Finally got around to a hap hazard test for desorbing sand with lanthanum. The sand has been churning around in my fluidised media reactor for a week on a tank currently measuring 0.6 ppm. From previous measurements in the Aragonite adsorption thread, Dan-P kindly calculated my sand had adsorbed approximately 20mg PO4, from results I had from testing in tank using 1.8 kgs of sand.
My mission here is to see if it’s feasible to re-use this sand cheaply, using lanthanum.
a) Firstly I quickly rinsed the sand in tapwater to remove detritus (there was actually very little).
b) then a very quick rinse in a little RODI.
c) put the sand (1.5 kgs) into RODI (4.5 litres) with a small power head for circulation.
d) added 5 ml of lanthanum according to Randy’s excerpt below.
e) waited 24hrs with occasional stirring.
f) added 3% ish Tropic Marin salt to the test sample so the Hanna would read correctly.
Now, unless I’ve calculated summit wrong with the lanthanum dosage,or done summit really daft, that should bind 23mg phos. My 1.5 kgs of sand is a little lower than the normal 1.8 kgs that I have used previously, so it would churn over better.
Testing the water results in a 0.2 to 0.25ppm concentration. Therefore I’ve concluded that all of the Lanthanum in the dose has been consumed already, so re-dosed.
Ive assumed lanthanum is ok to use in RODI.
My mission here is to see if it’s feasible to re-use this sand cheaply, using lanthanum.
a) Firstly I quickly rinsed the sand in tapwater to remove detritus (there was actually very little).
b) then a very quick rinse in a little RODI.
c) put the sand (1.5 kgs) into RODI (4.5 litres) with a small power head for circulation.
d) added 5 ml of lanthanum according to Randy’s excerpt below.
e) waited 24hrs with occasional stirring.
f) added 3% ish Tropic Marin salt to the test sample so the Hanna would read correctly.
Now, unless I’ve calculated summit wrong with the lanthanum dosage,or done summit really daft, that should bind 23mg phos. My 1.5 kgs of sand is a little lower than the normal 1.8 kgs that I have used previously, so it would churn over better.
Testing the water results in a 0.2 to 0.25ppm concentration. Therefore I’ve concluded that all of the Lanthanum in the dose has been consumed already, so re-dosed.
Ive assumed lanthanum is ok to use in RODI.