Removal Of Dissolved Oxygen Research Articles

Dissolved Oxygen Removal in Wines by Gas Sparging, Its Optimization and Chemical Impact

Sparging is a technique to remove an excess of dissolved oxygen from the wine with inerting gases before bottling to avoid negative consequences for its chemical and sensory properties. However, its effectiveness on these properties has not been studied in depth. This work investigates the effectiveness of different inerting gases (N2, CO2, and argon) in removing dissolved oxygen in different volumes of a model wine. The efficacy of these gases was also studied in white and red wine, as was their effect on the physicochemical characteristics. Sparging with N2 in the model wine gave the best results in terms of cost–benefits, and with CO2 the worst. The scaling in tanks of different sizes allowed us to establish that the N2 expenditure ranged between 0.09 L and 0.23 L of gas per liter of model wine, establishing an index (Lgas/Lwine) that can be very useful for wineries to remove the dissolved oxygen. Sparging treatments in white and red wine showed very similar results to the model wine. The effect on the chemical properties of the wines was, in some cases, different for white and red wine and for each gas used. The incorporation of oxygen and the subsequent sparging produced a significant loss of some volatile compounds of sensory interest and increased the content of others that have a negative sensory effect. In addition, it had a negative effect on the chromatic properties of red wines.

Influence of pH and dissolved oxygen control strategies on the performance of pilot-scale microalgae raceways using fertilizer or wastewater as the nutrient source

Dissolved oxygen concentration and pH are controllable and cost-effective variables that determine the success of microalgae-related processes. The present study compares different control strategies for pH and dissolved oxygen in pilot-scale microalgae production systems. Two 80 m2 raceway reactors were used, one operated with freshwater plus fertilizer and the other with wastewater as the nutrient source. Both were in semi-continuous mode at a fixed dilution rate of 0.2 day−1. A comparison between the classical On-Off and more advanced pH control strategies, such as PI and Event-based control, was performed, focusing on biomass productivity and the influence of all the process parameters on microalgae growth; "No control" of pH was also assayed. The results show that Event-based control was the best algorithm when using freshwater plus fertilizer. In contrast, no significant differences were observed using the different control strategies when wastewater was the nutrient source. These experiments were performed through selective control strategy, prioritizing pH over dissolved oxygen; however, it was demonstrated that they did not allow to achieve satisfactory dissolved oxygen removal results, especially for the fertilizer system. After modifying the gas diffuser configuration and improving the mass transfer, independent on-off strategies have been developed, permitting effective control of both variables and increasing productivity by up to 20% in both systems. Concluding, a detailed analysis of the energy demand for each strategy implemented in terms of gas consumption and gas flow to biomass ratio is provided.

Membranes Based on PTMSP/PVTMS Blends for Membrane Contactor Applications.

In this work, perspective polymeric materials were developed for membrane contactor applications, e.g., for the dissolved oxygen removal from amine CO2 capture solvents. Several polymeric blends based on poly[1-trimethylsilyl-1-propyne] (PTMSP) and poly[vinyltrimethylsilane] (PVTMS) were studied. The gas and water vapor sorption and permeability coefficients for the PTMSP/PVTMS blend membranes at different PVTMS contents (0-100%) were obtained under temperatures of 30 and 60 °C for the first time. As the PVTMS content increases, the O2 and CO2 permeabilities decrease by 160 and 195 times at 30 °C, respectively. The fractional accessible volume of the polymer blends decreases accordingly. The transport of the CO2 capture solvent vapors through the PTMSP/PVTMS blend membranes were determined in thermo-pervaporation (TPV) mode using aqueous monoethanolamine (30%), N-methyldiethanolamine (40%), and 2-amino-2-methyl-1-propanol (30%) solutions as model amine solvents at 60 °C. The membranes demonstrated high pervaporation separation factors with respect to water, resulting in low amine losses. A joint analysis of the gas permeabilities and aqueous alkanolamine TPV data allowed us to conclude that the polymer blend composition of PTMSP/PVTMS 70/30 provides an optimal combination of a sufficiently high oxygen permeability and the pervaporation separation factor at a temperature of 60 °C.

