WERF Report 03-HHE-2
Available as an ebook
Please purchase via www.iwaponline.comOpens in new window
Also part of Water Intelligence Online Digital Reference Library
Standard ePrice: £29.00
+ VAT
Available as an ebook
Please purchase via www.iwaponline.comOpens in new window
Also part of Water Intelligence Online Digital Reference Library
Standard ePrice: £29.00
+ VAT
Direct analysis of potable water for pathogenic micro-organisms has generally been avoided by water suppliers because pathogens are frequently present intermittently and in low numbers. Direct analysis for pathogens would require concentration of large sample volumes and more complex analytical procedures both of which are expensive and currently considered not to be more protective of public health than using appropriate pathogen index organisms or surrogates. Human feces contain about 1012 bacteria per gram, hence Escherichia coli is always present in high numbers in domestic wastewater (around 109 cfu/g) and can be detected relatively cheaply by culture methods. Hence, E. coli has become the chosen indicator for fecal pollution of water. While E. coli is a valuable warning indicator in potable water supplies, its value in domestic wastewater and biosolids applications is reduced because the source water and sludge is always fecally polluted. Instead, an indicator more clearly linked to pathogen presence, an index organism, is required. An index organism is defined as a group or species indicative of pathogen presence, such as E. coli as an index organism for Salmonella. An approach is to find indicators which are removed or inactivated similarly to pathogens by wastewater and biosolids treatment processes. Such process indicators, called model organisms or surrogates, are defined as a group of organisms that demonstrate the efficacy of a process). When coupled with data collected over time on the numbers of pathogens in the matrix prior to treatment, can indicate the risk attached to using treated water. As climate change continues to place stress on water resources, communities are increasingly looking to recycled water as a supplementary water source. Hence identification of process indicators for recycled water is becoming imperative so that recycled water can be used appropriately so as to minimize risks. As pathogen reduction in primary and secondary wastewater treatment processes is not as great as in tertiary and disinfection treatment processes, the latter treatment processes have been the focus of this study. Similarly, as disposal of biosolids to landfill sites becomes increasing costly and inorganic fertilizer feedstocks decline, the beneficial use of biosolids is becoming more important. Identification of process indicators for biosolids will encourage these beneficial uses as the risk to human health can be better assessed.
Online Only
Molecular techniques are emerging as a rapid and powerful approach for microorganism detection. This project reviewed the efficacy of PCR assays for Cryptosporidium, Microcystis, adenovirus and...
Direct potable reuse (DPR) is the planned introduction of recycled water either directly into a public water system or into a raw water supply immediately upstream of a water treatment plant. DPR...
The Gulf Coast hurricanes of 2005 and horrific events of 9/11/2001 have spawned a new emphasis on domestic security and emergency preparedness. Governments at all levels are taking action to...
There is a tremendous amount of literature on and experience with wastewater disinfection alternative. However, it is difficult for wastewater professionals to sift...
Ten years into the 21st Century, municipal and county leaders are facing significant water challenges, including: high water use rates, population growth, aging infrastructure, and the impact of...
Government agencies and water utilities have mechanisms in place for managing a range of emergencies and disasters such as earthquakes, hurricanes, disease epidemics, and...
These case studies focus on the CH4 emissions from wastewater treatment in photosynthetic oxidation ponds and facultative sludge lagoons. These area-intensive processes are for cryophilic-to-...
The book provides a scientific approach into appraising Intermittent Water Supply (IWS) on a global scale through the analysis of available information and data based on a structured methodology...
Available as eBook only
This document seeks to collect into one place current and new technologies about, or related to, sewerage system design so that wastewater...