J. Cho
Keyword(s):  
Water Quality ◽  
Vadose Zone ◽  
Unsaturated Zone ◽  
Phosphate Removal ◽  
Soil Aquifer Treatment ◽  
Soil Columns ◽  
Nitrogen And Phosphorus ◽  
Aquifer Characteristics ◽  
Zone Depth ◽  
Flooding Period

Three soil aquifer treatment (SAT) columns were operated for five months to investigate the dependence of the treated water quality upon the depth of unsaturated vadose zone in terms of its organics, nitrogen and phosphorus contents. It was found that DOC removal was independent of the unsaturated vadose zone depth except during the initial flooding period when the effluent was injected into each column. From tests to study the nitrate profile, it was found that the pattern of nitrification was dependent on the depth of the unsaturated zone during the initial periods of SAT flooding. However, no further nitrification occurred at the end of the flooding since the injection of the effluent continued to provide a high loading concentration to the SAT columns. The lack of phosphate removal in this study indicates that its removal is more dependent upon the soils and aquifer characteristics than on the depth of unsaturated zone.

Anaerobic bioventing of unsaturated zone contaminated with DDT and DNT

2001 ◽  
Vol 43 (2) ◽  
pp. 35-42 ◽  
Author(s):  
J. K. Shah ◽  
G. D. Sayles ◽  
M. T. Suidan ◽  
P. Mihopoulos ◽  
S. Kaskassian
Keyword(s):  
Electron Donor ◽  
Vadose Zone ◽  
Unsaturated Zone ◽  
Degradation Products ◽  
Gas Mixture ◽  
Anaerobic Conditions ◽  
Soil Columns ◽  
Waste Streams ◽  
Anaerobic Microorganisms ◽  
Anaerobic Environment

Initial degradation of highly chlorinated compounds and nitroaromatic compounds found in munition waste streams is accelerated under anaerobic conditions followed by aerobic treatment of the degradation products. The establishment of anaerobic environment in a vadose zone can be accomplished by feeding appropriate anaerobic gas mixture, i.e., “anaerobic bioventing”. The gas mixture contains an electron donor for the reduction of these compounds. Lab scale study was conducted to evaluate potential of anaerobic bioventing for the treatment of an unsaturated zone contaminated with 1,1,1-trichloro -2,2-bis(p-chlorophenyl)ethane (DDT) and 2,4-dinitrotoluene (DNT). Hydrogen was used as the electron donor. Using the soil columns innoculate with anaerobic microorganisms, it was observed that by feeding a gas mixture of 1% hydrogen, 1% carbon dioxide and nitrogen, methanogenic conditions were established and DDT was reductively dechlorinated. 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD) accumulated as the intermediate product. The half life of DDT was calculated to be 8.5 months. DNT completely disappeared after six months of operation and no intermediates could be detected.

Conception of vadose zone research in the area of Goczałkowice reservoir.

2013 ◽  
Vol 2 (1) ◽  
pp. 22-26
Author(s):  
Joanna Czekaj ◽  
Kamil Trepka
Keyword(s):  
Vadose Zone ◽  
Unsaturated Zone ◽  
Vertical Profile ◽  
Structural Model ◽  
Historical Data ◽  
Integrated System ◽  
Nitrate Transport ◽  
Strategic Research ◽  
Research Site ◽  
Observation Wells

Abstract Goczałkowice reservoir is one of the main source of drinking water for Upper Silesia Region. In reference to Water Frame Directive matter since 2010 the strategic research project: „Integrated system supporting management and protection of dammed reservoir (ZiZoZap)”, which is being conducted on Goczałkowice reservoir, has been pursued. In the framework of this project complex groundwater monitoring is carried on. One aspect is vadose zone research, conducted to obtain information about changes in chemical composition of infiltrating water and mass transport within this zone. Based on historical data and the structural model of direct catchment of Goczałkowice reservoir location of the vadose zone research site was selected. At the end of November 2012 specially designed lysimeter was installed with 10 MacroRhizon samplers at each lithological variation in unsaturated zone. This lysimeter, together with nested observation wells, located in the direct proximity, create the vadose zone research site which main aim is specifying the amount of nitrate transport in the vertical profile.

scholarly journals Stream Restoration for Legacy Sediments at Gramies Run, Maryland: Early Lessons from Implementation, Water Quality Monitoring, and Soil Health

