Wastewater

A comparative risk assessment of wastewater disposal methods in southeast Florida has only been performed once and it was over 20 years ago. Since then, methods has changed and research have been developed. This study follows the methods used in the 2000 study, and assesses the following disposal methods: ocean outfalls, deep injection wells, surface water discharge, reuse for non-potable applications, indirect potable reuse, and direct potable reuse. This assessment assembled a team of qualified experts to complete a modified delphi survey to assess the human risks of wastewater disposal methods. Using the delphi results in a Bayesian Assessment Model, this assessment found that deep injection well and direct potable reuse were the disposal methods with the least risk.

In this research, a multistage (i.e., three stages) planar, and a tubular passive permeateside-heated interfacial solar membrane distillation (ISMD) has been developed. The three-stage system had an system energy efficiency of 62% in producing distilled water at an average daytime irradiance of 422 W/m2 with average distillate flux of 5 kg/(m2·day), which is higher than that of the single-stage planar systems. Production rate of distilled water in each stage of the three-stage planar system per unit area of footprint was 3.3 kg/(m2·day), while the production rate per unit area of footprint of single-stage system was 1.6 kg/(m2·day). Also, a hydrophilic nanoporous (PES NF) membrane was used in our study, which has not been found in the research of conventional MD systems. No penetration of hydrophilic nanoporous membrane was found during the operation of single-stage planar systems under simulated sunlight. The membrane was able to produce distilled water for 114 days under simulated sunlight using municipal wastewater as feed water. On the other hand, hydrophobic (0.20 and 0.45 μm) PVDF membranes were penetrated by feed water (i.e., wastewater) after approximately 50 days.