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Starch separation from water possibilities?

Posted: Wed Sep 14, 2022 2:01 pm
by Mr Gus
Guys, the newly adopted "rinse your rice" is killing me in terms of water useage, just under 2 litres of water per cup of rice, which I'm throwing outside to go to earth.

But is there a better way, maybe a simple filtration technique in unaware of in order to use it in something like a dishwasher or similar, having got rid of the glue / lessened anything microbial, ..Wife doesn't want it in dog bowls for reasons of contamination (possible stomach upsets)

How to ratchet down on this?

Re: Starch separation from water possibilities?

Posted: Wed Sep 14, 2022 3:12 pm
by Stinsy
Maybe save the water and use it to thicken your soups/stews?

I too baulk at wasting water by rinsing, so I "soak' the starch off instead. I just dip the sieve of rice in a bowl of water, leave it for a few mins, then give it a shake. Starch definitely comes out of the rice and those eating the rice haven't complained that it is "too starchy".

Re: Starch separation from water possibilities?

Posted: Wed Sep 14, 2022 3:40 pm
by Oldgreybeard
Filtration is the only fairly easy way to reduce it. Starch is a swine to get rid of from water, as, apart from anything else, it doesn't easily biodegrade, at least not quickly, so even sewage treatment plants struggle to handle it. The flip side is that it doesn't cause issues when used for watering, as it doesn't noticeably increase the BOD of the water.

A sand filter is probably the cheapest way to reduce it, but would need to be a fair volume, as starch clogs filters very effectively. The posh way to do it might be to get, or build, a proper backwashing sand filter. We have one to filter our well water, that automatically backwashes every couple of days, overnight, but it does waste a LOT of water doing this. Our backwash cycle lasts about 15 minutes and runs at around 30 litres per minute, so uses about 450 litres of water, water that just gets flushed down the drain (well, into the setting tank and then into the stream, so not really wasted as such).

Re: Starch separation from water possibilities?

Posted: Wed Sep 14, 2022 5:01 pm
by Thebeeman
Oldgreybeard wrote: Wed Sep 14, 2022 3:40 pm A sand filter is probably the cheapest way to reduce it, but would need to be a fair volume, as starch clogs filters very effectively. The posh way to do it might be to get, or build, a proper backwashing sand filter. We have one to filter our well water, that automatically backwashes every couple of days, overnight, but it does waste a LOT of water doing this. Our backwash cycle lasts about 15 minutes and runs at around 30 litres per minute, so uses about 450 litres of water, water that just gets flushed down the drain (well, into the setting tank and then into the stream, so not really wasted as such).
Our borehole filter uses 500 lts to backwash but we direct into IBC's that also catch rain water for garden use. The very high iron content does sludge up the tanks some what. Without the filter if you pour a glass of water you have to wait for the 'rust' to settle out.

Re: Starch separation from water possibilities?

Posted: Wed Sep 14, 2022 5:12 pm
by Oldgreybeard
Thebeeman wrote: Wed Sep 14, 2022 5:01 pm Our borehole filter uses 500 lts to backwash but we direct into IBC's that also catch rain water for garden use. The very high iron content does sludge up the tanks some what. Without the filter if you pour a glass of water you have to wait for the 'rust' to settle out.
Our water is similar, full of "clear water iron" (ferrous oxide), around 480ppm of the stuff (which is a lot). We have an air injector ahead of the sand filter that oxidises the ferrous iron to ferric iron (rust) and the sand filter then traps all the bits of rust, that get back flushed out. Always amazes me how quickly air oxidises the ferrous iron in the water, it happens near-instantly. I had a length of clear 25mm PVC pipe just after the air injector and you could see the cloud of rust particles forming as the air mixed with the water. The air also gets rid of the trace of hydrogen sulphide that's in the well water just as quickly.

I wonder if you get your water from the same aquifer as ours? Our well is about 50m deep and draws water from the Lower Greensand aquifer, that I believe stretches over a fair bit of SW England.

Re: Starch separation from water possibilities?

Posted: Thu Sep 15, 2022 5:56 am
by Thebeeman
We're about 4 miles away from the top edge of Dartmoor, Thin topsoil over shillet and then solid rock, on occasions the water table is above ground level. My OH gardens with a crowbar.