Acknowledgement to Reviewers of Advances in Environmental and Engineering Research in 2021

The editors of Advances in Environmental and Engineering Research would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2021. We greatly appreciate the contribution of expert reviewers, which is crucial to the journal's editorial process. We aim to recognize reviewer contributions through several mechanisms, of which the annual publication of reviewer names is one. Reviewers receive a voucher entitling them to a discount on their next LIDSEN publication and can download a certificate of recognition directly from our submission system. Additionally, reviewers can sign up to the service Publons (https://publons.com) to receive recognition. Of course, in these initiatives we are careful not to compromise reviewer confidentiality. Many reviewers see their work as a voluntary and often unseen part of their role as researchers. We are grateful to the time reviewers donate to our journals and the contribution they make.

Carbon–CO2 Gasification to CO by Microwave Heating

Renewable energies such as solar or wind energy are highly unreliable, owing to uncertain energy intensity and discontinuity. This shortcoming could be overcome by converting renewable energies to a form such as chemical fuel storage. In the present study, we created an energy conversion system that uses microwave heating and a carbon receptor to transform CO2, a greenhouse gas, into CO chemical fuel. The parametric investigation found that increasing the gasification temperature and feed gas temperature decreased the gas feed rate. In addition, the use of a carbon or charcoal receptor enhanced CO2 conversion and heating values. Under ideal operating circumstances, CO2 conversion was 83%, indicating that steady functioning was maintained consistently.

Examination of Sustainable Water Management at Norway’s Major Hub Airport: The Case of Oslo Airport Gardermoen

The present study used a detailed qualitative longitudinal research approach to examine the trends of water consumption, wastewater volumes, and drainage water volumes in Oslo Airport Gardermoen, which is Norway’s major hub airport, between the years 2005 and 2020. An overall upward trend was observed in the water consumption at Oslo Airport Gardermoen, which was consistent with the growth in air traffic and aircraft movements during the study period. The annual water consumption per enplaned passenger was observed to fluctuate during the study period. While the lowest water consumption per passenger (8 liters per passenger) was recorded in 2008, the highest levels (14.6 liters per passenger) were recorded in 2020. The annual water consumption (cubic meter per aircraft movement) increased during the study period, which was consistent with the growth in aircraft movements and the use of larger aircraft. The annual wastewater volume generally increased during the study period, while the annual drainage water volume fluctuated remarkably during the study period, with the latter reflecting varying drainage patterns at the airport. Oslo Airport Gardermoen has implemented a range of sustainable water management practices to supplement its existing water management practices and policies.

Standardized Precipitation Index Comparison along the Limbe-Bamenda Axis of the Cameroon Gulf of Guinea

Mean monthly rainfall decline with continentality is a commonplace phenomenon that has been used in this study to compare its trend in Bamenda in the Western Highlands and Limbe on the Atlantic lowland coast. This study attempts to bridge some of the methodological gaps in the previous studies on rainfall variability in Cameroon that had emphasized only the inter-annual variability and coefficient of variation without focusing on the specific indices and contrasts between different ecological zones. In this study, a comparative analysis has been done of the standardized precipitation index (SPI) for Bamenda and Limbe, using data from 1985–2015. The analysis involved the mean annual rainfall (176.88 mm and 419.9 mm), its standard deviation (SD) (22.98 and 102.42), and the coefficient of variation (CV) (12.99% and 24.41%) for Bamenda and Limbe, respectively. The results show that the mean annual rainfall for Bamenda is decreasing, whereas that of Limbe is increasing. The mean SPI is –0.01 (mild dryness) and 0.02 (mild wetness) for Bamenda and Limbe, respectively. These results have far-reaching implications for the development of agriculture, water resources management, and other man-environment interaction variants.

A System Dynamics Modelling Approach for Electronic Waste Recycling after Floods in Jakarta and New Orleans

Due to climate change, flood-related disasters are expected to increase. Floods generate enormous amounts of waste, including electronic waste (e-waste). E-waste should be recovered not only because it can have detrimental effects on human health and the environment but also because of the valuable metals contained in it. In this study, a system dynamics model based on current practices and waste management was established using Vensim to determine the revenue that can be generated by e-waste recycling after floods in two socio-geographic and economic contexts: Jakarta and New Orleans. At current recovery rates, the formal systems employed for recovering valuable materials would yield 8% (€58 million) and 14% (€80 million) of the potential yield for the Jakarta and New Orleans models, respectively. Moreover, the model estimated that informal e-waste recycling would yield €1.2 billion. The model also highlighted several problems encountered in post-disaster waste management in both scenarios, such as low capacities of temporary storage sites, increased landfilling rates, low yields of recovered e-waste components, and limitations on the transportation of waste. For optimizing the recovery of valuable metals, regulations addressing e-waste must be implemented more thoroughly, and post-disaster waste management guidelines must be revised to contextually address flood disasters. When more data are available, an improved model can be established and used as a basis for policymaking to improve the infrastructure of solid waste management to optimize e-waste recovery.