Development of a gas-permeable bag photobioreactor for energy-efficient oxygen removal from algal culture

Closed photobioreactors are ideal for the production of high-purity and high-value microalgal and cyanobacterial products. However, dissolved oxygen accumulation in closed reactors is detrimental to the growth. Conventional aeration for oxygen removal comprises up to 40% of the total culture cost, and energy-efficient dissolved oxygen removal is demanded. In this study, a novel gas-permeable bag photobioreactor was developed by the incorporation of a gas-permeable film. A hydrophobic microporous film was the most effective for both oxygen permeability and cost compared to silicone or fluororesin. The microporous film was placed on the backside of the reactor as an irradiation reflector. In a culture of Euhalothece sp., less than half of the steady-state dissolved oxygen concentration was demonstrated in the gas-permeable reactor than a non-permeable reactor. The gas-permeable reactor exhibited an oxygen transfer coefficient of 0.084 min−1 under continuous mixing, which is high enough to maintain approximately 300% dissolved oxygen concentration with 58 mg L−1 h−1 biomass productivity without aeration (equivalent to 1.4 g L−1 d−1 under 24-h light). The estimated energy requirement for the gas-permeable reactor can be less than 1% of the aerated reactor of the same size. These results suggested the effectiveness of the gas-permeable reactor for energy-efficient algal mass culture.

Impact of dissolved oxygen removal on solvent degradation for post-combustion CO2 capturew

One of the major issues encountered in the Post Combustion CO2 Capture processes is the degradation of the solvent which can be in great part attributed to the presence of oxygen in the solution. The present report focuses on the demonstration of DORA (Dissolved Oxygen Removal Apparatus), a technology developed by TNO as a counter-measure of oxidative degradation. The DORA was first operated in combination with TNO's mobile bench-scale CO2 capture pilot (5 Nm3/h flue gas capacity) with artificial flue gas, showing an instant drop of 15% and an overall reduction of approximately 70% in the ammonia emissions from the absorber, which is an indication of reduced degradation. The technology was also demonstrated using the same pilot in an industrial environment in collaboration with the facility PlantOne bringing DORA from TRL5 to TRL6. This campaign proved that DORA contributed to the deacceleration of solvent degradation. The tests were executed with a porous membrane, and it was observed that exposure to degraded solvents led to solvent leakage through this membrane. Therefore, the use of a coated membrane was proposed to optimize the operation and increase oxygen removal. The use of this membrane is demonstrated at TRL3. Along with that, a model was developed to determine mass transfer resistances and the membrane area required to remove different levels of dissolved oxygen.

Removal of dissolved oxygen from industrial raw water in a microchannel

The aim of this study is to reach the maximum percentage of dissolved oxygen removal from industrial raw water using microchannel. In this study, two continuous and batch systems were used for the deoxygenation of water. Nitrogen and natural gas were studied as deoxygenation agents for the evaluation of microchannel efficiency. For an accurate investigation of the issue, the Box–Behnken response surface method was utilized for experiment design and analysis of results. The parameters of temperature (T), gas/liquid flow ratio (G/l), and residence time (t) were the effective factors on the efficiency of the system. The temperature was set in the range of 80−120 °C, G/L in the range of 2–8 for both systems, and the residence time was 1–5 s for the continuous system and 120-480 s for the batch system. The maximum elimination percentage for nitrogen and natural gas were obtained to be 97.105 and 98.530 when experiments were carried out at the optimum conditions predicted by Design Expert software (T = 80 °C, G/L = 7.8952, and t = 1.1414 s). • Nitrogen and natural gas were used for dissolved oxygen removal from water. • The effect of temperature, gas/liquid flow ratio, and residence time were studied. • The highest removal were obtained by nitrogen and natural gas to be 97.1 and 98.5%.

