This study aims to investigate the validity of pollution haven hypothesis for the period from 1982 to 2013 in ten newly industrialized countries. For this purpose, we examine the relationship between real income, foreign direct investment, energy consumption, and ecological footprint using second-generation panel data methodology to take into account the cross-sectional dependence among newly industrialized countries. In doing so, the possible nonlinear relationship between foreign direct investment and environmental degradation is also searched. The results show that increased energy consumption and economic growth lead to increase in ecological footprint. Moreover, the U-shaped relationship between foreign direct investment and ecological footprint is confirmed in newly industrialized countries.

In this study, we focused on the rate of adsorption of phosphate on to the surface of magnetite in the presence of coexisting anions, organic matters and heavy metals. Magnetite particles were prepared using a co-precipitation method. Iron (II) sulfate heptahydrate and iron (III) chloride hexahydrate were mixed and then a sodium hydroxide solution was added drop-wise in the mixed iron solution. Coexisting anions were found to have no effect on the decrease in phosphate adsorption. However, phosphate adsorbed on to magnetite surface decreased with increasing total organic carbon (TOC) concentration of natural organic matter (NOM) such as citric, oxalic, and humic acid. The amount of phosphate adsorbed rapidly decreased with the increase of NOM concentration; therefore, it can be noted that NOM concentration considerably affects the adsorption of phosphate due to the negative charge exiting on the surface of NOMs. Glucose and ethanol, meanwhile, were found to have no effect on the phosphate adsorption. The amount of phosphate adsorbed did not change in the presence of heavy metals, namely, Pb and Cd, under acidic conditions. However, under alkaline conditions, the amount of phosphate adsorbed decreased with increasing concentrations of Pb and Cd. In the case of coexisting As(III), the amount of phosphate adsorbed decreased at all pH levels with increasing As(III) concentrations.

Gas sparging is used as a traditional way to control membrane fouling in submerged membrane bioreactors (MBRs) in wastewater treatment. However, the gas sparging accounts for the largest fraction in operational cost to run the MBR systems. In this study, membrane fouling was controlled by integrating scouring media with gas sparging to reduce fouling rate at relatively low operational energy. Comparative study was performed using a fluidized membrane reactor treating synthetic feed solutions between polyethylene terephthalate (PET) scouring media (SM) fluidized by gas sparging (GS), liquid recirculation (LR), and combination of them to control membrane fouling. Addition of PET scouring media reduced the gas flow rate by 67% more with 30% less in fouling rate than gas sparing only. Combined usage of gas sparging and liquid recirculation to fluidize the PET scouring media (LR + GS + SM) showed 37% lower in fouling rate than that obtained by the scouring media fluidized by liquid recirculation (LR + SM) only through the reactor. The LR + GS + SM configuration reduced energy consumption by 90% more than that required by gas sparging alone. Mechanical cleaning driven by fluidizing PET scouring media could reduce membrane fouling due to removing deposit of inorganic particles from membrane surface effectively. However, the PET scouring media was not very effective to reduce membrane fouling caused by organic colloids which are expected to contribute pore fouling significantly.

We report an arrangement on the effect of anthropogenic litter on marine and estuarine reptiles, checking for evidence about different types of impact (ingestion vs. entanglement) and pressure (three size-based categories). From 1976 to 2018, we obtained a “blacklist” of 11 species impacted by marine litter (about 13% of 85 species of marine and estuarine reptiles), belonging to three orders (Testudines, Squamata, and Crocodilia). We obtained only occasional evidence of an impact for Squamata (Hidrophis elegans, Disteira major) and Crocodilia (Crocodylus porosus). Regarding the different types of pressure, the highest number of evidence has been obtained for macro-litter (10 species) and the lowest for micro-litter (4 species, all Chelonidae). Among Testudines, Lepidochelys kempii and Natator depressus evidenced a lack of data for micro-plastic. In Squamata, information is lacking for micro-plastic with only occasional references for meso-plastic (in Hydrophis elegans) and macro-plastic (Disteira major and Crocodylus porosus). We obtained a direct correlation between the research effort and the number of citations regarding different types of pressure and impact of marine litter: therefore, our blacklist of impacted species could be increased, carrying out further research focused on other poorly studied marine and estuarine reptiles. We suggest the use of a standardized nomenclature to reduce the amount of lost information.

