Textile dye Victoria Blue-B (VB-B) was approached in two different ways: one to get rid of the color for its easy disposal to the environment, and the other is to reuse the decolorized water for coloring the same dye. Shewanella decolorationis (MBTD16) isolated from Dona Paula Bay, identified by 16S rRNA gene and its action over decolorization was monitored by Fourier transform infrared spectroscopy, UV–Vis spectrum, and a color scanner. Dye removal index increased L*, a*, and b* to 91.585, −2.856, and −0.132 against 62.29, −4.93, and −20.75 within 42 h as a first report. A maximum extent of decolorization (94.83 %) could be achieved with minimum dye concentration of 50 mg L⁻¹. The colored water treated by free and immobilized bacterial cells tested to reuse (VB-B dye) could give 35–50 % more color than the original. Process parameters optimized to achieve maximum decolorization indicated pH 7, temperature 32 ± 2 °C, inoculum size 8 % with co-substrates of glucose and yeast extract 5 g L⁻¹ for its supremacy. Synthesis of lignin peroxidase and tyrosinase augmented in strain S. decolorationis only after being exposed into the dye signifies the enzymes in decolorization, and it was confirmed through one-way ANOVA. Results obtain by this work could suggest that S. decolorationis can be used very well to decolorize the textile dye, and the same water could be recycled to get back its original color by adding around half the quantity of dye. Thus, by the use of water, dye and pollution levels could be minimized.

The present study deals with the effect of trace metals on the endangered limpet Cymbula nigra. The Bay of Algeciras (Strait of Gibraltar) was used as the study site. Important industrial activity takes place in the area, including frequent oil spills. However, it is home to important populations of C. nigra. The objective of this work was to determine if these animals were being affected at a subcellular level by the pollutants present in their environment and to analyze the trace metal concentrations in the animal’s soft tissues. To determine the effects of water quality on the antioxidant activity and concentrations through field experimentation, a total of six sites were selected in Algeciras Bay, three located in the inner areas (environmentally degraded sites with higher levels of pollutants) and three in the outermost areas of the Bay. Stress associated to reactive oxygen species formation was assessed on digestive glands and gills as the enzymatic antioxidant activity of catalase (CAT), superoxide dismutase (SOD), and glutathione S-transferase (GST) and as the concentrations of lipid-soluble (α-tocopherol and β-carotene) and the water-soluble antioxidants (reduced and oxidized glutathione (GSH and GSSG)). Gills and digestive glands of those animals located in the inner areas of Algeciras Bay showed higher CAT activity values than those located in the outer areas. As a general pattern, we observed higher antioxidant activities and concentrations in digestive glands that in gills, suggesting the possibility that pollutants are mainly being incorporated by limpets through the food. As a general rule, larger animals showed greater concentrations of these compounds. Iron, zinc, and manganese, in this order, were present in the tissues at the highest concentrations. Chromium and manganese were found in significantly higher concentrations in those animals collected from the inner areas of the Bay. Through the present study, we provide the first data regarding the antioxidant defense levels and metal accumulation capacity of this species, and we reinforce the idea that this endangered species may be, in fact, relatively tolerant to degraded environments.

Stormwater is a potential and readily available alternative source for potable water in urban areas. However, its direct use is severely constrained by the presence of toxic pollutants, such as heavy metals (HMs). The presence of HMs in stormwater is of concern because of their chronic toxicity and persistent nature. In addition to human health impacts, metals can contribute to adverse ecosystem health impact on receiving waters. Therefore, the ability to predict the levels of HMs in stormwater is crucial for monitoring stormwater quality and for the design of effective treatment systems. Unfortunately, the current laboratory methods for determining HM concentrations are resource intensive and time consuming. In this paper, applications of multivariate data analysis techniques are presented to identify potential surrogate parameters which can be used to determine HM concentrations in stormwater. Accordingly, partial least squares was applied to identify a suite of physicochemical parameters which can serve as indicators of HMs. Datasets having varied characteristics, such as land use and particle size distribution of solids, were analyzed to validate the efficacy of the influencing parameters. Iron, manganese, total organic carbon, and inorganic carbon were identified as the predominant parameters that correlate with the HM concentrations. The practical extension of the study outcomes to urban stormwater management is also discussed.

