Utilization of wastewater treated by membrane bioreactor (MBR) process in safflower cultivation and investigation of biodiesel production from safflower harvested

Increased water demand caused by population growth forced the reuse of wastewater after treatment. Safflower is a salinity tolerant plant that can be irrigated with moderate saline water. In this study, cultivation of safflower plant by irrigation with membrane bioreactor (MBR) treated wastewater, NF treated wastewater, mixture of RO treated waste water with MBR treated wastewater and tap water were investigated. Safflower seeds were further utilized in oil and then biodiesel production, and the quality of the obtained biodiesel were evaluated according to TS EN 14214 standards. Furthermore, the effect of using different types (gel and macroporous) of cation exchange and anion exchange resins in different ionic forms (H+ and Na+ and OH-) on transesterification of corn oil into fatty acid methyl esters (FAME) and free fatty acid (FFA) conversion were investigated. Also, Taguchi experimental design was used for the optimization of reaction conditions (catalyst amount, temperature, reaction time, molar oil / mol methanol ratio) using these heterogenous catalysis. MBR effluent was not found as appropriate water for irrigation because of its high salinity. According to the results of SAR-EC analyses, the mixture of MBR effluent with RO permeate at a volume ratio of 1:2 (MBR effluent:RO permeate) was found to be suitable for irrigation to suppress the harmful effects of MBR permeate such as salinity. Also the biodiesel produced from the oil extracted from seeds of safflower plants irrigated with MBR and RO mixture were of better quality in means of meeting biodiesel standards. When ion exchange resins (Purolite-PD206, Purolite-CT175 and Purolite A500TLPlus) in different ionic forms (H+, Na+ and OH-) were used as heterogeneous catalysts in the production of biodiesel, the highest ester content and FFA conversion were achieved in experiments using Purolite-A500TLPlus anion exchange resin.