The degradation of roxithromycin (ROX) by hydroxyl radical (·OH) generated by UV/H₂O₂ was systematically investigated in terms of degradation kinetics, effects of water chemistry parameters, oxidation products, as well as toxicity evaluation. The degradation of ROX by UV/H₂O₂ with varying light irradiation intensity, initial ROX concentration, and H₂O₂ concentration in pure water and wastewater all followed pseudo-first-order kinetics. The second-order rate constant for reaction between ROX and ·OH is 5.68 ± 0.34 × 10⁹/M/s. The degradation rate of ROX increased with the pH; for instance, the apparent degradation rates were 0.0162 and 0.0309/min for pH 4 and pH 9, respectively. The presence of natural organic matter (NOM) at its concentrations up to 10 mg C/L did not significantly affect the removal of ROX. NO₃⁻ and NO₂⁻ anions inhibited the degradation of ROX due to the consumption of ·OH in reactions with these ions. Fe³⁺, Cu²⁺, and Mg²⁺ cations inhibited the degradation of ROX, probably because of the formation of ROX-metal chelates. A total of ten degradation products were tentatively identified by HPLC/LTQ-Orbitrap XL MS, which mainly derived from the attack on the oxygen linking the lactone ring and the cladinose moiety, tertiary amine and oxime side chain moiety by ·OH. The toxicity evaluation revealed that UV/H₂O₂ treatment of ROX induced the toxicity to bioluminescent bacteria increased.

In this study, we effectively suppressed arsenic and cadmium uptake into a plant using magnetic nanoparticle powder (MNP) and fermented bark amendment (FBA) in agar medium. The MNP (which consists of FeO·Fe₂O₃) quantitatively adsorbed arsenite (As(III)) and the FBA (which mainly consists of bark waste) adsorbed cadmium, regardless of the pH. The properties of MNP and FBA in agar medium were compared based on the amounts of arsenic and cadmium in cultivated radish sprouts. While adding FBA selectively suppressed cadmium uptake by radishes, adding MNP suppressed the uptake of both arsenic and cadmium. Considering that the uptake of analytes was slightly reduced even in agar without any additives, the agar itself might also have contributed to the suppression of analyte uptake into plants. In addition, even when radish sprouts were cultivated in agar containing arsenic and cadmium (100 μg/L each) mixed with 25 g MNP and 1.25 g FBA per 25 mL agar, arsenic and cadmium absorption decreased by 90% and 82%, respectively, versus agar without additives. Furthermore, adding the mixed amendment to agar accelerated the growth of radishes, whereas MNP significantly inhibited radish growth even though it reduced analyte uptake. Our results indicated that mixing inorganic and organic adsorbents could simultaneously inhibit cadmium and arsenic uptake by plants and accelerate plant growth in the cadmium and arsenic-contaminated agar medium.

The aim of our study was to investigate the concentrations of toxic metals in the feathers of predatory birds in the Hortobágyi Madárpark (Bird Hospital Foundation). Samples were collected from different predatory birds originated from the eastern and north-eastern region of Hungary. Inductively coupled plasma optical emission spectrometry was used to determine the concentration of toxic metals. The mean values varied between bird species groups, their concentrations were between 0.29 ± 0.24 and 0.40 ± 0.30 mg/kg for arsenic (As), 0.09 ± 0.03 and 0.20 ± 0.18 mg/kg for cadmium (Cd), 1.15 ± 1.40 to 2.30 ± 1.52 mg/kg for lead (Pb) and 0.58 ± 0.31 to 2.19 ± 1.25 mg/kg for mercury (Hg), respectively. The measured values are not over the considered threshold values for these toxic metals and in accordance with similar concentrations of them recorded in similar species within Europe. No significant differences were found in their concentration between genders or age in the species. According to the detected concentrations of these metals, their levels accumulated in the feather of the investigated birds do not indicate the possibility of poisoning.

The feasibility of using floating treatment wetlands (FTWs) to treat runoff typical of commercial nurseries was investigated using two 8-week trials with replicated mesocosms. Plants were supported by Beemat rafts. Five monoculture treatments of Agrostis alba (red top), Canna × generalis ‘Firebird’ (canna lily), Carex stricta (tussock sedge), Iris ensata ‘Rising Sun’ (Japanese water iris), Panicum virgatum (switchgrass), two mixed species treatments, and an unplanted control were assessed. These plant species are used for ornamental, wetland, and biofuel purposes. Nitrogen (N) and phosphorus (P) removals were evaluated after a 7-day hydraulic retention time (HRT). N removal (sum of ammonium-N, nitrate-N, and nitrite-N) from FTW treatments ranged from 0.255 to 0.738 g·m⁻²·d⁻¹ (38.9 to 82.4% removal) and 0.147 to 0.656 g·m⁻²·d⁻¹ (12.9 to 59.6% removal) for trials 1 and 2, respectively. P removal (phosphate-P) ranged from 0.052 to 0.128 g·m⁻²·d⁻¹ (26.1 to 64.7% removal) for trial 1, and 0.074 to 0.194 g·m⁻²·d⁻¹ (26.8 to 63.2% removal) for trial 2. Panicum virgatum removed more N and P than any other FTW treatment and the control in both trials. Results show that species selection and timing of FTW harvest impact the rate and mass of nutrient remediation. FTWs can effectively remove N and P from runoff from commercial nurseries.

