High ammonia (NH₃) emissions from fertilized soil in China have led to various concerns regarding environmental safety and public health. In response to China's blue skies protection campaign, effective NH₃ reduction measures need to consider both mitigation efficiency and food security. In this context, we conducted a meta-analysis (including 2980 observations from 447 studies) to select effective measures based on absolute (AV) and yield-scaled (YSAV) NH₃ volatilization reduction potential, with the aim of establishing a comprehensive NH₃ mitigation framework covering various crop production sectors, and offering a range of potential solutions. The results showed that manipulating crop density, using an intermittent irrigation regime for paddy field rice, applying N as split applications or partially substituting inorganic fertilizer N with organic N sources could achieve reductions in AV and YSAV reduction of 10–20 %; adopting drip irrigation regimes, adding water surface barrier films to paddy fields, or using double inhibitor (urease and nitrification), slow-release or biofertilizers could achieve 20–40 % mitigation; plastic film mulching, applying fertilizer by irrigation or using controlled-release fertilizers could yield 40–60 % reduction; use of a urease inhibitor, fully substituting fertilizer N with organic N, or applying fertilizer by deep placement could decrease AV and YSAV by over 60 %. In addition, use of soil amendments, applying suitable inorganic N sources, or adopting crop rotation, intercropping or a rice-fish production model all had significant benefits to control AV. The adoption of any particular strategy should consider local accessibility and affordability, direct intervention by local/government authorities and demonstration to encourage the uptake of technologies and practices, particularly in NH₃ pollution hotspot areas. Together, this could ensure food security and environmental sustainability.

Monitoring water at high spatial and temporal resolutions is important for maintaining water quality because the cost of pollution remediation is often higher than the cost of early prevention or intervention. In recent decades, the availability and affordability of satellite images have regularly increased, thus supporting higher-frequency and lower-cost alternative methods for monitoring water quality. The core step in satellite remote sensing detection is inverse modeling, which is used to calibrate model parameters and enhance the similarity between the model and the real system being simulated. The reflectance values measured at water quality stations are extracted from atmosphere-corrected satellite imagery for analysis. However, various external environmental, hydrological, and meteorological factors affect the evaluation results, and the results obtained with different parameters can vary. This literature review shows that nonpoint-source pollution caused by stormwater runoff can also be monitored using satellite imagery. To improve the accuracy of satellite-based water quality prediction, the temporal resolution of field measurements can be increased, thus better considering the influence of seasonality. Then, the atmospheric correction module can be improved by using available atmospheric water content products. Moreover, because water surface ripples affect reflectance, wind speed and direction should be considered when comparing water quality scenes.

Clean, affordable, and efficient energy sources are inevitable for a sustainable world. Energy crisis, especially the poor access and affordability, demand–supply mismatches, energy inequality, and high dependence on non-renewable energy sources, are the challenges before the attainment of clean energy goals for sustainable development. The 5-year review from the adoption of sustainable development goals (SDGs) by using bibliometric and thematic analysis was conducted in this review. This review is a synthesis of 175 scientific papers on SDG 7. Policy reforms and better funding; technology innovation and inclusion; and economic growth, rapid promotion of renewable, and alternative fuels are the recommendations for the achievement of the energy goals. Future research on energy-related goals should focus on energy justice, policy reforms, energy poverty, poor affordability, off-grid transmissions, renewable energy sources, alternative fuels, reforms in the energy supply chain, and international cooperation for better implementation of projects and for attracting foreign capital and private funds. This paper invites the attention of practitioners, academicians, funding agencies, and international agencies to collaborate in the initiatives for a clean, green, and energized world.

Nanoadsorbents having large specific surface area, high pore volume with tunable pore size, affordability and easy magnetic separation gained much popularity in recent time. Iron-based nanoadsorbents showed higher adsorption capacity for different pollutant removal from water among other periodic elements. Spinel ferrite nanomaterials among iron-bearing adsorbent class performed better than single iron oxide and hydroxides due to their large surface area, mesoporous pore, high pore volume and stability. This work aimed at focusing on water treatment using magnesium ferrite (MgFe₂O₄) nanomaterials. Synthesis routes, properties and pollutant adsorption were critically investigated to explore the performance of magnesium ferrite in water treatment. Structural and surface properties were greatly affected by the factors involved in different synthesis routes and iron and magnesium ratio. Complete removal of pollutants through adsorption was achieved using magnesium ferrite. Pollutant adsorption capacity of MgFe₂O₄ and its modified forms was found several folds higher than Fe₂O₃ and Fe₃O₄ nanomaterials. In addition, MgFe₂O₄ showed strong stability in water than other pure iron oxide and hydroxide. Modification with graphene oxide, activated carbon, biochar and silica was demonstrated to be beneficial for enhanced adsorption capacity. Complex formation was suggested as a dominant mechanism for pollutant adsorption. These nanomaterials could be a viable and competitive adsorbent for diverse pollutant removal from water.

Energy poverty poses a serious threat to the urban population residing in Himalayan towns. The present study aims to assess energy vulnerability in the urban settlement of Indian Himalayan Region (IHR). The study addresses energy access and affordability; its requirement, practices, and efficiency, considering the quality of electricity, dwelling type, transport facilities, energy expenditure, household chores (cooking, heating, cooling, lighting, etc.), awareness, and social interactions. The study uses an energy vulnerability framework based on IPCC indices to investigate the status of energy vulnerability in the urban space of Dehradun, the Indian Himalayan Region. The primary data was collected from two circular regions of the city, an area close to the central place and an area outlying from the central place, respectively. The energy vulnerability index was 0.31 and 0.34 with varying degrees of exposure, sensitivity, and adaptive capacity. The findings reveal that energy vulnerability could jeopardize the well-being of the society and could be mitigated through appropriate policy measures, intensive support to sensitive societies, and a developmental approach focusing on sustainable energy. The study provides a theoretical base to conduct extensive research addressing a similar issue in other Himalayan towns.