Impact of Dissolved Oxygen Removal on Solvent Degradation for Post-Combustion Co2 Capture

One of the major issues encountered in the Post Combustion CO2 Capture processes is the degradation of the solvent which can be in great part attributed to the presence of oxygen in the solution. The present report focuses on the demonstration of DORA (Dissolved Oxygen Removal Apparatus), a technology developed by TNO as a counter-measure of oxidative degradation. The DORA was first operated in combination with TNO’s mobile bench-scale CO2 capture pilot (5 Nm3/h flue gas capacity) with artificial flue gas, showing an instant drop of 15% and an overall reduction of approximately 70% in the ammonia emissions from the absorber, which is an indication of reduced degradation. The technology was also demonstrated using the same pilot in an industrial environment in collaboration with the facility PlantOne bringing DORA from TRL5 to TRL6. This campaign proved that DORA contributed to the deacceleration of solvent degradation. The tests were executed with a porous membrane, and it was observed that exposure to degraded solvents led to solvent leakage through this membrane. Therefore, the use of a coated membrane was proposed to optimize the operation and increase oxygen removal. The use of this membrane is demonstrated at TRL3. Along with that, a model was developed to determine mass transfer resistances and the membrane area required to remove different levels of dissolved oxygen.

Effect of Membrane Hydrophobicity and Thickness on Energy-Efficient Dissolved Oxygen Removal From Algal Culture.

Removal of dissolved oxygen from algal photobioreactors is essential for high productivity in mass cultivation. Gas-permeating photobioreactor that uses hydrophobic membranes to permeate dissolved oxygen (pervaporation) from its body itself is an energy-efficient option for oxygen removal. This study comparably evaluated the characteristics of various commercial membranes and determined the criteria for the selection of suitable ones for the gas-permeating photobioreactors. It was found that oxygen permeability is limited not by that in the membrane but in the liquid boundary layer. Membrane thickness had a negative effect on membrane oxygen permeability, but the effect was as minor as less than 3% compared with the liquid boundary layer. Due to this characteristic, the lamination of non-woven fabric with the microporous film did not significantly decrease the overall oxygen transfer coefficient. The permeability in the liquid boundary layer had a significantly positive relationship with the hydrophobicity. The highest overall oxygen transfer coefficients in the water-to-air and water-to-water oxygen removal tests were 2.1 ± 0.03 × 10–5 and 1.39 ± 0.09 × 10–5 m s–1, respectively. These values were considered effective in the dissolved oxygen removal from high-density algal culture to prevent oxygen inhibition. Furthermore, hydrophobicity was found to have a significant relationship also with water entry pressure, which needs to be high to avoid culture liquid leakage. Therefore, these results suggested that a microporous membrane with strong hydrophobicity laminated with non-woven fabric would be suitable characteristics for gas-permeating photobioreactor.

The Evaluation of Dissolved Oxygen Removal Efficiency for Membrane Degassing Process in Ultrapure Water

The Evaluation of Dissolved Oxygen Removal Efficiency for Membrane Degassing Process in Ultrapure Water

A Mathematical Model and Design Calculation of a Thermal Deaerator with a Bubbling Storage Tank

A mathematical model of mass transfer in an atmospheric bubbling deaerator storage tank at thermal power stations (TPS) to calculate the removal efficiency of dissolved gases from water is considered. For mathematical simulation and calculation of the deaerator efficiency, a system of differential equations of mass and heat transfer is written in a local form for the liquid phase of the layer with volume interphase sources of mass and heat. Mass transfer of the dissolved gases from water to the vapor phase is taken into account using volume interphase sources and the balance equations. Parameters of the interphase sources and correlations for calculating the eddy viscosity of the liquid phase depending on bubbling conditions are given. Results from the system of equations' numerical solution are presented and compared with the available experimental data on the final concentration of dissolved oxygen at the deaerator outlet. Curves of the efficiency of dissolved oxygen removal depending on the operating conditions and design characteristics of the bubbling process are presented, and scientific-and-engineering solutions have been developed to upgrade the bubbling storage tank. It has been found that an increase in gas velocity sharply raises the deaeration efficiency to a certain value (depending on the specified initial parameters), and the efficiency growth is then retarded. Similarly, increasing the length of a bubbling device improves the efficiency in removal of dissolved oxygen from water. One of the causes of a decrease in the water deaeration efficiency is likely to be back mixing of the flow. Upgrading of the deaerator tank is in the installation of perforated baffles across the flow to considerably reduce back mixing of the liquid phase. This increases the driving force of mass transfer, and its efficiency improves by five to 20% depending on the steam velocity. The presented mathematical model can be generalized to a wide range of bubbling apparatuses with a high two-phase layer.

