Most of previous programming methods for air-quality management merely considered single pollutant from point sources. However, air pollution control is characterized by multiple pollutants from various sources. Meanwhile, uncertain information in the decision-making process cannot be neglected in the real-world cases. Thus, an inexact multistage stochastic programming model with joint chance constraints based on the air quality index (air-quality management model with joint chance constraints (AQM-JCC)) is developed for controlling multiple pollutants deriving from point and mobile sources and applied to a regional air-quality management system. In the model, integrated air quality associated with the joint probability existing in terms of environmental constraints is evaluated; uncertainties expressed as probability distributions and interval values are addressed; risks of violating the overall air-quality target under joint chance constraints are examined; and dynamics of system uncertainties and decision processes under a complete set of scenarios within a multistage context are reflected. The results indicate that useful solutions for air quality management practices in sequential stochastic decision environments have been generated, which can help decision makers to identify cost-effective control strategies for overall air quality improvement under uncertainties.

The presence of some anionic species, such as nitrate, nitrite, chloride, sulfide, fluoride, and cyanide, in water supplies may represent a serious environmental problem. In this work, the main sources and harmful effects of their bioaccumulation on living organisms are reviewed, as well as the most adopted technologies for their uptake. The major advantages and disadvantages of each methodology are also listed. In general, ion-exchange has been elucidated as the most suitable removal process. In view of that the most promising materials used to remove anionic pollutants from aqueous solutions are highlighted in this review. In particular, the major efforts towards the development of low-cost and easily available effective sorbents for water decontamination are covered. For instance, natural waste solid materials and derivatives have emerged as promising low-cost exchangers for selective anions uptake. Besides, a number of structural modifications including the introduction of more suitable surface functional groups or compensation species into the sorbent matrix have been investigated in order to enhance sorbents selectivity and capacity for anionic pollutants. The influence of speciation and removal conditions is also focused.

The well-known bacterium Sphingomonas wittichii RW1 catabolically degrades dibenzo-p-dioxin and dibenzofuran, as well as their chlorinated derivatives. The catabolic degradation of dioxin is initiated by a ring-hydroxylating dioxygenase. The biotransformation of carbazole by S. wittichii RW1 was determined in the present study. Dioxin dioxygenase from the dibenzofuran induced RW1 strain was thought to be unable to attack carbazole, which includes a heterocyclic aromatic dibenzopyrrole system. However, our results showed that carbazole was transformed to anthranilic acid and catechol. The color of the culture suspension changed upon addition of carbazole due to formation of a nitrogen-containing metabolite. Relevant metabolic intermediates were identified by gas chromatographic mass spectrometry and electrospray ionization time-of-flight mass spectrometry with comparison to the corresponding authentic compounds. The dioxygenase of the dibenzofuran induced RW1 attacked at the angular position adjacent to the nitrogen atom to give a dihydroxylated metabolic intermediate. Contrary to predictions made in previous reports, S. wittichii RW1 displayed positive catabolic activity toward carbazole.

The complete mineralization of the conazole fungicide triadimefon in water at pH 3 using electrochemical advanced oxidation processes, electro-Fenton and photo electro-Fenton, was achieved. The electrochemical system consisted of a one-compartment electrochemical cell of 100 mL provided with a glassy carbon mesh electrode (cathode) and a concentric outer steel mesh as anode. The electrolysis was realized at constant current. The most remarkable features are as follows: (1) photo electro-Fenton process reaches a complete mineralization of triadimefon after 2 h of electrolysis with respect to electro-Fenton method; and (2) 4-chlorophenol, hydroquinone, carboxylic acids, and inorganic ions were detected as intermediates of degradation processes, which end with the complete mineralization of triadimefon to CO₂ + H₂O. (3) A reaction pathway for the oxidation of triadimefon fungicide by hydroxyl radicals that accounts for almost all detected intermediates is proposed.

