Because cisterns are exposed to the environment via their direct attachment to catchment surfaces, cistern water quality is often poor. In the U.S. Virgin Islands cisterns are involved in supplying the water needs for private homes, hotels, businesses and public housing, making them subject to the mandates of the Federal Safe Drinking Water Act. This study compares the results of the occurrence of various water quality indicators in Private Residential, Public Housing, and Hotels and Guest House cisterns in the U.S. Virgin Islands in a side-by-side analysis. Forty-seven separate independent variables were created and tested for correlation, of which only the rate at which chlorination was applied was significant. A high degree of correlation was found to exist between total and fecal coliforms. A moderate, but still significant correlation between the coliform and the heterotrophic levels in the cistern was also noted. There was no correlation between any of the bacterial indicators studied and the opportunistic pathogen Pseudomonas aeruginosa. The results show, depending upon on the type and amount of chlorination received, different bacterial indicators will predominate and that there is a logical succession from one to the next with chlorination. On the unchlorinated end of the scale, normally associated with privateresidential homes, there is a correlation between the heterotrophic bacteria and total coliform. On the other end where chlorination is constant, normally associated with public water supply systems, correlation is between total coliform and fecal coliform. The proportion at which these indicators occur is a function of the diligence at which chlorination takes place. Regression analysis showed that the heterotrophs and total coliforms were the most sensitive to chlorination while the streptococci and fecal coliform were the most resistant. Thus, what is seen is fecal coliform unmasking based upon chlorination pattern. Depending upon whether the cistern is a private or public water supply which is mandated to be treated, an appropriate indicator system based upon the likelihood of treatment can be suggested. For unchlorinated private residential home cisterns the prime indicator should be the heterotrophic plate count and for chlorinated systems the take-action organism should be the fecal coliform. P. aeruginosa should be tested for in both domestic cistern water supplies and public cistern water supply systems.

This project is primarily focused on improving the storage stability of bio-oils or pyrolysis oils by varying feedstock, reactor, and storage conditions. Pyrolysis oil is a complex medley of oxygenated chemicals (aliphatic and aromatic) that are well known to undergo unstable polymeric reactions (auto-catalyzed) if suitable additives are not utilized. These reactions can be severely detrimental to the long-term storage stability of pyrolysis oils. Hence, a detailed investigation was conducted in four phases namely: 1) pyrolysis oil production 2) additive prescreening 3) concentration optimization and 4) stability testing. During the first phase a lab-scale semi-continuous auger reactor is utilized to produce 16 pyrolysis oils. The reactor variables include pyrolysis temperature and vapor residence time. The feed stocks include pine wood, pine bark, oak wood, and oak bark. During the second phase a range of chemical additives (26) are prescreened to obtain three best performing additives. Anisole, glycerol, and methanol are consequently utilized to perform concentration optimization studies during the third phase. Viscosity, water content, and pH of pyrolysis oils are timely measured to assess the accelerated storage stability of pyrolysis oils during the phases 2-3. During the fourth phase, pyrolysis oils produced from three different reactor systems (lab-scale auger, large-scale auger, and entrained flow) were tested for their storage stability. Viscosity, water content, pH, density, and acid value are timely measured to assess the ambient and accelerated storage stability of pyrolysis oils during phase 4. Extrinsic variables such as light and filtration are utilized during the experimental testing of phase 4. The rheological data (Newtonian/non-Newtonian) enhanced the understanding of pyrolysis oil storage stability both qualitatively and quantitatively. The stability performance of a chemical additive is very much dependent on the concentration and its organic functional group. Consequently, alcohols fared above all the other functional groups in stabilizing the pyrolysis oils. Glycerol is observed to have special blending and homogenizing properties compared to all other additives. Feedstock seems to be the single most important factor affecting storage stability of pyrolysis oils. Consequently, pine wood resulted in the most stable pyrolysis oil whereas pine bark resulted in the least stable pyrolysis oil.