The aim of the present work is to evaluate the rate and mechanisms of the aerobic biodegradation of biopolymer blends under controlled composting conditions using the CO2 evolution respirometric method. The biopolymer blends of poly (butylene adipate terephthalate) (PBAT) blended with poly (lactic acid) (PLA), and PBAT blended with poly (butylene succinate) (PBS) by melt extrusion, were tested to evaluate the amount of carbon mineralized under home and industrial composting conditions. The changes in the structural, chemical, thermal and morphological characteristics of the biopolymer blends before and after biodegradation were investigated by FT-IR, DSC, TGA, XRD and SEM. Both blends showed higher degradation rates under industrial composting conditions, when compared to home composting conditions. This was confirmed by FT-IR analysis showing an increase in the intensity of hydroxyl and carbonyl absorption bands. SEM revealed that there was microbial colony formation and disintegration on the surfaces of the biopolymer blends. The obtained results suggest that industrial composting conditions are the most suitable for an enhanced biodegradation of the biopolymer blends viz PBAT–PBS and PBAT–PLA.
This study investigated bioaccumulation factors and translocation factors of lead (Pb) by M. charantia so as to ascertain the bioaccumulation potentials of this medicinal plant. The elemental deposition of Pb were also assessed in order to compare the concentration of Pb present in plant tissues with the maximum permissible limits of 10 ppm recommended by WHO (1998, 2007). The experiment was a factorial combination of one heavy metal (Pb) at five levels of concentrations (0, 200, 400, 800 and 1,000 ppm) in a completely randomized design, replicated three times, with one medicinal plant species and two levels (0 and 9.4 g) of organic fertilizer (OBD- Plus). The seedlings were transplanted from nursery to experimental pots at the rate of one seedling per pot and grown for 10 weeks, after which the plants were harvested and dried for the analysis of Pb concentration both in soil and plant tissues using Atomic Absorption Spectrophotometry (AAS). The highest bioaccumulation factor for roots was 0.42 under fertilizer amendment, whereas the highest bioaccumulation factor for shoots was 0.26 under the same treatment. The highest transfer factor of M. charantia was 0.6. The results showed that M. charantia is a good phytostabilizer of Pb component. The highest lead deposition in the roots, which was 40% higher than in the shoots concentration, was above the safe limit; therefore this might pose health risks to human if consumed as herbal medicine.
In the evolution of CO 2 emission intensity, population, total CO 2 emission, annual gross domestic product growth, emission intensity, and emission per unit energy index is mainly an empirical issue that cannot resolve with certainty from the experience of a group of countries during a given period of time. The present empirical study reveals that the listed variables cannot be evaluated unambiguously using either variation in carbon emission factor or product of many factors put together as the criteria. Different levels of CO 2 emission intensities in different regions resulting from different causes are not a constant or evaluated using constant variables. The article focuses on the challenges of climate change on development in recent times-observed and future climate change and variability, which are a factor of the energy mix utilization within China for some years ago, thus establishing methodology that linked greenhouse gases effect and climate change by Sensitivity Model Prof. Vester in China, in an attempt to evaluate a sustainable indicator in greenhouse gases and change effects.
Contaminants in the environment occur naturally and/or through anthropogenic activities. These contaminants become a threat to all living organisms because of their increased in the environment and non-biodegradable nature. In order to protect the environment from these contamination, various techniques have been developed, and among them is phytoremediation. Phytoremediation is a technology that employed plant species for reclaiming contaminated soil, air, and water. This technology has been widely accepted in recent times, because of its low cost and environmentally friendly. In addition, augmentation of the contaminated soil, either chemo augmentation or bioaugmentation, have been used for the effective absorption of some of these contaminants. When the plants are grown in the contaminated sites, the contaminant in the soil maybe removed, immobilized, degraded or volatized. These phytoremediation technologies are: phytoextraction, phytovolatilization, rhizofiltration, phyto-stimulation, phyto-stabilization and phytodegradation. Based on the phytoremediation potentials of plants, pollutants are being removed from the environment thereby keeping the environment safe.
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