A novel tannin-based coagulant has been synthesized at lab scale. A multiparameter optimization was performed on the production process, and up to five variables were studied according to the response surface methodology in a face-centered design of experiments which included two temperatures, two pH levels, and the reaction time in the chemical process. The coagulant involved diethanolamine, formaldehyde, and a tannin extract from Acacia mearnsii de Wild. The results revealed an average optimum combination for dye and surfactant removal which was able to remove either Alizarin Violet 3R and sodium dodecylbenzene sulfonate efficiently from water effluents.

Fluvial mine tailing deposition has caused extensive riparian damage throughout the western USA. Willows are often used for fluvial mine tailing revegetation, but some accumulate excessive metal concentrations potentially detrimental to browsers. This greenhouse experiment evaluated growth and metal accumulation of Geyer willow (Salix geyeriana Andersson), Drummond’s willow (Salix drummondiana Barratt ex Hook.), diamondleaf willow (Salix planifolia Pursh), Bebb willow (Salix bebbiana Sarg.), thinleaf alder [Alnus incana (L.) Moench spp. tenuifolia (Nutt.) Breitung], water birch (Betula occidentalis Hook.), red-osier dogwood (Cornus sericea L. spp. sericea), and shrubby cinquefoil [(Dasiphora fruticosa (L.) Rydb. ssp. floribunda (Pursh) Kartesz)]. Bare-root shrubs were grown in tailings collected from three acidic, metal-contaminated (i.e., Cd, Cu, Pb, and Zn) fluvial deposits near Leadville, Colorado, USA. Tailings were amended with only lime to raise the soil pH to 7 s.u., or with lime and composted biosolids (224 Mg ha−1). All shrubs survived in the amended tailings; composted biosolids had little effect on plant biomass. Aboveground and belowground biomass increased during the 2-month greenhouse study by 3–9 and 1.5–5 times initial values, respectively. Most shrubs accumulated Pb and Cu in roots, and belowground Pb concentrations in all shrubs were significantly reduced by the addition of composted biosolids. Compared to other species, alder and cinquefoil accumulated Pb in aboveground growth, and concentrations exceeded animal toxicity thresholds, but these shrubs normally comprise a small proportion of animal diets. Dogwood, alder, and cinquefoil contained low Cd concentrations in aboveground new growth, whereas Bebb and Geyer willow contained zootoxic concentrations. Dogwood, alder, and cinquefoil are three good candidates for mine tailing revegetation, especially in fluvial deposits with elevated Cd concentrations.

The relationships between the Ni concentrations of the mudflat snails Telescopium telescopium and the surface sediments have not been reported yet from tropical intertidal areas. In this study, telescope snails and surface sediments were collected from 18 geographical sampling sites in intertidal areas of Peninsular Malaysia. The concentrations of Ni were measured in seven different soft tissues of the snails namely foot, cephalic tentacles, mantle, muscle, gill, digestive cecum, and remaining soft tissues. It was found that different concentrations of Ni were found in the different soft tissues, indicating different mechanisms of sequestration and regulation of Ni in these different tissues. By comparing the Ni concentrations in the similar tissues, spatial variations of Ni were found in the different sampling sites although there was no consistent pattern of Ni in these sites. The highest Ni variation based on the ratio of maximum to minimum values indicated that cephalic tentacle and foot were the main organs having high Ni variation. The use of correlation analysis and multiple linear stepwise regression analysis revealed that digestive cecum of T. telescopium could be used to reflect the Ni contamination of the sampling site. Also, the digestive cecum and gill were found to be the main bioaccumulation and storage sites for Ni. From the Ni accumulation patterns in all the populations investigated, tissue redistributions of Ni in gill was identified and could be proposed as an indicator of high Ni bioavailability and contamination in the sampling site. To our knowledge, this is the first and most comprehensive study on Ni accumulation in the different soft tissues of T. telescopium from tropical intertidal areas, in relation to the sediment data.

