Non-edible seeds are not used in any commercial applications, which implies that they can be used for biofuel applications. The present study aimed to maximise the process conditions for oil extraction and sterculia biodiesel production from Sterculia foetida (poon oil). GC-MS identified the methyl esters of sterculia oil as sterculic acid (32%), palmitic acid (15.88%), oleic acid (10.00%), linoleic acid (9.95%) and malvalic acid (9%). Response surface methodology (RSM) based parametric optimisation of oil extraction was carried out by choosing process variables such as sample weight, volume of solvent to seed ratio and time. The optimum sample amount of 7.5 g and the volume of solvent to seed ratio of 40 mL/g resulted in a maximum oil yield of 45.27% at 3 h. The results were statistically significant (P < 0.05) with a regression coefficient (R²) of 0.9988. Furthermore, the artificial neural network (ANN) resulted in an R² value greater than 0.9, which validates the RSM. Conventional optimisation of the temperature (55 °C), feedstock to methanol ratio (1:12), catalyst proportion (1.5%) and transesterification reaction time (60 min) yield 90.87% biodiesel production. The physicochemical characteristics of oil and biodiesel complied with the requirements of the ASTM standards. The rate constant and thermodynamic variables at the optimum temperature (333 K) were calculated from the experimental data. The activation energy (Eₐ), activation enthalpy in transition state theory (ΔH⁺⁺), activation entropy in transition state theory (ΔS⁺⁺) and Gibbs free energy in transition state theory (ΔG⁺⁺) were 37.91 kJ mol⁻¹, 35.14 kJ mol⁻¹, − 239.58 J mol⁻¹ K⁻¹ and 79.81 kJ mol⁻¹ respectively. Graphical abstract

The developing countries and emerging economies are crucially contributing to global economic development, energy transition, and climate governance. This paper employs panel cointegration technique to investigate the long-run relationship between carbon emissions and five impacting factors (per capita GDP, primary energy consumption, international trade, fossil proportion, and quadratic per capita GDP) in 50 representative developing countries during 1995–2017. The empirical findings confirm the existence of long-run equilibrium, and the regressing coefficients of fully-modified OLS (FMOLS) indicate that (a) impacting features of the inverted U-shaped curve of Environmental Kuznets Curve (EKC) theory appear in a few countries, such as Mexico, Croatia, Kazakhstan, Iran, Algeria, Indonesia, and Thailand; (b) the energy consumption has statistically positive and significant impacts on boosting the carbon emissions; (c) the negative effect of international trade emerges in the developing nations enjoying trade surpluses; and (d) fossil energy share poses a mixed impact. This paper reveals that the vast and inspiring contribution of developing countries to global carbon emission reduction should attract more international attention and assistance.

Source apportionment of atmospheric PM1 is important for air quality control, especially in urban areas where high mass concentrations are often observed. Chemical analysis of molecular inorganic and organic tracer compounds and subsequently data analysis with receptor models give insight on the origin of the PM₁ sources. In the present study, four source apportionment approaches were compared with an extended database containing inorganic and organic compounds that were measured during an intensive sampling campaign at urban traffic and urban background sites in Barcelona. Source apportionment of the combined database, containing both inorganic and organic compounds, was compared with more conventional approaches using inorganic and organic databases separately. Traffic emission sources were identified in all models for the two sites. The combined inorganic and organic databases provided higher discrimination capacity of emission sources. It identified aerosols generated by regional recirculation of biomass burning, secondary biogenic organic aerosols, harbor emissions, and specific industrial emissions. In this respect, this approach identified a relevant industrial source situated at NE Barcelona in which a waste incinerator plant, a combined-cycle power plant, and an industrial glass complex are located. Models using both inorganic and organic molecular tracer compounds improve the source apportionment of urban PM.

