The growth of white-rot fungus Pleurotus eryngii F032 in a suitable medium can degrade an azo dye Reactive Black 5 (RB5), because of its ability to produce ligninolytic enzymes such as lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase that able to degrade and transform the complex structure of the dye into a less toxic compound. The effect of environmental factors such as initial concentration of Reactive Black 5, pH, temperature of growth medium, surfactant (Tween 80), and agitation were also investigated. The productions of ligninolytic enzymes were enhanced by increasing the white-rot fungi growth in optimum conditions. The decolorization of Reactive Black 5 were analyzed by using UV–vis spectrophotometer at the maximum absorbance of 596 nm. The white-rot fungus, P. eryngii F032 culture exhibited 93.56 % decolorization of 10 mg/L RB5 within 72 h of incubation in dark condition with agitation. The optimum pH and temperature for the decolorizing activity was recorded at pH 3 and 40 °C, respectively. The addition of surfactant (Tween 80) increased the decolorization to 93.57 % and agitation of growth medium at 120 rpm enhanced the distribution of nutrients to the fungus thus optimized the enzymatic reaction that resulted maximum decolorization of RB5 which was 93.57 %. The molecular docking studies were performed using Chimera visualization software as to analyze the decolorization mechanism of RB5 at molecular level.

The decolorization and degradation of anionic sulphonated azo dye (Reactive orange 16 (RO16)), which is suspected to be carcinogenic, were investigated using ozone. The decolorization process of the reactive dye was carried out by bubbling ozone at the bottom of a bubble column reactor containing the dye solution. The effect of pH, reaction time, dye concentration, ozone concentration, and decolorization time was studied. Also, degradation products and possible degradation mechanism were investigated. The results showed that ozonation was a highly effective way to remove color from wastewater. The color of a synthetic waste solution containing water-soluble reactive dye was reduced to 69.69 % under the basic condition (pH 12), with complete RO16 degradation occurring in 8 min. Ozone consumption continued for a further 16 min after which time most of the degradation reactions were complete. Kinetic studies showed that direct ozonation of the aqueous dyes represented a pseudo-first-order reaction with respect to the dye. The apparent rate constant increased with both the applied ozone dose and higher pH values and declined logarithmically with the initial dye concentration. Intermediates such as 6-acetylamino-3-aminonaphthalene-2-sulfonic acid, 2-(4-nitrosophenyl) sulfonylethyl hydrogen sulfate, and 6-acetamido-4-hydroxy-3-nitroso naphthalene-2-sulfonic acid were detected by gas chromatograph coupled with mass spectrometry in the absence of pH buffer, while nitrate and sulfate ions and formic, acetic, and oxalic acids were detected by ion chromatography.

The use of peracetic acid (PAA) in the disinfection of sanitary effluents has been proposed by various authors. However, there are still doubts about its influence on the physical-chemical characteristics of the effluent after application. In the present study, it was observed that the composition of PAA leads to an increase in organic material, resulting in an increase of approximately 20 mg/L in the chemical oxygen demand of the effluent for every 10 mg/L of PAA applied. According to the kinetic tests, the degradation of PAA in the effluent was represented by a first-order reaction and its half-life in the effluent was estimated at 79 min. The formation of by-products resulting from degradation of PAA in the effluent was evaluated by considering by-products already detected by other authors in disinfection trials, these being nonanal, decanal, chlorophenols, and 1-methoxy-4-methylbenzene, which were not observed in the effluent being studied after application of PAA at a dosage of 10 mg/L. © 2013 Springer Science+Business Media Dordrecht.

