Bacterial systems have drawn an increasing amount of attention on lignin valorization due to their rapid growth and powerful environmental adaptability. In this study, Klebsiella pneumoniae NX-1, Pseudomonas putida NX-1, and Ochrobactrum tritici NX-1 with ligninolytic potential were isolated from leaf mold samples. Their ligninolytic capabilities were determined by measuring (1) the cell growth on kraft lignin as the sole carbon source, (2) the decolorization of kraft lignin and lignin-mimicking dyes, (3) the micro-morphology changes and transformations of chemical groups in kraft lignin, and (4) the ligninolytic enzyme activities of these three isolates. To the best of our knowledge, this is the first report that Ochrobactrum tritici species can depolymerize and metabolize lignin. Moreover, laccase, lignin peroxidase, and Mn-peroxidase showed high activities in P. putida NX-1. Due to their excellent ligninolytic capabilities, these three bacteria are important supplements to ligninolytic bacteria library and could be valuable in lignin valorization.

In this work, an environmental friendly industrial regeneration approach has been proposed to remove the surface poisoning and recover the catalytic activity of waste V₂O₅-WO₃/TiO₂ catalyst. Alkaline treatment and acid wash are combined for the waste catalyst regeneration process, which is applied for the arsenic and alkali metal removal, respectively. The crystal structure was well maintained as anatase phase and the surface area was increased during the regeneration, which is favorable for the following active component addition step and regenerated process. The XPS results illustrated that the surface contaminants (arsenic and sodium) were removed and V(IV) was loaded on the regenerated catalyst. Based on the deNOₓ evaluations, the catalytic activity of the regenerated sample is increased to the level of commercial fresh catalyst. The present industrial regeneration process provides a promising method for the comprehensive recovery of waste catalyst and further understanding in the field of secondary resource recycle.

Summer fallow is very common in dryland agriculture to conserve rainwater and replenish soil fertility. However, bare land and intensive rainfall during summer fallow might result in a potential risk of N loss. We used a ¹⁵N-labelling method to study the loss of residual N fertilizer during summer fallow and its use by next wheat in the Loess Plateau. Our study included three treatments: without the addition of N (N₀W₀), with the addition of 50 kg ha⁻¹ N (NW₀) and with the addition of 50 kg ha⁻¹ N plus 35% more water (NW). The N fertilizer (K¹⁵NO₃) in solution was injected into the soil at a depth of 35 cm of the polyvinyl chloride (PVC) columns in field. The fates of ¹⁵N were followed after summer fallow and in the next season’s wheat (Triticum aestivum L.). The summer fallow of this study was a dry summer; however, fertilizer ¹⁵N was still leached down to 40-cm depth for the NW₀ treatment; and for the NW treatment, the peak of ¹⁵N fertilizer was approximately 20 cm deeper. After summer fallow, the loss of the initially applied ¹⁵N was 26% in the soil profile for the NW₀ treatment; and for the NW treatment, it increased to 37%. Soil ¹⁵N abundance in 0–20 cm of the NW₀ and NW treatments was higher than the N₀W₀ treatment, indicating the upward movement of ¹⁵N in summer fallow. After the next wheat harvest, ¹⁵N uptake by wheat in the NW treatment decreased from 21.0 to 18.6% compared to the NW₀ treatment. High rainfall during summer fallow increased residual N loss during summer fallow but decreased its use by the next crop.

To explore the potential environmental and dietary factors during pregnancy affecting low-level prenatal lead exposure, we conducted a longitudinal study in Wujiang City, China. A total of 1976 mother-infant pairs were included from 2009 to 2010. An interviewed questionnaire was conducted and cord blood samples were collected. The geometric means of cord blood lead level was 30.3 μg/L (95% CI, 29.8–30.8) with 99.24% below 100 μg/L. Maternal age, passive smoking, and living in the countryside were significantly associated with cord blood lead concentrations. Multiple logistic models showed that some family environmental factors including using firewood and electricity as kitchen fuel were positively correlated with increased cord blood lead levels. Among dietary sources recorded in this study, meat consumption (> 3 times/week), fish consumption (1–3 times/week), vegetables consumption (> 1 times/day), and fruit intake (> 1 times/day) had inverse relationship with cord blood lead levels. In general, our findings may have important implications for family environmental and dietary direction during pregnancy to decrease prenatal lead exposure.

