Wastewater effluent from alkaloid processing plants has the potential adverse environmental influences. Mathematical modelling and simulations were carried out using computational fluid dynamics of mass and momentum transfer in a hollow fibre membrane extractor. Conservation equations were derived for tyramine extraction in the membrane extractor and solved based on the finite element method. Model findings based on the computational fluid dynamics validated well with the experimental data. The results showed that increase in organic-phase flow rate, as well as the fibre length and its porosity, has a positive impact on the performance of the extractor, whereas the enhancement of aqueous-phase flow rate led to the reduction of tyramine extraction.

Recycled moisture, mainly originated from evapotranspiration (surface evaporation and transpiration), is the main sources of precipitation. Influenced on the different regional/local environments, the contributions of recycled moisture to precipitation present as different proportions. Recycled moisture has an important impact on the hydrological cycle, further occurred a series of environmental effect for regional/local. Aimed to estimate the contribution of recycled moisture to precipitation in an enclosed basin, Guanzhong Basin of northern China, precipitation and lake/reservoir samples were collected. The isotope ratio analysis was done for the summer season, and a three-component mixing model based on the stable hydrogen and oxygen isotopes was applied. The results indicated that the averaged contribution of recycled moisture to precipitation was 17.44% in Guanzhong Basin of northern China, while the mean proportions of surface evaporation moisture and transpiration moisture were found to be 0.38% and 16.97%, respectively. Comparatively, most of the recycled moisture mainly comes from transpiration moisture rather than evaporation moisture, suggesting that transpiration moisture from cropland, vegetation, and plants instead of evaporation is dominant in moisture recycling of the Guanzhong Basin.

Municipal wastewater reverse osmosis concentrate (ROC) poses health and environmental risks on its disposal as it contains nutrients and harmful organic compounds at elevated concentrations. This study compared a freshwater microalga Chlorella vulgaris and a marine microalga Nannochloropsis salina in suspended and alginate-immobilised cultures for batch and semi-continuous treatment of the ROC. The immobilised algae gave comparable nutrient removal rates to the suspended cells, demonstrating immobilisation had no apparent negative impact on the photosynthetic activity of microalgae. Semi-continuous algal treatment illustrated that the microalgae could remove significant amounts of nutrients (> 50% and > 80% for TN and TP, respectively), predominantly through algal uptake (> 90%), within a short period (48 h) and generate 335–360 mg DCW L⁻¹ d⁻¹ of algal biomass. The treatment also removed a significant amount of organic matter (12.7–13.3 mg DOC L⁻¹ d⁻¹), primarily (> 65%) through the biotic pathway.

Biodiesel is a mixture of fatty acid methyl esters (FAME) from either vegetable oils or animal fats. Although biodiesel biodegrades faster than diesel fuel, the impacts of this biofuel in environment throughout its biodegradation process should be investigated. For this reason, the objective of the present study was to evaluate the microbial activity, the phytotoxicity, and the formation of metabolites during biodegradation of the contaminated soil with biodiesel. Microbial activity was evaluated using culture-dependent methods in soil samples artificially contaminated with biodiesel—followed by pH adjustments. The formation of metabolites during biodegradation was identified using gas chromatography coupled with mass spectrometry (GC/MS). Respirometric method was also applied to evaluate total microbial activity. Seeds of Cucumis sativus were sown in soil samples before and after biodegradation to expand our knowledge on the impacts of such metabolites in a eukaryotic test-organism. Culture-dependent assays successfully allowed the quantification of microorganisms during biodegradation. According to CO₂ production, biodiesel initially acted as a biostimulation agent increasing microbial activity. Indigenous microbiota degraded biodiesel into smaller compounds such as pentane, free fatty acids, and methanol. Soil pH significantly dropped from 5.4 to 3.0 after 120 days of biodegradation as a result of high concentration of free fatty acids. These free fatty acids inhibited further microbial growth after biodegradation. It was proposed that correcting soil acidity during biodegradation would be enough to sustain microbial growth. However, pH decrease was just one of the factors that inhibited microbial growth and plant root development. It was proposed that biodegradation yielded toxic metabolites such as methanol. These metabolites contributed to impair the root elongation due to alcohol-specific properties to solubilize a wide variety of lipids within the seed. Therefore, the present study draws attention to metabolites from biodegradation of biodiesel and their potentially harmful environmental impacts.Biodegradation of biodiesel changes soil pH, as it generates metabolites that are phytotoxic, and reduces microbial counts (CFU g⁻¹ dry soil).