Climate change seriously affects habitat suitability for coldwater fish. Amur whitefish (Coregonus ussuriensis) is a commercially important coldwater fish species found in northeast China that is particularly sensitive to water temperature. We use water temperature models for Songhua (Harbin to Yilan) and Mayi rivers to predict habitat suitability for Amur whitefish and other coldwater fish species during the months of July and August in 2014 and 2100—2 months during which river temperatures can reach extremes. The predict-results showed that fish habitat was to deteriorate over time, and to be less suitable for survival of coldwater fish species in 2100 than that in 2014. Under scenario RCP4.5 (Representative Concentration Pathway 4.5), the time period during which habitat for Amur whitefish was unsuitable increased continually; under scenario RCP8.5 (Representative Concentration Pathway 8.5), Amur whitefish might even disappear from the river basin. A significant increase in river water temperature will compromise coldwater fish survival and possibly lead to their disappearance. Practical measures to control greenhouse gas emissions and reduce the impact of global warming on aquatic ecosystems must be taken.

High retention membrane bioreactors (HR-MBR) combine a high retention membrane separation process such as membrane distillation, forward osmosis, or nanofiltration with a conventional activated sludge (CAS) process. Depending on the physicochemical properties of the trace organic contaminants (TrOCs) as well as the selected high retention membrane process, HR-MBR can achieve effective removal (80–99%) of a broad spectrum of TrOCs. An in-depth assessment of the available literature on HR-MBR performance suggests that compared to CAS and conventional MBRs (using micro- or ultra-filtration membrane), aqueous phase removal of TrOCs in HR-MBR is significantly better. Conceptually, longer retention time may significantly improve TrOC biodegradation, but there are insufficient data in the literature to evaluate the extent of TrOC biodegradation improvement by HR-MBR. The accumulation of hardly biodegradable TrOCs within the bioreactor of an HR-MBR system may complicate further treatment and beneficial reuse of sludge. In addition to TrOCs, accumulation of salts gradually increases the salinity in bioreactor and can adversely affect microbial activities. Strategies to mitigate these limitations are discussed. A qualitative framework is proposed to predict the contribution of the different key mechanisms of TrOC removal (i.e., membrane retention, biodegradation, and sorption) in HR-MBR.

Eggshell ash was used as an adsorbent to remove phosphorus from wastewater. Adsorbent dose, initial phosphorus concentration, and contact time were investigated to determine the optimum conditions. Results indicate that 5 g of eggshell ash adsorbent with 1.5 mg L⁻¹ of initial phosphorus concentration removed over 90% of the phosphorus. When the temperature was increased, phosphorus removal potential also increased. Specific surface area, morphological features, and structure of the adsorbent were characterized by Brunauer-Emmett-Teller (BET) surface area analysis, scanning electron microscopy with energy dispersive X-ray spectrometer (SEM-EDS), and X-ray diffraction (XRD). Results showed prominent calcium, magnesium, and phosphorus in the eggshell ash surface after adsorption. The elemental composition of eggshell ash surfaces before adsorption did not contain phosphorus, revealing that calcium carbonate-based eggshell ash was co-precipitated with calcium phosphate. The adsorption mechanism was studied by applying Langmuir and Freundlich isotherm models. Experimental data fit well with the Langmuir model, which indicates monolayer adsorption. Eggshell ash was also applied as an adsorbent in wastewater at Srinakharinwirot University dormitories, resulting in 80% phosphorus removal within 2 h. These findings indicated that eggshell ash could be applied as an adsorbent for phosphorus treatment and removal from domestic and industrial wastewater.

