Ponds, Lagoons, and Wetlands for Wastewater Management by Matthew E. Verbyla

Author:Matthew E. Verbyla
Language: eng
Format: epub
Publisher: Momentum Press
Published: 2017-07-08T16:00:00+00:00

4.6.1 REMOVAL OF PATHOGENS AND FECAL INDICATOR ORGANISMS

There are hundreds of different types of human pathogens in wastewater, including viruses, bacteria, protozoa, and helminths. Different types of pathogens are removed at different rates (Table 4.4). Pathogen removal goals in pond systems will depend on the type of permit issued for the wastewater treatment plant, on the method of discharge or reuse of the treated wastewater, and on the local health concerns in the region (Verbyla et al., 2015). In many tropical regions and developing countries, helminth diseases (e.g., soil-transmitted helminthiasis, foodborne trematodiases, cysticercosis, schistosomiasis) are both widespread and neglected (Hotez et al., 2008). In other regions (particularly nontropical regions), viral diseases or bacterial infections may be more important. Refer to the Global Water Pathogens Project publications (www.waterpathogens.org) for more information about pathogens in wastewater.

Fecal indicator bacteria are the most commonly used measure of the microbial quality of treated wastewater. The removal of fecal indicator bacteria in maturation ponds is characterized by an equation based on the dispersed flow model (von Sperling, 2005, 2003, 2002, 1999) (Table 3.2, Equations 3.6 and 3.7). For this approach to be used in design, the dispersion number (δ) is assumed to be equal to the (unitless) ratio between the pond width and the pond length (i.e., δ = width/length). However, instead of using Equation 3.8, von Sperling recommends calculating the pseudo-first-order reaction rate (k) with the following equation

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.