In this study, Broussonetia papyrifera leaves collected from land near a restored manganese mine in the Hunan Province of China were converted into biochar under high-temperature anaerobic conditions, regeneration and utilization of agricultural and forest waste, and applied to the prevention of eutrophication. The physicochemical properties of the B. papyrifera biochar were characterized using Micromeritics 3Flex analyzer, scanning electron microscope (SEM), Fourier transform infrared spectrometer (FT-IR), thermogravimetric analyzer (TGA), X-ray photoelectron spectrometer (XPS), zeta potential meter (zeta), and X-ray diffraction (XRD). The effects of pH, ionic strength, coexisting ions, time, initial concentration, and temperature on the decontamination process of phosphate in water were studied. The results indicated that adsorption was enhanced under alkaline conditions. The pseudo-second-order model of adsorption kinetics was applied to illustrate the adsorption processes. The chemical adsorption reaction was the main rate-limiting step in the adsorption process. Isotherm experimental data were best fitted by the Freundlich model at 25 °C and by the Langmuir model at 35 °C. The phosphate combined with B. papyrifera biochar mainly in the forms of exchangeable phosphorus (Ex-P), Al-bound phosphorus (Al-P), and Fe-bound phosphorus (Fe-P). These results indicate that B. papyrifera biochar is a suitable candidate for the treatment of a eutrophic body of water.

Transporters play an important role in the uptake and redistribution of agrochemicals to the site of insect feeding. The product of the Arabidopsis thaliana gene AtAAP1 substantially contributes to inorganic nitrogen acquisition under ecologically relevant amino acid concentrations. Here, the transporter ability of AtAAP1 to a chlorantraniliprole-alanine conjugate (CAP-Ala-1) was tested both in planta and in vitro. Thirty-day-old and 15-day-old plants overexpressing AtAAP1 increased the uptake of CAP-Ala-1 into the roots, whereas AtAAP1 deficiency did not completely block the uptake of CAP-Ala-1. An uptake experiment carried out in Xenopus laevis oocytes expressing AtAAP1 showed that CAP-Ala-1 interacted with AtAAP1. Although little native AtAAP1 transcription was present in the leaves, constitutive expression of AtAAP1 in plants significantly increased the ability of the leaf mesophyll protoplasts to take up CAP-Ala-1. The observations supported the possibility of exploiting AtAAP1 as a component of a novel delivery and redistribution system for amino acid-based pesticide conjugates.

A novel hybrid UV-C/microfiltration process for water disinfection is presented, and its application in continuous mode operation to the removal of different pathogen germs (Escherichia coli, Enterococcus faecalis, and Candida albicans) present in urban wastewater. The membrane photoreactor is based on porous stainless steel membranes coated with a TiO₂ layer and illuminated by a UV-C lamp (254 nm). A valve actuator in the outlet of the UV-C stream allows operation of the system under conditions of constant transmembrane pressure (TMP) keeping the UV-C contact time in few seconds, significantly lower than the typical irradiation time employed in TiO₂ photocatalytic processes. An E. coli removal of up to 4-log in the permeate stream and up to 2-log in the UV-C outlet was achieved with a 0.2 μm membrane operating with a TMP of 0.5 bar and a UV-C contact time as low as 8 s. The microbial balance data from the cells recovered from the membrane confirmed that 96–98% of the removed microorganisms died due to the UV-C action over the membrane surface. Modification of the membrane with a TiO₂ layer has been also shown to be a suitable way to improve both the UV-C inactivation and the filtration efficiency. The results reported in this work constitute a proof of concept of the synergy between UV-C and filtration that can be achieved in a hybrid UV-C/microfiltration system, being a good example of process intensification where two products of different quality can be simultaneously obtained.

