Page 83 - Materials Chemistry, Second Edition

78 4. Life cycle sustainability assessment: An ongoing journey

The authors conclude that a more resilient design can significantly reduce the environmen-
tal, economic, and social impacts in the use phase of the structure. Their proposed framework
could be used to compare alternative designs for informed decision making. According to the
authors, their proposed framework, even though successfully applied to the case study, has
the following limitations:
• Anticipated differences in reliability of data sources due to the use of several databases.
• Several assumptions made in predicting the extent of damage corresponding to each
damage state.
• Exclusion of nonstructural components and contents of the buildings from the assessment.
• Aging-induced impact factors were not considered.

4.4.5 Dimethyl sulfoxide solvent recovery from hazardous wastewater
An ethylene-vinyl alcohol copolymer (EVOH) based adsorbent developed by S-Metalltech
98 Ltd., Szentendre, Hungary is used to remove arsenic (As(III) and As(V)) from water.
The process of manufacturing the EVOH produces hazardous wastewater containing 20wt
% dimethyl sulfoxide (DMSO). The current manufacturing process (linear, open technology)
involves incineration of the wastewater including the DMSO. To minimize environmental
impact, a closed technology, which involves the recovery of DMSO using distillation and
incineration of about 2% wastewater has been developed. Zaja ´ros et al. (2018), applied LCSA
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on a functional unit of 1 m adsorbent to compare the sustainability of two scenarios:
• 98% DMSO recovery (DMSO_R).
• 98% DMSO recovery and usage as renewable resources (DMSO_R+PV).
The LCA results for the two scenarios were compared with the original data for DMSO
from databases. Their assessment was based on ISO 14040 standard using SimaPro 7.2 demo,
GaBi 4 programs, and Ecoinvent database.
The results of the LCSA (Fig. 4.13), reveals that the DMSO_R+PV reduces environmental,
social, and economic impacts. Specifically:
• the recovery and reuse (50% renewable energy) reduces the amount of water usage in
manufacturing process and the resultant hazardous wastewater production by 27% and
98%, respectively; and
• recovery by distillation produces DMSO of at least 95% purity.

The authors noted that LCSA can be used to identify sustainability of future development.

4.4.6 Fly ash substitutions for cement in concrete structures
Wang et al. (2017) used an LCSA model to assess the sustainability of fly ash (FA) concrete
(C50) structures with FA substitutions (0%, 20%, 30%, 40%, and 50%) for cement. The case
study was applied on a 9 20m prestressed concrete simply supported girder bridge. The
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system boundary and function unit were respectively “cradle to gate” and 1m FA concrete.
Life cycle impact data for concrete (such as cement and aggregates) were obtained from