Sunday, 26 November 2017

Plastic bottles: recycling is good, reducing is better!

 Plastic bottles take 450 to 1000 years to biodegrade. PET or PETE bottles never biodegrade.

A 1 litre bottle of my favourite still water costs on average 0.58 EUR. An empty bottle weighs 25 g. My husband and I drink 1 litre of water a day each, easily. With bottled water, that would costs us 423.40 EUR a year. That also leaves us with 730 empty plastic bottles of 25g each. A total of 18.25 kg of plastic a year!

If we drank 730 litres of tap water, that would cost us 3.38 EUR. That is not a typo! Bottled water is 125 times more expensive than tap water!

So there we are, and tap water it will be from now on! The problem is: we don’t like its taste. So let’s find affordable ways to improve it.

In 2013 a Belgian consumer magazine, Test Aankoop, has tested 40 samples of tap water all over Belgium. The outcome was that our tap water is generally safe and healthy. No old pollutants (nitrates, pesticides,…) were found in alarming quantities. Also hardly any new pollutants (antibiotics residue, hormones,…) were found. So it is safe and healthy, I believe that.

But I still don’t like its taste. In 2015, tap water was tested for a radio programme. A water sommelier was asked to blind taste and identified tap water immediately. So those who claim that the taste of tap water and bottled water is the same are wrong.

The taste of tap water is mainly caused by the chlorine they add to keep it free from bacteria. Also the amount of calcium and magnesium in water can influence its taste and its hardness. And of course there are tens of other pollutants in tap water, maybe not harmful ones, but they do have an impact on its taste.

The term ‘water hardness’ refers to the amount of calcium and magnesium salts in water and is expressed in French degrees (°F) or German degrees (°D). These salts are necessary for our health, but they do cause calcification of our household equipment (kettles, coffee maker, washing machines,…). On a scale of 0 to over 50, water hardness in Antwerp is between 17.7 and 18.3 French degrees, 0 degrees being very soft, 50 degrees and higher being ultrahard. So the water coming out of our taps in Antwerp is fairly soft. Nothing to worry about there. We don’t need to put an expensive water softening device at the entrance of our house.

Heavy metals can also be found in tap water. A 2016 analysis of Antwerp tap water did not show any alarming heavy metal levels. Lead can still end up in your own tap water if the original water pipes in your house have not yet been replaced. I’ve checked ours, they have been replaced recently by copper ones, so no problem there.

With this information about our own tap water, I started looking for a filtering system that could enhance its taste. I studied Brita filters, ceramic pipes and activated carbon sticks.

1.    Brita filters

Brita, the obvious choice. Or is it? Most reactions I had on the first post of this blog were “we use a Brita filter”. We contemplated buying one but we didn’t. And here is why.

Brita uses a double filtration system: (i) silver-impregnated activated carbon and (ii) ion-exchange resin. That is a mouthful, I know.

·         The activated carbon removes substances that may impair taste, such as chlorine and chlorine compounds.

·         The ion exchange resin reduces the carbonate hardness (limescale), accordingly softening tap water, and reduces metals, such as copper and lead, that can occur as a result of domestic installation.

The silver in the filters is used to slow down any bacterial growth, but in itself, the silver is not entirely harmless, according to the World Health Organisation. For that reason, large water treatment plants do not use silver but ultraviolet light to control bacterial growth.

The Brita pitcher itself is styrene methyl methacrylate copolymer. There are several types of pitchers so for the sake of this exercise, I’m just picking one out randomly. It costs about 21.50 EUR.

It is recommended to change the filter every month. This will cost you some 76.90 EUR/year.

On a yearly basis, this is:

·         12 filters: 76.90 EUR
·         730 litres of tap water: 3.38 EUR

This totals an initial investment of 21.50 EUR and a running cost of 80.28 EUR/year.

Pros: your water is filtered instantly. It is relatively cheap. The filter is 100% recyclable, every single element, from the plastic to the activated carbon and ion exchanger, but you have to take it back to the shop. Recyclable is not the same as recycled!

Cons: microbes can still accumulate in the filter. Silver is used to slow that process down. Tiny silver particles will then end up in your water.

I contacted Brita directly with the question: what is the percentage of filters sold, that are actually returned to the collection points for recycling. (I did not ask how many filters are being recycled!) Until today, I have not yet had a reply from them.  Therefore, I have to assume that not many filters are returned for recycling.


2.    Activated carbon sticks

Activated carbon is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions. It is part of the filtration system of a Brita filter. It is used worldwide in all sorts of applications. Again, a mouthful…

Activated carbon traps toxins and chemicals in its millions of tiny pores through adsorption. Adsorption is the chemical reaction where elements bind to a surface.

