Wastewater Microbiology

Removal of Pathogens by Membrane Bioreactors: A Review of the Mechanisms, Influencing Factors and Reduction in Chemical Disinfectant Dosing

“…Protozoa are single-cell organisms that are important to public health because they cause life threatening diseases including giardiasis, cryptosporidiosis, dysentery and amoebic meningoencephalitis [20]. Protozoan parasites are numerous in wastewater, including Cryptosporidium, Giardia, Entamoeba and Microsporidia.…”

“…Enteroviruses, the most commonly detected viruses in wastewater, can cause paralysis, meningitis, respiratory disease, encephalitis and congenital heart anomalies, along with a range of other conditions with varying severity [19,23]. Other human viruses in wastewater include coxsackie A and B, reovirus, norovirus, rotavirus, hepatitis A and E, adenovirus, echovirus and poliovirus, which can potentially cause upper respiratory and gastrointestinal illness [3,20]. Gastroenteritis is the most common wastewater related illness and can be caused by bacteria, virus or protozoa [20,24].…”

“…Other human viruses in wastewater include coxsackie A and B, reovirus, norovirus, rotavirus, hepatitis A and E, adenovirus, echovirus and poliovirus, which can potentially cause upper respiratory and gastrointestinal illness [3,20]. Gastroenteritis is the most common wastewater related illness and can be caused by bacteria, virus or protozoa [20,24]. The leading viruses responsible for gastroenteritis are rotavirus, calicivirus, enteric adenovirus and astrovirus [24].…”

“…The size of different viruses ranges within a few tens of nm. For example, nominal size of hepatitis A, hepatitis E, calicivirus and astrovirus has been reported to be around 30 nm, while the nominal size of rotavirus and enteric adenovirus can be around 70 nm [20,24].…”

“…Protozoan cysts or oocysts range in size from 3 to 14 μm, which is significantly larger than the pore size of an MF or UF membrane, so total removal of protozoa is expected [20,37]. Due to the nominal pore size of the MF or UF membranes used and the size of the coliform bacteria, size exclusion by membrane is considered the dominant mechanism for also the removal of coliforms by intact membranes.…”