In this paper, a phthalic acid ester (PAE) three-dimensional quantitative structure-activity relationship (3D-QSAR) model with a double activity (toxicity and estrogenic activities) combination was established using a comprehensive evaluation method, in which the database of the combined activities consisted of 17 and 13 employed in the training sets and test sets, respectively. Ditridecyl phthalate (DTDP) derivatives with low-toxicity and estrogen combined activities were designed with DTDP as the target molecule. Four environmentally friendly DTDP derivatives were screened out by evaluating their environmental friendliness (expressed by persistence, bioaccumulation and migration) and practicability (expressed by insulation). Through the toxicity and estrogen single-activity model validation and contour map analyses, the results showed that the 3D-QSAR model for PAE toxicity and estrogen combined activities was feasible and the weight setting was reasonable. In addition, the mechanism analysis showed that the toxicity and estrogen combined activities of the four DTDP derivatives (2-CH₃-DTDP, 2-OCHO-DTDP, 2-CH₂COOH-DTDP, 2-CH₂OH-DTDP) decreased in turn and were consistent with the single-activity model prediction. Meanwhile, it was speculated that the binding effect of the DTDP derivative molecules and estrogen-related proteins might be related to their hydrophobic interaction.

The net greenhouse gas (NGHG) emissions and net greenhouse gas intensity (NGHGI) were investigated via the determination of nitrous oxide (N₂O) emission in loess soil under rainfed winter wheat monocropping system during 3 years of field study in Northwest China. Five treatments were carried out: control (N₀), conventional nitrogen (N) application (NCₒₙ), optimized N application with straw (SNOₚₜ), optimized N application with straw and 5% of dicyanodiamide (SNOₚₜ + DCD), and optimized N rate of slow release fertilizer with straw (SSRFOₚₜ). Over a 3-year period, the NGHG emissions were achieved 953, 1322, 564, and 1162 kg CO₂-eq ha⁻¹, simultaneously, and the NGHGI arrived 158, 223, 86, and 191 kg CO₂-eq t⁻¹ grain in NCₒₙ, SNOₚₜ, SNOₚₜ + DCD, and SSROₚₜ grain, respectively. Contrasted with conventional farming system, optimized farming methods reduced 32% of N fertilizer use without significant decrease in grain yield, but brought about 38% increase in N₂O emissions, up to 28% gained in soil CH₄ uptake. Thus, it was observed that the straw incorporation performs noticeable increased in N₂O emissions in the winter wheat cropping season. Among the optimized N fertilizer rates compared with the SNOₚₜ treatment, the SNOₚₜ +DCD and SSROₚₜ treatments decreased in N₂O emissions by approximately 55% and 13%, respectively. Additionally, the N₂O emission factor across over a 3-year period was 0.41 ± 0.08% derived from N fertilizer, and it was half of IPCC default values for upland corps. It is expected possibly due to low precipitation and soil moisture with the monocropping system. The 25% higher in the amount of rainfall (almost 300 mm in 2013–2014) during a cropping season underwent into 1–2-fold increase in N₂O emissions from N-fertilized plots. As the statistical differences among annual cumulative emissions coincided with that during winter wheat growing season, it can be concluded that crop growing season is a vital important period for the determination of N₂O emissions from under rainfed monocropping system.

