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.

A novel combined biosorption-precipitation process has been designed and applied to recycle Pb²⁺ from low concentration lead containing wastewater. Pb²⁺ was firstly removed selectively from wastewater by pyromellitic dianhydride (PMDA) modified sugarcane bagasse (SB) fixed-bed column, and then, it was desorbed into the concentrated eluate and recycled by adding chemical precipitant. Adsorption performance of the column and optimum desorption and precipitation condition for Pb²⁺ were investigated in detail. Results showed that the as-prepared column could efficiently remove Pb²⁺ from aqueous solution and optimum condition for Pb²⁺ precipitation in eluate was at pH 3.0 and molar ratio of precipitant to Pb²⁺ of 5:1 by using Na₃PO₄ as precipitant. Recovery experiment illustrated that Pb²⁺ was selectively removed from wastewater containing ions of Pb²⁺, Zn²⁺, Cd²⁺, Ca²⁺, K⁺, and Na⁺ through competitive substitution adsorption on the modified SB, and mass ratio of the five metal ions in eluate was 96.8:0.7:0.7:0.7:0.5:0.5. Pb²⁺ in this concentrated and purified eluate solution was recycled efficiently by adding Na₃PO₄. The combined method had great potential in application of heavy metal recovery from wastewater.

Although sludge piles from drinking water treatment plants can contain harmful substances, in many countries, their disposal methods are still unregulated. Besides aluminum, which is a major constituent in these residues, many other contaminants—like trace metals—can be present and may result from the quality of the raw materials used for water treatment. The application of these chemicals for the treatment of drinking water can generate toxic sludge and contaminate the produced water. In the present work, mercury contamination in the sludge piles of two drinking water treatment plants located along the margins of the Juturnaíba Reservoir, Southeast Brazil, was evaluated to verify whether contaminants are incorporated during water treatment. In the summer 2012, five cores were collected from the piles, and were analyzed for Eh, granulometry, total carbon, total nitrogen, and total mercury. The results indicated an anoxic environment, reflecting composition of the suspended matter. Carbon and nitrogen presented elevated concentrations, but also seemed to reproduce the characteristics of the suspended matter in the raw water. The concentrations of mercury were extremely variable but presented unexpectedly high values in some of the layers, reaching 18,484 ng g⁻¹. On the other hand, concentrations ten times lower than those observed in the natural system (8 ng g⁻¹) could be observed. It was concluded that the only possible source for the contamination of the sludge was the chemicals used for water treatment.