PRODUCTION OF DUNALIELLA SALINA AND SPIRULINA PLATENSISBY REUSING DESALINATION CONCENTRATE TO IMPROVESUTAINABILITY OF INLAND DESALINATION

摘要

In the past several years, the western United States has continued to face moderate to severedrought. Brackish water resources have a potential to augment the available potable sources ofwater. By 2025 it is expected that a significant portion of the world population living in arid areawill suffer from water shortage. One of the major problems with inland desalination is thedifficulty of disposing the reject brine (the concentrate). This has a major impact on the total costof the desalination. With current options for the disposal such as evaporation ponds and deepwell injection are not sustainable, hence; the objective of our research is to use desalinationconcentrate for microalgae production to sustain the inland desalination.Microalgae species Dunaliella salina and Spirulina platensis were cultured using the concentratestream from Brackish Groundwater National Desalination Research Facility (BGNDRF),Alamogordo, NM. Anaerobic Digested Sludge (ADS) were used in the same experiment in orderto study and compare the sludge as source of nutrients with the commonly used nutrient to growalgae. Two levels of conductivities of concentrate were used in our studies. The data indicatedlonger culturing times are required for D. salina and S. platensis to reach the maximal growthdue to the high conductivities (31,800 and 25,442 microS/cm for D. salina; 35,900 and 21,500microS/cm for S. platensis). However, the dried weights of both species using supernatant fromADS achieved from our studies are 1.49 g/L (D. salina) and 1.98 g/L (S. platensis) arecomparable to that of literature data (D. salina 1.06 g/L and S. platensis 0.8-2.99 g/L).It was found that both D. salina and S. platensis are feasible to be grown in desalinationconcentrate as water media and ADS as nutrient. The final finding from this research will bepresented to the conference.