Effect of mechanical scouring driven by granular activated carbon (GAC) fluidization on membrane fouling was investigated using a laboratory-scaled, fluidized membrane reactor filtering the effluent from anaerobic fluidized bed bioreactor (AFBR) in domestic wastewater treatment. The GAC particles were fluidized by recirculating a bulk solution only through the membrane reactor to control membrane fouling. The membrane fouling was compared with two different feed solutions, effluent taken from a pilot-scaled, AFBR treating domestic wastewater and its filtrate through 0.1-μm membrane pore size. The GAC fluidization driven by bulk recirculation through the membrane reactor was very effective to reduce membrane fouling. Membrane scouring under GAC fluidization decreased reversible fouling resistance effectively. Fouling mitigation was more pronounced with bigger GAC particles than smaller ones as fluidized media. Regardless of the fluidized GAC sizes, however, there was limited effect on controlling irreversible fouling caused by colloidal materials which is smaller than 0.1 μm. In addition, the deposit of GAC particles that ranged from 180 to 500 μm in size on membrane surface was very significant and accelerated fouling rate. Biopolymers rejected by the membranes were thought to play a role as binding these small GAC particles on membrane surface strongly.

Although plastic induces environmental damages, almost the consumption of poly(vinyl chloride) never stops increasing. Therefore, this work abstracted by two parts, first, synthesis of Schiff bases 1–4 compounds through the reaction of amino group with appropriate aromatic aldehyde, reaction of PVC with Schiff bases compounds 1–4 in THF to form a new modified PVC-1, PVC-2, PVC-3, and PVC-4. The structures of Schiff bases 1–4 and the modified PVC-1, PVC-2, PVC-3, and PVC-4 have been characterized by different spectroscopic analyses. Second, the influence of introducing 4-amino-1,2,4-triazole as a pendent groups into PVC chain investigated on photostability rules of tests. The modified polymers photostability investigated by observing indices (ICO, Iₚₒ, and IOH), weight loss, UV and morphological studies, and all results obtained indicated that PVC-1, PVC-2, PVC-3 and PVC-4 gave lower growth rate of ICO, IPO, and IOH through UV exposure time. The photostability are given as PVC-4 < PVC-3 < PVC-2 < PVC-1 from different mechanisms which suggested building on existence of 4-amino-1,2,4-triazole moieties in the polymer chain.

Only a small proportion of pharmaceuticals available for commercial use have been monitored in the aquatic environment, and even less is known about the effects on organisms. With thousands of pharmaceuticals in use, it is not feasible to monitor or assess the effects of all of these compounds. Prioritisation schemes allow the ranking of pharmaceuticals based on their potential as environmental contaminants, allowing resources to be appropriately used on those which are most likely to enter the environment and cause greatest harm. Many different types of prioritisation schemes exist in the literature and those utilising predicted environmental concentrations (PECs), the fish plasma model (FPM), critical environmental concentrations (CECs) and acute ecotoxicological data were assessed in the current study using the 50 most prescribed drugs in the UK. PECs were found to be overestimates of mean measured environmental concentrations but mainly underestimations of maximum concentrations. Acute ecological data identified different compounds of concern to the other effects assessments although the FPM and CECs methods were more conservative. These schemes highlighted antidepressants, lipid regulators, antibiotics, antihypertensive compounds and ibuprofen as priority compounds for further study and regulation.

The vine mealybug (VMB), Planococcus ficus (Hemiptera: Pseudococcidae), is a key insect pest of vineyards. While pheromone-based mating disruption (MD) has been successfully tested against a wide range of insect pests, knowledge about its efficacy against key mealybug species, such as P. ficus, is scarce. In this study, a novel MD product, Isonet® PF, was evaluated by testing 300, 400, and 500 dispensers/ha at four study sites located in Northern (Veneto) and Southern (Sicily) Italy. Experiments were carried out over 2 years by monitoring the mealybug populations in wine grape and table grape vineyards managed with and without the application of MD. Pheromone dispensers were periodically collected during the grapevine-growing season, extracted, and analyzed by GC-MS, to determine their pheromone content and the release in mg/ha/day. The results showed that use of the MD dispenser Isonet® PF reduced the percentage of VMB-infested bunches and the number of VMB specimens per bunch compared with the untreated controls. This was recorded over 2 years at all experimental sites. Differences in the incidence of infested bunches among the three tested rates of Isonet® PF were not detected. Overall, the results presented here contribute to optimizing the sex pheromone dosage used in MD control programs against VMB allowing a reduction of broad-spectrum insecticides currently employed to manage this important pest.

