Characterizing the fate and transport of Chemicals of Emerging Concerns (CECs) from integrated bioenergy and manure management system

Animal manure and human wastewater contains Chemicals of Emerging Concerns (CECs) that potentially cause undesirable ecological or health effects. For instance, estrogenic hormones such as 17β - estradiol (E2) can have adverse effects on the reproductive biology of vertebrates at low concentration range (10-100 ng/L) (Irwin et at., 2001; Routledge et al., 1998; Schuh et ai, 2011). Antibiotics resistant bacteria that cause life threatening infections can be developed from exposure to low level of antibiotics because 30 - 90% of drugs are excreted unaltered state in urine and feces (Wise et al., 1998; Sarmah et al., 2006; Berge et al., 2006). Another important aspect of the manure management is to reduce the sustainability concerns and increase the application of waste to energy process by enhancing renewable energy production. The Liquid Portion of Animal Manure (LPAM) was produced using 0.45 pm filter from swine manure slurry that contains many bioactive compounds because livestock manure is typically more concentrated with less treatment than human waste. A mixed algal bacterial bioreactor was operated to extract CECs from the LP AM with increasing organic loading rates (190.5 to 571.4 mg sCOD/Ud), and biomass was harvested for biofuel feedstock. Hydrothermal liquefaction (HTL) and catalytic hydrothermal gasification (CHG) were performed with 8 different conditions (Tempt: 200 - 350 °C; Time: 30 - 60 min) to determine the optimal conditions for renewable energy production and their effects on the fate of bioactive CECs. Assay Design ELISA tests and GC/MS analysis were used to measure concentrations of the CECs (17β - estradiol) pre-and post-algal bioreactor and hydrothermal conversion processes. The goal of research is to investigate a novel treatment system, using the combination of the thermochemical waste to energy processes with the algal treatment, can synergistically extract CECs from manure and convert them into valuable bioenergy. The concentration of sCOD and E2 in the LPAM were 3937 mg/L and 132 - 165 ng/L. The biomass productivity of mixed algal bioreactor was 819mg/Ud under 517 mg sCOD/Ud loading rate, and influent sCOD and TN (3937 mg/L; 1540 mg/L) were decreased to 720 mg/L and 430 mg/L. The optimal operating conditions of HTL for bioenergy and CECs removal was 300 °C and 60 min. This research will contribute to develop a cost-effective system to reduce water pollution and increase bioenergy production opportunities for reuse of the aqueous fraction of manure. The main approach of this research is to develop and analyze a novel and cost-effective manure management system that can simultaneously produce bioenergy and remove emerging contaminants. These following list identifies the specific objectives designed to achieve this goal: 1) Develop and apply analytical methods to characterize the liquid portion of animal manure (LPAM) and the impacts of bioactive chemicals of emerging concern (CECs) in the LPAM. Develop a fluctuation test to measure antibiotic resistance in bacterial populations exposed to antibiotics in wastewater and eliminates false negatives. 2) Demonstrate the ability to extract and concentrate CECs and other organics from LPAM to create a feedstock for bioenergy production. 3) Survey a range of reaction temperatures and reaction times for the determination of suitable conditions for providing both removal of bioactive CECs and bio-energy production via hydrothermal conversion processes. Develop a method to analyze antibiotics and their breakdown products in LPAM and the HTL aqueous phase. 4) Integrate the process.