Page 211 - Materials Chemistry, Second Edition

192 Life Cycle Assessment of Wastewater Treatment

PNEC water is calculated from the available toxicity data, applying assessment
factors depending on the availability of long-term no observed effect concentration
(NOEC) values for species from three, two, or just one trophic level (assessment fac-
tors of 10, 50, and 100, respectively) or at least one short-term L(E)C from each of
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three trophic levels (fish, Daphnia, and algae) (assessment factor of 1000) (EC-TGD,
2003).
In Table 9.4, PEC, PNEC, and RQ values for the pharmaceutical compounds are
shown. PEC values were calculated from the highest concentrations measured in
anaerobically digested sludge from four WWTPs and in compost samples from a
composting plant where the digested sludge from the above-mentioned WWTP is
composted. Nine digested sludge samples were sampled from each WWTP and from
the composting plant. PNEC values were calculated from short-term L(E)C data
soil
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available in literature (Martín et al., 2012b), applying an assessment factor of 1000.
RQ values were higher than 1 for ibuprofen, 17α-ethinylestradiol, and 17β-estradiol.
Nevertheless, after sludge application to soils, RQ values were lower than 1, except
for 17β-estradiol in digested sludge–amended soils; therefore, no significant ecotoxi-
cological risk is expected to occur. The RQ for 17β-estradiol is still slightly higher
than 1 (RQ: 1.08) in digested sludge–amended soils, but this value corresponds to
the worst-case scenario. It was calculated from the highest concentration measured
in the digested sludge samples analyzed.

9.4 CONCLUSIONS AND FUTURE TRENDS
Several multiresidue methods have been reported for the determination of a wide
group of pharmaceuticals belonging to different therapeutic groups and with differ-
ent physico-chemical properties. Reported multiresidue methods allow the determi-
nation of up to 148 pharmaceuticals (Gago-Ferrero et al., 2015) by UAE and LC-MS/
MS or 119 pharmaceuticals (Peysson et al., 2013) by QuEChERS and LC-TOF-MS
determination. The most widely reported techniques for sample extraction are UAE,
PLE, and MAE, and afterward, clean-up by SPE using Oasis HLB cartridges is
commonly applied. Recently, QuEChERS (Bourdat-Deschamps et al., 2014; Peysson
et al., 2013) and MSPD (Li et al, 2016; Triñanes et al., 2016) have been applied to
the determination of pharmaceuticals in sewage sludge. In both methods, extrac-
tion and clean-up are carried out simultaneously, reducing analysis time. Analytical
determination is carried out by LC-MS/MS and to a lower extent, by GC-MS/MS
and HPLC-DAD-(Fl).
Future investigations should focus on the occurrence of metabolites, the stere-
oselective degradation of chiral pharmaceuticals, and pharmaceuticals with a high
sorption potential in treated sludge. More investigation is needed about the fate of
pharmaceuticals in different types of sludge and in sludge-amended soils. The main
drawbacks of the most commonly extraction techniques reported (UAE, PLE, and
MAE) are the need for a further clean-up step to remove interfering compounds and
the use of high-cost equipment (PLE and MAE). QuEChERS and MSPD are prom-
ising low-cost extraction techniques requiring low solvent volumes, which have been
reported for multiresidue extraction of up to 136 pharmaceuticals and hormonal ste-
roids (Peysson et al., 2013) and 45 pharmaceuticals (Li et al., 2016), respectively. The