Raw coal fly ash was activated to an adsorbent by sulfuric acid impregnation. The activation condition, the adsorption capacity, and the regenerative valorization of the adsorbent were studied. The results show that the optimal preparation conditions of the adsorbent are [H₂SO₄] = 1 mol L⁻¹, activation time = 30 min, the ratio of coal fly ash to acid = 1:20 (g:mL), calcination temperature = 100 °C. The adsorption of p-nitrophenol on the adsorbent accords with the pseudo-second-order kinetic equation and the adsorption rate constant is 0.089 g mg⁻¹ min⁻¹. The adsorption on this adsorbent can be considered enough after 35 min, when the corresponding adsorption capacity is 1.07 mg g⁻¹ (85.6% of p-nitrophenol removal). Compared with raw coal fly ash, the adsorbent has a stable adsorption performance at low pH range (pH = 1–6) and the adsorption of p-nitrophenol is an exothermic process. Ninety minutes is required for the regenerative valorization of saturated adsorbent by Fenton process. The regenerative valorization for this saturated adsorbent can reach 89% under the optimal proposed conditions (30 °C, pH = 3, [H₂O₂] = 5.0 mmol L⁻¹, [Fe²⁺] = 5.5 mmol L⁻¹). Within 15 experimental runs, the adsorbent has a better and better stability with the increase of experimental runs. Finally, the mechanism of activating coal fly ash is proposed, being verified by the results of the SEM and BET test.

Geochemical and geophysical surveys employing radon deficit, resistivity, and induced polarization (IP) measurements were undertaken on soil contaminated with non-aqueous phase liquids (NAPLs) in two different sites in India and in Italy. Radon deficit, validated through the comparison with average soil radon in reference unpolluted areas, shows the extension of contamination in the upper part of the unsaturated aquifers. In site 1 (Italy), the spill is not recent. A residual film of kerosene covers soil grains, inhibiting their chargeability and reducing electrical resistivity difference with background unpolluted areas. No correlation between the two parameters is observed. Soil volatile organic compounds (VOCs) concentration is not linked with radon deficit, supporting the old age of the spillage. NAPL pollution in sites 2a and 2b (India) is more recent and probably still active, as demonstrated by higher values of electrical resistivity. A good correlation with IP values suggests that NAPL is still distributed as droplets or as a continuous phase in the pores, strengthening the scenario of a fresh spill or leakage. Residual fraction of gasoline in the pore space of sites 2a and 2b is respectively 1.5 and 11.8 kg per cubic meter of terrain. This estimation is referred to the shallower portion of the unsaturated aquifer. Electrical resistivity is still very high indicating that the gasoline has not been strongly degraded yet. Temperature and soil water content influence differently radon deficit in the three areas, reducing soil radon concentration and partly masking the deficit in sites 2a and 2b.

The object of this study was to investigate the effect of saturated zone depth (SZD) and plant on the removal of organics and nitrogen in four continuous-feed vertical flow-constructed wetlands (VFCWs). Three VFCWs were planted with Iris pseudacorus and operated at different SZDs (19, 51, and 84 cm), and the other one was non-planted and operated at 51 cm SZD. The VFCWs were operated with an organic loading rate (OLR) of 79 g chemical oxygen demand (COD) m⁻² day⁻¹, a total nitrogen loading rate (NLR) of 11 g N m⁻² day⁻¹, and a hydraulic loading rate (HLR) of 0.35 m³ m⁻² day⁻¹. Simultaneous transformation of ammonium and nitrate occurred in all of the four systems. In the planted bed with 51 cm SZD, suitable conditions for nitrification and denitrification could be created and the best performance for total nitrogen (TN) removal was realized via simultaneous nitrification and denitrification (SND), achieving TN removal efficiency of 67.4–80.3%. Higher ammonium nitrogen (NH₄⁺-N) and COD removal efficiency was obtained in the system operated with 19 cm SZD, whereas higher NO₃⁻-N removal could be achieved in the bed with 84 cm SZD. With the same SZD of 51 cm, the planted VFCW performed preferable removal of COD, NH₄⁺-N, and TN in comparison with the non-planted one. All the VFCWs showed high removal efficiencies for total phosphorus (> 60.15%). Adsorption of phosphorus was primarily observed in the top and upper-middle layers filled with carbon burn slag. It has been proved that the partially saturated VFCW operated with continuous feed could achieve good performance in removal of organic matter and nitrogen by SZD adjustment to develop appropriate aerobic and anoxic regions.

