Emerging contaminants present a challenge for water preservation, threatening humans’ health and all ecosystems. They consist of a variety of molecules ranging from pharmaceutical and personal care products to pesticides and endocrine disruptors detectable in wastewater, sewage effluent, surface water, drinking water, and ground waters at trace level concentrations (e.g., ng/L, μg/L). Conventional wastewater treatment plants (WWTPs) possess low efficiency to remove them. Therefore, new technologies capable of removing such residues are needed. Lignin recognized as a renewable and abundant biopolymer is transformed through electrospinning into an anionic nanofibrous nonwoven adsorbent to extract those contaminants and dispose them safely. Electrospinning allows the manufacture of fibers at the micro- or nanoscale under the influence of an electric current. In this study, nanofibers of alkali lignin and a co-polymer, poly(vinyl alcohol), were developed and tested on the adsorption of a pharmaceutical contaminant (fluoxetine) in an aqueous solution. Results showed that the lignin nanofibers, of 156 nm in diameter, adsorbed 70% of fluoxetine in solution which corresponds to 32 ppm of contaminants removed in water.

The aim of this work is to study the byproducts formed as a result of the photocatalytic process under different conditions of light wavelength and photocatalyst doping, rendering valuable information about the fate of pollutants for water treatment applications. Salicylic acid was selected as a model emerging pollutant and powders of nitrogen-doped titanium dioxide (N-TiO₂) and TiO₂ were prepared by the sol-gel process, using TiO₂ P-25 Degussa as benchmark. Two light sources, UVA fluorescent tubes (372 nm) and blue LEDs (462 nm), were employed for photolysis and photocatalysis experiments. Transformation products formed during the process were studied by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). Major differences were found in the amount and identity of the transformation products due to the different light sources, detecting similar transformation products among the studied catalysts. Under UVA light, hydroxylated and carbonylated byproducts were the first intermediates to reach maximum abundances whereas presumed ring opening products were the last ones. On the other hand, under blue LED illumination byproducts accumulated with decreased mineralization. Photocatalytic degradation pathways were proposed based on the findings.

In this study, the magnetic fraction (MF) of a low-grade titanium ore (TO) was successfully used as an alternative Fe²⁺ source in five reuse cycles, in combination with persulfate (PS) and simulated sunlight (SSL) for the degradation of ciprofloxacin (CIP). The best response of the CIP initial concentration, irradiation time, and doses of MF and PS to degrade completely this pollutant were determined based on an experimental design. However, the individual application of MF, PS, or SSL fails to achieve this goal at the optimal experimental condition. Furthermore, the MF-PS-SSL system showed a higher production of sulfate radicals and a concentration of dissolved Fe²⁺ ions compared with data obtained for the MF-PS system. The best performance attained by the former system is due to the synergy produced between the photo-generated electrons, and the reaction of PS with the Fe²⁺ ions leached gradually from the MF, which increased sulfate radical production. After five reuse cycles of the MF, the oxidation system showed a CIP degradation of 100% in 100 min, no residual content of PS, a CIP mineralization of 6%, a marginal increase in the biodegradability (BOD₅/COD ratio), a MF loss of 7.5%, and a twofold increase in toxicity; however, this parameter was lower than the effective concentration at 50% inhibition (EC₅₀). The substitution of MF with an iron salt decreased the degradation efficiency of the antibiotic by 14%, probably owing to the immediate excess of Fe²⁺ in the solution, which can be oxidized to Fe³⁺ ions, and as a consequence of this, the production rate of the sulfate radical was also reduced.

To explore an effective approach of simultaneous nitrification and denitrification in wastewater with low C/N ratios, integrated packed bed bioreactors based on poly(3-hydroxybutyrate-hydroxyvalerate) (PHBV) with different dosing methods were designed. The removal efficiency of NH₄⁺-N in bioreactor with aeration was 88.62%, and higher NO₃⁻-N removal efficiency was observed in bioreactor filled with grainy PHBV (95.21%) than bioreactor filled with strip PHBV (93.34%). Microbial study indicated that microbes harboring amoA and nirS genes preferred to attach on the surface of ceramsite, and significant differences in microbial community compositions at phylum and genus levels were observed. To summarize, it is feasible to utilize grainy PHBV for simultaneous and efficient removal of NH₄⁺-N and NO₃⁻-N from wastewater with low C/N ratios.

