Control - CORDIS · This pilot plant was also used to investigate step-feeding. ... Angle of bubble...

Fig. 1 – Representation of the pilot plant used for ascertaining the optimal dissolved oxygen values and temperature for the HSSF wetlands. This pilot plant was also used to investigate step-feeding.

Fig. 2 - The dependence of bubble size as a function of the aeration pipe hole aperture. Error bars were generated by taking the standard deviation of the observed bubble sizes.

Control

ARBI

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Hole Size, mm

Ave

rage

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ble

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Dependence of Bubble Size on Apperture

Fig. 3 - The dependence of bubble cone as a function of the aeration pipe hole aperture. Error bars were generated by taking the standard deviation of the bubble cone angles.

Fig. 4 - Rate of oxygen transfer as a function of aeration pipe hole aperture.

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sfer

rate

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Fig. 5 - Effect of the air flow rate on distribution of bubbles using the 1 mm hole aperture aeration pipe.

Fig. 6 - Measurement of dissolved oxygen concentration recorded within the constantly aerated bed (air 5) and control (No air) wetlands when air pump was working 24h/day ( during period 1).

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data 6 linear

Fig. 7 - Dissolved oxygen values of the control (No air) and the aerated wetlands (Air) with oxygen concentration set at 3 mg/L (Air 3) (during period 1).

Fig. 8 - Inlet and effluents concentrations of Chemical Oxygen Demand (COD) in the control and aerated wetlands (average ± standard deviation) under different operating conditions during period 1.

Fig. 9 - Influent and effluent concentrations of the Chemical Oxygen Demand (COD) in the control and aerated (ARBI) wetlands (average ± standard deviation) during period 2. The vertical line indicates the separation between cold (day 1-65) and warm seasons (with greenhouse, day 66-100). Each value is the result average of the three replicas.

Fig. 10 - Difference in the COD concentrations between the control and aerated (ARBI) effluents during period 2.

Fig. 11 - Influent and effluent concentrations of ammonium nitrogen (NH4+-N) in the control

and aerated (ARBI) wetlands under different operating conditions (average ± standard deviation) during period 1.

Fig. 12 - Influent and effluent concentrations of ammonium nitrogen (NH4+-N) in the control

and aerated (ARBI) wetlands (average ± standard deviation) during period 2. The vertical line indicates the separation between cold (day 1-65) and warm seasons (with greenhouse, day 66-100). Each value is the result average of the three replicas.

Day of experiment (d)

0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95100105

NH

4+ -N c

once

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L)

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60Control ARBIInfluent

Cold season Warm season

Fig. 13 - Influent and effluent concentrations of organic nitrogen in control and aerated (ARBI) wetland (average ± standard deviation). The vertical line indicates the separation between cold (day 1-65) and warm seasons (with greenhouse, day 66-100). Each value is the result average of the three replicas.

Fig. 14 - Thermal image of hot air aerated bed showing hotter water and gravel near aeration bar than in water. SP1 is 10.1, SP2 is 9.7.


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ogen

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n (m

g/L)

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Fig. 15 - Influent and effluent concentrations of chemical oxygen demand (COD) in the control and heated (ARBI) wetlands (average ± standard deviation) during period 2. The vertical line indicates the separation between cold (day 1-65) and warm seasons (with greenhouse, day 66-100). Each value is the result average of the three replicas.

Fig. 16 - Influent and effluent concentrations of the ammonium nitrogen in control and heated (ARBI) wetlands (average ± standard deviation) in period 2. The vertical line indicates


0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95100105

CO

D c

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the separation between cold (day 1-65) and warm seasons (with greenhouse, day 66-100). Each value is the result of three averages.

Fig. 17 - Influent and effluent concentrations of organic nitrogen in Control and ARBI wetlands (average±s.d.) in period 2. The vertical line indicates the separation between cold (day 1-65) and warm seasons (with greenhouse, day 66-100). Each value is the result average of the three replicas.


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n (m

g/L)

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Fig. 17 - Scheme of the two feeding positions in the ARBI wetland. The inlet pump is represented in blue, red represents the compressor to inject air (for period 1) and white shows the collection tank were the outlet flow was measured.

Fig. 18 - Influent and effluent concentrations of chemical oxygen demand (COD) in the control and ARBI wetlands (where heating and aeration was applied) for the two feeding positions during period 1. Average and standard deviation values are shown.

Fig. 19 - Influent and effluent concentrations of chemical oxygen demand (COD) in control and ARBI wetlands (average ± standard deviation) during period 2. The vertical line indicates the separation between the period without greenhouse (day 1-65) and with greenhouse (day 66-100). One and two refer to the inlet and middle feeding positions. Each value is the result average of three replicas.

