The impact of variable temperatures on the redox conditions and the behaviour of pharmaceutical residues during artificial recharge

This study was carried out to examine the impact of an artificial recharge site on groundwater level and salinity using treated domestic wastewater for the Korba aquifer (north eastern Tunisia). The site is located in a semi-arid region affected by seawater intrusion, inducing an increase in groundwater salinity. Investigation of the subsurface enabled the identification of suitable areas for aquifer recharge mainly composed of sand formations. Groundwater flow and solute transport models (MODFLOW and MT3DMS) were then setup and calibrated for steady and transient states from 1971 to 2005 and used to assess the impact of the artificial recharge site. Results showed that artificial recharge, with a rate of 1500 m3/day and a salinity of 3.3 g/L, could produce a recovery in groundwater level by up to 2.7 m and a reduction in groundwater salinity by as much as 5.7 g/L over an extended simulation period. Groundwater monitoring for 2007–2014, used for model validation, allowed one to confirm that the effective recharge, reaching the water table, is less than the planned values.

Download Full-text

Mobilization, release and speciation of arsenic in an As-contaminated gold mine spoil under varied soil redox conditions

10.5194/egusphere-egu2020-1360 ◽

2020 ◽

Author(s):

Albert Kobina Mensah ◽

Bernd Marschner ◽

Jianxu Wang ◽

Sabry M. Shaheen ◽

Jörg Rinklebe

Keyword(s):

Extraction Procedure ◽

Mineralogical Composition ◽

Redox Conditions ◽

Mine Spoil ◽

Residual Fraction ◽

Reductive Dissolution ◽

Gold Mine ◽

Soil Redox ◽

Reducing Conditions ◽

The Impact

Redox-induced release dynamics of arsenic (As) in an abandoned geogenic arsenic-contaminated gold mine spoil in Ghana has never been studied. Therefore, our aim was to investigate the effects of varied soil redox conditions on mobilisation and speciation of As from an abandoned highly contaminated gold mine spoil (with 4,283 mg As/kg soil) using an automated biogeochemical microcosm set-up. We also studied the impact of redox potential (EH)-dependent changes of pH, Fe, Mn, Al, S, Cl-, SO42-, DOC, DIC, DC, DN and SUVA on the release dynamics of As. As mineralogical composition and speciation were further determined using a synchrotron-based X-ray absorption spectroscopy (XANES). Linear combination fits of XANES results indicated that scorodite (FeAsSO4) and arsenopyrite (FeAsS) are the two major As-containing minerals in the studied mine spoil. Geochemical fractionation using sequential extraction procedure indicated greater proportions of the extracted As in the amorphous iron oxide fraction III (1390.13 mg kg-1, 32.5% of the total As) and residual fraction V (2591.67 mg kg-1, 60.5% of the total As). Concentrations of dissolved Fe and SUVA were higher during reducing conditions and decreased under oxidising conditions and both showed negative significant relationships with EH (EH and SUVA: r = -0.76, P < 0.01; EH and Fe: r = -0.75). Mobilisation of As was greater under reducing conditions (dissolved As = 136.68 mg/L) than in oxidising environments (dissolved As = 8.06 mg/L). The release of As under low EH can be explained by the associated reductive dissolution of Fe oxides, as demonstrated by the high positive significant relationship between Fe and As (r = +0.97, P < 0.01). Dissolved As release dynamics can also be linked to desorption of aromatic carbon compounds on the surfaces of dissolved organic carbon, as demonstrated by the high positive significant correlation between SUVA and As (r = +0.573, P < 0.01). Further, the release dynamics of dissolved As was also affected by changes in pH (r = -0.4, P < 0.05), but were not affected by redox-induced dynamics of Mn, Al, S, Cl-, SO42-, DOC, DIC, DC, DN. We conclude that conditions such as flooding and high rainfall in this contaminated mine spoil could create reducing conditions, leading to reductive dissolution of the arsenopyrite As-bearing primary mineral and may lead to higher As release into the groundwater, translocation into the food chain with potential impacts on human health.Keywords: Arsenopyrite, redox chemistry, arsenic mobilisation, gold mine spoil, reductive and oxidative dissolution.

Download Full-text

The Impact of Artificial Recharge Plans on Aquifer and Demand Management Techniques in Shahrekord, Iran

World Environmental and Water Resources Congress 2011 ◽

10.1061/41173(414)85 ◽

2011 ◽

Author(s):

Foroozan Rajaei ◽

Hossein Samadi-Borujeni ◽

Saeid Eslamian ◽

E. Zia Hosseinipour

Keyword(s):

Artificial Recharge ◽

Demand Management ◽

Management Techniques ◽

The Impact

Download Full-text

The impact of redox conditions on the rare earth element signature of redoximorphic features in a soil sequence developed from limestone

Geoderma ◽

10.1016/j.geoderma.2011.10.014 ◽

2012 ◽

Vol 170 ◽

pp. 25-38 ◽

Cited By ~ 35

Author(s):

Cédric Laveuf ◽

Sophie Cornu ◽

Luiz Roberto G. Guilherme ◽

Annie Guerin ◽

Farid Juillot

Keyword(s):

Rare Earth ◽

Rare Earth Element ◽

Earth Element ◽

Redox Conditions ◽

Redoximorphic Features ◽

The Impact ◽

The Rare Earth

Download Full-text

The impact of oscillating redox conditions: Arsenic immobilisation in contaminated calcareous floodplain soils

Environmental Pollution ◽

10.1016/j.envpol.2013.02.028 ◽

2013 ◽

Vol 178 ◽

pp. 254-263 ◽

Cited By ~ 44

Author(s):

Christopher T. Parsons ◽

Raoul-Marie Couture ◽

Enoma O. Omoregie ◽

Fabrizio Bardelli ◽

Jean-Marc Greneche ◽

...

