Urban market gardening in Africa is suffering from increasing environmental contamination due to sources of contamination as varied as traffic, industry, and agriculture practices. A field study was therefore conducted to determine the global influence of the polluted environment (atmosphere, soil, and irrigation waters) on vegetable quality in a large urban-farming area. For leafy vegetables collected in 15 ha of squatted land belonging to the international airport of Cotonou, total concentrations of metal(loid)s measured in consumed parts of Lactuca sativa L. and Brassica oleracea were 52.6–78.9, 0.02–0.3, 0.08–0.22, 12.7–20.3, 1.8–7.9, and 44.1–107.8 mg kg⁻¹for Pb, Cd, As, Sb, Cu, and Zn, respectively. Human gastric bioaccessibility of the metal(loid)s was measured, and the obtained values varied according to the considered metal(loid) and the plant species. The results identified values that are commonly found in non-polluted soils and roots associated with contaminated edible parts, raising the possibility of atmospheric contamination. Such a hypothesis is in agreement with values of magnetic susceptibility, since iron oxides and probably their associated metal(loid)s do not translocate from the roots toward the upper parts of the plants. (Bioaccessible) estimated dose intake ((B)EDI) and total (bioaccessible) target hazard quotient (Σ(B)THQ) were calculated to assess the health risk of consuming vegetables from this area. Pb and Sb were the major risk contributors. Taking the bioaccessible fractions into account, ΣBTHQ values were lower than ΣTHQ but were all still >1 for both males and females, leading to the conclusion that consuming these vegetables from this area is not risk-free.

Bauxsol is a chemico-physically modified product of red mud and is a promising material for the removal and recovery of phosphorus from wastewater. In this study, response surface methodology (RSM) and artificial neural network (ANN) were employed to develop prediction models and also to investigate the interactions of independent experimental factors for phosphorus adsorption onto acid-activated Bauxsol. The experimental results indicated that HCl activation was effective to improve the adsorption capacity of Bauxsol. The maximum adsorption capacity of acid-activated Bauxsol was 55.72 mg/g (as P) with HCl concentration of 10.20 mol/L, temperature of 41.00 °C, and time of 5.60 h, which increased by 10.53 and 6.62 times compared with the raw red mud and Bauxsol before acid activation, respectively. The relative importance of HCl concentration in RSM and ANN models was 51.78 and 54.25 %, respectively, which illustrated that HCl concentration played the predominant role on improving the adsorption capacity of Bauxsol. The predictive capability of RSM and ANN models was compared, and the results showed that both models provided excellent predictions with R² > 0.93. However, the ANN model showed the superiority over RSM for estimation capability.

As the popularity and use of soft plastic lures (SPLs) by recreational anglers have increased in recent years, so does the number of anecdotal reports of SPLs being found in aquatic environments and in the digestive tract of a variety of fish species. We used a multistep approach to determine the possible consequences of SPLs on fish and aquatic environments. Field work focussed on lake trout (Salvelinus namaycush) and smallmouth bass (Micropterus dolomeiu) in Charleston Lake in eastern Ontario, a system identified by resource managers and the lake association as potentially having an SPL problem based on numerous anecdotal reports from anglers. Snorkel surveys revealed that the deposition rate of SPLs was potentially as high as ~80 per km of shoreline per year. In the laboratory, eight different types of SPLs were immersed in water at two temperatures (4 and 21 °C) for a 2-year period to evaluate change in SPL size (both swelling and decomposition). Despite SPLs varying by manufacturer and in composition, there was little evidence of decomposition. Indeed, most SPLs swelled and remained that way throughout the study. In cold water, SPLs increased an average of 61 % in weight and 19 % in length, while warm water treatments experienced an increase of 205 % in weight and 39 % in length. A summer creel survey conducted on Charleston Lake revealed that 17.9 % of anglers interviewed reported finding at least one ingested SPL when cleaning lake trout. However, when we sampled lake trout (using gill nets) and smallmouth bass (by rod and reel), we found few ingested SPLs (2.2 and 3.4 %, respectively). Based on the examination of fish that contained SPLs and the near-shore surveys, the most common SPLs were soft stick baits/wacky worms. The most promising approach to address the SPL problem is to educate anglers about the need to rig SPLs in a manner such that they are less likely to be lost during fishing and to always discard SPLs appropriately. Moreover, the tackle industry should continue to investigate SPLs that are less likely to be pulled off by fish and/or that degrade rapidly.

This work has evaluated the efficiency of two coagulants, aluminum sulfate (AS) and polyaluminum chloride (PACl), combined with the adsorption process using powdered activated carbon (PAC) on the removal of diclofenac (DCF), sulfamethoxazole (SMX), ethinylestradiol (EE2), estradiol (E2), estrone (E1), estriol (E3), and bisphenol-A (BPA) from low- and high-turbidity waters. The results have shown that the concomitant application of PAC and either coagulant has worsened the removal efficiency for all pharmaceuticals and endocrine disruptors tested, which might have occurred due to the covering of adsorption sites by aluminum hydroxide particles. In this configuration (coagulation in the presence of PAC, 10 mg L⁻¹), the best removal efficiency (∼40 %) was obtained for E1 and EE2 when AS was used as coagulant in contact times that varied from 13.5 to 23.5 min. When the coagulant was the PACl, contact times were lower (8.5 to 13.5 min) and the highest removal efficiency was observed for EE2 (∼52 %). When PAC was added as a pre-treatment (before addition of coagulant), the removal efficiency was greatly increased for all microcontaminants and the application of 2.5 mg L⁻¹of PAC with 120 min of contact led to removal efficiencies varying from 30 to 99.9 %.

