In October 2022, we bought three small (actually, very small) flowering cherries (Kojo-no-mai) from Thompson & Morgan. The plants arrived in 9 cm pots and were upgraded to 12 cm pots after a month or so. By the following March (2023), two of the three shrubs were flowering (Photo 1) but one was looking rather sad (by sad, I mean dead). A quick e-mail (with picture) to Thompson & Morgan and a replacement was on its way. These shrubs grow to about 8 feet tall (2.5 m) so ours have a long way to go.
Photo 1: Flowering Kojo-no-mai (March 2023)
Mary noticed the other day that one of the Kojo-no-mai had a miniature forest of flowering bryophytes covering the soil surface. Now I cannot tell my mosses & liverworts from my hornworts but I did hear Mary mention the liverworts. Here is the long-distance view showing the autumn colours of the cherry with flowering cyclamen in the background ...
Photo 2: Kojo-no-mai growing out of bryophyte jungle
... followed by a close-up of the bryophyte jungle (Photo 3) ...
It was a warm, sunny September day - ideal for a trip out into the Herefordshire countryside. The first port of call was the North Herefordshire village of Brampton Bryan ...
Photo 1: Brampton Bryan village
The village, itself, is very picturesque but we were visiting for another purpose: Aardvark Books & Cafe. The bookshop sells new books, mainly of local interest, but most of the space is taken over with second-hand books, maps, music scores, etc. You can spend a very pleasant few hours browsing the stock while sitting on the many chairs and sofas ...
Photo 2: The Upstairs Collection of Second-hand Books
Since you cannot read a book on an empty stomach, lunch was ordered from the small cafe. A simple lunch menu (baked potatoes, soup, toasted sandwiches), choice of scrummy-looking cakes and excellent tea and coffee. We sat outside (had I mentioned the warm sun?) where another visitor had parked their electric tandem ...
Photo 3: Electric Tandem, Brampton Bryan
It brought back memories of our own tandem adventures in Norfolk nearly 50 years ago. Of course, it was only pedal power in those days but it was still possible, albeit a little scary, to hit 40 mph downhill with a following wind. We bought our Gitane tandem new while living in Norwich; very similar, if not identical, to this touring model with drop handlebars on the front. Equipped with panniers, we loaded up the camping gear and set off for the North Norfolk coast about 25 miles away. Happy days.
The yew hedges are a feature of the village (our visit obviously coincided with auditions for Village Idiot!?!?) ...
Photo 4: Brampton Bryan Yew Hedges
Photo 5: Brampton Bryan Yew Hedges
Photo 6: Brampton Bryan Yew Hedges
The Grade I listed St Barnabus Church is worth a visit ...
Photo 7: St Barnabus Church, Brampton Bryan
Photo 8: St Barnabus Church, Brampton Bryan
where you will find lots of information on the Harley family who own most of the village and surrounding estate. Time to leave the village and move on ...
Photo 9: Leaving Brampton Bryan
On our way to Brampton Bryan, we passed what seemed an inordinately large number of road signs pointing towards Lingen, a small village in North Herefordshire and not far from Brampton Bryan. Time to see what all the fuss was about. There was a secondary reason for visiting; one of my 19th-century ancestors was a farm bailiff in Lingen.
We stopped by the small church (St Michael & All Angels) ...
Photo 10: St Michaels and All Angels, Lingen, Herefordshire
beside this dovecote ...
Photo 11: Dovecote, Lingen
Not sure the dovecote was leaning quite like that but it might have explained why most of the residents were enjoying the sun on a nearby roof ...
Photo 12: Awayday for the Doves
... although a few moments after this picture was taken, the appearance of a sparrowhawk led to a mass departure. By the time we had visited the church and returned ...
Photo 13: Inside St Michael's and All Angels, Lingen
... the doves had also returned and were all accounted for.
Just two short stops on the way home. First port of call was Wapley Camp, an Iron Age hillfort ...
Photo 14: Information Board at Wapley Hill Wood Car Park
... we have walked to the fort in the past - made mental note to come back and do it again.
The final stop was at The Bush Inn where I had spotted this on the way out but Mary, who was driving, had not ...
Photo 15: Autumnal Doorscape, The Bush Inn, Herefordshire
A little late to the party but we have bought an air fryer ...
Photo 1: Air Fryer, 11L, £89, Argos
I've yet to be convinced it is as cost-effective as it is claimed to be but Mary has been convinced by several family testimonials. I noticed cost savings claimed in the publicity material are around 30%, considerably less than the outlandish claims suggested when they first arrived on the scene. I can see the time, economic, and health advantages of air fryers (c.f. ovens) when preparing meals for one or two people. But I do wonder whether most purchasers will only use it to cook frozen chips, ready meals, and pizzas. Maybe there is an advantage when cooking meat but we won't be testing that as vegetarians/vegans.
