There is an urgent need for the availability of clean water in the developing world, as well as to provide drinking water after a natural disaster. The main city of Port-au-Prince in Haiti was struck by a 7.0 magnitude earthquake this past January 12, 2010 at 4:53 pm local time. The death toll has risen to over 200,000 people, and the over 1 million survivors are in need of essential services including drinking water. Earthquakes can have severe detrimental effects on the quality of drinking water from several sources. Unusual pollutants are expected to appear in the water due to the extreme conditions that influence the flow of water when urban settings are hit by a devastating earthquake. This RAPID proposal has two important objectives: (i) To determine how earthquakes impact water quality and accessibility, especially in urban settings; and (ii) To test the effectiveness of the cactus mucilage in cleaning polluted water. Cactus mucilage is a natural flocculant that has been proven to remove contaminants such as particulates, heavy metals and bacteria from water.
The results from the proposed work will provide information on water quality and detrimental changes on this valuable resource due to natural events such as an earthquake in an urban setting. Also the required amount of cactus mucilage to provide clean drinking water in terms of gallons of water per family per period of time will be determined. In addition, important information will be obtained to establish how cactus mucilage treatments compare to current relief methods for providing drinking water to the affected population.
It is expected that this project will objectively assess if cactus mucilage is a possible long-term solution to provide clean drinking water in such events. The research team will coordinate with regional and international relief agencies, so that surveys, sampling and monitoring is not reduplicated. It is expected that our research will serve as part of a global framework to assess water quality in regions affected by earthquakes and other natural disasters (i.e., floods, volcano eruptions, etc.), and a path for sharing ideas and data on tests performed with the cactus mucilage.
This award is co-funded by the NSF Office of International Science and Engineering (OISE).
Summary: The need for safe drinking water becomes a priority following major natural and anthropogenic events such a hurricanes or Earthquakes. This project’s major outcomes were the following. First, we studied the quality of ground water after the January 12, 2010 major earthquake in Port-au-Prince (PauP), Haiti. Second, we evaluated how an extract from a cactus plant (i.e., cactus mucilage) could be implemented to improve the quality of ground and surface water in PauP. Third, we determined the optimal parameters at which cactus mucilage was able to remove common contaminants including sediments, bacteria, and heavy metals from Haitian water. Our visit to Haiti: Mr. Dominique Maison from the World Health Organization (WHO) helped us to organize our visit to Haiti in August of 2010. We were hosted by Ms. Julie Longpré. Ms. Longpre is an Engineer working for "Développement Durable et Santé Environnementale", which is part of the Pan American Health Organization. She was able to connect us with Ms. Cynthia Batista from CAMEP (Centrale Autonome Métropolitaine d'Eau Potable), and Mr. P. Y. Rochat from DINEPA (National Directorate for Water Supply and Sanitation in the Ministry of Public Works). Both of them work at local governmental organizations in Haiti dedicated to supervise the quality and provide water to the region. Results: During our visit to Haiti, seven months after the occurrence of the earthquake, we were able to witness the reminiscence of the catastrophic impact that such event had on the local life (Figure 1). We collected samples of tap water (as distributed from treatment centers), well water (from two boreholes), surface water (as it has been stored for consumption in refugee camps), and transported water (water distributed in tanker trucks) from 10 different locations in PauP. The samples were transported to the "Nanochemistry and Green Engineering laboratory" at the University of South Florida for further analysis. Turbidity, total suspended solids, total coliforms, biochemical oxygen demand, conductivity, pH, and trace metals were analyzed to establish the water quality and type of contamination. Fifty percent of the evaluated samples had positive presence of E. coli bacteria and coliforms (Figure 2). A positive test turns the solution green as shown in Figure 2’s flasks (i.e., sample ID: A, D, E, F, G). This Figure also shows the location and sample description of the different urban regions of PauP, where water samples were collected. Detailed analysis of metal presence by our lab showed concentrations of lead, iron, boron, barium, and selenium above the maximum contaminate level and provisional guidelines recommended by US-EPA. Samples from the top of water columns treated with the mucilage revealed that high metal removal rates of barium, boron, iron, selenium and lead ranging between 80 and 100% were achieved using both mucilage extracts (i.e., non-gelling, NE, and gelling extracts, GE). Cactus mucilage was able to remove such metals at optimal concentrations of 10 mg/L. Conclusions: Sediments in water samples were separated using the cactus mucilage extracts. Settling rates were compared to the efficiency of a commercial flocculant (alum) usually used in water treatment plants. In addition, simple batch experiments were performed with the mucilage in natural and spiked samples. Both mucilage extracts (GE and NE) were able to decrease the concentration of the elements mentioned above to levels accepted by regulatory agencies. The extraction of cactus mucilage is simple and affordable. Further, cactus mucilage has the potential to be implemented to remove contaminants from water in emergency events. This award supported both undergraduate and graduate students, and postdoctoral trainees. Two papers have been published and one more is under review. Fifteen presentations both oral and poster at numerous International, National, and Regional meetings have resulted from the work funded under this grant.