The volatile monoterpene alpha-pinene has been measured in sediments of a selected area at "Carlos Anwandter" Nature Sanctuary, a Ramsar protected wetland located at the northwest of Valdivia City, south-central Chile. The ecosystem was seriously damaged by an uncontrolled liquid emission of a pulp mill (CELCO-Arauco) located about 15 km upstream of Rio Cruces during 2004. Exploratory data analysis was applied to analytical data collected from sediment samples, having found alpha-pinene as a reiterative chemical at relatively high concentrations in some specific areas of the wetland. The decrease of the total concentration of alpha-pinene in the area under study is coincident with a point contamination that occurred during 2004 (12,240 ng g(-1)) showing a decay in 2005 (7,890 ng g(-1)) and middle of 2006 (4,060 ng g(-1)). The following years, last 2006, 2008, and 2009, show a relatively constant concentration with a clear tendency toward baseline levels (2,460-2,640 ng g(-1)). Since the decrease of concentrations of alpha-pinene in sediments in the period 2004-2009 shows an opposite trend as compared to the surface area increase of pine and eucalyptus plantation in Region de Los Rios, and not having found potential sources of alpha-pinene by anthropogenic activities other than the pulp mill in the area under study, it may be finally concluded that this compound did not enter the bodies of water from a gradual and natural process; instead there is a base to sustain anthropogenic input. alpha-Pinene in sediments may be a plausible chemical tracer capable of detecting pollution events over time and its impacts in aquatic ecosystems as well as changes in aquatic ecosystems produced by improperly treated pulp mill liquid emissions that use pine and eucalyptus species.

The effectiveness of activated carbon sample (Carbonₑₓₚ) prepared by KOH chemical activation in hampering oligomerization of multicomponent adsorption was systematically examined. Anoxic (absence of molecular oxygen) and oxic (presence of molecular oxygen) adsorption isotherms of single-solute (2,4-dimethylphenol), binary solute (2-methylphenol/2,4-dimethylphenol), and ternary solute (phenol/2-methylphenol/2,4-dimethylphenol) were studied, using Carbonₑₓₚ and commercial granular activated carbon F400. Both binary solute adsorption and ternary solute adsorption on Carbonₑₓₚ indicated no impact of the presence of molecular oxygen on the adsorptive capacity. No significant differences between oxic and anoxic environment were noticed for any multicomponent adsorption systems, which indicated the effectiveness of Carbonₑₓₚ in hampering the oligomerization of phenolic compounds. On the other hand, in F400, which has lower microporosity and acidic functional groups, significant increases in the adsorptive capacity had been observed when molecular oxygen was present.

Heavy metals occur naturally in soil, at concentrations that depend on the parent material from which the soil was formed, the processes of formation, and the composition and the proportion of the components of its solid phase. Quantifying these concentrations is important for environmental studies of soil contamination and pollution, and choosing the methods for doing so is a key step in establishing heavy metal contents in soil samples. We evaluated two digestion methods (aqua regia and EPA 3051, both microwave oven-assisted) for assessing pseudo-total concentrations of Cd, Co, Cr, Cu, Ni, Pb and Zn in the surface layer (0–20 cm) of soil samples from the Brazilian agricultural frontier in the southwestern Amazon. Nineteen composite samples of the most representative soil classes for the states of Mato Grosso and Rondônia were collected under native vegetation undisturbed by human intervention. Canonical discriminant analysis and principal component analysis were used for multivariate exploration of the data. Aqua regia extracted higher amounts of Co, Ni, Pb, and Zn than EPA 3051, while levels of Cr and Cu did not differ between methods. In general, aqua regia recovered more of the metals when compared to reference soil samples.

With the constant development of new ionic liquids, the understanding of the chemical fate of these compounds also needs to be updated. To this effect, the interaction of a number of novel ionic liquids with soils was determined. Therefore, three novel headgroups (ammonium, phosphonium, or pyrrolidinium) with single or quaternary substitution were tested on a variety of soils with high-to-low organic matter content and high-to-low cation exchange capacity, thereby trying to capture the full range of possible soil interactions. It was found that the ionic liquids with single butyl alkyl chain interacted more strongly with the soils (especially with a higher cation exchange capacity), at lower concentrations, than the quad-substituted ionic liquids. However, the quad-substituted ionic liquids interacted more strongly at higher concentrations, due to the double-layer formation, and induced stronger dipole interaction with previously sorbed molecules.