This study describes a novel wastewater treatment technology suitable for small remote northern communities. The technology is based on an enhanced biodegradation of organic carbon through a combination of anaerobic methanogenic and microbial electrochemical (bioelectrochemical) degradation processes leading to biomethane production. The microbial electrochemical degradation is achieved in a membraneless flow-through bioanode–biocathode setup operating at an applied voltage below the water electrolysis threshold. Laboratory wastewater treatment tests conducted through a broad range of mesophilic and psychrophilic temperatures (5–23 °C) using synthetic wastewater showed a biochemical oxygen demand (BOD₅) removal efficiency of 90–97% and an effluent BOD₅ concentration as low as 7 mg L⁻¹. An electricity consumption of 0.6 kWh kg⁻¹ of chemical oxygen demand (COD) removed was observed. Low energy consumption coupled with enhanced methane production led to a net positive energy balance in the bioelectrochemical treatment system.

Sawdust biochar (SDB) was for the first time applied to rice paddy field to evaluate its effects on potential nitrogen (N) runoff and ammonia (NH₃) volatilization losses in a soil column experimental system. Results showed that total N concentration of surface floodwater under SDB treatments was reduced by 7.29–35.16, 16.34–32.35, and 12.21–28.12% after three split N fertilizations, respectively. Particularly, NH₄⁺–N was decreased by 11.84–27.08, 14.29–36.50, and 2.97–19.64%, respectively. However, SDB addition has no significant influence on NO₃⁻–N concentration. Meanwhile, SDB application increased NH₄⁺–N and total N content of top (0–15 cm) soil. Furthermore, these SDB-induced influences were more pronounced for 3 wt% SDB treatments. SDB treatments recorded 3.56–5.78 kg ha⁻¹ higher NH₃ volatilization than urea control treatment, which was attributed to the elevated pH values of floodwater and top soil induced by SDB. Fortunately, the yield-scale NH₃ volatilization was not increased dramatically.

In this study, cardiac and locomotor activities of signal crayfish Pacifastacus leniusculus were investigated under exposure to a range of natural (i.e., odors of conspecific crayfish, predatory fish, food, and injured conspecific) and one chemical (i.e., disinfectant chloramine-T) stimuli. Crayfish locomotion was simultaneously initiated with an increase in heart rate only when affected by chloramine-T, while locomotor response was delayed in all cases (or was not manifested at all by some specimens) when disturbed by the natural stressors. The heart rate differences measured before and during the stimulation were arranged as follows: odor of conspecific crayfish (9.2 ± 7.1%) < predator (18.4 ± 13%) < food (33.5 ± 15.7%) < chloramine-T (41.1 ± 14.7%) < injured conspecific (51.8 ± 28.4%). Analysis of the peculiarities of crayfish heartbeat under exposure to the tested stimuli revealed complex cardiac responses as was previously observed by an electrocardiography approach, that is, a slowed heart rate followed by a delayed increase. Evaluation of the intrinsic parameters of crayfish bioindicators remains essential due to the possibility of detection of the substantial ethological responses even in motionless animals. The role and appropriateness of signal crayfish as a bioindicator of water quality is discussed; they seem to be an applicable species for this task due to their sufficient sensitivity and broad availability. In addition to providing a better understanding of stereotypic crayfish behaviors induced by common and chemical stressors, the results of this study may serve as reference data for the evaluation of crayfish suitability for water quality tests.