With the departure of all but two team members, this blog has suffered some severe abandonment.
The project, however, has successfully passed from stage one (water sampling, NGO visits) to stage two (lab testing) where the bear filter surprised us all with excellent results.
It started when, due to a problem with the membrane filtration device, we were forced to switch to simple Whatman filters, but found that this did not compromise the effectiveness of the process.
Next, we went about running a sample with the configuration that was found to be optimal during the Berkeley testing: The original concentration of 500-1000 ppb was brou ght down to the WHO standard of 0-10ppb according to the rough quicktest measures that we were able to perform. More and more boldly, we increased the flow rate from 9 to 18 liters per hour – corresponding to a significant increase both in the possible output and in the total quantity of water that can be purified with one BEAR sushi*.
These settings still proved sufficient, contrary to the tests perfomed in Berkeley – a welcome surprise, possibly thanks to the higher iron content in the Cambodian ground water.
Next, we retested the impact of the mixing step, one part of the process that we haven't developed a field prototype for. Using the magnetic stirrer of the RDI laboratory, we tested the reduction at 0, 10, 20, 30, 45 and 60 min utes of stirring – time in which the Arsenic ions are brought into contact with rust particles so they (now part of a bigger structure) can be filtered out later. And again, the results surprised: Even with zero seconds of mixing time, the Arsenic was almost completely removed.
The change in color on the small Quick test strips was impressive. Hopefully, the more accurate ICPMS measures that will be conducted by a specialized lab in the US will confirm our promising findings!
The project, however, has successfully passed from stage one (water sampling, NGO visits) to stage two (lab testing) where the bear filter surprised us all with excellent results.It started when, due to a problem with the membrane filtration device, we were forced to switch to simple Whatman filters, but found that this did not compromise the effectiveness of the process.
Next, we went about These settings still proved sufficient, contrary to the tests perfomed in Berkeley – a welcome surprise, possibly thanks to the higher iron
Next, we retested the impact of the mixing step, one part of the process that we haven't developed a field prototype for. Using the magnetic stirrer of the RDI laboratory, we tested the reduction at 0, 10, 20, 30, 45 and 60 minThe change in color on the small Quick test strips was impressive. Hopefully, the more accurate ICPMS measures that will be conducted by a specialized lab in the US will confirm our promising findings!


