Membrane and Desalination Technologies - TCE Moodle Website

164 N.K. Shammas and L.K. Wang
Fig. 4.1. Schematic of acceptable and unacceptable sample injection ports.
Once the concentration of the stock solution has been determined, the stock solution
delivery rate (SSDR) for the in-line injection method of seeding can be calculated using
Eq. (8):
SSDR ¼ CtestQp=CssR; (8Þ
where SSDR is the stock solution delivery rate, gpm; Ctest is the feed concentration of
challenge particulate, number or mass/volume; Qp is the filtrate flow, gpm; Css is the
challenge particulate concentration in the stock solution, number or mass/volume; and R is
the system recovery during test, decimal percent.
The SSDR represents the setting for the chemical feed pump used to inject the challenge
particulate into the feed stream.
4.9. Challenge Test Systems
A system used for challenge testing must be carefully designed to both meet the objectives
of the test and simulate full-scale operation to the greatest practical extent. Guidance for both
designing an appropriate test apparatus and determining operational parameters for challenge
testing is provided in the following subsections.
4.9.1. Test Apparatus
The equipment used to conduct challenge testing is product-specific to some extent,
although there are some basic components that are common to all systems. In many cases,