Keyword(s):

Redox Conditions ◽

Floodplain Soils ◽

The Impact

Download Full-text

Versatile soil gas concentration and isotope monitoring: optimization and integration of novel soil gas probes with online trace gas detection

Biogeosciences ◽

10.5194/bg-19-165-2022 ◽

2022 ◽

Vol 19 (1) ◽

pp. 165-185

Author(s):

Juliana Gil-Loaiza ◽

Joseph R. Roscioli ◽

Joanne H. Shorter ◽

Till H. M. Volkmann ◽

Wei-Ren Ng ◽

...

Keyword(s):

Real Time ◽

Trace Gases ◽

Soil Gas ◽

Redox Conditions ◽

Trace Gas ◽

Soil System ◽

Isotopic Signatures ◽

Gas Measurements ◽

The Impact

Abstract. Gas concentrations and isotopic signatures can unveil microbial metabolisms and their responses to environmental changes in soil. Currently, few methods measure in situ soil trace gases such as the products of nitrogen and carbon cycling or volatile organic compounds (VOCs) that constrain microbial biochemical processes like nitrification, methanogenesis, respiration, and microbial communication. Versatile trace gas sampling systems that integrate soil probes with sensitive trace gas analyzers could fill this gap with in situ soil gas measurements that resolve spatial (centimeters) and temporal (minutes) patterns. We developed a system that integrates new porous and hydrophobic sintered polytetrafluoroethylene (sPTFE) diffusive soil gas probes that non-disruptively collect soil gas samples with a transfer system to direct gas from multiple probes to one or more central gas analyzer(s) such as laser and mass spectrometers. Here, we demonstrate the feasibility and versatility of this automated multiprobe system for soil gas measurements of isotopic ratios of nitrous oxide (δ18O, δ15N, and the 15N site preference of N2O), methane, carbon dioxide (δ13C), and VOCs. First, we used an inert silica matrix to challenge probe measurements under controlled gas conditions. By changing and controlling system flow parameters, including the probe flow rate, we optimized recovery of representative soil gas samples while reducing sampling artifacts on subsurface concentrations. Second, we used this system to provide a real-time window into the impact of environmental manipulation of irrigation and soil redox conditions on in situ N2O and VOC concentrations. Moreover, to reveal the dynamics in the stable isotope ratios of N2O (i.e., 14N14N16O, 14N15N16O, 15N14N16O, and 14N14N18O), we developed a new high-precision laser spectrometer with a reduced sample volume demand. Our integrated system – a tunable infrared laser direct absorption spectrometry (TILDAS) in parallel with Vocus proton transfer reaction mass spectrometry (PTR-MS), in line with sPTFE soil gas probes – successfully quantified isotopic signatures for N2O, CO2, and VOCs in real time as responses to changes in the dry–wetting cycle and redox conditions. Broadening the collection of trace gases that can be monitored in the subsurface is critical for monitoring biogeochemical cycles, ecosystem health, and management practices at scales relevant to the soil system.

Download Full-text

Characterizing redox conditions and monitoring attenuation of selected pharmaceuticals during artificial recharge through a reactive layer

The Science of The Total Environment ◽

10.1016/j.scitotenv.2015.01.030 ◽

2015 ◽

Vol 512-513 ◽

pp. 240-250 ◽

Cited By ~ 21

Author(s):

Cristina Valhondo ◽

Jesús Carrera ◽

Carlos Ayora ◽

Isabel Tubau ◽

Lurdes Martinez-Landa ◽

...

Keyword(s):

Artificial Recharge ◽

Redox Conditions

Download Full-text

Study on Artificial Regulation of Water Resources in West of Daqing City

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.2510 ◽

2012 ◽

Vol 550-553 ◽

pp. 2510-2514

Author(s):

Chun Yan Zhang ◽

Long Cang Shu ◽

Bo Liu ◽

Emmanuel Kwame Appiah-Adjei ◽

Su Li ◽

...

Keyword(s):

Water Resources ◽

Artificial Recharge ◽

Groundwater Table ◽

Water Diversion ◽

Confined Aquifer ◽

Visual Modflow ◽

Supply Source ◽

Depression Cone ◽

Over Exploitation ◽

The Impact

Since the development and construction of Daqing City, groundwater resource has been their main water supply source. However, over-exploitation of the groundwater is causing a series of environmental and geological problems. Thus it is essential to ensure sustainable development of groundwater and control the worsening of groundwater related environmental problems in the City. Practical scenarios of groundwater recovery based on several different water resources artificial regulation scenarios are designed to reduce exploitation after the completion of water diversion from Nen River Expansion Project. These scenarios include three different exploitation reducing scenarios and scenarios of artificial recharge based on reducing exploitation. The simulation results of Visual Modflow indicate that both reducing exploitation and artificial recharge based on reducing exploitation can accelerate the recovery of groundwater table in the confined aquifer. Considering the speed of the recovery of groundwater and the impact of reducing exploitation on domestic, industrial and agricultural utilization of water resources, artificial recharge based on reducing exploitation Scenario B is better. Under this condition, the groundwater table of the confined aquifer in the center of depression cone will be recovered by 5 to 8 m up to the end of 2020.

Download Full-text