Nutrient removal from municipal wastewater using moving bed biofilm reactor (MBBR)

Sammanfattning

Effective wastewater treatment is of utmost importance in order to safeguard marine life and ensure universal access to clean water and proper sanitation. There are many different conventional treatment methods, including activated sludge, biotrickling filters, rotating biological contactors, and fluidized bed reactors. More recently, biological treatment methods have gained a lot of traction for their simple setup and sustainability. Since its invention in the late 1980s, moving bed biofilm reactors (MBBR) have emerged as a competitive alternative to conventional treatment methods. In this report, the efficiency of MBBR is assessed for removal of organic matter and nutrients through a theoretical study based on previous research, and a practical investigation in a laboratory setting. An aerobic and anaerobic system were set up separately. Biocarriers were used throughout the treatment, and activated sludge was added for biofilm growth. Hach kits were used for analysis of total organic carbon (TOC), phosphate, nitrate, and ammonium levels in the wastewater. Two anaerobic bioreactors were used, one where the effluent from the aerobic treatment was added without dilution, and one where the effluent was diluted two times before. The full treatment, where the anaerobic treatment used the undiluted reactor, resulted in removals for ammonium, nitrate, total nitrogen (TN), phosphate, and TOC of 99.13%, 48.71%, 51.87%, 88%, and 73.44%, respectively. The full treatment, where the anaerobic treatment used the 2x diluted reactor, resulted in removals of 96.76%, 59.55%, 59.51%, and 53.27%, for ammonium, nitrate, TN, and TOC. Phosphate did however increase by 26.46%. Due to the simplicity of the experimental set-up, and the uncertainty of the results, further experiments are needed for drawing clear conclusions. An experiment conducted over a longer time, with more precise monitoring, will give more conclusive answers.