Electrochemical Corrosion Prevention in Oilfield Wastewater for Effective Dissolved Oxygen Removal Using a Novel Upflow Bioelectrochemical System

Towards the corrosion issues of oilfield wastewater for water recycling, the dissolved oxygen (DO) is a subsequent corrosive factor after the air desulfurization tower for high-efficiency removal of sulfides. However, an in situ biological technology for efficient DO removal has not been well developed by using organics in oilfield wastewater. A novel upflow bioelectrocatalytic system assembled with three electrodes (cathode-anode-cathode) was designed in this study, in which waste organic matter of oil wastewater was degraded by a bioanode for electron production and dissolved oxygen was efficiently reduced by a biocathode under an assistant external voltage. The results showed that the average current was kept over 6 mA by applying a fixed voltage of 0.8 V to treat oil wastewater with DO as high as 3–5 mg/L. The bottom cathode contributed the largest to DO removal rate, reaching 67%; contribution of the middle anode and the upper cathode for DO removal was 11% and 9%, respectively. The whole DO removal rate by the bioelectrocatalytic system was up to about 90%, and the effluent DO was reduced to below 0.6 mg/L by removing 40–50% COD.

Fast Photomineralization of Dissolved Organic Matter in Acid Mine Drainage Impacted Waters.

Acid mine drainage (AMD) formed from pyrite (iron disulfide) weathering contributes to ecosystem degradation in impacted waters. Solar irradiation has been shown to be an important factor in the biogeochemical cycling of iron in AMD-impacted waters, but its impact on dissolved organic matter (DOM) is unknown. With a typical AMD-impacted water (pH 2.7-3) collected from the Perry State Forest watershed in Ohio, we observed highly efficient (>80%) photochemical mineralization of DOM within hours in a solar simulator resembling twice summer sunlight at 40°N. We confirmed that the mineralization was initially induced by •OH formed from FeOH2+ photodissociation and was inhibited 2-fold by dissolved oxygen removal, suggesting the importance of both the photochemical reaction and oxygen involvement. Size exclusion chromatography and Fourier transform ion cyclotron resonance mass spectrometry elucidated that any remaining organic matter was comprised of smaller and highly aliphatic compounds. The quantitative and qualitative changes in DOM are likely to constitute an important component in regional carbon cycling and nutrient release and to influence downstream aquatic ecosystems in AMD-affected watersheds.

Electrochemical method for dissolved oxygen consumption on-line in tubular photobioreactor

A new electrochemical tubular photobioreactor is designed for the efficient cultivation of chlorella, alongside eliminating the inhibition of the growth of microalgae caused by the high dissolved oxygen content. With the aid of anion-exchange membrane alkaline fuel cell, the dissolved oxygen in the photobioreactor which is produced by the photosynthesis of microalgae can be consumed and the energy consumption of photobioreactor can be reduced. Besides, the effects of different components and operating parameters on the efficiency of dissolved oxygen removal and the cell performance have been detailed investigated. The experiment results are shown as follows. First, by applying the double-cylinder alkaline direct glucose fuel cell to consume the dissolved oxygen of the microalgae suspension in the tubular photobioreactor on-line, the dissolved oxygen content rapidly decreases from over 20.0 mg L−1 to 10.72 mg L−1 below within 45 min. Second, the efficiency of dissolved oxygen consumption and cell performance increase significantly by using the bimetallic catalyst Pt-Ru as the cathode catalyst in the double-cylinder alkaline direct glucose fuel cell compared with the mono-metallic cathode catalyst by adopting Pd and Pt. Third, it exists an optimal cathode catalyst loading (1.5 mgPtRu·cm−2) to consume the dissolved oxygen with the fuel cell yielding the best performance.