The concerns regarding potential environmental release and ecological risks of multi-walled carbon nanotubes (MWCNTs) rise with their increased production and use. As a result, there is the need for an analytical method to determine the environmental concentration of MWCNTs. Although several methods have been demonstrated for the quantification of well-characterized MWCNTs, applying these methods to field samples is still a challenge due to interferences from unknown characteristics of MWCNTs and environmental media. To bridge this gap, a recently developed microwave-induced heating method was investigated for the quantification of MWCNTs in field samples. Our results indicated that the microwave response of MWCNTs was independent of the sources, length, and diameter of MWCNTs; however, the aggregated MWCNTs were not able to convert the microwave energy to heat, making the method inapplicable. Thus, a pre-treatment process for dispersing bundled MWCNTs in field samples was crucial for the use of the microwave method. In the present paper, a two-step pre-treatment procedure was proposed: the aggregated MWCNTs loaded environmental samples were first exposed to high temperature (500 °C) and then dispersed by using an acetone-surfactant solution. A validation study was performed to evaluate the effectiveness of the pre-treatment process, showing that an 80–120% recovery range of true MWCNT loading successfully covered the microwave-measured MWCNT mass.

Schizophyllum commune is a filamentous basidiomycete which can degrade complex organic macromolecules like lignin by the secretion of a large repertoire of enzymes. One of these white rot enzymes, laccase, exhibits a broad substrate specificity and is able to oxidize a variety of substances including carbonaceous rocks. To investigate the role of laccase in bioweathering, laccase gene lcc2 was overexpressed, and the influence on weathering of black slate, originating from a former alum mine in Schmiedefeld, Germany, was examined. The metal release from the rock material was enhanced, associated with a partial metal accumulation into the mycelium. A sequestration of metals could be shown with fluorescent staining methods, and an accumulation of Zn, Cd, and Pb was visualized in different cell organelles. Additionally, we could show an increased metal resistance of the laccase overexpressing strain.

This study investigates the biodegradation of crude oil by a mixed culture of bacteria isolated from the Qinghai-Tibet plateau using gas chromatography-mass spectrometer (GC-MS) and the gravimetric method. The results showed that a mixed culture has a stronger ability to degrade hydrocarbon than pure cultures. Once both Nocardia soli Y48 and Rhodococcus erythropolis YF28-1 (8) were present in a culture, the culture demonstrated the highest crude oil removal efficiency of almost 100% after 10 days of incubation at 20 °C. Moreover, further analysis of the degradation mechanisms used by the above strains, which revealed utilization of different n-alkane substrates, indicated the diversity of evolution and variations in different strains, as well as the importance of multiple metabolic mechanisms for alkane degradation. Therefore, it is concluded that a mixed culture of Y48 and YF28-1 (8) strains can provide a more effective method for bioremediation of hydrocarbon-contaminated soil in permafrost regions.

Expectedly, urbanization is often associated with constant degradation of natural habitat. In most cases, as demand for housing increases, natural habitat like agricultural land, forestry, and water bodies gradually gives way to building structures. Against this backdrop, the current study investigates the asymmetric nexus of agricultural land and housing market vis-à-vis house prices. The study employed the yearly data from 1976 to 2015 for the case of Sweden and used economic policy uncertainty (EPU) as a control variable in non-linear autoregressive distributed lag (NARDL) approach. The finding notes a significant and positive short- and long-run relationship between housing price and agricultural land especially when there is a negative shock on agricultural land. But when there is a negative shock on EPU, the impact on housing price is significant and negative for both short run and long run. While an asymmetric long-run relationship is significant and positive between EPU and housing price, such significant occurrence do not exist for agricultural land. Hence, in meeting housing demand and mitigating an escalated growth in house prices, implementation of effective land use policy is encouraged.

Rodents infest urban environments, causing damage and acting as vectors for disease transmission. Currently, anticoagulants are the most widely used chemical rodenticides, and their extensive and widespread use can contaminate the environment. To ensure effectiveness and avoid accumulation of rodent baits in the environment, it is important to evaluate how long rodent baits maintain their palatability and efficacy. In rodent control programs, rodent baits are placed in locations such as sewers, but after a few days, baits appear altered, causing doubts about the control efficacy. For this reason, baits are replaced periodically, which increases costs and generation of chemical waste. The objective of this study was to evaluate the palatability and efficacy of commercial paraffin-type rodent bait blocks placed in sewers in São Paulo City over a period of 90 days. Bait blocks were placed in sewers and collected after 30, 60, and 90 days. Additionally, in a laboratory two-choice test, wild-caught urban Norway rats were offered 40–60 g of bait and an equal volume of standard rat pellets. The amount of bait and rat pellet consumed was registered, the palatability was calculated, and the efficacy was measured as the percentage mortality over 14 days. The results showed that, even when they had an altered appearance, bait blocks remained palatable to the rats and were effective after at least 90 days. Leaving bait blocks for longer periods could be an effective strategy for reducing costs and could help to ensure the control of urban rodents in an environmentally sustainable way.

A new synergistic method was developed to inactivate marine microalgae using combined longwave ultraviolet (UVA) and shortwave ultraviolet (UVC)-photocatalysis (UVA/UVC-TiO₂) technology. Five kinds of representative marine microalgae in three phyla were used as inactivating targets to examine the inactivation effect. Compared with the photocatalytic systems using UVA or UVC alone as the light source, the algae inactivation ratio in the newly developed system increased by 0.31 log or 0.19 log, and the chlorophyll a removal rate increased by 17.5% or 9.7%, respectively. Total suspended solids (TSS) of the seawater did not cause remarkable impact on the inactivation process, and the increase of UV radiation intensity improved the treatment effect significantly. Further, UVA/UVC-TiO₂ treatment causes irreversible damage to microalgae cell membrane. The content of lipid peroxidation product malondialdehyde (MDA) increased rapidly within a short period of time, and a large number of proteins leaked out. The results of this study indicated that UVA/UVC-TiO₂ was an effective method to solve the challenge of efficient inactivation of plankton in ballast water containing a high density of suspended matter.