Cities have turned to permeable pavements as one tool to mitigate the detrimental effects of urban runoff. Permeable pavements permit rainfall to infiltrate through a series of aggregate layers, where pollutants are filtered out before the water discharges via an underdrain or exfiltrates into native soils. This study reports on the water quality performance of a parking area retrofitted with permeable interlocking concrete pavement in Vermilion, OH, USA. The practice was constructed in 2015, received run-on from an asphalt traffic lane and was operational for 2 years before the onset of monitoring. During the 15-month monitoring period, the permeable pavement provided significant reductions of sediment and particulate nutrients, which were removed via filtration in the upper aggregate layers. Despite poorly draining underlying soils, runoff volumes were reduced by 26%, leading to significant load reductions for nearly all nutrient and heavy metals in the study. Seasonal variations in runoff and effluent composition were investigated, showing that restorative maintenance performed in spring and fall has the potential to further improve the treatment provided by the practice by removing entrained particulates from the upper aggregate layers and restoring the filtering capacity of the system. Correlation analyses revealed a first flush of particulate nitrogen species, as well as the potential occurrence of erosive flows within the aggregate subbase which resulted in elevated sediment concentrations during high intensity rain events. Results from this study demonstrate the effectiveness of permeable pavements several years after construction, even when design features to specifically improve treatment were not implemented and additional run-on is routed onto the pavement from adjacent impervious surfaces. Findings also highlight the importance of timely maintenance of these practices, which could further improve their performance by removing seasonally deposited pollutants throughout the year.

Humic-like substances (HULIS) are an important mixture of organic compounds, which account for a great part of water-soluble organic compounds in ambient aerosols. In this study, individual carboxylic and hydroxylic species in HULIS extracts of PM₂.₅ samples collected in Hong Kong during summer were measured by gas chromatography mass spectrometry with prior chemical derivatization. Significantly higher levels of HULIS were observed on days mainly impacted by regional pollution (regional days, 4.11 ± 1.76 μg m⁻³) than on days under local emission influences (local days, 0.56 ± 0.30 μg m⁻³). Positive matrix factorization was applied to identify the major sources and apportion their contributions to HULIS. Simultaneous monitoring and analysis data from four different sampling sites showed that sources of HULIS in Hong Kong were mainly regional with small spatial variations. Secondary aerosol formation (both organic and inorganic) had a predominant contribution (52.7%) to HULIS during the whole sampling period. It accounted for 1.88 ± 0.91 μg m⁻³ of HULIS on regional days, which was about 5 times higher than its contribution (0.39 ± 0.34 μg m⁻³) on local days. Of the three identified primary sources, biomass burning had the largest contribution on both regional (34.9%) and local days (24.6%). Marine vessels were also a significant contributor, especially on local days (20.3%). Vehicle exhaust, on the other hand, showed a negligible contribution to HULIS (2.1%) in Hong Kong in this study.

Polluted sterilization condensate discharged from palm oil mill may contain polyphenols that are rich in the antioxidant property. Emulsion liquid membrane (ELM) process is a promising method for polyphenol recovery due to its several attractive features such as high selectivity, simple operation, and low energy consumption. In this study, the condensate was characterized to determine its total phenolic content (TPC), ionic elements, and pH. ELM formulation containing tributylphosphate (TBP) as a carrier, kerosene as a diluent, sorbitan monooleate (Span 80) as a surfactant, and sodium hydroxide (NaOH) as a stripping agent was developed. The results show that sterilization condensate contains 700–1500 mg GAE/L of TPC. During the ELM process, more than 91% of extraction with 83% recovery and 8.3 enrichment were achieved at the favorable condition of 0.1 M TBP, external phase pH 5, 1 M NaOH, 1:5 treat ratio, 5% v/v of octanol as a modifier, and 100 mg GAE/L external phase concentrations. Thus, ELM offers a potential alternative technology to extract and recover polyphenols from palm oil mill sterilization condensate while contributing to sustainable production. Graphical abstract Extraction of polyphenols from palm oil mill sterilization condensate using ELM process