Fig. 20 - Influent and effluent concentrations of ammonium nitrogen in control and ARBI wetlands (average ± standard deviation) in period 2. The vertical line indicates the


0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95100105

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D c

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separation between the cold (day 1-65) and the warm seasons (with greenhouses, day 66-100). One and two refers to the inlet and middle feeding position. Each value is the average of the results taken from three identical beds.

Fig. 21 - Influent and effluent concentrations of organic nitrogen in control and ARBI wetlands (average ± standard deviation) in period 2. The vertical line indicates the separation between the cold (day 1-65) and the warm seasons (with greenhouse, from day 66). One and two refers to the inlet and middle feeding position. Each value is the average of the results taken from three identical beds.

Fig. 22 - Photo of the first prototype horseshoe arrangement. Two magnets were place atop an iron base. The magnet holder was built from acrylic.


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Fig. 23 - Photograph of the second (large) prototype horseshoe magnet arrangement. The magnet holder was built from acrylic as before. Copper tape was added to reduce magnet RF loading and covered with a protective layer of tape.

Fig. 24 - A photograph of the Halbach cylinder built from neodymium magnets.

Fig. 25 – (a) Schematic of the four magnet unilateral surface sensor. A uniform magnetic field is generated in the magnet gap. A two-turn surface coil is used for RF transmission and receiving. (b) A photograph of one of the finished four-magnet surface sensors.

Fig. 26 - T1 measurement taken using multiple CPMG sequence with different repetition times on the four magnet surface sensor using two different samples, 64 echoes summed, τE = 100 µs. T1 values were extracted from the fittings, they are displayed along with their associated fitting parameter errors.

Fig. 27 - A simple bar magnet unilateral MR sensor.

Fig. 28 - T1 measurement taken using multiple CPMG sequence with different repetition times on the bar magnet sensor; 2048 scans on the two different samples, 16 echoes summed, τE = 50 µs.

Fig. 29 – (a) Photograph of the final sensor for embedding. This sensor uses a 3D printed ABS former for the magnets. The unit (such as this one) can be sealed with ABS making it completely water-tight. (b) A diagram of the Helmholtz-style MR sensor.

Fig. 30 - Photograph of the larger Helmholtz-like sensor. This sensor had a significantly larger sensitive volume but subsequently had a poorer SNR.

Fig. 31 - T1 measurements taken using the embedded sensor, with additional laboratory measurements. Echo time = 300 µs, 512 averages. Errors in the normalised integral sum are small, and therefore have not been included in the graph. A systematic error occurred for the final two points of the 8.39 % solid mass curve at 200 ms (shown) and 800 ms (not shown). These points have not been included in the fitting. The 75 ms point is omitted from 7.92 % solid point due to an equipment failure.

Fig. 32 - Magnetic field strength as a function of temperature for final ARBI prototype sensor. Field strengths were measured as the sensor cooled (blue) or warmed (red) to room temperature. Note that the centre frequency was not 10.7 MHz as used for most of the experiments conducted, and instead 10.6 MHz at room temperature when the sensor was built (around 15 °C).

Fig. 33 –Signal intensity as a function of tuned frequency at three different temperatures.

Fig. 34 – Signal intensity as a function of temperature. Each point is taken from four repeat measurements and are extracted from the 15 000 ms delay time values from the T1 measurements shown in Fig. 15.

Fig. 35 – T2eff as a function of temperature for the final ARBI probe on water. Five

temperatures were explored in this study. T2eff is seen to increase with a decrease in

temperature until 5 °C.

Fig. 36 – T1 relaxation for the ARBI final probe and T1 relaxation of oxygen-free water taken from the literature between 0 and 50 °C. Both sets of data have the same intercept (within error) however there are different gradients.

Fig. 37 –T1 relaxation for a variety of wetlands samples. Three wetland samples have been explored at five different temperatures exceeding the maximum range experienced by ARBI. Despite some minor reductions at high and low temperature unlike pure water T1 does not appear to change significantly with temperature changes for samples using 10 mm gravel. For the 20 mm gravel sample the results observed are very similar to those of pure water.

Fig. 38 - T1 measurements taken on the protons from solutions containing propylene glycol and water as a function of propylene glycol percentage. The relationship observed is linear, with an increase in the propylene glycol in the solution reducing the T1 relaxation time; the fitting presented has the relationship y = 2200 ± 130 – (22 ± 3)x.

Fig. 37 – T1 relaxation measurements recorded on three embedded probes at wetlands operated by ARM. The maximum repetition time used for the saturation recovery was 15 s, which was appropriately long given the T1 times being recorded.