The air fryer got its first use cooking Sunday breakfast - hash browns, halloumi, and mushrooms (Photo 1) together with baked beans heated up in the microwave. I have to admit it was rather tasty!
The second meal, prepared later the same day, comprised roast vegetables from the kitchen garden (potatoes, carrots, parsnip and beetroot, see Photo 2), a couple of vegetarian sausages (frozen, cooked in the frying pan as the air fryer was full!!), French beans from the garden (cooked in the microwave), Yorkshire puddings (frozen, cooked in the air fryer), and gravy. Another tasty & healthy meal.
Photo 2: Root Veg from the Kitchen Garden
Please note that one of the carrots was normal instead of the usual misshaped vegetables. The parsnip was a little on the small size but it is a bit early to be harvesting them now. The white and yellow beetroot were deliciously sweet when roasted in the air fryer (although my beetroot is always delicious and sweet no matter how you cook it!).
Verdict so far on the air fryer? Bit early to say. Our appliance has a capacity of 11 litres and comes with three trays. We were only able to cook part of our meal for two - with a slightly bigger model we could have 'cooked' the sausages in it as well. There was certainly a time-saving (about 25-33 %) and, no doubt, a similar energy/cost saving.
We will still be using our conventional fan oven for batch baking of bread, cakes and biscuits, preparing larger meals such as my cauliflower bake that takes 3 days to consume ...
Photo 3: Cauliflower Bake (smaller version)
and commercial-scale vegetable roasting destined for the freezer.
In Part 1, I discussed the type of trace contaminants found in potable water and, specifically, Hereford tap water processed by the Broomy Hill Water Treatment Works. I also reported on some analytical tests performed at home that confirmed the concentration of some of these trace materials.
In this post, I want to look at a simple option for purifying tap water. In the third and final part. I will discuss the economics of this process along with the environmental impacts.
Potable water has already been through a number of purification processes before it reaches your tap (or faucet for our American friends). These may include some or all of the following: filtration, flocculation, sedimentation, coagulation, adsorption, aeration, precipitation, biodegradation, and disinfection (e.g. chlorination).
Here, we are talking about the final 'polishing' step(s) needed to produce highly purified water, as would typically be used in laboratory/scientific applications, from potable water . The three most widely used forms of purification are distillation, de-ionization and reverse osmosis. The oldest method, distillation, has largely been replaced with reverse osmosis (RO) because it is less energy-intensive and more convenient. The three processes may be used individually or in combination to produce high purity water (sometimes in conjunction with an activated carbon filter to remove organic contaminants).
Since I do not have a RO or ion-exchange system at home, choosing distillation was easy. My distillation kit is shown in Photo 1; a Beko Heat Pump Tumble Dryer with an A++ energy rating.
Photo 1: Distillation Equipment
The distilled water is collected in the tray (upper left) - approximately one litre per drying load. The water is stored in 5L repurposed plastic containers previously used for cleaning products. Residual cleaning materials (e.g. laundry liquids, handsoap, fabric conditioner, toilet cleaner) are rinsed out with hot water (10 times), cold water (5 times) and distilled water (5 times) prior to use as storage vessels.
The next thing to do is test the purity of the home-distilled water using a sample taken directly from the collector tray of the tumble dryer. Table 1 compares the test results for Hereford tap water before and after distillation.
Table 1: Analytical Data on Hereford Tap Water and 'Distilled' Hereford Tap Water
Analytical Test
Hereford Tap Water
‘Distilled’ Hereford Tap Water
Orthophosphate
1.94 mg/L (ppm)
0.00 mg/L
Nitrite
0 mg/L (ppm)
0 mg/L
Nitrate
2 mg/L (ppm)
0 mg/L
NH3-N (ammoniacal nitrogen)
0.00 mg/L (ppm)
2.31 mg/L
pH
7.8
8.0
Conductivity
207 μS/cm (25 oC)
20 μS/cm (25 oC)
With the exception of ammoniacal nitrogen (NH3-N), the reuslts are as expected. The inorganic anions (orthophosphate, nitrite and nitrate) have been reduced to below detectable levels, presumably, along with any associated cations. A 10-fold reduction in conductivity confirms the reduction in inorganic ions.
Surprisingly, ammoniacal nitrogen that was absent in tap water is now present at relatively high concentrations. Where has that come from?