A thin film of well-ordered anatase TiO₂ nanotubes prepared by anodic oxidation of titanium metal were synthesised and used as adsorbent medium for the purification of water from aqueous uranium and lead. The amount of subtracted metal ions was quantified by using X-ray photoelectron spectroscopy at the surface of the reacted TiO₂ surface. Batch experiments for the sorption of U and Pb at the surface of the titania substrate were carried out in separated solution equilibrated with air of uranyl acetate and lead nitrate, in the pH range 3–9. For uranium, the experiments were also repeated in anoxic (N₂) atmosphere. The amount of metal ions adsorbed onto the titania medium was quantified by measurements of the surface coverage expressed in atomic percent, by recording high-resolution XPS spectra in the Ti2p, U4f and Pb4f photoelectron regions. Adsorption of the uranyl species in air atmosphere as a function of pH showed an adsorption edge near pH 4 with a maximum at pH 7. At higher pH the presence of very stable uranyl–carbonate complexes prevented any further adsorption. Further adsorption increased until pH 8.5 was obtained when the uranyl solution was purged from dissolved CO₂. Lead ion showed a sorption edge at pH 6, with a maximum uptake at pH 8. The results showed that the uptake of uranium and lead on the selected titania medium is remarkably sensitive to the solution pH. This study demonstrates the reliability of this type of material for treating water polluted with heavy metals as well as leachates from radioactive nuclear wastes.

Lake water calcium (Ca) decline has recently been recognized as a stressor impacting softwater lake districts that have experienced long-term patterns of acid deposition and/or timber harvesting. Declining aqueous Ca levels may impact the survival of aquatic biota, particularly Ca-rich cladoceran taxa such as daphniids. Daphnia pulex are sensitive to laboratory Ca levels below 1.5 mg l−1; however, responses of cladoceran communities to Ca decline in natural environments require further study. Dickie Lake (Ontario, Canada) is the site of an inadvertent natural experiment, providing insight into the effects of changing aqueous Ca availability upon cladoceran communities, as the lake has a history of acidification, followed by recent (1990s) Ca additions to the watershed via applications of calcium-rich road dust suppressants. Paleolimnological analyses were used to examine changes in cladoceran community structure (with a focus upon Ca-rich daphniids) from pre-industrial times to present day. Three distinct temporal stages were apparent in Dickie Lake’s daphniid community: 1870–1950, 1950–1990, and 1990–present. The daphniid community of the pre-industrial assemblages was dominated by members of the Daphnia longispina species complex, but shifted in the late 1950s to more acid- and Ca-insensitive members of the D. pulex species complex. During the most recent stage, coincident with dust suppressant applications, both daphniid complexes are well represented. Observed transitions between daphniid species complexes provide further evidence of the influence of Ca availability upon cladoceran community structure, indicating the potential importance of the controlled addition of Ca to freshwater systems (i.e., liming) as a mitigation/recovery strategy as Ca declines continue.

Grazing livestock excrete large volumes of faecal material on pasture. Understanding the magnitude of this faecal burden is important for attributing sources of agricultural pollutants to different spatial and temporal scales. This field-based study evaluated the utility and transferability of a rapid approach often used in plant ecology (the line intercept method (LIM)) for estimating faecal burden from grazing cattle on pasture. Results from the LIM were of equivalent magnitude, with no significant difference observed, to those derived from more time-consuming sampling of faecal material from pasture using a quadrat-style methodology (herein termed burden sampling). However, the variability in estimates using the LIM was much larger (839–7,079 kg fresh weight faeces over the 50,000 m² field) compared with estimates provided by the burden sampling of pasture at 0.2 % area sampled (1,616–3,979 kg/50,000 m²), 0.4 % area sampled (1,753–2,723 kg/50,000 m²) and 0.8 % area sampled (1,212–2,344 kg/50,000 m²). The LIM offers a rapid and cost-effective alternative to time-consuming sampling campaigns of faecal burden on pasture and provides estimations that are preferable to back-of-the-envelope calculations based on the over-simplification of livestock excretion rates.