Damage to the inferior and fragile water and sanitation infrastructure of Haiti after Hurricane Matthew has created an urgent public health emergency in terms of likelihood of cholera occurring in the human population. Using satellite-derived data on precipitation, gridded air temperature, and hurricane path and with information on water and sanitation (WASH) infrastructure, we tracked changing environmental conditions conducive for growth of pathogenic vibrios. Based on these data, we predicted and validated the likelihood of cholera cases occurring past hurricane. The risk of cholera in the southwestern part of Haiti remained relatively high since November 2016 to the present. Findings of this study provide a contemporary process for monitoring ground conditions that can guide public health intervention to control cholera in human population by providing access to vaccines, safe WASH facilities. Assuming current social and behavioral patterns remain constant, it is recommended that WASH infrastructure should be improved and considered a priority especially before 2017 rainy season.

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This study focuses on developing and demonstrating feasibility of an integrated chemical precipitation and membrane filtration method for recovering phosphorus (P) and ammonia (NH 3 -N) in two separate streams from anaerobic digestate generated from municipal wastewater. Nutrient recovery from waste streams creates alternative raw material sources of fertilizers and offers opportunities for reduced energy usage and CO 2 emissions compared with their conventional production processes.Using both synthetic and real anaerobic digestates, the effects of ferrous dosage and precipitation pH on P recovery through vivianite precipitation was examined. Fe/P molar ratio 2.1 at circumneutral pH was found as an optimal condition for ~100% P recovery. The P-free digestate was further treated with polyelectrolyte-modified nanofiltration (NF) membranes to separate NH 3 -N and the organic constituents as a means of N recovery. The surface-modified membranes demonstrated ~2X NH 3 -N/ organic carbon selectivity versus commercial NF membranes. This integrated Fe-enabled chemical precipitation and membrane-based process demonstrates a unique approach to sustainably recover critical nutrients from wastewater.

This study explicated the functional activities of microorganisms and their interrelationships under four previously reported iron reducing conditions to identify critical factors that governed the performance of these novel iron-dosed anaerobic biological wastewater treatment processes. Various iron-reducing bacteria (FeRB) and sulfate reducing bacteria (SRB) were identified as the predominant species that concurrently facilitated organics oxidation and the main contributors to removal of organics. The high organic contents of wastewater provided sufficient electron donors for active growth of both FeRB and SRB. In addition to the organic content, Fe (III) and sulfate concentrations (expressed by Fe/S ratio) were found to play a significant role in regulating the microbial abundance and functional activities. Various fermentative bacteria contributed to this FeRB-SRB synergy by fermenting larger organic compounds to smaller compounds, which were subsequently used by FeRB and SRB. Feammox (ferric reduction coupled to ammonium oxidation) bacterium was identified in the bioreactor fed with wastewater containing ammonium. Organic substrate level was a critical factor that regulated the competitive relationship between heterotrophic FeRB and Feammox bacteria. There were evidences that suggested a synergistic relationship between FeRB and nitrogen-fixing bacteria (NFB), where ferric iron and organics concentrations both promoted microbial activities of FeRB and NFB. A concept model was developed to illustrate the identified functional interrelationships and their governing factors for further development of the iron-based wastewater treatment systems.