in unit of nitrogen equivalents, while freshwater eutrophication in
unit of phosphorus equivalents [39, 41].
Human toxicity, terrestrial, marine, and freshwater ecotoxicity
quantify the effect of pollutant emissions and distribution within
the system. The absorption of heavy metals from seawater during
biomass growth may result in improved water quality [58]. However, the analysis should consider the pollutant flows in the system
and identify potential reemissions. For example, production of
fertilizers from seaweed may move heavy metals from seawater to
agricultural field, modifying the potential exposure to humans and
animals [18].
6 Interpretation
The interpretation phase identifies significant issues or hotspots of
the system. The practitioner evaluates the completeness, sensitivity,
and consistency of the study. Here, he draws conclusions, exposes
the limitations, and provides recommendations for the readers.
Completeness is achieved when the conclusions satisfy the goal
and scope of the assessment. Interpretation is an iterative phase: if a
lack of data is observed, the practitioner might decide to either
improve the data collected or adapt the goal and scope to what is
practically achievable.
Uncertainty and sensitivity analyses help the practitioner to
evaluate how reliable the results and conclusions are [8]. The
uncertainty analysis should estimate the limits of the measurement
and provide a range of final results. The sensitivity analysis applies
variations to the input parameters to highlight which process will be
mostly affected. For example, a sensitivity analysis can consider
variations of input values by 10% increments varied from 50 to
150%. The key parameters can be transport distance, biomass moisture content, water reduction during drying phase, biomass yield,
biomass composition, and material lifetime [29].
7 Dealing with Allocation
The complex biological structure of seaweed allows the extraction
and use of different components. For example, seaweed can be
converted into bioethanol, fertilizer, and protein [18]. This process
requires a first pretreatment step, i.e., milling, to increase active
surface. Secondly the biomass is hydrolyzed and fermented in a
reactor. It follows a separation of the solid and liquid fraction. The
solid fraction is dried and used as high protein content ingredient
for fish feed. The liquid fraction is distilled to obtain bioethanol and
liquid fertilizer (Fig. 4). If the goal of the analysis is to evaluate the
impact of a single output, e.g., only bioethanol, the practitioner has
112
Michele Seghetta and Pietro Goglio
unit of phosphorus equivalents [39, 41].
Human toxicity, terrestrial, marine, and freshwater ecotoxicity
quantify the effect of pollutant emissions and distribution within
the system. The absorption of heavy metals from seawater during
biomass growth may result in improved water quality [58]. However, the analysis should consider the pollutant flows in the system
and identify potential reemissions. For example, production of
fertilizers from seaweed may move heavy metals from seawater to
agricultural field, modifying the potential exposure to humans and
animals [18].
6 Interpretation
The interpretation phase identifies significant issues or hotspots of
the system. The practitioner evaluates the completeness, sensitivity,
and consistency of the study. Here, he draws conclusions, exposes
the limitations, and provides recommendations for the readers.
Completeness is achieved when the conclusions satisfy the goal
and scope of the assessment. Interpretation is an iterative phase: if a
lack of data is observed, the practitioner might decide to either
improve the data collected or adapt the goal and scope to what is
practically achievable.
Uncertainty and sensitivity analyses help the practitioner to
evaluate how reliable the results and conclusions are [8]. The
uncertainty analysis should estimate the limits of the measurement
and provide a range of final results. The sensitivity analysis applies
variations to the input parameters to highlight which process will be
mostly affected. For example, a sensitivity analysis can consider
variations of input values by 10% increments varied from 50 to
150%. The key parameters can be transport distance, biomass moisture content, water reduction during drying phase, biomass yield,
biomass composition, and material lifetime [29].
7 Dealing with Allocation
The complex biological structure of seaweed allows the extraction
and use of different components. For example, seaweed can be
converted into bioethanol, fertilizer, and protein [18]. This process
requires a first pretreatment step, i.e., milling, to increase active
surface. Secondly the biomass is hydrolyzed and fermented in a
reactor. It follows a separation of the solid and liquid fraction. The
solid fraction is dried and used as high protein content ingredient
for fish feed. The liquid fraction is distilled to obtain bioethanol and
liquid fertilizer (Fig. 4). If the goal of the analysis is to evaluate the
impact of a single output, e.g., only bioethanol, the practitioner has
112
Michele Seghetta and Pietro Goglio