Our Time at PCER

posted Jun 1, 2013, 1:54 PM by greg ewing

Today we arrived in Pocone after almost three weeks at PCER. During out time in the Pantanal we worked on Adrienne´s biodigester, our own telescoping biodigester and an assessment of solid waste generated at PCER and the Jaguar Ecological Reserve.

We began with Adrienne´s biodigester. Because it was dismantled after Adrienne´s team left PCER in 2010, we tried to reconstruct it to Adrienne´s specifications. Unfortunately one of the three PVC pipes was broken so we could only use two of them. We built supports using brick and cement to create a meter grade from one end to the other. We filled the biodigester 75% of the way with slurry (1 part cow manure, two parts water). We observed leaks at the bottom of the biodigester and one small one at the elbow. We allowed the leaks to clog themselves with sediment from the manure. We checked for gas production every day for six days using a pressure guage on one of the valves. After not observing any change in pressure in the biodigester, we decided to empty it and start over. We emptied the biodigester and reconstructed it this time without the elbow to minimize possible locations for leaks. After resealing the biodigester and letting the seals dry, we refilled the bidigester, this time filling it all the way to the valve. When we checked for pressure 24 hours after filling the biodigester. the guage read 3psi. We do not know if the guage is reading air pressure or water pressure inside the biodigester.

Testing the telescoping biodigester proved to be much less labor intensive. In order to install the valves and PVC pipes, we punctured holes in our buckets using a hot metal rod, which necessitated liberal sealing. We filled the upright bucket with enough slurry to cover the top of the inside bucket to ensure an anaerobic environment. Within 48 hours, the inside bucket had risen above the slurry line indicating gas in the biodigester. Due to pig traffic in the back porch of PCER, the gas escaped from the bucket when a pig ran into it. We took this opportunity to reseal the valves and holes in the bucket before refilling it with slurry. We put a brick on the inside bucket to make sure it stayed below the slurry line. Now we are waiting to confirm if it has produced gas.

While staying at PCER we also assessed the solid waste generated and the waste management systems in place at PCER and Jaguar Ecological Reserve. First, we observed several piles of trash located on the grounds of both facilities. These included a pit that was originally intended to be the septic tank for the house next to PCER, an approximately 25 foot deep well that is full with solid waste, and several smaller piles on the grounds of the Jaguar Ecological Reserve. The types of solid waste that was most prevalent in these piles were plastic bottles, aluminum cans, cardboard, organic waste, ceramics, and palm fronds. We performed a quantifying assessment of the trash in the well by measuring the volumes of each type of trash in a 17.3 feet cubed sample, finding that about 30% was plastic bottles and about 20% was paper/cardboard. Lastly, we talked to an employee at Jaguar Ecological Reserve named Leonardo and he told us that all solid waste except for some plastic bottles is burned in various pits on the grounds of Jaguar Ecological Reserve on frequencies of every other day during the dry season and once a week during the wet season. Leonardo also told us that plastic bottles can be recycled in Pocone for R$3 per kilo. This price makes it worth the Jaguar Ecological Reserve~s effort to bring the bottles to Pocone, but the 15 centavos per kilo of cardboard and 20-25 centavos per kilo of other plastics does not make it worth the Jaguar Ecological Reserve´s effort to recycle these materials.