In this work, two recyclable phosphotungstic acid salts/reduced graphene oxides were successfully prepared. The prepared samples were characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), infrared spectroscopy (IR), X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA), Raman spectroscopy, and photoluminescence spectroscopy (PL). The structure and catalytic performance of two composites were comparatively investigated, and the reduced graphene oxide mass ratios in K₃[PW₁₂O₄₀]/reduced graphene oxide (denoted as KPW-RGO) and (NH₄)₃[PW₁₂O₄₀]/reduced graphene oxide (denoted as NH₄PW-RGO) were optimized and their roles in them were explored. The results indicate that the Keggin structures of KPW and NH₄PW are still kept after being anchored on the RGO surface, but their morphologies change a lot in composites. The photocatalytic activities of KPW-3RGO (0.01989 min⁻¹) are 5.42 times than that of KPW (0.00367 min⁻¹), and NH₄PW-1RGO (0.0184 min⁻¹) is 2.26 times than that of NH₄PW (0.00814 min⁻¹). The enhanced photocatalytic activity is mainly ascribed to photo-induced interfacial charge transfer on the heterojunction between RGO and NH₄PW or KPW and strong adsorption ability of RGO towards MO. Moreover, NH₄PW-1RGO and KPW-3RGO had much better photocatalytic activity, good recyclable ability, and stability compared to HPW-RGO, which cannot be recycled.

Uncertainty in future availability of irrigation water and regulation of nutrient amount, management strategies for irrigation and nitrogen (N) are essential to maximize the crop productivity. To study the response of irrigation and N on water productivity and economic return of maize (Zea mays L.) grain yield, an experiment was conducted at Water Management Research Center, University of Agriculture Faisalabad, Pakistan in 2015 and 2016. Treatments included of full and three reduced levels of irrigation, with four rates of N fertilization. An empirical model was developed using observed grain yield for irrigation and N levels. Results from model and economic analysis showed that the N rates of 235, 229, 233, and 210 kg ha⁻¹ were the most economical optimum N rates to achieve the economic yield of 9321, 8937, 5748, and 3493 kg ha⁻¹ at 100%, 80%, 60%, and 40% irrigation levels, respectively. Economic optimum N rates were further explored to find out the optimum level of irrigation as a function of the total water applied using a quadratic equation. The results showed that 520 mm is the optimum level of irrigation for the entire growing season in 2015 and 2016. Results also revealed that yield is not significantly affected by reducing the irrigation from full irrigation to 80% of full irrigation. It is concluded from the study that the relationship between irrigation and N can be used for efficient management of irrigation and N and to reduce the losses of N to avoid the economic loss and environmental hazards. The empirical equation can help farmers to optimize irrigation and N to obtain maximum economic return in semi-arid regions with sandy loam soils.

The rice husk ash (RHA) was used as an alternative source of silica for the synthesis of the functionalized mesoporous material, which was used in the removal of the PAHs naphthalene (Nap), benzo[b]fluoranthene (B[b]F), benzo[k]fluoranthene (B[k]F), and benzo[a]pyrene (B[a]P) from aqueous media. The PABA-MCM-41 (RHA) was characterized using FTIR, TGA, SAXS, and N₂ adsorption–desorption analyses. Removal experiments were performed to determine the initial concentrations, individual adsorption in comparison with the mixture of the PAHs, PABA-MCM-41 (RHA) amount, pH, time, and temperature, and the results obtained were statistically analyzed. The PABA-MCM-41 (RHA) presented the SBET, VT, and DBJH values of 438 m² g⁻¹, 0.41 cm³ g⁻¹, and 3.59 nm, respectively, and good thermal stability. The qₑ values found in the kinetic equilibrium for the PAHs mixture followed increasing order: Nap < B[a] P < B[k]F < B[b]F, with removal percentages of 89.08 ± 0.00, 93.85 ± 0.28, 94.54 ± 0.10, and 97.80 ± 0.05%, respectively. Graphical abstract