Fish are important in constructed wetland (CW) ecosystem. An 80-day experiment was conducted by exposing juvenile grass carp (Ctenopharyngodon idellus) to 0, 0.5, 2.0, 4.5, 9.0, and 18.0 mg L⁻¹ total ammonia nitrogen (TAN) stress to determine the severity of physiological changes in fish organs (liver, gills, and muscle) in CW. Specific growth rate results indicated that low TAN (≤ 2.0 mg L⁻¹) help maintain or enhance grass carp growth. Fish physiological indexes did not significantly change during exposure, except for the gill’s reactive oxygen species (ROS) level that is susceptible to TAN exposure. Under high TAN (≥ 4.5 mg L⁻¹), physiological changes and organ-specific responses were revealed. The ROS and malondialdehyde levels were higher in the gills than in the liver. At 9.0 mg L⁻¹ TAN, the muscle cells manifested toxicity. The antioxidant system of different organs responded differently because the gills were more susceptible to low TAN than other organs. After TAN removal from the low TAN system, the antioxidative enzymes and antioxidants were increased to scavenge extra ROS and reverted to the normal level. However, grass carp cannot recover from the oxidative damage at ≥ 9.0 mg L⁻¹ external TAN, resulting in organ dysfunction and failed ROS scavenging. This study provides information in maintaining CW sustainability.

This study assessed the contaminant removal potential of a low-cost alum synthesized from bauxite slime waste compared to industrial grade alum [Al₂(SO₄)₃.18H₂O] in treating car wash wastewater using standard jar tests. The synthesized alum was subsequently applied as a coagulant to test the short-term performance of a bench scale flocculation–flotation system for treating car wash wastewater. Coagulant dosages and mixing intensities were optimized for both coagulants and differences were analyzed with R using two-way ANOVA with Tukey’s (HSD) post hoc testing. Per the jar tests, percentage removal of up to 99%, 34%, and 75% of turbidity, anionic surfactants (AS), and COD, respectively, was achieved with 90 mg/L of the synthesized alum compared to 100%, 37%, and 74% for industrial grade alum. Contaminant removal efficiencies of both coagulants were comparable (p > 0.05). However, coagulant dosage strongly influenced the removal of turbidity, AS, and COD (p < 0.05) while mixing intensity influenced all but COD. The bench-scale flocculation–flotation system completely removed turbidity (100%) and reduced AS and COD by up to 92% and 99% respectively. The results of this study demonstrate the potential of alum synthesized from bauxite slime waste as a cheaper alternative for industrial grade alum in wastewater recycling for the car wash industry.

The removal of three over-the-counter pharmaceuticals from aqueous solution using four different adsorbents was analyzed. To study the effect of infused pharmaceutical and adsorbent on the adsorption system, both the concentration of drug and adsorbent dosage were varied, with constant temperature and pressure at different contact time. Adsorption kinetics, isotherm models, and ANOVA allegorized a generic trend for pharmaceutical removal efficiency of the adsorbents that varied as follows: activated carbon > fly ash > bentonite > sugar cane bagasse ash. The Tempkin model appears to fit the isotherm data better than Freundlich and Langmuir. Correspondingly, the kinetic studies implied a pseudo-second-order fit, to understand the mechanism by which the solute accumulates on the surface of a solid and gets adsorbed to the surface via intra-particle diffusion. Furthermore, some special cases of removal tendencies were noted based on sorbate-sorbent interaction. Effectively, it was observed that at an adsorbent loading of 2 g and initial concentration of 0.2 mmol L⁻¹, bentonite, fly ash, and activated carbon were able to strip more than 80% of all pharmaceuticals from urine. A framework for the highest significance of the experiments was obtained using response surface methodology by the combination of ciprofloxacin-bentonite followed by paracetamol-activated carbon and ibuprofen-activated carbon. Quasi-Newton and Bayesian regression methods were implemented on Langmuir isotherm by designing the neural network for the batch adsorption experiments. Based on the numerical calculations and graphical representations, the proposed model leads to the result that error is minimized and the values are optimized for different pharmaceuticals such as paracetamol, ibuprofen, ciprofloxacin that can be removed from wastewater streams by locally available adsorbents. Graphical abstract