Preparation of the value-added products from e-waste resources is an important step in the recycling process. The present paper aims to propose a methodology for the recovery of In from scrap LCD panel via preparation of InBO₃ nanostructure. Discarded LCD panel was subjected to a recycling process through crushing, milling, and oxalic acid leaching to prepare In₂(C₂O₄)₃·6H₂O. Through the leaching process, B(OH)₃ from glass part (alumina borosilicate) has been leached out along with indium oxalate hydrated. Further thermal treatment on these extracted materials at 600 °C could result in the formation of InBO₃ nanostructures with an average particle size of 20 nm. A multistep mechanism based on thermodynamic calculations for the recycling of the InBO₃ form extracted precursors was proposed. Graphical abstract

Composting is considered as one of the main sustainable methods for the treatment of livestock manure. In this study we investigated the effects of additives (urea and rice straw) on methane (CH₄), nitrous oxide (N₂O), and carbon dioxide (CO₂) emissions using a traditional Chinese pig slurry composting method over an 81-day period, as well as examining total organic carbon and total nitrogen loss. Four common treatment strategies were examined in this study: a control (MC), urea nitrogen addition (MN), composting using rice straw cover (MScₒᵥₑᵣ), and compost mixed with rice straw (MSₘᵢₓ). Our results indicate that the addition of urea resulted in the lowest total CH₄ emissions and the highest N₂O emissions. MScₒᵥₑᵣ treatment had the highest and most significant effect on CH₄ emissions, while MSₘᵢₓ treatment had the lowest CO₂ emissions. Carbon lost through CH₄ and CO₂ released during the experiment was 0.1–0.9 and 2.4–3.9% of total carbon loss, respectively, and nitrogen lost through N₂O release was 11.1–17.9% of total nitrogen. In general, although MSₘᵢₓ, MScₒᵥₑᵣ, and MN treatments increased global warming potential by 21.4, 41.6, and 50.9% per kg of pig slurry, respectively, no statistical differences between the four treatments were recorded. By considering carbon and nitrogen conservation, as well as the improvement of the quality of compost and the mitigation of greenhouse gases (GHGs), the small-scale composting method of pig slurry alone is an acceptable environmentally friendly strategy for use in China.

Based on the China’s 1997, 2002, 2007, and 2012 multiregional input–output model, this study calculates China’s provincial CO₂ emissions from investment demand and interprovincial transfer of CO₂ emissions caused by investment demand. The findings of this study are as follows: (1) From 1997 to 2012, the CO₂ emissions from China’s investment demand have seen rapid growth—the CO₂ emissions from investment demand has increased by 4.52 times, and the per capita CO₂ emissions caused by investment demand has increased by 4.13 times. Investment demand is an important driver of growth of China’s CO₂ emissions. The proportion of CO₂ emissions from investment demand in CO₂ emissions from China’s three final demands rose from 37.72% in 1997 to 50.68% in 2012. (2) The CO₂ emissions from investment demand are relatively large in provinces which have large-scale industries. Affected by investment-driven economic growth, CO₂ emissions from investment demand in central, western, and northeastern provinces have increased more rapidly. (3) Large amounts of CO₂ are emitted in the less-developed central and western provinces to meet the investment demand of the developed eastern provinces. As China’s economy enters the “new normal,” economic growth is shifting from investment-driven to consumption-driven, and the growth of CO₂ emissions from investment demand will slow down.

A study of pesticides in the Bizerte lagoon watershed on the Mediterranean coast of Tunisia showed that herbicides and fungicides are the most commonly used compounds. A survey was made of selected farmers. Pesticide contamination was monitored in the water column and sediments at four selected sampling sites (lagoon (A) and in three oueds—Chegui (B), Garaa (C), and Tinja (D)). Polar organic chemical integrative samplers (POCIS) were used to assess pesticide contamination. Thirty-two pesticides were investigated; the total concentration of active ingredients ranged from 35.9 ng L⁻¹ in Tinja oued to 1246 ng L⁻¹ in Chegui oued. In the lagoon, the total concentration of pesticides was 67.7 ng L⁻¹. In the sediments, the highest concentration was measured in Chegui oued in the spring (31 ng g⁻¹ dw). The main compounds found in the analyzed sediments were prosulfocarb and tebuconazole molecules.