Effects of the Ultrasound Treatment on Reaction Rates in the RH Processor Water Model System

Ruhrstahl–Heraeus (RH) processor is widely applied to the refining process to produce steel with very low carbon contents. In this study, to investigate the effect of ultrasound treatment on RH decarburization process, we have developed two kinds of the water models simulated the RH process and study the removal rate of dissolved oxygen. The one is the RH water model of 1/8 size of actual RH degasser simulated the late-stage of the RH process when surface reaction and plume reaction mainly occur. Through this model, it is found that the ultrasound treatment accelerates dissolved oxygen removal reaction and this tendency is maintained even at low concentrations. Also, the results show that there is a difference in the degassing efficiency depending on the frequencies and the positions of the ultrasonic transducer. Also, to simulate the Early-stage Reaction of the process including the inner-site reaction which is difficult to investigate through the RH water model, the other water model has been developed (the RH-ER water model). This model shows that the ultrasound treatment facilitates the early-stage reaction including inner-site reaction, like the RH water model. These results show that the addition of the ultrasound treatment can accelerate decarburization reaction during RH process compared to conventional process.

Trace Dissolved Oxygen Removal Using a Hydrocyclone to Enhance Denitrification

AbstractDissolved oxygen (DO) is entrained by mixed liquid recirculation (MLR) into the anoxic basin in the pre‐denitrification biological nitrogen removal (PDBNR) process and should be removed to enhance denitrification. A laboratory‐scale PDBNR reactor with an anoxic basin divided into two isometric components was built to investigate the effect of a hydrocyclone on DO removal from the MLR and the subsequent denitrification. The denitrification rate of the mixture of influent and hydrocyclone‐treated nitrified wastewater increased with increasing DO and was higher than that of the wastewater in a conventional anoxic component. More total nitrogen was removed in the anoxic component due to the application of the hydrocyclone in the MLR of a laboratory‐scale reactor and a full‐scale anoxic/aerobic reactor.

Electrochemical Deoxygenation of Aqueous Solutions Using Symmetric Activated Carbon Electrodes in Flow-through Cells

We present a simple electrochemical flow cell using symmetric, unmodified commercially available carbon cloth electrodes that removes 97+% of incoming aqueous dissolved oxygen (DO). The electro-deoxygenation (EDO) cell achieves net O2 removal by leveraging the high overpotential of the oxygen evolution reaction on activated carbon and its propensity to oxidize under anodic polarization in aqueous solution: oxygen is reduced at the cathode via the oxygen reduction reaction (ORR) while water is oxidized and incorporated into surface oxide functional groups at the anode, effectively sequestering dissolved oxygen. The polarized electrodes promote the two-step reduction of DO resulting in some residual hydrogen peroxide in the effluent, which may be beneficial for certain water treatment applications. We modified a cell with Ni cathodes downstream to reduce all H2O2 to water for particularly sensitive applications; in this cell >99% of incoming DO could be removed to sub-10 ppb levels. EDO cells, which currently employ sacrificial anodes, can deaerate 30 L g-1 anode of water at an energy cost of 1 kWh (~$0.10) per 104 L. The technique is versatile, successfully deoxygenating solutions from dilute to seawater concentrations and at flow rates beyond 50 ml min-1 (O2 flux = 10-4 mol s-1 m-2), more than 50x higher throughput DO removal than similar technologies. We demonstrate the utility of an EDO cell as a component in an electrochemical water desalination process; dissolved oxygen removed upstream of a capacitive deionization cell enhances salt adsorption capacity and cell lifetime. Figure 1. (a) Dissolved oxygen removal by an electro-deoxygenation cell stack with six pairs of electrodes (up to t = 1.1 h) and subsequently with an additional H2O2 removal stack (six Ni cathodes and two additional anodes electrically connected in parallel downstream, t > 1.1 h). The device is operated by holding the cathodes, connected in parallel, at an oxygen-reducing potential versus an in situ reference electrode to achieve E c = -0.2 V vs. SHE. The electrolyte is 0.1 M NaCl with an initial flow rate of 50 ml min-1, and the effect of increasing flow to 75 and 100 ml min-1 is shown at t > 4.2 h. (b) Salt removal performance of a capacitive deionization (CDI) cell downstream of our EDO cell; the electrolyte is 10 mM NaCl flowing at 20 ml min-1 and the CDI cell consists of four pairs of carbon cloth electrodes totaling 3.2 g with charging/discharging at V cell = 1.2/0.0 V in a single-pass mode. At t = 24 h, the EDO cell is turned off to highlight its effect on deionization performance. Figure 1