This study intends to examine the impact of ICTs (i.e., internet usage and mobile cellular subscriptions), globalization, electricity consumption, financial development, and economic growth on environmental quality by using 1994–2014 panel data of BRICS economies. This study employed a second-generation panel unit root test accounting for the presence of cross-sectional dependence and indicated that carbon dioxide emissions, electricity consumption, financial development, internet usage, mobile usage, globalization, and economic growth have integration of order one. The results from Westerlund panel co-integration test confirms that the variables are co-integrated and revealed that ICT-finance-globalization-electricity-GDP-CO₂ nexus has long-run equilibrium relationship. The results from dynamic seemingly unrelated regression (DSUR) indicate that internet usage and mobile cellular subscriptions (ICTs) have significant, adverse impact on carbon dioxide emissions. To put it simply, ICT positively contributes towards environmental quality. Similarly, economic growth also has an adverse effect on carbon dioxide emissions. On the other hand, electricity consumption, globalization, and financial development have a significant positive effect on carbon emissions. In addition, Granger causality test results show the presence of a bidirectional causal relationship between internet usage and environmental quality, financial development and electricity consumption, ICT and financial development, mobile cellular subscription and globalization, economic growth and environmental quality, and internet usage and economic growth. A unidirectional causal link is detected running from mobile cellular subscriptions towards environmental quality, ICT towards electricity consumption, financial development towards environmental quality, globalization towards environmental quality, and globalization towards economic growth. Moreover, time series analysis has also been done in this study to analyze the findings for each of BRICS countries which are directed towards important policy implications. For instance, ICT policy can play an integral part in improving environmental quality policy.

The indoor air quality issue and its potential health problems are attracting increasingly attentions. In this study, micro-orifice uniform deposit impactor (MOUDI) was used to sample suspended particles from four typical indoor environments, including residence, office, cyber classroom, and chemical analysis room. Size-dependent concentrations of perfluoroalkyl substances (PFASs) and heavy metals in suspended particles were analyzed. Then, the International Commission on Radiological Protection deposition model was employed to estimate deposition efficiencies and fluxes of size-fractioned PFASs and heavy metals in the human respiratory tract. Most of the contaminants deposited in head airways, where coarse particles (aerodynamic diameter or Dp > 1.8 μm) contributed the most. By contrast, in the alveolar region fine particles (Dp < 1.8 μm) were dominant. The chronic daily intake through inhalation of PFASs and heavy metals via airborne particles were 10.3-37.5 pg kg⁻¹days⁻¹ and 3.1-25.9 mg kg⁻¹days⁻¹, respectively. The estimated total hazardous quotient of PFASs and heavy metals were 4.4 × 10⁻⁵-1.7 × 10⁻³ and 9.9 × 10⁻³-1.05 × 10⁻¹, which is far lower than the acceptable threshold of 1. However, the incremental lifetime cancer risk induced by As, Cd, Co, Cr, and Ni were estimated to be 1.11 × 10⁻⁵-1.41 × 10⁻⁴ in total, which exceeded the acceptable threshold of 10⁻⁶. These findings implicate that there were health risks, especially cancer risks caused by heavy metals associated with airborne particles in urban indoor environments.

The biochar which was characterized with well-developed facial structure and O-/N-containing functional groups could effectively remove Cd (II) from water. In this paper, Typha orientalis–based biochar (BCS) with well-developed N containing functional groups was modified with shrimp bran which was rich in crude protein for the first time. There are more well-developed O-/N-containing functional groups in the structure of BCS than that of pure Typha orientalis–based biochar without any modification (BC), and this conclusion was depended on their comparisons of Brunauer-Emmett-Teller (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental analysis (EA), Boehm titration, Fourier transform infrared (FTIR), and other characterization techniques. Moreover, according to the experiment, the phenomenon that the adsorption capacity of Cd(II) on these two adsorbents (BCs) decreased with the increase of solution ionic strength could be carried out. The Cd(II) adsorption studies combined with X-ray photoelectron spectroscopy (XPS) analysis revealed that the adsorption mechanism was mainly attributed to physical microporous filtration and chemical interaction between Cd(II) and the surface functional groups (surface complexation, ion exchange, and electrostatic attraction).