Removal of petroleum hydrocarbon (PHC) contamination that is hazardous and often prevalent in soils would benefit from a rapid detection technique. Visible and near-infrared spectroscopy (VIS-NIRS) has a large potential as a rapid detection technique for PHC in soils. Nevertheless, the combined influence of oil concentration, moisture content and clay content on soil reflectance spectra and the accuracy of the technique have yet received little attention. The objective of this study was to investigate the combined influence of oil concentration and moisture and clay contents on the spectral characteristics of diesel-contaminated soils and the quality of calibration models developed for polycyclic aromatic hydrocarbons (PAH) in soils using VIS-NIRS. With partial least-squares regression data from a systematic experimental design using 150 artificially contaminated soil samples, results showed that soil diffuse reflectance decreased with increasing oil concentration, clay and moisture contents. The trend was less defined in relation to moisture and clay due mainly to the interaction effects of the soil matrices as mediated by the oil. The PAH partial least squares cross-validation showed best performance with the lowest oil concentration and clay content at 20 % moisture with r ² of 0.89, root mean square error of prediction of 0.201 mg/kg and ratio of the standard error of prediction to the standard deviation of the reference data in the validation set of 2.75. Analysis of variance showed that the interaction effects of oil concentration, moisture and/or clay content significantly (p < 0.05) affected the quality of the PAH models.

Buenos Aires Province (República Argentina) has undergone, in the last years, a great increase in agricultural activities based on the incorporation of new technologies and reduction of diversity to meet the increasing food demand. The increase of intensive agricultural systems in Argentina involves the use of fertilizers and pesticides such as herbicides, insecticides, and fungicides. Chlorpyrifos is one of the insecticides most widely used in these crops and constitutes a risk for human health, birds, and aquatic biota such as macroinvertebrates and fishes. In order to assess the possible contamination that the use of this product may represent for the environment, it is necessary to study its interaction with the different types of soils because fate and transport of environmental pollutants may be influenced by their interactions with soil particles. The behavior of chlorpyrifos was analyzed through the study of the recoveries from spiked solid environmental matrices. A strong dependence with organic matter content was observed along with an important dependence with the initial concentrations employed. Here, we show that chlorpyrifos behavior on solid matrices not only depends on soil chemical composition. A significant dependence of recovery percentages with initial concentrations of the pesticide was evident in all cases. Recovery percentages decreased with an increase of the initial concentration employed, no matter the variations in matrices of chemical compositions.

In this work, a coal combustion ash (CCA) has been tested as an alternative low-cost sorbent to commercial activated carbons (GAC) for cadmium and zinc removal from polluted water. To this aim, the effect of pH and metal concentration on CCA adsorption capacity has been investigated, and a comparative analysis with GAC has been carried out in the same experimental conditions. Furthermore, in order to improve CCA adsorption capacity, two different activation treatments of raw CCA have been tested. In particular, the CCA was subjected to a gasification process conducted with steam and to different acidic treatments, conducted either with hydrochloric acid or nitric acid at different acid concentrations. Experimental results showed that all the acid treatments determined a substantial reduction of both cadmium and zinc adsorption capacity. Differently, the steam gasification determined a substantial increase in adsorption capacity with respect to raw CCA, in particular for zinc as its adsorption capacity resulted even higher than the correspondent of GAC. Finally, a thorough analysis of sorbent physical and chemical properties and of adsorption data allowed the individuation of the main cadmium/zinc adsorption mechanism both on CCA and activated carbon, adequately described by the Freundlich model.

N-Nitrosodimethylamine (NDMA) is recently defined as one of nitrogenous disinfection by-products with high carcinogenicity and can be frequently detected in finished water. The decomposition of NDMA in water using nanoscale zero-valent iron (NZVI) in the presence of aluminum and iron salts was investigated in this paper. The results showed that some salts can enhance the removal of NDMA by commercial NZVI in the order of Al(SO) >> AlCl > FeSO > NaSO ≈ NZVI alone, and the highest NDMA removal was 87.3 % in the presence of Al(SO). NDMA removal varied with the addition of Al(SO), NZVI dosage, initial NDMA concentration, solution pH, and temperature. The reduction of NDMA increased with the dosage of Al(SO) and NZVI, which follows a pseudo-first-order kinetics model. The removal of NDMA by NZVI was higher in acidic pHs than in alkaline ones, and the highest removal was found at pH 5. Higher reaction temperature can improve the removal of NDMA and reduce the reaction time. Based on the total nitrogen balance, most nitrogen of NDMA was converted to ammonium and dimethylamine.