My first and, let's face it, only idea was that it must have come from the laundry detergent (Ecover Wool & Silk Laundry Liquid). The only other laundry product I currently use is an oxygen-based bleach based on sodium percarbonate. Ammonium lauryl sulfate (ALS) seemed a possible candidate as this anionic surfactantis widely used in detergents. However, only sodium lauryl sulfate is mentioned in the list of ingredients. Ethylene diamine tetraacetatic acid (EDTA), usually as the sodium salt, is another common ingredient in detergents where it acts as a water softener by complexing with calcium and magnesium. Although not mentioned in the list of ingredients, I have requested an MSDS from the manufacturers as well as asking the direct question - does your product contain EDTA? I am awaiting their reply.
The Nesslerization test method used to quantify ammoniacal nitrogen (NH3-N) requires the sample solution to be made alkaline (basic) to convert any ammonium ions to free ammonia which then reacts with a tetraiodomercuric salt to form a coloured complex. I have searched for possible interferents such as other amino componuds (e.g. EDTA) but have not found anything, yet. As noted in Table 1, the pH of the distilled tap water has increased to 8.0; i.e. is more alkaline (basic) than the original tap water. The presence of compounds such as ALS and EDTA would make the water more acidic. Ammonia would increase the pH (more basic) of the water though at the concentrations indicated in Table 1, the pH would be expected to be nearer 10, unless something is buffering it at pH 8. The low conductivity of the distilled water suggests not much in the way of impurites.
In the meantime, I thought I'd try a few more experiments. Could I remove the ammonia/ammonium in the distilled tap water by (i) bubbling air through the solution, or (ii) boiling the water. My sample of distilled tap water was taken directly from the tumble dryer water collector tray. Some of the sample was used to rinse all the 'equipment', i.e. a mug and a pan, prior to the experiment. Test 1: the sample was placed in a mug and air bubbled through for 5 minutes using an aquarium air pump on maximum setting (Photo 2).
Photo 2: Sample Degassing with an Air Pump
Test 2: the sample was placed in a small non-stick pan brought to a rolling boil (Video 1) maintained for 5 minutes and then allowed to cool for 2 hours.
Video 1: Sample Degassing by Boiling
Sample analysis results for Test 1 & 2 are summarised in Table 2. Degassing with air (Test 1) has increased the electrical conductivity of the distilled water (lower dissolved oxygen content?)) and reduced its pH (increased carbonation?) but had no effect on the concentration of ammoniacal nitrogen. Boiling the distilled water (Test 2) has reduced the ammoniacal nitrogen content with little or no change in pH and conductivity - loss of ammonium as ammonia? A better experiment would be to repeat Test 2 after increasing the pH (addition of alkali) of the distilled water to 'convert' ammonium to ammonia in order to drive off the ammonia gas more easily. Now where can I get some sodium hydroxide?
Table 2: Analytical Data for Test 1 and Test 2
Analytical Test
Distilled Hereford
Tap Water
‘Distilled’ Hereford Tap Water
(Air degassed - Test 1)
‘Distilled’ Hereford
Tap Water (Boiled - Test 2)
Nitrite
0 ppm
0 ppm
0 ppm
Nitrate
0 ppm
0 ppm
0 ppm
NH3-N
1.53 ppm
1.52 ppm
1.00 ppm
pH
8.3
7.8
8.2
Conductivity
15 μS/cm (25 oC)
91 μS/cm (25 oC)
24 μS/cm (25 oC)
Time to bring this post to an end. The home-distilled water is free of phosphate, nitrate and nitrite and can be used for cleaning and storing the cuvettes used for phosphate analysis. It is also suitable for diluting high phosphate samples prior to analysis in order to bring them within the 0 - 3 ppm range of the Hanna Low Range Phosphate checker. I am also happy to continuing to water my indoor plants with the distilled water but I will not be using it to top up my goldfish tank (Video 2). Ammonia (NH3) is toxic to fish and could present a danger at these concentrations, pH values and temperatures.
Video 2: Hoover the Goldfish at Feeding Time*
In the third and final instalment, I will look at the economics and environmental impacts of producing distilled water using a tumble dryer.
* Hoover's nickname is Lucky - he is well past the 20 year old mark (actual age unknown), has a bent tail fin and is blind in one eye.
There are times when a cheap and ready supply of 'pure' water would be handy. For example, watering indoor plants, topping up the car window-wash reservoir and radiator, cleaning and storage of cuvettes used for river water analysis, cleaning/rinsing conductivity and pH meters, and replenishing/topping-up the goldfish tank. In Part 1 of this series, I will discuss the 'purity' of the tap water supplied to our house. In Part 2, I will evaluate whether the 'distillate' from a tumble dryer produces a higher purity water sample. Part 3 will address the costs and sustainability of this option.
