Untreated landfill leachate can harm the environment and human health due to its organic debris, heavy metals, and nitrogen molecules like ammonia. Microbial fuel cells (MFCs) have emerged as a promising technology for treating landfill leachate and generating energy. However, high concentrations of total ammonia–nitrogen (TAN), which includes both ammonia and the ammonium ion, can impede MFC performance. Therefore, maintaining an adequate TAN concentration is crucial, as both excess and insufficient levels can reduce power generation. To evaluate the worldwide research on MFCs using landfill leachate as a substrate, bibliometric analysis was conducted to assess publication output, author-country co-authorship, and author keyword co-occurrence. Scopus and Web of Science retrieved 98 journal articles on this topic during 2011–2022; 18 were specifically evaluated and analysed for MFC ammonia inhibition. The results showed that research on MFC using landfill leachate as a substrate began in 2011, and the number of related papers has consistently increased every 2 years, totaling 4060 references. China, India, and the USA accounted for approximately 60% of all global publications, while the remaining 40% was contributed by 70 other countries/territories. Chongqing University emerged as one of the top contributors among this subject’s ten most productive universities. Most studies found that maintaining TAN concentrations in the 400–800 mg L−1 in MFC operation produced good power density, pollution elimination, and microbial acclimatization. However, the database has few articles on MFC and landfill leachate; MFC ammonia inhibition remains the main factor impacting system performance. This bibliographic analysis provides excellent references and future research directions, highlighting the current limitations of MFC research in this area.

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PurposeThe feasibility and viability appraisal technique is becoming increasingly crucial in the planning systems, theory, applications and outputs for property development and project investments. This paper aims to account for the findings of the practices associated with risk in the feasibility and viability appraisal process. Also, it examines the need for a practical framework for conducting a feasibility and viability appraisal, which can be employed by estate surveyors and valuers in NigeriaDesign/methodology/approachThis study adopted purposive sampling techniques to administer 240 sets of questionnaires, out of which 210 sets were well-thought-out to be useable for the analysis after data screening. Statistical package for social sciences (SPSS), structural equation modelling (SEM) and analysis of movement structures (AMOS) were the main analytical tools used to carry out the reliability test, normality test, exploratory factor analysis, confirmatory factor analysis, measurement and structural model.FindingsThe analysis results indicated that the P-values of the various forms of concepts of risks in feasibility and viability appraisal process (preparation) for property development and the investment market was statistically significant: technological factor - 0.000; political factor- 0.000 and economic factor- 0.000. However, a non-significant effect was found with socio-environmental factors on the preparation of housing development appraisal with P-value 0.155, and that risk management is neither holistically implemented in the feasibility and viability appraisal process nor extensively taken into cognisance.Research limitations/implicationsThis paper reports the results of the practices among estate surveyors and valuers in regarding the risk associated in the preparation stages of the feasibility and viability appraisal processPractical implicationsThere are limited studies that suggest risk management factors in the appraisal reports for property development. Although previous studies have identified the risk factors, there is a lack of emphasis on management, which entails identification, assessment, monitoring and control. This study, therefore, recommends the incorporation of risk management into the feasibility and viability appraisal process implemented by estate surveyors and valuers. It is envisaged that the process will protect investors from the potential risk factors associated with investments in property development.Originality/valueThe study highlighted the need for practical or empirical research to be used to assess the significant risk factors that are needed to be reflected in the preparation stages of the feasibility and viability appraisal conduct of estate surveyors and valuers in Abuja, Nigeria.

Through administrative research and media records, this paper aims to examine and highlight the effects of the COVID-19 pandemic on Malaysian workers, property development, construction sites, and the national economy. The development of real estate and the construction industry can significantly impact socio-economic growth and infrastructure development. Adequate building and infrastructure construction can ensure national economic stability, job creation, community cohesion, and higher living standards. Since the COVID-19 pandemic began in 2019, many countries, including Malaysia, have reported an increased number of virus cases. According to the Ministry of Health, 9316 cases and 314 COVID-19 clusters were discovered in Malaysia, with a 38.55–48.06% prevalence for factories, a 12.55–15.29% prevalence for community spreading, an 8.6–11.56% prevalence for construction sites, a 5.53–7.96% prevalence for educational sites, and a 7.01% prevalence for shopping areas. Several governments-imposed lockdowns, movement, and proximity restrictions during the pandemic due to the high infection rates at property development sites. However, due to inactivity in various sectors such as the construction industry, these measures have significantly impacted the national economy. As a result, the pandemic has had an impact on workers, production costs, and project completion timelines, resulting in operational issues and policy concerns. Overall, the records reviewed revealed that the COVID-19 pandemic has significantly impacted real estate development, the housing market, and the construction industry. As a result, sustained and targeted policies are required to support Malaysia’s construction industry’s socio-economic growth and infrastructure development.