Geochemical characterization of two landfills, one closed and the other still active, both located near Komotini (Thrace, Greece), has been carried out. The aim was to provide an integrated and reliable methodology for a rapid assessment of the real impact of a municipal solid waste landfill, in the main environmental matrices (air and water) of the surrounding areas. The chemical (CO₂, CH₄, CO, H₂, N₂, and O₂ + Ar) and isotopic characterization (δ¹³C₍CO₂₎ and δ¹³C₍CH₄₎) of landfill gas and chemical (Na⁺, K⁺, Ca²⁺, Mg²⁺, Cl⁻, SO₄ ²⁻, HCO₃ ⁻, NH₄ ⁺, NO₃ ⁻, NO₂ ⁻, B, COD, Fe, Mn, As, Cr, Ni, Cu, Zn, Cd, Pb, and Hg) and isotopic analysis (δD, δ¹⁸O, tritium content, and δ¹³CDIC) of leachate, stream waters and groundwaters, and flux survey on the air–soil interface has been carried out. Combined chemical and isotopic analysis of the fluids collected inside and in the surroundings of the Komotini landfills supply a detailed picture of biogas emission and composition as well as of leachate chemistry and interaction with local waters. The results arising in this case study demonstrate that it is possible to propose a quick and reliable geochemical protocol to get a detailed picture of the state of health of the environment around a landfill.

A neutrophilic, autotrophic bacterium that couples iron oxidation to nitrate reduction (iron-oxidizing bacteria [IOB]) under anoxic conditions was isolated from a working bioremediation site in Trail, British Columbia. The site was designed and developed primarily to treat high concentrations of Zn and As that originate from capped industrial landfill sites. The system consisted of two upflow biochemical reactor cells (BCR) followed by three vegetated wetland polishing cells with sub-surface flow and a holding pond. During a 5-year period (2003–2007), the system treated more than 19,100 m³ of contaminated water, removing and sequestering more than 10,700 kg of As, Zn and sulfate at average input water concentrations of: As, 58.6 mg l⁻¹ (±39.9 mg l⁻¹); Zn, 51.9 mg l⁻¹ (±35.4 mg l⁻¹) and SO₄ ²⁻, 781.5 mg l⁻¹ (±287.8 mg l⁻¹). The bacterium was isolated in order to better understand the mechanisms underlying the consistent As removal that took place in the system. Analysis using Basic Local Alignment Search Tool (BLAST) database showed that the closest homologies are to Candidatus accumulibacterphosphatis (95 % homology), Dechloromonas aromatica (94 %), and Sideroxydans lithotrophicus ES-1 (92 %) Within the BCR cells, the IOB oxidized Fe²⁺ generated by iron-reducing bacteria (IRB); the source of the iron was most likely biosolids and coatings of iron oxide on locally available sand used in the matrix. We have provisionally designated the novel bacterium as TR1.

Aquatic birds are often used as a health indicator of the marine ecosystem. African penguins living in the zoo make good research material as they form a link between the marine and the terrestrial ecosystem in terms of xenobiotic circulation. Tests were performed on whole herring—the food of the penguins—as well as on bird muscle, liver, brain, eggs, feathers and guano in order to determine total mercury, aldrin, dieldrin, endrin, isodrin, endosulfan isomers, endosulfan sulfate, methoxychlor, dichlorodiphenyltrichloroethane (DDT) and its metabolites. In herring and penguin, the tests did not show the presence of β-endosulfan, endosulfan sulfate, aldrin and isodrin. It was shown that penguins absorb about 36.8 μg of organochlorine pesticides and 4.6 μg of mercury with their food on a daily basis. Xenobiotics accumulate mostly in the liver, from where they are transported to the muscles and the brain, where the highest bioaccumulation factor is reached by endrin and pp’-DDT. Conceivably, the older the penguin, the higher is the concentration level of pesticides in its liver and brain. Molting was found to be the most effective way of eliminating mercury, dieldrin and methoxychlor from the system. Insecticides, such as DDT and its metabolites, were removed most effectively by females through laying of eggs. The standard four eggs laid within a year may have contained up to 20 % of the total amount of pesticides which had been absorbed with food, but no more than 5 % of mercury.