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2164
Author(s):  
Katie Mattern ◽  
Alyssa Lutgen ◽  
Nathan Sienkiewicz ◽  
Grant Jiang ◽  
Jinjun Kan ◽  
...  
Keyword(s):  
Water Quality ◽  
Riparian Vegetation ◽  
Stream Restoration ◽  
Soil Health ◽  
Water Quality Monitoring ◽  
Quality Monitoring ◽  
Nutrient Inputs ◽  
Nitrogen And Phosphorus ◽  
Partial Removal ◽  
Riparian Trees

While stream restorations are increasingly being adopted to mitigate sediment and nutrient inputs and to meet water quality regulatory targets, less information is available on the drivers behind the design, implementation, effectiveness, and cost of restorations. We address these issues for a $4.2 million stream restoration for legacy sediments implemented for a rural Piedmont stream in Maryland, USA. A total of 1668 m of stream was restored in three phases, which included the partial removal of legacy sediments, the grading of streambanks, floodplain creation, channel reshaping with meanders and pool-riffle forms, the raising of the stream bed, and the planting of riparian vegetation. The sediment, nitrogen, and phosphorus concentrations and fluxes were monitored before- and during the restoration phases. The sites selected for restoration had legacy sediments vulnerable to erosion and were on state-owned land. The restoration design was based on the need to maintain mature riparian trees and preserve existing sensitive wetland habitats. Water quality monitoring indicated that the sediment and nutrient fluxes increased during the restoration phase and were attributed to disturbance associated with construction activities and increased runoff. We also recommend that soil health needs to be included as an integral component to enhance the effectiveness and resilience of stream restorations.

scholarly journals Feasibility of nanoscale zero-valent iron loaded sediment-based biochar (nZVI-SBC) for simultaneous removal of nitrate and phosphate: high selectivity towards dinitrogen and synergistic mechanism

2021 ◽  
Author(s):  
Xiaohui Liu ◽  
Jia Wei ◽  
Liangang Hou ◽  
Yuhan Zhu ◽  
Yaodong Wu ◽  
...  
Keyword(s):  
High Selectivity ◽  
Phosphate Removal ◽  
Zero Valent Iron ◽  
Polluted Water ◽  
Nitrogen And Phosphorus ◽  
Nanoscale Zero Valent Iron ◽  
Synergistic Mechanism ◽  
Loading Ratio ◽  
Anoxic Environment ◽  
Complexation Mechanism

Abstract In the process of water treatment, excessive nitrogen and phosphorus pollutants are of great concern. Therefore, we prepared nanoscale zero-valent iron loaded on sediment-based biochar (nZVI-SBC) to conduct nitrate and phosphate removal at the same time. The characterization demonstrated that nZVI-SBC was successfully synthesized, which had obvious advantages for larger specific surface area and better dispersion compared with pure nZVI. The batch experiments indicated that the best loading ratio of nZVI to SBC and optimum dosage for nitrate and phosphate were 1:1and 2 g·L-1, respectively. Their removal by nZVI-SBC was an acid-driven process. Anoxic environment was more conducive to the reduction of nitrate while the phosphate removal was fond of oxygen environment. 77.78% of nitrate and 99.21% of phosphate have been successfully removed, mainly depending on reduction and complexation mechanism, respectively. Moreover, nZVI-SBC had higher N2 selectivity and produced less ammonium than nZVI. The interaction between nitrate and phosphate was studied to manifest that they had different degrees of inhibition during the removal of the other. Our research indicated that nZVI-SBC has great potential for remediation of nitrogen and phosphorus polluted water.

scholarly journals Modelling the hydrology and water quality of 3S river system (Sekong, Sesan and Srepok)

2016 ◽  
Vol 19 (2) ◽  
pp. 107-117
Author(s):  
Trang Thi Thuy Nguyen ◽  
Khoi Nguyen Dao
Keyword(s):  
Water Quality ◽  
Swat Model ◽  
Model Performance ◽  
River System ◽  
Water Quality Assessment ◽  
River Basin Management ◽  
Analysis Tool ◽  
Nitrogen And Phosphorus ◽  
Model Soil