Corrosion Mitigation Activities Performed After the Fukushima Daiichi Accident

This synopsis describes corrosion issues and mitigation activities shortly after the Fukushima Daiichi Nuclear Power Station accident. An earthquake of magnitude 9.0 occurred on March 11, 2011; the subsequent tsunami removed the cooling capacity of fuels in both the reactors and spent fuel pools (SFPs). Seawater was temporarily used for emergency fuel cooling, which induced various corrosion issues. Just after the accident, the temperatures within the reactors of Units 1 to 3 increased to several hundred degrees Celsius and the water quality of the cooling water seems to have become similar to that of concentrated seawater. To stabilize the fuel cooling, corrosion mitigation actions were required for mainly carbon steel components. The following corrosion mitigation measures were applied to the reactors: (a) temperature decreases, (b) dissolved oxygen removal from feedwater via deaeration, (c) dissolved oxygen removal from cooling water in the reactors via nitrogen gas injection, (d) salt removal from cooling water, and (e) sterilization of feedwater by hydrazine addition. The temperatures of SFP water in Units 1 to 4 were between 47°C and 93°C just after the accident. The maximum chloride ion concentration was approximately 2,000 ppm and the pH was in the range from 7.5 to 11.2. The mitigation of localized corrosion of the stainless steel pool liners and alkaline corrosion of the aluminum fuel racks was the top priority. In addition to (a), (b), and (d) listed above, (f) dissolved oxygen removal and sterilization by hydrazine addition and (g) pH control were applied to the SFPs. In the six years since the accident, no major corrosion problems have yet arisen. However, continued efforts to increase plant stability are underway for the long-term goal of decommissioning.

Application of a new ceramic hydrophobic membrane for providing CO2 in algal photobioreactor during cultivation of Arthrospira sp.

Biological sequestration of CO2 using microalgal route emerges as a promising option due to its cleaner approach which can be used to produce various forms of bioenergy. The current study reports on development of a new ceramic hydrophobic membrane and its application in an algal photobioreactor towards an efficient dissolution of CO2 during cultivation of Arthrospira sp. Clay-alumina based ceramic capillary support elements were coated with bentonite clay and surface modified using polydimethyl siloxane (PDMS) to impart hydrophobicity. The prepared membrane indicated pore size of 5.0nm with around 35.3% porosity and contact angle of 147°. A two-element membrane module having 150mm length, 3.16 outer diameter and 2.16mm inner diameter was used as a nano bubble sparger to provide CO2 in 1L of the culture medium and an enhanced overall mass transfer coefficient of about 38×10−4m/s was obtained using 19.5% CO2 gas mixture and 0.23m/s gas velocity. The membrane was efficient in removal of dissolved oxygen produced during photosynthesis, resulting in higher algal growth and higher CO2 sequestration. Algal growth of about 178.2g(dwt)/m3/day were obtained at 24h interval of CO2 supply in the photobioreactor and subsequent CO2 sequestration obtained was 13.99g/m3/h. Under optimized growth conditions the produced biomass yielded biodiesel content of about 5.82% of dry weight of algae. Application of the ceramic hydrophobic membrane thus enables enhanced mass transfer coefficient and dissolved oxygen removal efficiency making it suitable in photobioreactor application towards algal bio-sequestration of CO2 and subsequent biomass and biofuel production.

