A laboratory trial was performed to test the sequestration capacity of two minerals (bentonite and zeolite) at three initial concentrations (2.5, 5 and 10%) in order to counter water-soluble nickel (Ni) exceeding the Italian legal limit (10 μg L⁻¹) in carbonation lime disposed of in a field and sampled for an 85-day lab study. The results show a noticeable reduction in water-soluble and bioavailable Ni in lime after the addition of sequestrants, especially at the dose of 5% bentonite or zeolite, thereby indicating a “ceiling effect” of the sequestrant, i.e., an increasing dose could reduce the adsorption capacity and be less effective. The alkaline pH and the presence of organic matter could be the main factors affecting the good performance of sequestrant addition, causing an increase in the negative charge of the organic and mineral colloids and the formation of unavailable Ni precipitates. The 85-day experiment seems to be sufficient to reach an adsorption equilibrium for water-soluble nickel, while for the bioavailable form a longer period appears to be necessary.

The study investigates the effect of cadmium (Cd), salinity (NaCl), and combined stress on rhizosphere pH, growth parameters, membrane leakage, and genotoxicity in Vicia faba. Germinated seeds were exposed for 48 h to 0.01 mM Cd(NO₃)₂ (Cd), 50 mM NaCl (S50), 150 mM NaCl (S150), and Cd-NaCl (CdS50 and CdS150). An accumulation of Cd and Na was found essentially in Vicia roots under each single stress factor associated with variations in rhizosphere pH. Additional NaCl in metallic solution significantly dropped the rhizosphere pH and decreased Cd concentrations in roots by 2.3 and 3.8 times for CdS50 and CdS150, respectively. Growth parameters (root length and fresh and dry matters), mitotic activity, and micronucleus formation were not influenced by Cd and low concentration of NaCl when applied separately or together, while 150 mM of NaCl, alone or combined with Cd, affected negatively all the studied parameters, as well as chromosome and nucleus stability. V. faba seems to reduce the transport of Cd in saline conditions and therefore salinity (50 mM) may act as a protection against Cd accumulation.

Water pollution and depletion of natural resources have motivated the utilization of green organic solvents in solvent extraction (SX) and liquid membrane (LM) for sustainable wastewater treatment and resource recovery. SX is an old and established separation method, while LM, which combines both the solute removal and recovery processes of SX in a single unit, is a revolutionary separation technology. The organic solvents used for solute removal in SX and LM can be categorized into sole conventional, mixed conventional-green, and sole green organic solvents, whereas the stripping agents used for solute recovery include acids, bases, metal salts, and water. This review revealed that the performance of greener organic solvents (mixed conventional-green and sole green organic solvents) was on par with the sole conventional organic solvents. However, some green organic solvents may threaten food security, while others could be pricey. The distinctive extraction theories of various sole green organic solvents (free fatty acid-rich oils, triglyceride-rich oils, and deep eutectic solvents) affect their application suitability for a specific type of wastewater. Organic liquid wastes are among the optimal green organic solvents for SX and LM in consideration of their triple environmental, economic, and performance benefits.

Ambient particulate matter is one of the main risk factors of chronic obstructive pulmonary disease (COPD) in developing countries. However, the studies were scant in China concerning the health effects of the fine particulate matter (PM₂.₅; particulate matter ≤ 2.5 μm in diameter) on hospital visits for COPD. We applied a generalized additive model (GAM) to calculate relative risks (RRs) with 95% confidence intervals (CIs) for the associations between hospital visits for COPD and an interquartile range (24.50 μg/m³) increment of ambient PM₂.₅ concentrations in Yinzhou District between 2016 and 2018. The ambient PM₂.₅ concentration was positively associated with hospital visits for COPD at a distributed lag of 0–7 days (RR = 1.073, 95% CI, 1.016, 1.133). In the stratified analysis, we found that the association between ambient PM₂.₅ and COPD was stronger during the warm season (April to September) than that during the cold season (October to March), but we did not observe statistically significant differences in age groups (< 60 years and ≥ 60 years) or gender groups (male and female) related to the effects of PM₂.₅. The associations between ambient PM₂.₅ and COPD became partially attenuated after the adjustment for gaseous pollutants in subgroups. Our findings could provide evidence that regulations for controlling both PM₂.₅ and gaseous pollutants should be implemented to protect the overall population.

