Improving the competitiveness of biodiesel production by microalgae cultures requires the application of several strategies to obtain a high content of lipids, rapid biomass growth and a capacity to adapt to different kinds of environment, with the aim of using non-renewable nutrient sources. Therefore, the use of an individual indigenous microalgae strain or a consortium from natural or anthropogenic sites is now considered an alternative for biofuel production. This study examined the temporal behaviour of secondary metabolites produced by a native microalgae and yeast consortium isolated from wastewater, which was characterized by a genetic identification method based on the MiSeq system. The predominant species in the consortium was Scenedesmus obliquus, representing 68% of the organisms. In addition, the consortium contained a number of yeast species, including Candida pimensis (43%), Arthroderma vanbreuseghemii (23%), Diaporthe aspalathi/Diaporthe meridionalis (25%) and Hericium americanum (3%). This indigenous co-culture of microalgae and yeast showed biomass productivity of 0.06 g l⁻¹ day⁻¹, with a content of 30% (w/w) carbohydrates, 4% (w/w) proteins and 55% (w/w) lipids. Transesterification of the extracted lipids produced fatty acid methyl esters (FAMEs), which were analysed by gas chromatography (GC). The FAMEs included methyl pentadecanoate (1.90%), cis-10-pentanedecanoic acid methyl ester (1.36%), methyl palmitate (2.64%), methyl palmitoleate (21.36%), methyl oleate (64.95%), methyl linolenate (3.83%) and methyl linolelaidate (3.95%). This composition was relevant for biodiesel production based on the co-culture of indigenous microalgae and yeast consortia.

Along with the development of urbanization and informationization, an increasing attention has been attracted to CO₂ emissions of China’s transportation sector and its influencing factors. Such researches mainly utilize single indicator or two indicators to represent technology process. This research aims to verify the influence of technology-environmental innovation indicator system on CO₂ emissions of China’s transportation sector by decoupling elasticity and econometric model. We firstly recognize the decoupling status of CO₂ emissions of China’s transportation sector from social economic development and aggregate China’s 30 provinces into two groups according to the varied decoupling status, namely expansive coupling and weak decoupling groups. Then, we develop a relatively comprehensive technology-environmental innovation indicator system to measure technology process. Finally, the multi-region comparison of emission drivers is studied among overall China and the two groups. The result shows that the decoupling elasticity of China’s transportation has experienced an evolution process trending to desired development status and all the provinces have experienced expansive coupling and weak decoupling from 2001 to 2016, except Qinghai. Innovation performance indicators exert most important influence on the CO₂ emissions of transportation sector. Finally, the influences of technology-environmental innovation indicators are similar across groups with different magnitude, suggesting that common but differentiated strategies should be provided when mitigating CO₂ emissions with technology process. Graphical abstract

Recent research interest has focused on microalgae cultivation for biogas slurry purification and biogas upgrading due to the requirement of high efficiency for nutrient uptake and CO₂ capture, with economic feasibility and environmental benefits. Numerous studies have suggested that biogas slurry purification and biogas upgrading can occur simultaneously via microalgae-based technology. However, there is no comprehensive review on this technology with respect to the nutrient removal from biogas slurry and biogas upgrading. This article summarizes microalgal cultivation with biogas slurry and biogas from anaerobic digestion. The parameters, techniques, and modes of microalgae cultivation have been discussed in detail to achieve high efficiency in biogas slurry purification and biogas upgrading. In addition, the evaluation of energy efficiency and safety has also been explored. Compared with mono-cultivation of microalgae and co-cultivation of microalgae and bacteria, microalgae-fungi symbiosis has demonstrated greater development prospect and higher energy efficiency and the energy consumption for pollutants and CO₂ removal were 14.2–39.0% · USD⁻¹ and 19.9–23.3% · USD⁻¹, respectively. Further, a sustainable recycling scheme is proposed for the purification of biogas slurry from anaerobic digestion process and biogas upgrading via microalgae-based technology.

Oxidative stress is considered as one of the main mechanisms by which airborne particles produce adverse health effects. Several methods to estimate the oxidative potential (OP) of particulate matter (PM) have been proposed. Among them, the dithiothreitol (DTT) assay has gained popularity due to its simplicity and overall low implementation cost. Usually, the estimations of OPᴰᵀᵀ are based on n-replicates of a set of samples and their associated standard deviation. However, interlaboratory comparisons of OPᴰᵀᵀ can be difficult and lead to misinterpretations. This work presents an estimation of the total uncertainty for the OPᴰᵀᵀ measurement of PM₁₀ and PM₂.₅ samples collected in Santiago (Chile), based on recommendations by the Joint Committee for Guides in Metrology and Eurachem. The expanded uncertainty expressed as a percentage of the mass-normalized OPᴰᵀᵀ measurements was 18.0% and 16.3% for PM₁₀ and PM₂.₅ samples respectively. The dominating contributor to the total uncertainty was identified (i.e., DTT consumption rate, related to the regression and repeatability of experimental data), while the volumetric operations (i.e., pipettes) were also important. The results showed that, although the OP measured following the DTT assay has been successfully used to estimate the potential health impacts of airborne PM, uncertainty estimations must be considered before interpreting the results.