The eddy covariance (EC) technique was used to measure variations of orchard-atmosphere CO₂ exchange, as a function of meteorological variables in an apple orchard in 2016–2017. The annual average CO₂ exchange rate was 2.295 kg m⁻². Excavations and biomass assessments demonstrated that the orchard stored close to 20.6 tC ha⁻¹ as plant C over a 15-year period. Seasonally, high rates of CO₂ uptake and low CO₂ emissions occurred between May and August and December and March, respectively. The maximum rates of monthly CO₂ exchange were 144.44 and 153.61 gC m⁻² month⁻¹ in August 2016 and June 2017, respectively. Partial least squares (PLS) regressions were used to analyze the influence of meteorological factors to on CO₂ exchange rates. Temperature and photosynthetic active radiation (PAR) were observed to exert the largest influence on driving variation in CO₂ exchange. The main meteorological factors affecting CO₂ exchange on daily and monthly time scales were soil temperature (Tₛₒᵢₗ), air temperature (Tₐ), PAR, below canopy CO₂ concentration (BCC), vapor pressure deficit (VPD), and soil water content at 50 cm (SWC₅₀cₘ). The regression model equation describing CO₂ exchange included Tₐ, VPD, precipitation (PPT), and sunshine duration (SD), as significant variables. This model curve fitting explains over 80% of the variation in CO₂ exchange. This study provides CO₂ exchange characteristics and a model equation capable of predicting CO₂ exchange of an apple orchard. Graphical Abstract

Besides adsorption rate constant, the half-life was also a basic factor that described the characteristics of adsorption kinetics. However, the direct prediction of the half-life was still a problem to be addressed urgently. In this work, the parameter τ was introduced into the pseudo-first-order (PFO), pseudo-second-order (PSO), pseudo-nth-order (PNO), and the corresponding fractal-like kinetic models (fractal-like PFO, fractal-like PSO, and fractal-like PNO) to directly predict the half-life by changing the boundary condition, i.e., the replacement of qₜ = 0, t = 0 by qₜ = qₑ/2, t = τ. The fitting performance of these kinetic models after modification was evaluated by nitrate adsorption on polyaniline-modified activated carbon (PAN/AC) and phosphate adsorption on zirconium-loaded Ca-montmorillonite. The results indicated that this type of model modifications did not influence the fitting performance and that the half-life was easily obtained only by the curve fitting. The practical significance of this work was to simultaneously predict the adsorption rate constant and half-life using the modified kinetic models.

The article examines the effects of renewable energy, trade, carbon dioxide emissions and international tourism on economic growth in EU-28, considering panel data for the period 1995–2014. The investigation finds the new determinants of economic growth. The empirical results find support from the panel fully modified least squares (FMOLS), panel dynamic least squares (DOLS) and fixed effects (FE) as estimation techniques. The econometric results are consistent with the existing literature. The variables considered in this study are cointegrated in the first difference, as suggested by the panel unit root test. The present study seeks to advance the knowledge of the growth determinants, paying attention to the effect that both the tourism and energy sector exerts on economic growth for EU-28 countries. The empirical results demonstrate that trade openness, tourism arrivals and renewable energy encourage economic growth. Therefore, according to the econometric results, renewable energy allows improving environmental quality. However, CO₂ emissions are positively correlated with economic growth, showing that growth is directly correlated by climate change and greenhouse gas. The results also confirm the tourism-led growth hypothesis (TLGH) for the panel. Finally, the empirical results confirm that trade openness, energy use and international tourism contribute to enhance economic growth. Based on these findings, further insights and policy prescription are offered in the concluding section.Graphical abstract

Biofilm, a consortium of microbial cells, protected by extracellular polymeric matrix, is considered a global challenge due to the inherent antibiotic resistance conferred by its lifestyle. Besides, it poses environmental threats causing huge damage in food industries, fisheries, refineries, water systems, pharmaceutical industries, medical industries, etc. Living in a community of microbial populations is most critical in the clinical field, making it responsible for about 80% of severe and chronic microbial diseases. The necessity to find an alternative approach is the need of the hour to solve these crises. So far, many approaches have been attempted to disrupt the initial stage of biofilm formation, including adherence and maturation. Bacteriocins are a group of antimicrobial peptides, produced by bacteria having the potential to disrupt biofilm either by itself or in combination with other drugs than antibiotic counterparts. A clear understanding on mechanisms of bacterial biofilm formation, progression, and resistance will surely lead to the development of innovative, effective biofilm control strategies in pharmaceutical, health care industries and environmental locales.