Removal of Nitrate from Contaminated Groundwater Using Solar Membrane Distillation

Abstract

Nitrate contamination is worldwide water pollution posing a major health hazard to human and animal life. Challenges are being faced to get fresh water for the areas having a low amount of usable water. This study aims to asses and evaluates the feasibility of removing nitrate from groundwater by using cheap approaches. A pilot-scale solar distillation membrane filter, was designed and constructed for this study, the set up was designed into two partitions: i) water heater and ii) membrane distillation. The effect of several operating parameters such as feed and distillate temperature, nitrate concentration, and pH, on water flux and nitrate removal efficiency, was investigated. The results showed that 85 and 93 percent removal efficiencies for nitrate and total dissolved solids, respectively. The effect of important parameters of solar performance membrane filter distillation (SPMFD) process including solar collector efficiency (í µí¼‚ í µí±), gained output ratio (GOR) and significant operating parameters containing feed and condensate temperature, feed nitrate concentration and pH were studied in this work and it could be concluded that water flux was increased exponentially with increasing feed temperature, and under the same operating conditions, average water flux changed from 9.52 to 34 kg/m2 per hour when temperature increased from 60 to 90 °C gradually. However, no significant effect was found by varying nitrate and TDS concentration and pH on water flux. It can be concluded that membrane distillation and solar desalination processes could be the efficient methodologies to exploit in the large nitrate-affected rural areas of Iraq and its surrounding with abundant sunlight, particularly during the critical dry season.