In this post, I want to look at the quality of the water supplied to our house. In the UK, all water companies must analyse their water on a daily basis and you can find typical results on their website (you can request the daily test results free of charge). Simply type 'water quality' into the search function on the website of your supplier - you might need to identify your location if your supplier has different water sources and/or water treatment plants.
Welsh Water provides two lots of information: first, the 'hardness' of the water ...
Figure 1 provides a breakdown of the various water hardness parameters for the supply to our particular area. Our potable water is described as 'moderately soft' - this is a qualitative description on an arbitrary scale from very soft to very hard. Figure 2 shows the water 'hardness' data for England and Wales, with Herefordshire highlighted.
Figure 2: Water Hardness (mg/L CaCO3) courtesy of DEFRA
To convert calcium (mg/L) to calcium carbonate (mg/L), the former needs to be multiplied by 2.5. So, our water has a hardness of 27.58 x 2.5 = 69 (i.e. moderately soft). Do not worry about the different values for hardness given in Figure 1. These arise because of different methods used to determine water 'hardness' (e.g. colorimetric titration, elemental analysis by atomic absorption spectroscopy and gravimetry) and the inclusion/exclusion of other inorganic species (e.g. magnesium carbonate) that cause water 'hardness'.
Hard water leads to a build-up of scale in heating appliances (kettles, washing machines, diswashers, boilers, etc), leaves 'tidemarks' in baths, sinks and toilets, and produces a surface 'scum' on hot beverages. We came across a couple who regularly visited the Malvern springs and wells to stock up with water and take it back to Oxfordshire where they now lived. It was, apparently, impossible to make a decent cup of tea with the hard/very hard water supplied in Oxfordshire!!
On the other hand, soft water is more corrosive to metal pipework than hard water and phosphate salts may be added to control the corrosion. Which leads nicely onto the second set of analyses carried out by water companies; namely, taste, smell and appearance, acidity (pH), and levels of inorganics (including heavy metal pollutants), organics (e.g. PAHs and pesticides) and bacterial colonies. Some typical values for selected parameters are:
pH 7.61
Nitrite 0.01 mg/L
Nitrate 4.92 mg/L
Ammonium 8.4 μg/L
Phosphorus572.50 μg/L
Orthophosphate1.75 mg/L
The reasons for choosing these parameters will be become clear below.
Through my citizen science activities, I have the means to directly test for all the above properties with the exception of elemental phosphorus. Fortunately, dividing the measured orthophosphate, [PO₄]³⁻, concentration by 3.066 will yield the elemental phosphorus value for the sample. Conversely, the elemental phosphorus content when multiplied by 3.066 will give the orthophosphate concentration.
[Note: the conductivity and pH meters both have automatic temperature compensation (ATC) so values are corrected to 25 ℃]
Table 1 summarises my home test results and compares them with the expected or typical values reported by the water company. The agreement is excellent.
Table 1: Comparison of Measured vs Typical Test Results for Home Tap Water (Hereford)
Analytical Test
Measured Value
‘Typical’ Values
Orthophosphate
1.94 mg/L (ppm)
1.75 mg/L
Nitrite
0 mg/L (ppm)
0.01 mg/L
Nitrate
2 mg/L (ppm)
5.4 mg/L
NH3-N (ammoniacal nitrogen)
0.00 mg/L (ppm)
0.007 mg/L (calculated)
Ammonium
0 mg/L (ppm)
0.009 mg/L
pH
7.8
7.6
Conductivity
207 μS/cm (25 oC)
199.6 μS/cm (20 oC)
[Note:pH and conductivity both vary with temperature; the former decreases and the latter increases with increasing temperature. To standardise measurements, pH and conductivity values are 'corrected' to a standard temperature, usually 25 ℃. Meters with ATC do this compensation automatically using the built-in thermometer. While most procedures and regulations report conductivity at 25 ℃, the UK Water Quality Supply Regulations use a standard temperature of 20 ℃.]
Photo 2: Orthophosphate Value for Hereford Tap Water
Welsh Water add phosphate to the Hereford tap water to reduce pipework corrosion. The concentration of phosphate (usually between 1.5 mg/L and 2.0 mg/L) in the potable water will have a very small fertilizer effect when watering plants/lawns etc; however, the levels are about 30 times lower than a foliar feed such as that used in the Greenhouse Sensation Quadgrow system. Nitrite/nitrate concentrations in the tap water are about 200 times more dilute than a foliar feed.
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