The field of bioethanol production has seen rapid advancements in the past few decades. Despite the advancements, bioethanol production’s recent trends cannot prove effective and efficient transportation fuel. Fossil fuels, which currently power-ups most energy demands, from nonrenewable energies, meaning it will bring adverse effects to the environment, including ozone layer depletion and global warming. It makes bioethanol the best alternative to fossil fuels, owing to the fact than it is considered carbon-neutral. In some parts of the world, bioethanol is utilized as an alternative fuel by using the lignocellulosic (LC) residues, and prioritizing its production as better feedstocks available could fulfill the void created in the transportation fuel sector. Separate hydrolysis and co-fermentation (SSCF) and Pre-hydrolysis and simultaneous saccharification and co-fermentation (PSSCF) are superior to all techniques to achieve saccharification, hexose, and pentose fermentation in a one-pot reaction. For the feedstock modification, the genome engineering and cell wall modification are advanced methods so far. As of not long ago, there is no cost-effective and financially achievable pretreatment technique for the removal of lignin that could be industrialized to satisfy the worldwide requirement for bioethanol. In this review we provide the present scenario of energy demand and advancement on bioethanol technology and challenges. Mainly, altering the LC biomass composition, the robust enzyme that enables to hydrolyzed and maximum fermentable sugar yield, and effectively fermenting bacteria and yeast, which is genetically engineered for simultaneous fermentation with the high rate, is future stepping research which should be emphasized in the bioethanol industry. Graphical abstract

The spread of COVID-19 is posing significant challenges to the household (HH) waste management sectors putting waste personnel and concerned bodies under massive pressure. The chain of collection, segregation, recycling, and disposal of household generated wastes is interrupted. This study aimed to assess how the household waste management chain was disrupted by novel coronavirus in Nepal and find the perception of the people towards the existing household waste management system (HHWMS). A descriptive online survey was carried out among 512 people using a cross-sectional research design and data was collected through a self-administered questionnaire method. Both descriptive, as well as inferential tests, were conducted using SPSS software. The finding of this study showed that 62.3% of respondents were not satisfied with the present HHWMS. Furthermore, there was a significant association of the satisfaction level of household waste management during coronavirus outbreak with gender, waste volume change in lockdown, PPE for waste collectors, and education on waste handling techniques provided by the government sector at 5% level of significance (p < 0.05). Proper HH waste management has become a challenge, and to address this some innovative works such as awareness programs for people, health and hygiene related support to waste workers, and effective policy formulation and implementation should be done by the Government of Nepal.