The huge volume of wastes generated from industries kindles immediate attention, especially those wastes that bring adverse effects to humans and the environment. For one, cassava waste pulps (CWPs) from starch-producing industries are needing attention for its alternate disposal by making value-adding products out of it. In this work, the CWP with pig manure as inoculum was anaerobically digested for the possible production of biogas. The effect of the concentration of pig manure (CPM) and biomass to water ratio (BMR) was scientifically analyzed in relation to biogas yield. The central composite design of the response surface methodology was used as the design of the experiment. Biogas yield was modeled and characterized according to essential properties. The result of the batch experiment obtained a biogas yield of 4.9–7.3 L per kg of CWP. At optimized conditions of 250 gVS of CPM and 1:1.22 BWR (kg/L), the optimum biogas volume was 7.43 ± 0.58 L per kg of CWP. Analysis of the produced biogas via gas chromatography showed a significant concentration of biohydrogen (18.69 ± 1.71%), a highly desirable upshot considering that this gas is highly flammable with less emissions when combusted. Other percent components of the produced biogas include carbon dioxide (38.02 ± 0.71), nitrogen (20.77 ± 1.59), and a trace of methane (0.73 ± 0.28). This work, therefore, proved that CWP can be used for the production of biogas and would eventually provide practical solutions to starch processing industries as it gives promising lucrative routes of CWP with added commercial worth in the production of high-value energy resources like the desirable H2 gas. It poises high potentials with less socio-economic apprehensions while offers numerous environmental advantages.
The Belt and Road Initiative offers interaction among beneficiary countries that fosters economic cooperation spanning education, energy consumption, economic development, environmental change, and quality of life. Of these benefits, carbon dioxide emissions generated by economic growth and related environmental changes have garnered great attention. This paper empirically studies the causal relationships among urbanization, economic growth, energy consumption, economic structure, trade, and carbon dioxide emissions according to an income classification of the Belt and Road Initiative countries. The results from the Westerlund bootstrap cointegration test indicate long-run associations among the variables under study. Estimation from the common correlated effect mean group indicates that a percentage increase in urbanization increases emissions of CO2 by 1.1533% and 1.0454% in lower middle-income and low-income countries, respectively. The elasticity of energy consumption with emissions is higher in low-income countries than in countries in the other three classifications. The Dumitrescu–Hurlin causality test shows a bidirectional causal effect between gross domestic product and emissions in lower middle-, upper middle-, and low-income countries. A bidirectional association was found between urbanization and carbon emissions in low- and lower middle-income countries. These methods take cross-sectional correlations into account in their estimation; hence, some important policy implications can be drawn from the empirical results.
In Costa Rica, a diversification of the energy matrix has been developed, regarded as a source of energy of great potential in the short term. However, the current market is unclear and has multiple deficiencies that are necessary to identify and the government lacks studies that allow it to understand the current market. The study analyzed the perception of the biomass market with forest residues and agro-industrial in Costa Rica and their potential for development under a circular economy scheme. For that producers, intermediaries and consumers of arboreal and agro-industrial biomass in the North Zone of Costa Rica were employed, analyzing the market from a technical, environmental, financial and social perspective and identifying the variables that limit the market. The results showed similarity between agro-industrial and forest markets, as well as in ecological and social aspects, with similar perceptions between the sectors analyzed. However, the financial and technical elements presented significant differentiation, specifically in terms of the price of the biomass, homogeneity of the same (both species and presentation) and associated costs, in addition to the competence of other biomass fuels. The analysis showed that biomass variability in how much performance affects 42.5% of the market, species variation 24.8%, moisture content 10.6%, biomass availability in time 8.4%, organization and market structure 8.9% and other variables and 6.8%. If a market structure is needed in terms of biomass sales and articulation between producers and demanders together with key intermediaries for the viability of biomass market in Costa Rica.