The importance of information and communication technologies (ICTs) in environmental resource management opens a new debate for the policy makers in order to promote green technologies to mitigate high mass carbon emissions across the globe. “Digital Pakistan” initiative is taken by the government that aimed to use technology for country’s social welfare, which further be enhance for achieving environmental sustainability over a time horizon. This study examined the long-run relationship between ICTs, energy demand, and carbon emissions in a context of Pakistan by using a time series data from 1975 to 2017. The results show that energy demand increases economic growth in the short-run while it decreases economic growth in the long-run. The country’s economic growth substantially increases along with an increase in trade openness and mobile-telephone subscription (ICTs) in the short-run; however, the result is changed in the long-run due to increase in carbon emissions in a given time period. The results provoke that continued economic growth and ICT penetration substantially decreases energy demand, whereas urbanization increases energy demand in a country. The results show that variations in emissions associated with proportionate changes in ICTs penetration, economic growth, energy demand, and population growth. Human capital, trade openness, and energy demand are the significant drivers of ICT penetration in a country. The study concludes that the use of green technology is imperative for achieving long-term sustainable growth in a country.

This research aims to explore the existence of a new concept known as “environmental Phillips curve” (EPC) developed by the authors. Taking annual data of 30 countries for 26 years, a panel data estimation method is applied. The invented function shows an inverse relationship between pollution and unemployment. In most of the cases, the industrialized countries show that the relationship is valid. The notion is proved effective in every format of investigation. It seems that curbing pollution in the world is only possible at the cost of human employment. Therefore, if countries want to curb environmental pollution without affecting the generation of employment and reducing poverty, they should contemplate both innovation and enforcement alternative technologies that would be less polluting but employment friendly. Moreover, this research also suggests that if a country can treat pollution efficiently, it can increase the national income without a deteriorating unemployment level.

The entropy generation analysis is an approach to optimize the performance of different thermal systems by investigating the related irreversibilities of the system. This paper provides a concise review of the entropy generation analysis performed for different solar thermal energy systems including solar collectors, solar heaters, solar heat exchangers, and solar stills. The mathematical formulation and the equations for calculating the entropy generation are briefly presented. Moreover, main passive techniques including the usage of nanofluids, porous materials, and inserts which are used to improve the efficiency of different solar systems are discussed. It is shown that using entropy generation minimization method is an efficient tool to find the optimal design of solar systems. The current review aims to motivate researchers in the field of solar energy for using entropy generation analysis to reduce the lost work and consequently improving the system performance.

Widely distributed western mosquitofish (Gambusia affinis) has been used as a new model species for hazard assessment of environmental stressors such as polycyclic aromatic hydrocarbons (PAHs). However, most of the PAH studies using G. affinis rely on targeted biomarker-based analysis, and thus may not adequately address the complexity of the toxic mechanisms of the stressors. In the present study, the whole transcriptional sequencing of G. affinis liver after exposure to a PAH model, benzo[a]pyrene (BaP) (100 μg/L), for 20 days was performed by using the HiSeq XTen sequencers. In total, 58,156,233 and 51,825,467 clean nucleotide reads were obtained in the control and BaP-exposed libraries, respectively, with average N50 lengths of 1419 bp. In addition, after G. affinis was exposed for 20 days, 169 genes were upregulated, and 176 genes were downregulated in liver. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were applied to all the genes to determine the genes’ biological functions and processes. The results clearly showed that the differentially expressed genes were mainly related to immune pathways and metabolic correlation pathways. Interestingly, almost all the pathways related with the immunity were upregulated, while the metabolism pathways were downregulated. Lastly, quantitative real-time PCR (qRT-PCR) was performed to measure expressional levels of twelve genes confirmed through the DGE analysis. These results demonstrate that BaP damages immunity and enhances the consumption of all available energy storage to activate mechanisms of the detoxification in G. affinis. Up until now, the present study is the first time that a whole transcriptome sequencing analysis in the liver of G. affinis exposed to BaP has been reported.

The study aims to understand the influence of environmental and lifestyle factors and more specifically the role of tobacco smoke–infused water (tuibur) on Helicobacter pylori infection. It was a cross-sectional study to measure the epidemiological risk factors associated with H. pylori infection among the tribal population in Northeast India. Endoscopic samples were collected from the antrum region of the stomach from 863 participants with gastritis. H. pylori infection was confirmed in 475 samples by the rapid urease test and PCR-based methods. Information on demographic and lifestyle factors was collected using a validated and standardized questionnaire. Logistic regression was used to estimate odds ratio (OR) and 95% confidence interval (CI) for the association between the various factors and H. pylori. The use of tuibur was associated with an increased OR of H. pylori infection (OR = 3.32, 95% Cl = 1.95–5.83). Tobacco chewers (OR = 1.49, 95% Cl = 1.06–2.09), smokers (OR = 1.81, 95% Cl = 1.26–2.61), and alcohol consumers (OR = 1.81, 95% Cl = 1.19–2.76) were also infected with H. pylori. The results were not attenuated after adjusting for major well-known risk factors of H. pylori infection. The habit of tuibur consumption may be a contributing factor to the high prevalence of H. pylori infection and in turn, may contribute to the high prevalence of gastritis among the Mizo population.