Episodes of pollution resulting from high concentrations of environmental ozone frequently occur in different parts of the world. The ozone can affect human health, natural vegetation, and agricultural productivity. The monitoring of ozone concentrations is essential to aid investigation of its effects and it is also required to assess progress in public management of this pollutant. A new effective and simple technique is presented for the determination of ambient ozone concentrations using a visual procedure. The method is based on the reaction between the dye indigo and ozone, with the formation of colorless products. The bleaching intensity is proportional to the amount of ozone. An indigo color standard scale was developed with the utilization of digital image-based (DIB) calibration and printed as a wheel-chart test kit. Ozone sampling is performed using a passive sampler containing a filter impregnated with indigo. The amount of reacted ozone can be determined by visual comparison using the wheel-chart test kit. The method enables determination of ozone concentrations from 2 to 97 ppb, with intervals of 3 ppb. It does not require an energy source or any post-sampling chemical treatment or analysis, and the ozone concentration can be known immediately, in situ, at the end of the sampling period. The method offers substantial advantages in large-scale mapping and monitoring of ozone or measurements concerning occupational exposure to ozone.

Titanate whiskers were prepared by hydrothermal method starting from hydrous metatitanic acid and potassium hydroxide. The titanate whiskers were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma, and N₂ adsorption/desorption techniques. When the concentrations of potassium hydroxide ranged from 6 to 12 mol L⁻¹, titanate whiskers were formed by bundling layer-structured nanoribbons. The titanate whiskers were certified with the formula of H₂ ₋ ₓKₓTi₃O₇ · nH₂O (x = 0.6, n = 3.8–4.0). After hydrochloric acid treatment, the potassium content and the layer distance decreased due to the replacement of potassium ions by protons. The maximum adsorption capacities of titanate whiskers for Cu(II), Pb(II), and Cr(III) ions were 142.0, 395.7, and 97.0 mg g⁻¹ when their initial concentrations were 150, 300, and 80 mg L⁻¹, respectively. The adsorption equilibriums were almost established in 30 min. The adsorption of Cu(II), Pb(II), and Cr(III) ions on titanate whiskers followed the pseudo-second-order adsorption kinetics. The Langmuir adsorption isotherms well fitted the adsorption equilibriums of Cu(II) and Pb(II) ions while the Freundlich adsorption isotherm well fitted the adsorption equilibrium of Cr(III) ions.

The novel adsorbent Cu-impregnated activated coke (CAC) has been successfully prepared using a Cu(NO₃)₂solution impregnated activated coke (AC). The optimum preparation conditions of CAC are the concentration of Cu(NO₃)₂of 0.1 mol/L, pH of 6, loading time of 4 h, and loading temperature of 333 K. The characterizations of CAC are analyzed by N₂adsorption, X-ray diffraction, scanning electron microscope, and energy dispersive X-ray spectroscopy. Also the adsorption behavior of CAC to organic materials in TNT red water is studied. The adsorption data are simulated by Freundlich isotherm and Langmuir isotherm. Below 333 K Freundlich isotherm is more suitable, while Langmuir isotherm model is more fitted when the temperature is higher than 333 K. The adsorption kinetics follows a pseudo second-order model, and thermodynamic analysis indicates an endothermic and spontaneous adsorption processes, and the process appears to be controlled by the chemisorption process. Chemical oxygen demand of 85.34 % can be removed as CAC prepared under optimized conditions is used as absorbent. In summary, CAC has excellent absorption characteristics and can be used in the removal of organic materials from TNT red water.

The nanoscale zero-valent iron grafted on acid-activated attapulgite (A-nZVI) was prepared by a liquid-phase reduction method and used for Cr(VI) removal from solution with enhanced efficiency. The structure of the composite A-nZVI was characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller surface area analysis. nZVI was well-dispersed on the surface of acid-treated attapulgite, and no obvious aggregation was observed due to the support of rod-like structure of attapulgite, which is beneficial to Cr(VI) removal. Batch experiments revealed that the removal of Cr(VI) using A-nZVI was consistent with pseudo-first-order reaction kinetics, and removal efficiency was up to 98.73 % within 60 min for 100 mL 20 mg/L Cr(VI) at the initial pH 7.0 and 4.0 g/L A-nZVI. The pseudo-first-order rate constant kₒbₛwas independent of initial Cr(VI) concentration, but there was a good linearity (r² = 0.95) between kₒbₛand the A-nZVI dosage. This study demonstrates that A-nZVI has the potential to become a promising material for in situ groundwater remediation.

Forest ecosystems in the Eastern USA are threatened by acid deposition rates that have increased dramatically since industrialization. We utilized two watersheds at the Fernow Experimental Forest in West Virginia to examine long-term effects of acidification on ecological processes. One watershed has been treated with ammonium sulfate (approximately twice the ambient deposition rate) since 1989 to simulate elevated acidic deposition, while the other served as a control. Prior to treatment, both watersheds were similar in age and species composition. Ten dominant overstory Prunus serotina and Liriodendron tulipifera trees were selected and cored from each watershed to measure bolewood concentrations of essential elements through time. In addition, changes in tree species basal area were analyzed utilizing 50 long-term growth plots. Results of this experiment show lower calcium and magnesium concentration and increased acidic cation concentration for both species in the treated watershed, indicating a negative treatment effect. Growth response, measured through relative growth rates of cored trees and changes in basal area from growth plots, was not as conclusive and appeared to differ by species. The resulting difference in species response indicates that acidification sensitivity is something that land managers should consider when managing forests affected by acidification.