In this study, chemical oxidation was applied to treat three contaminated sediments. All the sediments were contaminated with mineral oil, polycyclic aromatic hydrocarbons and heavy metals and had an organic matter content ranging from 2.4 to 7.6 %. The natural oxidant demand of the sediments was determined during treatment with two different types of oxidants (potassium permanganate and sodium persulfate), and the effect of these oxidants on the heavy metal release and on the microbial community was investigated. The natural oxidant demands of the sediments under persulfate treatment were lower (30–100 g kg⁻¹) than the ones treated with permanganate (50–450 g kg⁻¹). Cr was released during the application of permanganate whereas Zn and Pb were released under persulfate treatment. qPCR results showed that permanganate and persulfate, both at a concentration of 150 g kg⁻¹, caused a decrease (2 log units) in the number of 16S rRNA gene of total bacteria in the sediment having the lowest organic matter content. However, the total ATP, considered as a biomarker for microbial activity, was below detection limit in all sediments in the presence of at least 150 g kg⁻¹ oxidant. Only permanganate induced a shift in the structure of the microbial community.

Four species of trees were selected to evaluate the tolerance to heavy crude oil contamination by means of a tolerance index integrating germination, height, biomass and survival as variables. Fresh seeds to Cedrela odorata (tropical cedar), Haematoxylum campechianum (tinto bush), Swietenia macrophylla (mahogany) and Tabebuia rosea (macuilis) were planted in a Vertisol to which heavy crude petroleum was added at four different treatments (C0, 0; C1, 18,940; C2, 44,000; and C3, 57,000 mg kg⁻¹), with the control being uncontaminated soil. The experiment was carried out in a greenhouse during 203 days with a completely random design. The presence of petroleum in soil stimulated and increased germination of S. macrophylla and C. odorata, accelerated the germination of T. rosea and did not affect the germination of H. campechianum. The height and biomass of all species was reduced in the presence of petroleum in the soil. The survival of S. macrophylla and H. campechianum was not affected by petroleum at any concentration studied. On the other hand, C. odorata and T. rosea showed high mortality at all concentrations. The tolerance index showed that S. macrophylla was best at tolerating petroleum in soil and could be employed as a productive alternative for the advantageous use of contaminated sites. The use of tree species could be important because of the great potential of trees for phytoremediation due to their long life, biomass and deep roots that can penetrate and remediate deeper soil layers.

Robust and cheap, biofiltration is one of the most used methods for the biological treatment of industrial gaseous odours and VOCs emissions. The chemical, physical and microbial properties, as well as the economical impact of 11 organic and inorganic packing materials potentially suitable for biofiltration, have been investigated in order to select the most relevant for the treatment of rendering gaseous emissions. Fibrous materials such as peat and coconut fibres are predisposed to compaction. Moreover, according to their low expected running period, their implementation remains expensive, such as activated carbon which induce overweening costs (>100,000€ an -1 for the treatment of 40,000 m3 h-1 with a 60-s empty bed gas residence time). Considering economical aspects, physico-chemical and biological properties, pines barks, composted wood mulch and expanded schist seem fit for this application. The performance of these materials was therefore investigated in a pilot-scale study conducted on a rendering site. According to its appropriate pH (8.62) and water-holding capacity (1.41 g g-1) and its highest nutrients content and colonization at the biofilter start-up (93 g of ATP m-3, 29.10 13 CFU m-3), composted would mulch show the best odour removal efficiency during the 134 days of operation. Performances ranged between 75 and 93 % for the treatment of odourous inlet load between 1.16 and 10.10·106 ouE m-3 h-1 with an empty bed gas residence time of 47 s. However, the pressure drop of the compost bed decreased, suggesting structural changes which may impact the performances in the long term. © 2013 Springer Science+Business Media Dordrecht.