The objective of this study was to simulate the hydrologic characteristic and water quality of 3S rivers system (Sekong, Sesan and Srepok) using SWAT model (Soil and Water Analysis Tool). Agriculture and forest are the main land use types in this basin accounting for more than 80 % of the total area. Therfore, nitrogen and phosphorus were selected to be parameters for water quality assessment. SWAT-CUP model was applied to calibrate the model for stream flow and water quality based on SUFI-2 (Sequential Uncertainty Fitting version 2) method. The model performance has been assessed by three statistical indices, including coefficient corellation (R2), Nash-Sutcliffe efficient coefficience (NSE) and percentage Bias (PBIAS). The results showed that SWAT model was well calibrated for simulating the streamflow and water quality with the values of R2 greater than 0.5 except for the Attapeu and Kontum stations, and of PBIAS less than 10 % and 35 % for streamflow and water quality, respectively. The well-calibrated SWAT model can be applied in predicting the hydrology and water quality for other application. Furthermore, it is a tool supporting the policy makers to offer a suitable decisions regarding the sustainable river basin management.

scholarly journals Modelling of base flows by analysing the streamflow hydrograph

2012 ◽  
pp. 71-86
Author(s):  
Vesna Djukic ◽  
Vladislava Mihailovic
Keyword(s):  
Water Quality ◽  
Water Use ◽  
Local Minimum ◽  
Base Flow ◽  
Water Quality Protection ◽  
Small Streams ◽  
Aquifer Characteristics ◽  
Retention Characteristics ◽  
Increasing Demand ◽  
Base Flows

During dry periods, the flow of medium and small streams is significantly reduced and equal to groundwater flow. Since the base flows provide information about aquifer characteristics and retention characteristics of a basin, the possibilities of analysis and simulation of base flows gain importance under the conditions of intensive water use and the increasing demand for adequate water quality protection. In this paper, a model was established and used for the description of the principles governing the changes of base runoff on the basis of a streamflow hydrograph registered at the outlet of the basin on the example of the Kolubara basin up to the ?Valjevo? profile. Since the amount of base runoff from a basin cannot be measured, the results of base flows obtained using the local minimum method were adopted as the criterion for the comparison of the modelled values of base runoffs. The created model was applied for making simulations of the base runoff hydrograph during three characteristic years (rainy 1970, average 1985, and dry 1990). Deviations between the base flow values obtained using the established model and by applying the local minimum method are acceptable from the standpoint of general hydrological accuracy.

Soil contents and stoichiometry of carbon, nitrogen, and phosphorus in Finnish farmland and feedbacks on management patterns

2021 ◽  
Author(s):  
Sichu Wang ◽  
Oona Uhlgren ◽  
Anna-Reetta Salonen ◽  
Jussi Heinonsalo
Keyword(s):  
Organic Matter ◽  
Management Practice ◽  
Combustion Method ◽  
Agricultural Management ◽  
Soil Columns ◽  
Nitrogen And Phosphorus ◽  
Deep Soil ◽  
C:N:P Stoichiometry ◽  
Soil Layers ◽  
Soil C

<p>The coupled cycles and interactions of soil carbon (C), nitrogen (N), and phosphorus (P) are fundamental for soil quality and soil organic matter (SOM) formation. Low C:N ratios through nitrogenous fertilizer addition may accelerate SOM cycling and promote C mineralization in soil, whereas P limitations may decline C storage by reducing plant and microbial biomass production. Deeper soil layers’ C-N-P stoichiometry has an important role in regulating SOM formation in subsoils. However, there is little information on soil C:N:P stoichiometry in deep soil layers of farmland. In this study, soil columns up to one meter were collected from 32 farms distributing across Finland with different soil texture and agricultural management history. The one-meter soil columns were cut into 10 cm deep slices and analyzed for the total organic carbon (TOC), total nitrogen (TN) by dry combustion method and total phosphorus (TP) contents by aqua regia digestion and ICP-OES method. Overall, the TOC, TN and TP contents all dropped sharply in 30-40 cm soil layers, but TP contents rose again in deep soil. The role of agricultural management practice (including crop rotation, crop cover, crop diversity and fertilization) on soil C:N:P stoichiometry as well as organic matter accumulation in the deep soil layers were explored. The preliminary results will be presented in the poster. The data deepens our understanding of soil C, N and P coupling and interaction related to soil C sequestration.</p>

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