Day 56: Kiensvay and Filter Alteration

Chanveasna and I at the Phase I filters

I spoke with Dr. Davin Uy about my suggestion, whose detail I will reveal upon my return. Simply, the filter has been having two issues. First, it cannot output more than 40 liters of water per day. Any volume more than that results in poor removal of arsenic. The SONO filter, which is similar to many arsenic filters, does better in these situations. Its design differs in that the sand is on the very top and the iron core, which replaces the iron nails, is below that. On the other hand, the Kanshan filter has the placement of sand and iron reversed. Thus, I suggested the following experiment:

First, have 3 conditions, A: pour water into Filter 1 without nails and pour the fluent into filter 2 with iron nails. B: pour water into Filter 3 with nails and pour the fluent into filter 4 with iron nails. C: pour water into filter 5 twice. D. pour water into filter 6 just once.

In this experiment, we will test the hypothesis that having the water run through the filter twice help reduce arsenic much more than just once. In addition, have the water run through two different filters should be no different from running it through the same filter twice. However and most importantly, having no iron nails should give rise to the similar performance as the previous conditions because the sand alone in the first filter should remove all the coating elements, namely PO4-, that prevents the nails from removing arsenic. One thing to keep in mind is that Fe in water helps remove nearly 60% of the arsenic while the nails only works to remove 30% of the arsenic claimed. While the collateral damage is that this initial filtration would also remove Fe2+ and Fe(OH)2, arsenic is already trapped here at the first stage along with Fe. The iron nails should work just well as before. The additional layer of sand provides additional assurance that nearly all of arsenic is removed and that the filter will not need to cleaned as often as previously thought.

Dr. Davin Uy and I
So I went to Dr. Davin Uy. He first thought that due to the initial removal of iron, the filter would lose half of its functionality. It was rather dramatic when I told him what exactly I had in mind. He thought it was a good idea and will not just the pilot and will instead go the whole way by building a filter I suggested with a sand-nail-sand design from scratch! The whole filter will probably cost nearly $100. He said it is no problem and he will keep me updated on these designs. As of now, the Kanshan needs something like this as it would need to be replaced every half year since it will not produce any less than 50 ppb after 6 months. I am so anxious for this and its results!