Climate Change, CO2-Concentration, and the Impact on Long-Term Pollen Observation with Implications for Human Health

Climate change has a major impact on nature and influences ecological systems. The increase in the CO2-concentration in the atmosphere is a major driver of global warming. This study showed that global warming has a major impact on the release of pollen, and hence, on the people suffering from allergies in Switzerland. Basel is a station where long-term pollen observation is conducted, and the data was used to investigate the change during the last 52 years. There are stations throughout the world to measure the atmospheric CO2 concentration. Data from these stations showed an increase in temperature, which influences the biosphere. We found that the flowering time of Hazel, Birch, and Grass pollen has shifted forward in the corresponding season, inducing hay fever early in spring. Earlier pollen release is strongly correlated with and caused by an increase in temperature. This study showed the relationship between increasing CO2-concentration in the atmosphere, the increasing air temperature followed by increasing and earlier pollen counts, and finally, increasing prevalence of pollinosis over half a century.

Sources, Mobility, Reactivity, and Remediation of Heavy Metal(loid) Pollution: A Review

Heavy metal(loid)s are a group of elements present commonly in the environment, including Cr, Ni, Cu, Zn, Cd, Hg, Pb, and As elements, among others. While these elements could have their origins in natural sources, anthropogenic activities, such as mining, agriculture, industry, etc., are also responsible for enhancing the concentration of these elements in the ecosystems up to undesirable levels. A few of these metal(loid)s serve as necessary micronutrients for life, while the others are extremely harmful and might affect the entire trophic chain upon entering the natural ecosystems due to their mobility and toxicity characteristics. Most of these heavy metal(loid) pollutants are already recognized for their harmful effects; nevertheless, their environmental control encounters obstruction due to various factors. In this context, the present report details the key points regarding the anthropogenic sources of heavy metal(loid) pollution, which are increasing rapidly with time due to the emerging industry practices and processes, the elements causing this kind of pollution, and the physicochemical processes of these elements occurring in the environment–air interface, soil, and water-air interface. These elements exert a severe impact on the environment, which could be mitigated through the development and application of various remediation techniques. Therefore, the present report concludes with a final discussion on the various remediation treatments currently available for reducing the heavy metal(loid) contamination level in both water and soil.

Effects of Land Cover/Use Change and Altitude on Soil NPK Nutrients in Selected areas in the North West Region of Cameroon

Land-use change is one of the main indicators of soil quality. Soil physical and chemical properties vary with land use change and altitude as inferred from transect surveys and toposequences. Soil nitrogen, phosphorus, and potassium (NPK) are essential macronutrients for plant growth and soil nutrient balance. Their presence in the soil in appropriate quantities is important for maintaining crop yields and farmers income, particularly in developing countries where resources of soil chemical additives may be limited. This paper assesses the effects of land cover/use change and altitude on soil NPK nutrients in plots of 30 m2 in the North West Region of Cameroon for maintaining soil NPK levels and boosting crop yields. A total of 60 soil samples were collected at the 0-20 cm depth from the plots with various land cover/use types (eucalyptus plantation, farmland, grazing land, and natural forest). Soil samples were analyzed for nitrogen (N), phosphorus (P), and potassium (K) contents based on standard procedures. The concentrations of soil NPK nutrients were below the critical values for different land use types and the studied sites. The decline in soil NPK nutrient contents is partly linked to land use change, long-term nutrient mining through crop harvest, and rainfall-induced leaching of N and K nutrients. To increase food crop yields and sustain the livelihood of farmers, appropriate nature-based solutions of manure application, mulching, the intercropping of legumes, and sustainable use of appropriate chemical NPK fertilizers will help restore the soils and increase crop yields.

Planning for Simultaneous Regional/Urban and Tourism Development with Case Studies

This research suggests optimal planning and designing techniques for tourism complexes in urban master planning. Firstly, it explains the importance of the tourism industry through the theories of scholars and experts. It also emphasizes the connection between the development of urban economies and the tourism industry. This helps integrate the tourism industry and comprehensive regional/urban planning. It starts with planning and designing the tourism complexes in the early stages of the municipality’s master plan. This research paper suggests urban land-use policies and location techniques. This paper brings out land-use policies and centralized and symmetric urban design models for regional/urban sustainable development. It charts the following steps to meet the goal: determining a location for a tourism complex, setting a spatial table of required construction, preparing a land-use map, preparing a map album, developing investment and construction contracts. This paper assists civil engineers, urban and regional planners, tourism industry bodies, and students to develop rationally and optimally.

Degree-hours and Degree-days in Coastal Mediterranean Cities, Patras and Kalamata, Greece

The hourly ambient air temperature information was analyzed for two Greek coastal Mediterranean cities: Patras (for the entire 2018 year) with ten urban and one rural stations, and Kalamata (for the entire 2019 and 2020 years) with eight urban and two rural stations. The heating and cooling Degree Hours (DH) and Degree Days (DD) were calculated, for base temperatures of 18 °C and 26 °C, respectively. The urban heating degree hours for the cities of Patras and Kalamata were observed to be 19.2% and 24%, respectively, lower than that of the rural areas. Similarly, the urban cooling degree hours for the two cities were 9% and 22% higher than that of rural areas. These findings indicate a distinct urban heat island effect in both the cities, with greater effects in Kalamata than in Patras. Following comparisons with historical data from reliable sources, it could be observed that summers are trending warmer and winters are trending milder.