The massive plastic production worldwide leads to a global concern for the pollution made by the plastic wastes and the environmental issues associated with them. One of the best solutions is replacing the fossil-based plastics with bioplastics. Bioplastics such as polylactic acid (PLA) are biodegradable materials with less greenhouse gas (GHG) emissions. PLA is a biopolymer produced from natural resources with good mechanical and chemical properties, therefore, it is used widely in packaging, agriculture, and biomedical industries. PLA products mostly end up in landfills or composting. In this review paper, the existing life cycle assessments (LCA) for PLA were comprehensively reviewed and classified. According to the LCAs, the energy and materials used in the whole life cycle of PLA were reported. Finally, the GHG emissions of PLA in each stage of its life cycle, including feedstock acquisition and conversion, manufacturing of PLA products, the PLA applications, and the end of life (EoL) options, were described. The most energy-intensive stage in the life cycle of PLA is its conversion. By optimizing the conversion process of PLA, it is possible to make it a low-carbon material with less dependence on energy sources.

A three-component metal catalyst was prepared and used in the process of catalytic wet peroxide oxidation (CWPO) for the degradation of unsymmetrical dimethylhydrazine (UDMH) in propellant wastewater with H₂O₂.

A novel electrochemically-based biosensor was developed for the determination of hydrazine by modifying a glassy carbon electrode with an aqueous dispersion of carboxylic group-functionalized carbon nanofiber/chitosan solution, and then absorbing hemoglobin on the surface of chitosan-carbon nanofibers. Nafion was used to coat the hemoglobin membrane. The interactions of hemoglobin and the nafion/chitosan-carbon nanofibers were investigated by ultraviolet-visible absorption, infrared, and circular dichroism spectroscopies. The results indicated that the native structure of hemoglobin was retained post-immobilization. The circular dichroism results showed that the α-helical structure of hemoglobin was preserved though a small change was observed in the presence of the nafion/chitosan-carbon nanofibers. The modified nanofibers were further characterized by scanning electron microscopy, electron impendence spectroscopy, and cyclic voltammetry. The electrocatalytic mechanism of hemoglobin to the oxidation of hydrazine was investigated and an irreversible diffusion-controlled electrode process was obtained. The electron transfer rate constant (k_s), transfer coefficient (α), and Michaelis–Menten constant (K_m) were also evaluated. The peak current of the catalytic oxidation was linear with hydrazine concentration from 3.722 × 10⁻⁵ to 1.601 × 10⁻³ molar with a correlation coefficient of 0.995. The detection limit was estimated to be 2.7 micromoles per liter. The sensitivity, stability, and reproducibility of the nafion/hemoglobin/chitosan-carbon nanofiber/glassy carbon electrode for the oxidation of hydrazine were also investigated.