From: dlzc1@cox.net   
      
   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.  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...   
      
   > 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.   
      
   > > 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.   
      
   > 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.   
      
   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.   
      
   David A. Smith   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)