title: Sanitising black water by auto-thermal aerobic digestion (ATAD) combined with ammonia treatment.
abstract: The effect of a two-step process on the concentration of pathogens and indicator microorganisms in black water (0.9-1% total solids) was studied. The treatment combined auto-thermal aerobic digestion (ATAD) and ammonia sanitisation. First, the temperature of the black water was increased through ATAD and when a targeted temperature was reached (33, 41 and 45.5 °C studied), urea was added to a 0.5% concentration (total ammonia nitrogen >2.9 g L⁻¹). Escherichia coli and Salmonella spp. were reduced to non-detectable levels within 3 days following urea addition at temperatures above 40 °C, whereas when urea was added at 33 °C E. coli was still present after 8 days. By adding urea at temperatures of 40 °C and above, a 5 log10 reduction in Enterococcus spp. and a 3 log10 reduction in Ascaris suum eggs was achieved 1 week after the addition. With combined ATAD and ammonia treatment using 0.5% ww urea added at an aerobic digestion temperature >40 °C, black water was sanitised regarding the pathogens studied in 2 weeks of total treatment time.
authors.affiliation: Department of Energy and Technology, Swedish University of Agricultural Sciences, P.O. Box 7032, 750 07 Uppsala, Sweden E-mail: Annika.c.nordin@slu.se.
authors.forename: Annika C
authors.initials: AC
authors.lastname: Nordin
authors.affiliation: Department of Energy and Technology, Swedish University of Agricultural Sciences, P.O. Box 7032, 750 07 Uppsala, Sweden E-mail: Annika.c.nordin@slu.se.
authors.forename: Björn
authors.initials: B
authors.lastname: Vinnerås
mesh_terms: D000332:Aerobiosis; D000641:Ammonia / Q000008:administration & dosage / Q000378:metabolism*; D000818:Animals; D017165:Ascaris suum / Q000187:drug effects / Q000502:physiology; D001435:Bacteriophages / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D016983:Enterococcus / Q000187:drug effects / Q000302:isolation & purification; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification; D005243:Feces / Q000737:chemistry / Q000382:microbiology; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D012475:Salmonella / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D014508:Urea / Q000008:administration & dosage / Q000737:chemistry; D014867:Water / Q000737:chemistry / Q000469:parasitology / Q000592:standards*; D014871:Water Microbiology; D018508:Water Purification / Q000295:instrumentation / Q000379:methods* / Q000592:standards
chemical_list: D014867:Water; D000641:Ammonia; D014508:Urea