Environmental Engineering Reference
In-Depth Information
there is no safe nontoxic limit, and regulatory limits are assessed by cost/beneit analy-
sis. Treatment itself can create by-products that are just as harmful as the species being
removed.
16
Other species, such as endocrine disruptors, can be so well tailored to inter-
fere with biological processes that even tiny quantities can have effects at the population
level. This drives the relevant monitoring targets of the most harmful organic species
well below the ppb level, creating a monumental challenge for laboratory instruments
and a nearly insurmountable challenge for anyone trying to build an online instrument
or a ield test.
17
The ield is target rich. There is probably unlimited regulatory fodder among organic
species. Growing pesticide use, novel chlorination and chloramination by-products,
unusual by-products of industrial and municipal wastewater treatment, and waste prod-
ucts and by-products of industrial activity are all potential sources for highly bioactive
species.
18,19
Just as the Romans never understood the impact of their lead pipes and lead
pans on mental health, our chemistry-intensive society undoubtedly has created potent
biological threats that will go unrecognized far into the future, while lesser threats
receive attention simply because chance events or narrowly focused research reveals
them.
Most current examples of commercialized technology address higher-concentration spe-
cies, offering real-time solutions to what were once laboratory projects. Many also operate
in unclear solutions that would stymie traditional optics techniques.
OptiEnz, founded by a Colorado State University professor, is one of the irst companies
to try to commercialize iber optics luorescence sensors using enzymes overlaid on luo-
rescent material. Still a very early-stage company, it has projects ranging from measuring
lactose for milk processing to measuring benzene in aquifers near local shale gas fracking
sites. Sensitivity ranges down to around 1 ppb; however, the technology is lexible enough
to linearly measure lactose in milk at around 20%. This general technique of biological
molecules on iber optics, which has a wide history in the scientiic literature, is just now
edging its way into operational systems.
20
Israeli start-up High Check Control
21
can analyze a wide range of analytes in parallel
using high-resolution enhanced Raman enabled by advanced optics. With the instrument
behind glass, there is little risk of fouling.
In recent years, the so-called mass spec on a chip has emerged as a possible, unproven
tool for water analysis. Start-up Hydroconidence, for instance, plans to deploy miniatur-
ized mass spectrometers in an array around oil and gas wells to monitor aquifer quality.
22
The instruments could reassure local residents and provide ample evidence of a well's
safety even in the event an aquifer was compromised by surrounding activity.
10.7 Microbes and Viruses: A Challenge Current
Monitoring Does Not Address
Turbidity is a common substitute for microbial measurements in drinking water, since
both microbes and the particles they travel aboard show up in these measurements. Of
more speciic analysis, traditional cell counting methods take at least 24-72 h to generate
results. This is a very inconvenient gap: pharmaceutical processing, for instance, is gener-
ally inished before laboratory results,
23
causing entire batches of drugs to be thrown out