Because it is so porous, one gram of activated carbon can have a surface area of 500 m2 to over 3000 m²! The surface of activated carbon has a negative electric charge that causes positive charged toxins and gas to bond with it. For instance, active carbon is used for emergency toxin removal on patients that have overdosed through ingestion.

The activated carbon sticks are made from oak branches. Brita filters also have activated carbon but made from coconut.

The difference between a Brita filter and activated carbon is that, first of all, there is no silver involved when you use carbon sticks. Secondly, when using a Brita filter, the water is filtered immediately when it runs through the filter. The carbon sticks are placed directly in the water and need some time to do their job. But the longer you keep the stick in the water, the more metals and toxins it will adsorb.
When the stick loses its carbon activity, you boil it for 10 minutes. After 4 months, you put them at the bottom of your flower pots. They are 100% biodegradable.

Please do not use barbecue charcoal! 

Investment: a glass jar. You can find glass jars for any budget. Ours cost 14.99 EUR.
Running cost: 4 sticks cost you 17 EUR. You can do a year with 4 sticks. 700 litres of tap water: 3.38 EUR

Pro: they are fully biodegradable, the sticks don’t take up any space in your fridge or cupboard. You keep them in your water jar.

Con: it is only available in Japan or Taiwan for the moment. Since activated carbon is used all over the world for filtering and detoxing, I hope that the carbon sticks will be available in Belgium soon so we don’t have to fly them in from Japan. They do have their own carbon footprint at the moment!

3.    Ceramic pipes


Ceramic pipes can be used for a variety of things (swimming pools, bathtubs, coffee makers, water jars. They never need to be replaced. I can’t really find how it works on the internet but it is supposed to vitalise water, increase the energy of water, evaporate chlorine, reduce oxidation, reduce infrared radiation, reduce surface tension, break up large clusters of water molecules, break down water pollution and increase the transport of nutrients.

I don’t have a clue what all that means!  I’ll believe it. I have seen it in fish tanks and other applications. 

According to one website on ceramics water filtration: “Ceramic water filters work by simply allowing the water to seep through tens of millions of pores in the water cartridge surface. In the process, organic and inorganic particulates too large to pass through (often anything larger than 0.5 micron) accumulate on the ceramic surface.

So I am not sure how you use the pipes without filtration system. If you just put them in a jar, the water does not “seep through”.

Investment: 500 grams of ceramics pipes cost 34.95 EUR. And of course a jar.
Running cost: 730 litres of tap water: 3.38 EUR/year.

4.    So, which decision did we take?

Somehow the image of the fish tank inhibits me from trying the ceramic pipes, even though it is the cheapest solution. Also, I think I wouldn’t be able to stand the rattling noise of the pipes in a glass jar. And of course, the fact that I don’t really know how it works.

As we don’t have heavy metals in our tap water, and our water is relatively soft, we don’t really the ion exchanger that the Brita filter has. Also, we have a family of 2, so we don’t really need the instant filtering system. Brita is not our first choice. We decided to go for the activated carbon sticks. We keep 2 sticks in a glass jar in the fridge and 1 stick in reusable plastic bottles on the bedside table. We bought 4 colourful reusable bottles, so we can take them along on trips, holidays and concerts (if allowed).

If you have a Brita filtering system, remember that you can take the used filters back to the shop.

5.    The impact

Environmental impact
I have a big water tank in the office so this calculation is a bit hypothetical. We do think that we drink at least 730 litres of water a year. That is underestimated rather than overestimated.

Now we use 4 carbon sticks. They are flown in from Japan and are wrapped in a cellophane sheet.

That is a total reduction of (a hypothetical) 730 plastic bottles/year (wrapped per 6 in additional plastic). That is at least 18.25 kg of plastic, against 1 cellophane sheet.

Financial impact
730 hypothetical plastic water bottles a year cost 423.40 EUR/year.
The carbon stick solution costs 17 + 3.38 EUR/year + the purchase of one or two water jars and reusable plastic bottles.

The investment not included, this is a positive balance of 423.40 – 20.38 EUR /year: 403.02 EUR.

Space impact
We win the space of the water bottle stock.
We lose nothing because the space taken up by the jars in the fridge were also taken up by the plastic water bottles.

Time and effort impact
We lose once or twice a year we have to go online and order carbon sticks.
We win big time because we don’t have to transport all the bottles from the shop to our house anymore. We have no car so on the bicycle, I can tell you!


Thanks to Mick and Dominique for helping me pull this article together. The next one will be shorter and less technical, I promise!

Next post expected end of December 2017: fruit and vegetable shopping!

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