Evaluation of the microbiological quality of reclaimed water produced from a lagooning system

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• 作者：X. Fernandez-Cassi ; C. Silvera…
• 刊名：Environmental Science and Pollution Research
• 出版年：2016
• 出版时间：August 2016
• 年：2016
• 卷：23
• 期：16
• 页码：16816-16833
• 全文大小：602 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment
  Environment
  Atmospheric Protection, Air Quality Control and Air Pollution
  Waste Water Technology, Water Pollution Control, Water Management and Aquatic Pollution
  Industrial Pollution Prevention
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1614-7499
• 卷排序：23

文摘

The use of lagooning as a complementary natural method of treating secondary effluents of wastewater treatment plants has been employed as an affordable and easy means of producing reclaimed water. However, using reclaimed water for some purposes, for example, for food irrigation, presents some risks if the effluents contain microbial pathogens. Classical bacterial indicators that are used to assess faecal contamination in water do not always properly indicate the presence of bacterial or viral pathogens. In the current study, the presence of faecal indicator bacteria (FIB), heterotrophic bacterial counts (HBC), pathogens and opportunistic pathogens, such as Legionella spp., Aeromonas spp., Arcobacter spp., free-living amoeba (FLA), several viral indicators (human adenovirus and polyomavirus JC) and viral pathogens (noroviruses and hepatitis E virus) were analysed for 1 year in inlet and outlet water to assess the removal efficiency of a lagooning system. We observed 2.58 (1.17–4.59) and 1.65 (0.15–3.14) log reductions in Escherichia coli (EC) and intestinal enterococci (IE), respectively, between the inlet and outlet samples. Genomic copies of the viruses were log reduced by 1.18 (0.24–2.93), 0.64 (0.12–1.97), 0.45 (0.04–2.54) and 0.72 (0.22–2.50) for human adenovirus (HAdV), JC polyomavirus (JCPyV) and human noroviruses (NoV GI and GII), respectively. No regrowth of opportunistic pathogens was observed within the system. FLA, detected in all samples, did not show a clear trend. The reduction of faecal pathogens was irregular with 6 out of 12 samples and 4 out of 12 samples exceeding the EC and IE values, specified in the Spanish legislation for reclaimed water (RD 1620/2007). This data evidences that there is a need for more studies to evaluate the removal mechanisms of lagooning systems in order to optimize pathogen reduction. Moreover, surveillance of water used to irrigate raw edible vegetables should be conducted to ensure the fulfilment of the microbial requirements for the production of safe reclaimed water.KeywordsLagooningBacterial removalVirus removalRegrowthReclaimed waterFaecal indicator bacteriaHuman adenovirus