Dependence of rural population on traditional fuel sources namely biomass has increased because of easy accessibility and affordability. The use of biomass fuels results in many environmental and health-related hazards. Rural households have little awareness about the ill effects of using biomass energy sources. This study investigated the patterns of rural household energy use and identified the role of information on the effects of biomasses on human health, in addition to other factors influencing households’ choices of energy sources. For this purpose, primary data from 196 households were collected from four districts of the Punjab province in Pakistan. Results showed that use of clean energy sources was limited to basic appliances and 90% of the respondents depended on biomass fuels. Estimates of the multivariate probit model showed that awareness about adverse impacts of biomass fuels as energy sources were significantly related with the choice of energy sources. Further, household head’s education level, household income, landholding, children under the age of 5 years and higher number of adult females were significantly related with the cleaner energy source choices. Distance to market increased the probability of the use of biomass energy sources. The study concluded that awareness campaigns regarding the benefits of using clean energy sources should be launched through print and electronic media while targeting rural women.

China contributes 23 % of global carbon emissions, of which 26 % originate from the household sector. Due to vast variations in both climatic conditions and the affordability and accessibility of fuels, household carbon emissions (HCEs) differ significantly across China. This study compares HCEs (per person) from urban and rural regions in northern China with their counterparts in southern China. Annual macroeconomic data for the study period 2005 to 2012 were obtained from Chinese government sources, whereas the direct HCEs for different types of fossil fuels were obtained using the IPCC reference approach, and indirect HCEs were calculated by input-output analysis. Results suggest that HCEs from urban areas are higher than those from rural areas. Regardless of the regions, there is a similarity in per person HCEs in urban areas, but the rural areas of northern China had significantly higher HCEs than those from southern China. The reasons for the similarity between urban areas and differences between rural areas and the percentage share of direct and indirect HCEs from different sources are discussed. Similarly, the reasons and solutions to why decarbonising policies are working in urban areas but not in rural areas are discussed.

The affordability of candies and chocolates makes their consumption common especially in children. Heavy metal contamination of these candies is well known. This study has estimated health risks associated with heavy metals (HM; Pb, Cd, Cr, Ni, and Zn) in commonly consumed candies in Nigeria. Fifty candies/sweets and chocolates/chewing gums bought from different stores in Port Harcourt and Uyo in Niger Delta, Nigeria, were processed and digested in perchloric acid. The filtrate was analyzed for these heavy metals using atomic absorption spectroscopy (AAS). Pb/Zn and Cd/Zn ratios were calculated. Daily intake, the target hazard quotient (THQ), the hazard index (HI), and the cancer risk were estimated for children. About 80% of the samples exceeded the 0.1 mg/kg permissible lead level in candies. Milk sweet had the highest Pb:Zn and Cd:Zn ratios of 0.99 and 0.40 respectively. For chocolates, the Emperor had the highest Pb:Zn (0.50) ratios and Trident had the highest Cd:Zn (0.57) ratios. The calculated percentage provisional tolerable weekly intake (%PTWI) of cadmium from consumption of chocolates and candies was higher than the Joint Expert Committee for Food Additives (JECFA) standard, and the cancer risk of lead, cadmium, and chromium ranged between 10⁻⁷ and 10⁻³. Consumption of some candies by children in Nigeria may pose significant health risks.

Adsorption on low-cost biochars would increase the affordability and availability of water treatment in, for example, developing countries. The aim of this study was to identify the precursor materials and hydrochar surface properties that yield efficient removal of compounds of environmental concern (CEC). We determined the adsorption kinetics of a mixture containing ten CECs (octhilinone, triclosan, trimethoprim, sulfamethoxasole, ciprofloxacin, diclofenac, paracetamol, diphenhydramine, fluconazole, and bisphenol A) to hydrochars prepared from agricultural waste (including tomato- and olive-press wastes, rice husks, and horse manure). The surface characteristics of the hydrochars were evaluated via diffuse reflectance infrared spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), and N₂-adsorption. Kinetic adsorption tests revealed that removal efficiencies varied substantially among different materials. Similarly, surface analysis revealed differences among the studied hydrochars and the degree of changes that the materials undergo during carbonization. According to the DRIFTS data, compared with the least efficient adsorbent materials, the most efficient hydrochars underwent more substantial changes during carbonization.

An easily recoverable homemade TiO₂ catalyst (GICA-1) has been evaluated during the overall photodegradation process, understood as photocatalytic efficiency and catalyst recovery step, in the solar light-assisted photodegradation of isoproturon and its reuse in two consecutive cycles. The global feasibility has been compared to the commercial TiO₂ P25. The homemade GICA-1 catalyst presented better sedimentation efficiency than TiO₂ P25 at all studied pHs, which could be explained by its higher average hydrodynamic particle size (3 μm) and other physicochemical surface properties. The evaluation of the overall process (isoproturon photo-oxidation + catalyst recovery) revealed GICA-1 homemade titania catalyst strengths: total removal of isoproturon in less than 60 min, easy recovery by sedimentation, and reusability in two consecutive cycles, without any loss of photocatalytic efficiency. Therefore, considering the whole photocatalytic cycle (good performance in photodegradation plus catalyst recovery step), the homemade GICA-1 photocatalyst resulted in more affordability than commercial TiO₂ P25. Graphical abstract