There is an increasing concern that aquaculture has been implicated in the formation of antibiotic resistance gene (ARG) reservoirs; however, little is known about the consequences of their presence in groundwater. In this study, 22 antibiotics, including four acetylated metabolites, and 27 ARGs were analyzed in fish pond water, surface water, and groundwater of the Honghu Lake in China. Correlations between conventional parameters, ionic composition, antibiotic concentration, and relative abundance of ARGs in water samples were analyzed. Among the three different sources of water, total antibiotic levels were the highest in fish pond water and the lowest in groundwater, with moderate levels in lake water. In surface water, sulfonamides and their metabolites accounted for the highest antibiotic content, whereas tetracyclines were the most frequently found in groundwater samples. Despite the near-undetectable levels of antibiotics in groundwater, the relative abundance of ARGs in groundwater samples was even higher than that in surface waters. The magnitude and extent of ARG migration are likely to be dependent on local antibiotic contamination levels as well as on the local environmental and hydrogeological conditions, with the class 1 integrons (intI1) being essential for the dissemination of such ARGs. The effects of environmental parameters such as antibiotics, dissolved oxygen, HCO₃⁻, and pH on ARGs were highly significant, reflecting the potential impact of these factors on the abundance of ARGs. Our findings thus highlight the need for improved control of the spread of ARGs in and from aquaculture environments.

Increased alcohol consumption, especially among young people, is a major concern in Turkey as it is around the world due to negative effects on public health and safety. Regarding this, it is pivotal to monitor and therefore control alcohol use in public. In this case, wastewater-based epidemiology (WBE), which is the in-depth analysis of wastewater and a relatively new method, can deliver complementary information concerning the abuse of different substances. The proven potential of the WBE approach offers new promises in the process of monitoring alcohol use, namely the monitoring of the levels of ethyl sulfate (EtS) as a urinary biomarker of alcohol consumption, and it is a powerful mean to estimate alcohol use at the community level. In this study, raw 24-h composite wastewater samples were collected from Seyhan and Yüregir wastewater treatment plants (WWTPs) in Adana Province for one week per season (October 2016–August 2017). The fast and validated analytical method was performed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and therefore applied to the analysis of ethyl sulfate (EtS). Obtained concentration values were back-calculated, and regional and temporal social usage rates were determined. Higher values were calculated for both WWTPs on Sunday. Alcohol consumption in the region served by Seyhan WWTP was higher than Yüregir WWTP. The results showed that the levels of alcohol consumption during given periods in Adana ranged from 659.8 to 8998.7 mL/day/1000 per person with an average value of 4983.9 and 3924.2 mL/day/1000 inhabitant in Seyhan WWTP and Yüregir WWTP, respectively. This study shows that weekly and annual trends in alcohol consumption can be detected quickly from wastewater analysis.

Financial development is identified as one of the significant factors that affect energy consumption and has been widely discussed in the literature. However, the association between financial development and renewable energy consumption is still at its earlier stage and is limitedly explored. Therefore, the purpose of this study is to examine the non-linear association between financial development and renewable energy consumption in the top renewable energy consumption countries. The study utilized the newly introduced econometric technique panel smooth transition regression (PSTR) model with two regimes on annual panel data consisted of years 1997–2017. The result confirmed that all the financial development indicators increase renewable energy consumption but affect renewable energy consumption differently. Moreover, the economic growth and industrial structure showed a positive and significant association in both regimes, whereas the population showed a negative relationship with renewable energy consumption in a low growth regime but the association becomes positive in high growth regimes. The study suggested several policies for the top renewable consumption countries.