Nitrogen removal from wastewater using a hybrid membrane-biofilm process: pilot-scale studies.

The hybrid membrane biofilm process (HMBP) is a new approach to achieving total nitrogen removal from wastewater. Air-filled, hollow-fiber membranes are placed into an activated sludge basin and bulk aeration is suppressed. A nitrifying biofilm develops on the membranes, exporting nitrate and nitrite to the bulk liquid.

Detection of Cryptosporidium parvum in secondary effluents using a most probable number-polymerase chain reaction assay.

Polymerase chain reaction (PCR) was used to detect Cryptosporidium parvum oocysts in secondary effluent samples collected from activated-sludge facilities. Serial dilutions of the purified nucleic acid extracts from the samples were made and PCR was conducted to estimate the C. parvum oocyst concentration via a Poisson distribution-based most probable number (MPN).