Banana is the most cultivated fruit plant in the world. It is produced in Latin America, Asia and Africa. India and China are the world’s largest banana producers, with almost 41% of the world’s production. This fruit reaches a total world production of 158.3 million tons per year. However, during their production cycle, the banana agroindustry produces large volumes of solid waste derived from overripe fruit. It contributes between 8–20 percent of the waste (around 100 kg of banana waste for every ton of banana produced). Therefore, the use of overripe banana waste represents a huge opportunity for bioenergy production. This work demonstrates that banana waste can be further used for power generation using a microbial fuel cell (MFC) coupled with anaerobic digestion (AD). First, the maximum methane production (MMP), methane production rate (MPR) and biochemical methane potential (BMP) were measured using an anaerobic batch bioreactor for 64 days of monitoring. Finally, the digestate generated from AD was used in the MFC to determine the polarization curve, maximum voltage, maximum power density (MPD), resistance and current. As a result, the AD generated an MMP of 320.3 mL, BMP of 373.3 mLCH4/gVS and MPR of 18.6 mLCH4/Lb⋅day. The MFC generated 286 mV (maximum voltage), 41.3 mW/m2 (MPD), 580.99 Ω (resistance) and 0.0002867 A (current). Both processes together produced a total bioenergy of 13.38 kJ/gVS. This coupled system showed a suitable and promising use of banana waste for ecofriendly bioenergy generation. Therefore, this feedstock could be taken advantage of for generating sustainable processes and developing a circular economy in the banana agroindustry.
Cheese whey wastewater (CWW) is the major by-product of the dairy industry. CWW is produced in large quantities, has varied characteristics and is usually disposed of. The disposal of CWW causes a negative impact on the environment of different agroindustrial areas due to the physic-chemical composition that significantly increases its high organic load and nutrients. For this reason, the aim of this work was to carry out an evaluation of the anaerobic treatability of an Expanded Granular Sludge Bed (EGSB) bioreactor as a new sustainable alternative for treatment of these effluents with bioenergy production. In this study, the bioreactor was operated under stable conditions (i.e., buffer index of 0.23 ± 0.1, pH 7.22 ± 0.4 and temperature 26.6 ± 1.4 °C) for 201 days. During evaluation the hydraulic retention time (HRT) was 6 and 8 days, and it was buffered with NaHCO3. At these conditions, the COD removal rate and biochemical methane potential (BMP) were 90, 92%; and 334, 328 mLCH4/gCOD, respectively. The evidence found in this study highlighted that the CWW is a viable substrate to be treated in the EGSB bioreactor as long as it keeps buffered. Furthermore, the process to treat the CWW in an EGSB bioreactor can be a sustainable alternative to simultaneously solve the environmental pollution that this agro-industry confronts and produce renewable and environmentally-friendly bioenergy.
11 November 2021 in Journal of Food Processing and Preservation
The agro-food industry plays a crucial role in enhancing living standards; however, inadequate losses and waste management persists as significant challenges within its processes. Particularly, mango and cheese processing generate substantial waste, leading to ecological disruptions, economic losses, and concerns related to food security and public health. To address these issues, this study was aimed at utilizing this waste to produce a high-quality ice cream base, thereby valorizing the discarded materials. This approach not only adds nutritional value but also contributes to food security and sovereignty. The raw materials (cheese whey, oil, and starch) were subjected to physicochemical characterization, leading to the development of three different ice cream base formulations. Subsequently, the ice cream bases were evaluated for their physicochemical, functional, and sensory properties. The findings of this study revealed that mango seed kernel and cheese whey waste contain valuable components that enable the creation of an ice cream base with excellent physicochemical, functional, and sensory properties. Moreover, this research showcases a promising solution for effectively valorizing food waste and generating value-added products such as ice cream, thus promoting sustainability and resource optimization within the agro-food industry.
Natural freshwater streams harbor diverse microbial communities that support ecosystem functioning. Due to their great biodiversity and geomorphological characteristics, these ecosystems are often very attractive ecotourism destinations, which makes them highly vulnerable to anthropogenic disturbances. The Agua Azul Waterfalls (Cascadas de Agua Azul, in Spanish), a major ecotourist destination located in Indigenous territories of southeastern Mexico (Chiapas, Mexico), offer a unique setting to investigate how sustained human activity influences microbial diversity and quality of water and sediments, as well as the role of local management in conserving biodiversity. To determine the ecological sensitivity of this freshwater stream to tourism pressure, we sampled sites spanning gradients of ecotourist activity and performed an integrated analysis of the physicochemical properties, elemental composition and microbial community composition (bacteria, archaea and fungi) of water and sediment samples. Areas associated with ecotourism activities showed notable changes in physicochemical parameters and microbial community composition, indicating localized human-induced impacts on this ecosystem. Although no significant differences were observed between zones, the detection of anaerobic methanogenic archaea and ammonia-oxidizing archaea in shallow sediments suggests that oxygen availability, methanogenesis (both acetoclastic and hydrogenotrophic), and nitrogen metabolism may play important roles in shaping the functioning of this ecosystem. Our findings highlight the potential of microbial diversity in combination with physicochemical parameters as a tool to detect early stages of human impacts on freshwater ecosystems and establish a basis for future monitoring and conservation efforts. Importance: This study provides evidence of the early-stage impacts of ecotourism on biodiversity and water quality at the Agua Azul Waterfalls, a freshwater stream located within a protected natural area in southeastern Mexico. While the water still meets basic quality standards, areas with higher tourist activity show early signs of nutrient enrichment and measurable changes in the types of microbes present and the roles they play in this ecosystem. As the first analysis of microbial diversity in this ecosystem, our work highlights the value of microbes as early and sensitive indicators of human impact. By directly comparing tourist and non-tourist areas, we provide evidence of how recreational pressure is transforming this freshwater environment. We expect that our findings will serve as a guide for local communities and policymakers in developing more sustainable tourism practices, with the goal of preserving the biodiversity, as well as the cultural and economic value, of this ecosystem, before irreversible damage occurs.