Removal of nitrogen from wastewater of date processing industries using a Saudi Arabian mesophilic bacterium, Stenotrophomonas maltophilia Al-Dhabi-17 in sequencing batch reactor.

The main aim of the present study was to assess the technical feasibility of nutrients removal from the wastewater from the date processing industries in sequencing batch reactor. Heterotrophic nitrifying and aerobic denitrifying bacteria were isolated from the soil sediment samples. The bacterial strain Al-Dhabi-17 effectively removed nutrients than other isolates from the wastewater and characterized as Stenotrophomonas maltophilia Al-Dhabi-17. The nutrient removal efficacy was improved by optimizing process parameters. Removal of NH from the medium reached 42% within 60 h of cultivation and the nitrification rate was 111 ± 3.1 mg after 24 h. After 96 h, NO reached 6 ± 0.4 mg/mL concentration. The strain S. maltophilia Al-Dhabi-17 showed the ability to utilize NH ranged between 100 and 300 mg/L. The supplemented sucrose, glucose and date molasses reached maximum nitrification process after 72 h (p < 0.05). Reduction of NH -N reached 73.4% within 48 h time in the medium supplemented with date molasses. Nutrient removal was observed in the broad pH range (6.0-8.5) and maximum nutrient removal achieved at alkaline range (p < 0.05). Sequencing batch reactor was fed with wastewater and nutrient removal was analyzed under optimized condition. The associated chemical oxygen demand, phosphate and total nitrogen removal efficiencies for the suspended growth sequencing batch reactor were 96.5%, 97.9% and 88.4%, respectively. The sequencing batch reactor inoculated with S. maltophilia Al-Dhabi-17 showed promising for nitrogen removal.