RO does use a lot of energy to overcome the osmotic pressure and to create flux through the membrane. An interesting concept is using the reverse process, "forward" osmosis, to extract the energy where fresh water mixes with seawater, such as a river mouth. This is called pressure-retarded osmosis (PRO) and was tried at pilot scale by Norwegian power company Statkraft. Ultimately this trial was shelved due to being uncommercial [1], perhaps future membrane development will improve the viability of FO. And yes the membranes are quite different, RO membranes are relatively thick due to the transmembrane pressures required. FO requires a much thinner support for the active layer as there is no external pressure applied to push the water through (it is drawn through by the difference in salt concentration).
Having a diversity of water supplies and using water fit for purpose reduces demand for drinking water. Toilet flushing, irrigation and even washing machines do not need high quality drinking water. I have 5,000L of rainwater storage that I use for toilet flushing and irrigation. Combined with a water efficient shower head (typically the largest domestic water use in my country) we use 100 L/d/person. In some areas of my city there is dual supply plumbing that delivers highly treated wastewater for these uses.
I once worked with an environmental engineer who had a grandfather that worked at Wittenoom. He passed away due to mesothelioma, but her father who grew up there has not been affected, which is quite amazing given the circumstances. I have seen footage from Wittenoom of children playing in mounds of asbestos.
Today there are two general types of legacy asbestos products, friable and non-friable. Generally non-friable products such as asbestos-cement sheeting are considered safe to leave in place and are only dangerous when cut, broken or otherwise damaged. Friable products such as pipe lagging are very dangerous as they easily break down into fibers that can be inhaled.
It can be found in many old homes in odd places. I was removing some old putty around a window and a friend of mine who was an asbestos hygienist suggested that it could contain asbestos and took a sample for testing (all clear thankfully).
In another instance I worked on a demolition of a 1960's era multistory apartment complex. During construction of the concrete core walls the builder had used asbestos in the formwork, leaving some embedded in the wall at regular intervals. This meant that all of demolition waste was considered contaminated and was going to a special dump at a huge cost.
Finally, there was an infamous case in Canberra, Australia where a company called Mr Fluffy [1] installed loose friable asbestos as insulation in homes. A cleanup program in the 90's did not adequately fix the problem and so in 2014 the government finally purchased affected properties and demolished the houses.
Asbestos is bad stuff, but exposure causing mesothelioma seems to be a bit like Russian roulette. You might get it, you might not. But if you do, you will die.
From what I know and was also told by several doctors when a family member was dying of mesothelioma in his early 70's (despite never having worked more than casually a few times around asbestos in his much younger years), the illness is strongly suspected of being tied to a genetic predisposition that only affects a certain small percentage of people.
If one has this genetic disposition, it's apparently possible that even moderate or modest exposure early in life is enough to cause the (extremely deadly and almost impossible to treat) disease at some point later in life. This point can come years or decades after exposure.
And if one isn't predisposed, then even heavy exposure to asbestos probably won't cause mesothelioma. It is of course still possible to get other really shitty lung problems from the mineral regardless of genetic factors, but meso itself seems to be very selective. This apparently is why it's relatively rare despite widespread asbestos use for decades before recent years in much of the world.
> Do some people's lungs gradually clear away the asbestos particles more effectively than others'?
At least in terms of damage to the lungs, from what I gather (by reading wikipedia!) it's the degree of inflammatory response to the asbestos that is critical, not the presence of the asbestos itself. If your body thinks 'asbestos, oh shit!' and mounts a big response to attempt to wall off the particles etc. then you are in trouble.
Fun fact: asbestos is blowing around in the air pretty much everywhere at some level.
Fun fact: asbestos is blowing around in the air pretty much everywhere at some level.
Since it is naturally occurring, it could be that some sort of natural selection has happened over time to cause people who live in naturally asbestos-rich areas to develop far greater immunity to its presence.
One thing I always find interesting about Wittenoom Mine is that it's construction and then sale to CSR seems to be the seed capital for Lang Hancock and his daughter Gina Rinehart to build a giant empire in iron ore mining.
Gina Rinehart is the wealthiest person in Australia.
One of my dads friends had a business installing asbestos siding in the 1960's. He's in his 80's and seems fine. On the other hand his wife died of mesothelioma 20 years ago.
My father worked delivering asbestos, every one of his co-workers that did front line deliveries are dead, mostly lung health related issues seemingly related to asbestos. My dad is in his 60's and fine so far.
My uncle spent some weeks doing DIY projects with asbestos. Hes has mesothelioma now. Turns out he has (along with many in our family) a genetic disorder that makes certain cancers like mesothelioma much more likely.
Its a big pity that access to the region is tainted by the mining operations that made the area toxic, because Wittenoom and the gorges in the region are an absolutely astonishing part of the world - so much history of the original land owners in the area.
I visited it on school trips as a kid, and I'll never forget the sight of so many indigenous relics scrolling past the bus window. To think that it is all off-limits now, due to asbestos, is a real tragedy. Australia has so many of these kinds of deeply rich, deeply interesting sights that are tucked away behind a mining company's fence ..
So, its not like asbestos - in Australia - is only killing people. Its also masking a very significant degree of cultural heritage from the current generation that could benefit from understanding it more ..
A recent report [1] looked at the efficiencies of generating hydrogen at a waste water treatment plant to lower production costs. The WWTP provides the water and uses the oxygen that is also produced by electrolysis to increase the efficiency of the biological treatment process vs air. Some of the electricity for the electrolysis can also be sourced from biogas produced by the WWTP.
I put in a Sanden heat pump to replace an old electric gravity water heater 1.5 years ago. Based on power meter data it uses 30% of the energy of the old system on average. This is probably understated as hot water consumption has gone up as the new system and new pipes increased pressure and flow. I say on average as there is seasonality to the energy consumption. I live in a temperate climate, no snow.
We run it at night to take advantage of cheaper separately metered electricity rates ('controlled load'), it could be run even more efficiently during the day, but at higher cost. This and replacing the old gas ducted heating with reverse cycle air conditioning has allowed us to stop using gas, saving the fixed $~30/month service charge. Eventually the additional of solar will further increase our use of renewables.
[1] https://www.powermag.com/statkraft-shelves-osmotic-power-pro...