A-20 給水管への膜式脱気法による防食及び水質改善効果の調査

A-20 給水管への膜式脱気法による防食及び水質改善効果の調査

3D Printing the Way to Truly Remote, Autonomous, Solar Powered Sensor Networks for Environmental Monitoring of Trace Heavy Metals By Calibration-Less Anodic Stripping Coulometry of µl Sized Samples

The agency for toxic substances and disease registry has consistently listed As, Pb Hg, and Cd as the pollutants of most concern at Superfund sites (recently #1, 2, 3, 7, respectively, amongst hundreds of prioritized hazardous substances). Also of concern is the prevalence of arsenic in groundwater at hundreds of thousands of wells used for drinking by millions of people worldwide. Heavy metal monitoring in natural waters is currently performed in a snapshot fashion where analysis is occasionally possible by sophisticated instruments after sample collection and transportation to centralized laboratories or, less frequently, by technicians wielding portable instruments. Such a snapshot approach to analysis requires a sustained and coordinated effort to monitor many thousands of decentralized sites as frequently as possible, and a preferable approach is the deployment of remote sensor networks. Our group has therefore been interested in the development of truly remote sensor platforms that sufficiently deliver a trifecta of important attributes for heavy metals monitoring – practical, sensitive, and selective measurements– to direct the efforts of central laboratories and mobile operators to where they are most needed. The primary challenges of truly remote sensors revolve around the dual challenges of signal calibration and sample pretreatment, which are typically performed by the operator. We will demonstrate a sensor platform that is capable of low ppb level measurements of heavy metals such as copper and arsenite from 2 µL sample volumes – without any calibration. This calibration-less aspect is achieved by using anodic stripping coulometry after exhaustive deposition of dissolved metals from a finite volume within a stopped flow thin layer cell in about a minute. The use of coulometry in this configuration of electrochemical cell offers rapid analysis, independence from ambient conditions such as temperature, and also tolerates partial electrode fouling which is likely to occur during extended field operation. We will also demonstrate simple approaches for automated sample pretreatment including on-site acidification and dissolved oxygen removal. The use of a coulometric electrochemical method offers the advantage of inexpensive and simple to automate instrumentation with minimal energy requirements. The heart of the sensor is a microfabricated thin-film Au microelectrode array housed within a microfluidic chamber which offers practical advantages including mass-producible, redundant, inexpensive sensors, with a minimal need for on-site reagents. Additionally, we will overview how existing technologies such as miniature electronics and the prevalent communications networks for real-time data acquisition further support the feasibility of our approach. For instance, replacing the screen of even the most primitive smart phone with a solar panel already provides a platform which incorporates a micro-processor, communications ability, and a battery. The microprocessor and battery can be used to drive a miniature potentiostat and a host of commercially available, inexpensive micro-pumps to handle on-site sampling and mixing as required. Despite the commercial availability of many individual components and the promise of the methods we have developed, the remote use of the sensor in real world applications has been limited by the challenge of bridging the gap between a bulk volume of water and a microfluidic chamber where the measurements are made. Essentially, the ideal platform should consist of a fluidic inlet port which is compatible with the macro sized sample, and an outlet to discharge the analyzed sample. The focus of this presentation will therefore be a greatly simplified 3D printed version of platform which contains internal components such as channels and valves to direct and control the sample during operation. We also intend to explore how several modules which perform different pretreatment or measurement functions can be connected to a central 3D printed hub which contains a shared set of the most expensive components (i.e., pumps, valves, etc.). Such a design architecture would seem to offer benefits in terms of operational flexibility and simplicity and also offers the potential for the use of redundant sensors to lengthen intervals between manual maintenance. Lastly, we aim to demonstrate the stability of the platform under conditions as close to real world analysis as possible.