Fig. 38 – T1 as a function of the day that the measurement was taken for three different probe. Broadly speaking the T1 times are in agreement with one another within the error of the measurements.

Fig. 39 – T1 for six probes as a function of the day that the measurement was taken for probes embedded at the Nottingham Trent University wetlands. Broadly speaking the T1 times are in agreement with one another within the error of the measurements with a few exceptions (for example the first day measurement for Probe 42).

Fig. 40 - The echo trains at different repetition times are averaged for the red pitaya (o) based console and a commercial console (Tecmag Apollo) (o) to get the T1 of a sample of oil.

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Fig. 41 - Construction of the experimental plant at UPC for domestic wastewater treatment testing.

Fig. 42 - A photograph of the three prototype wetlands used to monitor the treatment of industrial wastewater. The bed on the right had no aeration, heating, or step-feeding changes applied. The bed on the left had constant aeration applied. The final bed had an

aeration system controlled to oxygenate the water to a set point at 0.5 mg/l. A fourth wetland is visible on the far left.

Fig. 43 - Dissolved oxygen concentration in the 3 beds used to treat domestic wastewater over the course of the experiment.

Fig. 44 - Dissolved oxygen concentration in the three beds used to treat industrial wastewater over the course of the experiment. The dissolved oxygen concentrations in the storage tank are also presented. Dissolved oxygen concentrations varied significantly, with a general trend showing a drop in dissolved oxygen over time.

Fig. 45 - Water temperature in the 3 beds used to treat domestic wastewater over the course of the experiment.

Fig. 46 - Water temperature in the three beds used to treat industrial wastewater over the course of the experiment. The temperatures in the storage tank are also presented. Temperatures roughly ranged between 5 and 40 °C, with temperatures for the ‘Air 24h’ bed being consistently lower. These values were not in line with other manually acquired readings, discussed below.

Fig. 47 - Water temperature in the three beds used to treat industrial wastewater over the course of the experiments taken manually at the same time that MR measurements were recorded.

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Fig. 48 - Redox values in the three beds used to treat industrial wastewater over the course of the experiment. The redox values in the storage tank are also presented. Redox values for the beds were roughly between 150 and 350 mV until late July, when the values dropped to between 0 and 150 mV. This was possibly due to an increase in microbial growth at this time. It is important to note that the zero values for the tank between the 25/06 and 05/07 correspond to a time when the tank was most likely empty.

Fig.. 49 - pH values in the 3 beds used to treat domestic wastewater over the course of the experiment. The pH values in the storage tank are also presented.

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V)

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Fig. 50 - pH values in the three beds used to treat industrial wastewater over the course of the experiment. The pH values in the storage tank are also presented. The graph shows a general trend of the pH values dropping with time, this was likely due to the corresponding drop in the concentration of propylene glycol (which is alkaline).

Fig. 51 - Propylene glycol concentration in the three beds used to treat industrial wastewater over the course of the experiment. The propylene glycol concentrations in the storage tank are also presented. The general trend has seen a reduction in the concentration of propylene glycol with time, with some notable large drops.

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Fig. 52 - Influent and effluent concentrations of Chemical Oxygen Demand (COD) in the three wetlands used for domestic wastewater treatment. The vertical line indicates the different step feeding positions.

Fig. 53 - Influent and effluent concentrations of Total Kjeldahl Nitrogen in the three wetlands. The vertical line indicates the different step feeding positions.

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Fig. 54 - Influent and effluent concentrations of ammonium in the three wetlands. The vertical line indicates the different step feeding positions.

Fig. 55 - Influent and effluent concentrations of organic nitrogen in the three wetlands. Organic nitrogen is calculated subtracting ammonium from TKN. The vertical line indicates the different step feeding positions.

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Fig. 56 - Influent and effluent concentrations of nitrite in the three wetlands. The vertical line indicates the different step feeding positions.

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Fig. 57 - Influent and effluent concentrations of nitrate in the three wetlands. The vertical line indicates the different step feeding positions.

Fig. 58 - Influent and effluent concentrations of total nitrogen in the three wetlands. Total nitrogen is calculated as the sum of TKN, nitrite and nitrates. The vertical line indicates the different step feeding positions.

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Fig. 59 - COD removal efficiency in the 3 beds corrected for evapotranspiration.

Fig. 60 - Total nitrogen removal efficiency in the 3 beds corrected for evapotranspiration.

Control - CORDIS · This pilot plant was also used to investigate step-feeding. ... Angle of bubble...

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Transcript of Control - CORDIS · This pilot plant was also used to investigate step-feeding. ... Angle of bubble...