The colossal applications of phthalates make them ubiquitous. Several studies reported toxicity and ecological effects of phthalates. However, toxicological studies using Allium cepa assay are not well explored. Therefore, the current study envisages the morphological toxicity, cytotoxicity, and genotoxicity of two phthalates using Allium cepa assay. To study the effects of phthalates on roots length, the plant was subjected to different concentrations of benzyl-butyl phthalate (BBP) and di-n-butyl phthalate (DBP) for 24 and 120 h. After 120 h treatment, the effect was > 50%; therefore, for further investigations, the treatment durations were set at 24 and 48 h. The roots length was significantly declined with increase in phthalates concentrations. From microscopic studies, it was observed that phthalates significantly decreased mitotic index (MI) after 24 and 48 h exposure. After 24 h exposure, the decline in MI was maximum with BBP treatment, while after 48 h, it was maximum with DBP treatment. On the other hand, a significant increase in percent chromosomal anomalies was induced by phthalates and the maximum increase was with DBP treatment under both exposure durations. The changes in root surface morphology were observed using scanning electron microscope. The loss in cell viability was also observed in treated and untreated root samples using laser confocal scanning microscopy. UHPLC was used to analyze the accumulation of phthalates in the roots. It can be concluded that phthalates cause deleterious effects on A. cepa and extent depends on their concentrations and treatment durations.
Elemental composition of sand fraction of Nigerian oil sand was determined with a view to assessing the human and ecological risks to the sand fractions. Soxhlet extraction of bitumen from the oil sand was done using toluene as the extracting solvent. Elemental analysis was done using energy-dispersive X-ray fluorescence spectrophotometry and risks calculated using elemental concentrations as variables. Fe had the highest mean concentration (9453 ± 1477.72 µg/g), while As had the least mean concentration (81.75 ± 17.91 µg/g) in the sand fractions. It was observed that the elemental concentrations in this study were comparatively higher than those of Nigerian oil sands and bitumen, indicating that the larger percentages of the elements were extracted into the sand fraction which is part of the tailings (including water) that will be discarded as wastes during the recovery of bitumen from the oil sands. Close inter-element clustering existed between the elements (Fe and V) and (Cu, As, Nb, Sc, Ga, Rb, Ca, Se, V, Mn, Zn, K, Ti, Ni, Sr and Zr), indicating chemical affinity and/or similar sources. Contamination factor results indicated varying degrees of contamination by the elements, while modified degree of contamination (mCd > 32) indicated an ultra-high degree of contamination of the sand fractions by the elements. Pollution load index (PLI > 1) indicated deterioration of site quality, while potential ecological risk index and modified ecological risk index results indicated very high ecological risks by the elements. Study concluded that the elemental levels were high enough to degrade the environment and cause ill-heath to humans upon long exposure if the sand fraction (tailing) is disposed indiscriminately. Therefore, regular environmental monitoring assessment should be carried out to screen uncritical disposal of tailings during the development of the natural resource.
The need to adapt to the changing climate is one of the important concerns of our time. However, the use of local ecological knowledge (LEK), which farmers have built up over the years to adopt climate-smart agriculture (CSA) practices, has been less explored by researchers and policy scientists. Leveraging on LEK, this study explores various local CSA practices, their benefits and management constraints and suggests ways to improve local CSA practices to enhance farmers’ resilience to climate change (CC). We conducted eight focus group discussions (FGD) in eight farming communities in the Western region of Ghana. The data from the FGD was complemented by secondary data from sources such as peer-reviewed journal articles, organisational websites, and quarterly reports. The study found that farmers used LEK to identify key local CSA practices, including agroforestry, cover cropping, crop rotation, mulching, and mixed cropping. However, some of their farming practices are not consistent with sustainable agricultural practices. Key issues that need immediate attention include (i) limited access to agricultural inputs prevented farmers from adopting CSA, (ii) land tenure issues adversely affected access to arable land for farming, (iii) inadequate agricultural training for farmers on CSA practices, (iv) limited access to agricultural information on CSA options, and (v) high labour-intensive activities for some CSA practices. We maintain that governmental efforts to improve local CSA, and in the context of increasing resilience of farmers and local communities, need to engage relevant stakeholders and communities to formulate and develop an effective climate-smart agricultural action plan. The policy implications of these findings and recommendations for future research are also discussed and documented.