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| <p> <br>After analyse and discuss this question our principal discussions and conclusions were: | | <p> <br>After analyse and discuss this question our principal discussions and conclusions were: |
− | A Life Cycle Assessment (LCA) would bring us a lot quantitative information about our project, because could us to know the specific impact in term of equivalent CO2 (carbon dioxide) generation . Nevertheless, we knew LCA late in the project so we didn’t have the necessary time to do this quantitative analyse because we should look for all input and output of CO2 of each stage of our system which is complex.</p> | + | A Life Cycle Assessment (LCA) would bring us a lot quantitative information about our project, because could us to know the specific impact in term of equivalent CO2 (carbon dioxide) generation[1] . Nevertheless, we knew LCA late in the project so we didn’t have the necessary time to do this quantitative analyse because we should look for all input and output of CO2 of each stage of our system which is complex.</p> |
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− | <p> We infer PLA can degrade to lactate that could enter into metabolic cycle of anaerobic bacteria, generating CH4 (methane) and/or CO2 . This condition with no oxygen could be found it at typical landfills so in a hypothetical situation where PLA would be established in our society (it means we would use PLA instead of fossil plastic) huge amount of PLA could aggravate the global warming (due to greenhouse gases) . Nevertheless, a controlling degradation of PLA would permit take advantage of CH4 gene- | + | <p> We infer PLA can degrade to lactate that could enter into metabolic cycle of anaerobic bacteria, generating CH4 (methane) and/or CO2[2] . This condition with no oxygen could be found it at typical landfills so in a hypothetical situation where PLA would be established in our society (it means we would use PLA instead of fossil plastic) huge amount of PLA could aggravate the global warming (due to greenhouse gases)[3] . Nevertheless, a controlling degradation of PLA would permit take advantage of CH4 generation to produce energy if it is combusted and would help reduce the effects of climate change[4]. If we implemented our project in long term we would promote cultivation of macroalgae which could contribute to economic development of Chile. Also, macroalgae don’t require arable land, fertilizer or fresh water resources and is a renewable resource , so it is a better alternative than corn cultivation. Nevertheless, a Chilean regulation of macroalgae uses should be constantly checked to avoid overexploitation and imbalance of natural ecosystem where macroalgae live. </p> |
− | ration to produce energy if it is combusted and would help reduce the effects of climate change. If we implemented our project in long term we would promote cultivation of macroalgae which could contribute to economic development of Chile. Also, macroalgae don’t require arable land, fertilizer or fresh water resources and is a renewable resource , so it is a better alternative than corn cultivation. Nevertheless, a Chilean regulation of macroalgae uses should be constantly checked to avoid overexploitation and imbalance of natural ecosystem where macroalgae live. </p>
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− | <p> On the other hand, the big problem of fossil plastic is it accumulation . For example, if we suppose a constantly production of the same amount of PLA and PET (a fossil plastic), after 5 years, it would expect find a higher amount of PET than PLA due to a percentage of PLA should be degraded in the first two years . But if PLA had a short degradation time, we guess people maybe would replace it more frequently, so higher amount of PLA product could be thrown away and maybe accumulation rate could be higher than degradation rate. We think this kind of trade off should need further analysis to evaluate the real impact of uses of PLA. | + | <p> On the other hand, the big problem of fossil plastic is it accumulation[5] . For example, if we suppose a constantly production of the same amount of PLA and PET (a fossil plastic), after 5 years, it would expect find a higher amount of PET than PLA due to a percentage of PLA should be degraded in the first two years[6] . But if PLA had a short degradation time, we guess people maybe would replace it more frequently, so higher amount of PLA product could be thrown away and maybe accumulation rate could be higher than degradation rate. We think this kind of trade off should need further analysis to evaluate the real impact of uses of PLA. |
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| According to functionality of PLA, we recommend it to products which will have a short life-time (<2 years), for example plastic glasses or bags. Contrarily, to products that need a long life-time, for examples piping, big structures, it would be appropriate to remain using fossils plastic. On the particular case of medical use, we think PLA should be used like suture, because sutures need to be degraded in a short time [ref suture].</p> | | According to functionality of PLA, we recommend it to products which will have a short life-time (<2 years), for example plastic glasses or bags. Contrarily, to products that need a long life-time, for examples piping, big structures, it would be appropriate to remain using fossils plastic. On the particular case of medical use, we think PLA should be used like suture, because sutures need to be degraded in a short time [ref suture].</p> |