The commonly employed design of detention tanks cannot effectively control overflow pollution because of non-stormwater entry and sewer sediments in the urban drainage system. Herein, a multi-source overflow model considering both overflow water quality and quantity has been developed for simulating real overflow events. Subcatchment and drainage information is extracted through geographic information system (ArcGIS) and a multi-source overflow model is developed in Stormwater Management Model (SWMM) by coupling runoff mode, non-stormwater mode, and sediment mode. This model is successfully calibrated and validated with the reasonable root-mean-square error (RMSE) of 8.2 and 5.8% for water quality and quantity, respectively. The simulated results suggest that the misconnected non-stormwater entry can affect overflow contaminant concentrations over the period of overflow due to its continuous pollution, while sewer sediments mainly exert effects on the peak pollution period of overflow. Based on model prediction, an approach called overflow peak pollution interception (OPPI) is proposed for model application and design optimization. The OPPI designed detention tank is suitable for high non-stormwater entries and long antecedent dry days (large amount of sediment). A case study is conducted in a high-density urban area of Shanghai, and compared with two commonly employed design methods in Germany and China, which have the similar design principle of volume, relying on amount of precipitation multiplying area of region, the combination of overflow model and OPPI approach enables to offer more accurate and effective design of detention tanks for pollution control in urban areas. Graphical abstract .

Biosolids are regarded as a major source of pharmaceutically active compounds (PhACs) in soil and may lead to their accumulation in plants and potential human risks through dietary intake. Using ¹⁴C labeling, we explored the effect of biosolids on the uptake and tissue distribution of carbamazepine (CAB) by three ready-to-eat vegetables (i.e., carrot, celery, and pak choi) under greenhouse conditions. The ¹⁴C-CAB was consistently detected in vegetables and plant tissues with bioconcentration factors in a range of 1.28–37.69, and it was easily translocated from root to leaf and/or stem with translocation factors > 1. The inhibition on the uptake and accumulation of ¹⁴C-labeled carbamazepine from soil by the addition of biosolids was consistently observed, and such inhibitory effect was related to the biosolid amendment rates, the category of vegetable, and the plant growth stages. The influence of biosolids on behavior of CAB and other emerging pollutants in the soil-plant system should be considered in their environmental risk assessment.

The Chinese government, as a policy response, has continued to invest efforts and resources to implement cost-effective air pollution control technologies and stringent regulation to reduce emissions from the most contributing sectors to protect the environment and public health. The higher density of monitoring stations (> 1600) distributed across China provides a timely opportunity to use them to study in detail the national pollution trends in light of more stringent air pollution control policies. In the present study, air quality datasets comprising hourly concentrations of PM₂.₅, O₃, NO₂, and SO₂ collected across 1309, 1341, 1289, and 1347 monitoring stations respectively were obtained from the National Environmental Monitoring Centre over 4 years (2015–2018) and trend analysis was performed. Results indicate that the overall annual trends for PM₂.₅ and SO₂ were − 2.9 ± 2.7 and − 3.2 ± 3.2 μg/m³/year, while the winter trends were − 4.8 ± 5.8 and − 6.9 ± 8.4 μg/m³/year respectively across China. The daily maximum 8-h average (DMA8) ozone concentration showed a significant positive trend of 2.4 ± 4.6 μg/m³/year, which was comparatively higher in summer at 4.4 ± 9.0 μg/m³/year. On the other side, NO₂ trend is not great in number (− 0.45 ± 2.0 μg/m³/year). Overall, 62.2%, 61.8%, and 20.9% of PM₂.₅, SO₂, and NO₂ monitoring stations were associated with a negative trend of ≥ − 2 μg/m³/year. For O₃ DMA8 concentrations, 50.7% of the monitoring stations showed a significant positive trend of ≥ 2 μg/m³/year. In light of the Chinese government’s increasing impetus on combating air pollution and climate change via new policy regulations, it is important to understand the spatio-temporal distributions and relative contributions of the spectrum of gaseous pollutants to the pollution loads as well as identify changing emission loads across sectors. The results of this study will facilitate the formulation of evidence-based air pollution reduction strategies and policies.

