From: |||newspam|||@nezumi.demon.co.uk   
      
   On 14/11/2016 15:36, dlzc wrote:   
   > Dear Martin Brown:   
   >   
   > On Monday, November 14, 2016 at 4:51:07 AM UTC-7, Martin Brown   
   > wrote:   
   >> On 11/11/2016 15:10, dlzc wrote:   
   >>> Let's say I am looking to reuse irrigation water, for   
   >>> irrigation. I will apply some prescription dose of ozone, for   
   >>> pathogen inactivation (at minimum).   
   >>>   
   >>> The source water contains: - Potassium > 90 ppm - Ammonium as   
   >>> NH4-N > 61 ppm - Phosphate > 90 ppm - soluble Iron and Manganese   
   >>> (not permanganate) are present at elevated levels, but not   
   >>> toxically high   
   >>>   
   >>> Need at least a factor of 10 reduction in Potassium, "Ammonium",   
   >>> and Phosphate   
   >>   
   >> Why?   
   >   
   > The crops being grown, suffer if those contaminants are that high.   
      
   But these "contaminants" are actually recognised NPK fertilisers!   
   You might need to add a bit of KNO3 and H2SO4 to balance out the ammonia   
   and keep the pH right but that should be moron grade chemistry.   
      
   Trace magnesium may also need to be added.   
      
   > I suspect also that the fertilizers being applied "by prescription"   
   > also carry these as cations. So they'd have to get a water analysis a   
   > lot more often...   
      
   That should be possible with test papers to the level needed.   
   >   
   >> Wouldn't it be simpler to reuse the irrigation water by cutting it   
   >> with fresh water   
   >   
   > No.  There *is* no fresh water, since we divert ever more water to   
   > "drinking" in cities, leaving the only water source ever deeper water   
   > wells.  Liberating ever more heavy metals, and contaminants we had   
   > thought had left the biosphere.   
   >   
   >> at the appropriate rate and at the same time cut back on the   
   >> application of artificial NPK fertilisers to the land.   
   >   
   > Makes sense, but these guys are not chemists, in general.  They are   
   > businessmen, and tend to like simple scrape-house-grow operations...   
   > operations that have low cost employees, lowest possible overhead,   
   > and stable product.   
      
   So what you are saying is they are happy to pollute their outflow water   
   to a point where they cannot reuse it in order to cut labour costs?   
      
   They deserve what they get in that case.   
      
   >>> Will electro-deionization remove some of this?   
   >>>   
   >>> Water re-use is a big deal.   
   >>>   
   >>> Would this "large fishing net" be of any interest to chemists?   
   >>>   
   >>> Where would someone go with a water chemistry problem, for   
   >>> solutions?   
   >>   
   >> I doubt that you can do anything cost effective against NPK.   
   >   
   > But if there were such a system, or a trainable approach, it might be   
   > a selling point.  A few more acres required, and additional power,   
   > with reduced chemical purchases.   
      
   Fast growing reed beds are about as good as anything but it is unclear   
   if they are suited to what are presumably desert conditions.   
   >   
   >> There might be some tricks to chelate out iron and manganese based   
   >> on the relative insolubility of Ferric oxide and Manganese   
   >> Dioxide.   
   >   
   > Ozonation (or even aeration) and filtration, takes care of those, and   
   > those in turn pull out other (unmentioned) heavy metals too.  That is   
   > the easy part.   
      
   May well be good enough if you could persuade them to actually pay   
   attention to how much NPK they actually need for optimum cropping.   
      
   https://en.wikipedia.org/wiki/Liebig%27s_law_of_the_minimum   
      
   Might be worth drawing to their attention. Minimum inputs famring aided   
   by GPS to apply the right amount of the right nutrients to soils is the   
   new way of doing things. Excess NPK in waste water is lost profit.   
      
   More so if you cannot reuse the water for irrigation as a result.   
      
   > Did not want to consider ion exchange, since I am sure chloride and   
   > sodium ions are also concentrated.  Besides those media don't like   
   > ozone, or biogrowth either.   
      
   Clay soils might be able to do something useful for you though.   
      
   --   
   Regards,   
   Martin Brown   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)