title: Ensuring safe reuse of residential wastewater: reduction of microbes and genes using peat biofilter and batch chlorination in an on-site treatment system.
abstract: OBJECTIVE
  A batch chlorination system was optimized for on-site wastewater treatment and reuse system (OWRS) and its efficiency was evaluated for reducing viruses, protozoa, bacteria and antimicrobial resistance in cold and warm seasons.
  
  
  RESULTS
  The OWRS performance in reducing microbial contaminants was determined by assessing three different faecal indicators (Escherichia coli, F-specific coliphages and Clostridium perfringens for measuring the disinfection efficiency of bacteria, viruses and spore-formers and surrogate for protozoa, respectively) using culture-based methods. Quantitative PCR was used to quantify pathogenic bacteria (Shiga-toxin-producing E. coli (STEC), Campylobacter spp., and Arcobacter spp.), a human-associated faecal marker (gyrB), and tetracycline resistant bacteria (tetQ). The levels of E. coli, coliphages and Cl. perfringens showed 5·4, 2·3, 2·5 log reduction, respectively, upon disinfection. In the final effluents, coliphages (1·7 × 102PFU 100 ml-1) and Cl. perfringens (3·4 CFU 100 ml-1) were detected in 80 and 100% of the samples, but E. coli was not found. The removal and inactivation of E. coli and Cl. perfringens were not significantly different across the seasons, however, efficacy of removal and inactivation of F-specific coliphage was significantly reduced during the winter/spring season compared to the summer/autumn season (P = 0·009). The reduction of Arcobacter, gyrB and tetQ by 3·1, 2·3 and 2·3 log, respectively, was mostly due to peat biofiltration under the study conditions.
  
  
  CONCLUSIONS
  This study demonstrated that peat biofiltration was the most important step of the OWRS to remove microbes and genes from wastewater before spray irrigation of the effluents. The irrigation system is not suitable for edible crops because of the potential presence of residual pathogens.
  
  
  CONCLUSIONS
  On-site wastewater treatment systems are a practical option for reusing the wastewater for landscape, especially for those areas where geological and seasonal limitations impact the removal of microbial contaminants by soil infiltration.
authors: Division of Environmental Health Sciences, College of Public Health, Ohio State University, Columbus, OH, USA.
authors: E
authors: E
authors: Park
authors: Department of Food, Agricultural and Biological Engineering, Ohio State University, Columbus, OH, USA.
authors: K M
authors: KM
authors: Mancl
authors: Department of Microbiology, Ohio State University, Columbus, OH, USA.
authors: O H
authors: OH
authors: Tuovinen
authors: Division of Environmental Health Sciences, College of Public Health, Ohio State University, Columbus, OH, USA.
authors: M S
authors: MS
authors: Bisesi
authors: Division of Environmental Health Sciences, College of Public Health, Ohio State University, Columbus, OH, USA.|Department of Food Science and Technology, Ohio State University, Columbus, OH, USA.
authors: J
authors: J
authors: Lee
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D003016:Clostridium perfringens / Q000302:isolation & purification; D003090:Coliphages / Q000302:isolation & purification; D004203:Disinfection; D004926:Escherichia coli / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005798:Genes, Bacterial; D054879:Halogenation; D006801:Humans; D012621:Seasons; D012987:Soil; D013753:Tetracycline Resistance; D062065:Wastewater / Q000382:microbiology*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
chemical_list: D012987:Soil; D062065:Wastewater
keywords: 
  Arcobacter
  ; 
  Clostridium perfringens
  ; 
  Escherichia coli
  ; F-specific coliphages; Shiga-toxin-producing E. coli; antibiotic resistance; biofiltration; on-site wastewater treatment; reuse