In the present study, the simultaneous adsorption degradation of norfloxacin (NOR) by graphene oxide from aqueous matrix was verified. Graphene oxide (GO, ~ 8 layers) was prepared using modified Hummers method through the oxidation/exfoliation of expanded graphite. Spectroscopic techniques confirmed the NOR adsorption onto GO surface and the partial antibiotic degradation promoted by hydroxyl radicals derived from GO. Furthermore, the mass spectra after the adsorption-degradation processes showed NOR degradation intermediates that was compared and confirmed by other studies. The nanomaterial showed a removal capacity of 374.9 ± 29.8 mg g⁻¹, observing greater contribution from the NOR in the zwitterionic form and removals up to 94.8%. The intraparticle diffusion process, assessed by Boyd’s model and Fick’s law, presented a greater contribution in the removal process, reaching the equilibrium 30 min after the beginning. In addition, the temperature increase would disadvantage the process, which was considered thermodynamically viable throughout the evaluated temperature range. Finally, the process was scaled-up in a single stage batch adsorber considering a NOR removal efficiency of 95%. This resulted in mass requirement of 63.6 g of GO in order to treat 0.5 m³ of contaminated water. In general, the simultaneous adsorption-degradation process was considered innovative and promising in pharmaceutical compounds remediation.

The Ocotea puberula bark powder (OPBP) was evaluated as an effective adsorbent for the removal of crystal violet (CV) from colored effluents. OPBP was characterized and presented a surface with large cavities, organized as a honeycomb. The main functional groups of OPBP were O-H, N-H, C=O, and C-O-C. The adsorption of CV on OPBP was favorable at pH 9 with a dosage of 0.75 g L⁻¹. The Avrami model was the most suitable to represent the adsorption kinetic profile, being the estimated equilibrium concentration value of 3.37 mg L⁻¹ for an initial concentration of 50 mg L⁻¹ (CV removal of 93.3%). The equilibrium was reached within 90 min. The data were better described by the Langmuir isotherm, reaching a maximum adsorption capacity of 444.34 mg g⁻¹ at 328 K. The Gibbs free energy ranged from − 26.3554 to − 27.8055 kJ mol⁻¹, and the enthalpy variation was − 11.1519 kJ mol⁻¹. The external mass transfer was the rate-limiting step, with Biot numbers ranging from 0.0011 to 0.25. Lastly, OPBP application for the treatment of two different simulated effluents was effective, achieving a removal percentage of 90%.

Endemic fish species of Armenian ichthyofauna—Sevan trout (Salmo ischchan Kessler, 1877)—is registered in the Red Book of Animals of the Republic of Armenia as “Critically Endangered” (corresponds to IUCN category: CR A2cd). Its natural reproduction hardly occurs as a result of numerous problems related to the use and management of water and bio-resources in the Lake Sevan drainage basin. Masrik River is formerly known as a spawning river for two ecological races of the Sevan trout, but there is no up-to-date and in-depth studies of its potential to support natural reproduction. Thus, a set of spawning criteria was arranged as matrix and state of Masrik River as spawning area for the Sevan trout was assessed. The results showed that the potential of different parts of Masrik River to support natural reproduction of Sevan trout varied from quite appropriate to inappropriate. The main limiting factors revealed were water temperature, velocity and substrate conditions.