Wastewater Treatment Performance of Rotating Perforated Tubes Biofilm Reactor with Liquid Phase Aeration

A novel biofilm reactor named as `rotating perforated tubes biofilm reactor' was used for treatment of synthetic wastewaterwith and without liquid phase aeration. Effects of major processvariables such as feed wastewater flow rate, COD concentration and loading rate, liquid phase aeration on the rate and extent ofCOD removal were investigated. Liquid phase aeration was provento be advantageous especially for high strength wastewaters at highCOD loading rates. Kinetics of COD removal was investigated andkinetic constants were determined by using the experimental data.An empirical design equation was developed to quantify the system's performance as a function of major process variables.     

Nutrient Removal in a Three-Step Sequencing Batch Reactor with Different Carbon Sources

A three-step sequencing batch reactor was used for nutrient (COD, NH₄-PO₄-P) removal from synthetic wastewater by using different carbon sources. The operation consisted of anaerobic, anoxic and oxic (An/Ax/Ox) phases with durations of 2/1/4.5 h. Different carbohydrates, glucose, lactose, sucrose, maltose and a mixture of glucose/maltose (50/50), were used as the sole carbon source in the first phase of experiments. Sludge age was kept constant at 10 days. Glucose was found to be the most suitable carbohydrate source with percent COD, NH₄-N and PO₄-P removals of 96%, 99% and 94%, respectively. Nutrient removals obtained with sucrose as the sole carbon source were close to those obtained with glucose. A mixture of glucose and organic acids (50/50) such as acetic, citric, propionic and butyric acid were used as carbon source in the second phase of the experiments. Maximum percent COD, NH₄-N and PO₄-P removals were 93%, 97% and 96%, respectively when a mixture of glucose and acetic acid (50/50) was used. Glucose-citric acid (50/50) combination also resulted in comparable nutrient removals.