summary of groundwater remediation and treatment techniques for alkaline aquifers

Infiltration capacity of soil mainly depends on two factors; the particle size and the moisture content of the soil. Groundwater increases the soil moisture, not only below the water table but also within the capillary zone, above the water table. Field experiment in a high groundwater area was conducted to understand the relationship among the groundwater, soil moisture and infiltration capacity. Using a single ring infiltrometer, the effect of groundwater in the infiltration rate was observed. This field experiment result shows that the groundwater influences significantly the infiltration capacity of the soil, and the infiltration rate follows a specific trendline.

Superconducting gravimeters (SG) measure temporal changes of the Earth's gravity field with high accuracy and long-term stability. Variations in local water storage components (snow, soil moisture, groundwater, surface water, and water stored by vegetation) can have a significant influence on SG measurements and — from a geodetic perspective — add noise to the SG records. At the same time, this hydrological gravity signal can provide substantial information about the quantification of water balances. A 4D forward model with a spatially nested discretization domain was developed to investigate the local hydrological gravity effect on the SG records of the Geodetic Observatory Wettzell, Germany. The possible maximum gravity effect was investigated using hypothetical water storage changes based on physical boundary conditions. Generally, on flat terrain, a water mass change of1 m in the model domain causes a gravity change of 42 µGal. Simulation results show that topography increases this value to 52 µGal. Errors in the Digital Elevation Model can influence the results significantly. The radius of influence of local water storage variations is limited to 1000 m. Detailed hydrological measurements should be carried out in a radius of 50 to 100 m around the SG station. Groundwater, soil moisture, and snow storage changes dominate the hydrological gravity effect at the SG Wettzell. Using observed time series for these variables in the 4D model and comparing the results to the measured gravity residuals show similarities in both seasonal and shorter-term dynamics. However, differences exist, e.g., the range comparison of the mean modeled (10 µGal) gravity signal and the measured (19 µGal) gravity signal, making additional hydrological measurements necessary to describe the full spatiotemporal variability of local water masses

A.A. Cronin, J.A.C. Barth, T. Elliot and R.M. Kalin (2005)

Manufacturer and designer of groundwater Monitoring Instrumentation including water level indicator, well water data logging, water level logger, water level gauges, water level sensor, groundwater data logger by Heron Instruments in Ontario, Canada.

Abstract In many coastal areas, land has been reclaimed by dumping fill materials into the sea. Land reclamation may have a significant effect on groundwater regimes, especially when the reclamation is at large scale. Analytical studies on the impact of land reclamation on steady-state ground water flow conditions were conducted previously, but transient analytical solutions are not yet available. Transient analytical solutions are derived to illustrate the temporal change of groundwater systems in response to land reclamation using two hypothetical models: a hillside aquifer and an oceanic elongated island. The analytical solutions show that when time is short, the water level in the reclaimed area increases significantly after reclamation while that in the original aquifer remains almost unchanged. When time is great, the change of water level in the reclaimed site becomes small but the increase of water level propagates into the original aquifer. For the specific parameters and aquifer geometry used in the examples, it takes at least over 100 years for the whole system to approach a new equilibrium. The island example demonstrates that land reclamation on one side of the island will eventually modify the groundwater regimes over the entire island, including the water level, water divide, and submarine groundwater discharge. The degree of the modification of the groundwater system and the time required for the system to approach a new equilibrium depend mainly on the hydraulic conductivity and storativity of the fill materials and the reclamation length. It is suggested that for a large reclamation project, the response of the groundwater regime to reclamation should be studied in detail to evaluate the long-term change of the flow system and the consequent environmental and engineering impacts. Received 16 February 2008; accepted 24 September 2008; published 25 November 2008. Keywords: Land reclamation; analytical solution; transient flow; submarine groundwater discharge; coastal aquifer. Index Terms: 1829 Hydrology: Groundwater hydrology; 1828 Hydrology: Groundwater hydraulics; 1834 Hydrology: Human impacts.

Abstract The combination of headspace solid phase microextraction (HS-SPME) [1] with fast chromatographic pre-separation by means of multi-capillary columns (MCC) coupled to an ion mobility spectrometer equipped with a 10.6 eV photoionisation source was applied to rapid on-site monitoring of ground and surface water contaminations. Under field conditions, water contaminants were directly detectable down to the upper mgrg/L range. The potential of the developed method is illustrated by measurements of BTEX, naphthalene, chlorinated alkenes and chlorinated benzenes in water. Practical results from investigations of contaminated groundwater at a former gasworks site and groundwater from the site of a metal processing plant, focusing on the key substances benzene, naphthalene and tetrachloroethene, demonstrate the feasibility of the system for field studies. Keywords Ion mobility spectrometry (IMS) - Headspace solid phase microextraction (HS-SPME) - Multi-capillary column (MCC) - Water contamination - On-site analysis - Field measurements

Multilayer ceramic packaging materials provide a versatile platform to fabricate a wide variety of devices from sensors to micro-nozzles. Our research is focused on developing robust sensors for underground deployment and monopropellant micro nozzles for satellite attitude adjustment applications. An LTCC monopropellant micro-nozzle is being developed and tested to provide small thrust vectors for satellite attitude adjustments. High purity hydrogen peroxide undergoes a strong exothermic decomposition reaction in the presence of a silver catalyst. A micro-nozzle and catalyst chamber has been designed to convert hydrogen peroxide liquid to functional thrust. The device uses internal fluidic channels to direct the propellant to a silver lined catalyst chamber. The catalyst decomposes the propellant into water vapor and oxygen at temperatures near 1029 K. The hot gases are then expelled through a contoured nozzle to provide thrust. Complex internal geometric features are created using a CNC milling machine. An ion mobility spectrometer (IMS) is being developed for permanent deployment below ground to continuously analyze groundwater pollutants. Each segment was constructed of multiple layers of green tape. Five Kovar inserts were embedded in the device to function as ion gates. Reduction in size, hermeticity and system integration was made possible by the novel use of LTCC packaging technology.

Using interactive archives in evolutionary multiobjective optimization: A case study for long-term groundwater monitoring design