The paper presents the first comprehensive account of congener profiles of polycyclic aromatic hydrocarbons (PAHs) in intertidal bivalve mollusks [Meretrix meretrix, Macoma birmanica, and Sanguilonaria (Soletellina) acuminata] of Sunderban mangrove wetland (India). The main aim of this work was to use the bivalves as bioindicators of the contamination of the 16 USEPA PAH. The PAH profile in bivalves is largely dominated by a petrogenic fingerprint, with over-imposition of pyrolytic PAH sources, as evidenced by diagnostic molecular ratios. Bioaccumulation factors (BAF) of individual compounds from the sediments were calculated, and it reveals overall higher values in the visceral mass of the bivalves. S acuminata showed significantly higher levels of PAHs, especially the high molecular weight (HMW) PAHs, compared to the other two species as a sensitive indicator of trace organic stress in future monitoring programs.

In the present paper, electrocoagulation (EC) has been employed for the reduction of chemical oxygen demand (COD) reduction of a distillery wastewater (biodigester effluent) in a batch EC reactor using aluminum electrode. The individual and interactive effects of the four main independent parameters have been studied on the COD removal efficiency using a central composite experimental design. The parameters studied are current density (j): 44.65-223.25 A/m²; initial pH (pH ₀): 2-8; inter-electrode distance (g): 1-3 cm; and electrolysis time (t): 30-150 min. Pareto analysis of variance of the results showed a high coefficient of determination value (R ² = 0.9693) and satisfactory prediction for second-order regression model. Maximum COD removal efficiency of 52.23% was obtained with j = 120 A/m², pH ₀ = 6.0, g = 1 cm, and t = 150 min.

Nineteen soil samples (SE Spain) with very different chemical physical properties and developed over different parent materials were contaminated by adding increments of an acidic solution from oxidised pyrite tailings. The quantities of Cu, Zn, Cd and Pb precipitated by the soil samples were directly and significantly related to the pH-buffering capacity. However, when the contamination caused the pH to fall below 3.0 the soil tended to release a fraction of the element adsorbed, which increased as the pH decreased. The quantity of each precipitated element at which the action value for each element is reached, was also directly related to the pH-buffering capacity. Nevertheless, in carbonate-rich soils, the precipitated Cu and Zn maintained a relatively high level of bioavailability, while Cd reached a critical level with a content exceeding 25 mg kg⁻¹, regardless of the pH-buffering capacity.

The constructions of Cultural and Architecture Patrimony are influenced by pollutants. Many of degenerative processes in the materials which constitute them have their origin in pollutants. That is the reason why a physical-chemical characterisation of the particulate pollutants in the air has been carried out. The deposition and, as a consequence of that, the interaction of the pollutants with the different materials of the monuments depend on the reactivity of the chemical elements that form the atmospheric particulate. Studies of both, bulk dust deposition and total suspended matter, a mineralogical and chemical characterisation of them have been made. Lastly, starting from these data, it can be established that the interactions and degenerative processes are taking place in the monuments of the studied locations. In the present work, the methodology carried out in the study of the particulate atmospheric pollutants, which are capable of accumulating on monuments and buildings with artistic and historical interest in the area of Castellon, is displayed. By means of a network of captors, important samples of sedimentary and suspension atmospheric pollutants, total suspension particles (TSP) were obtained. Firstly, by gravimetric methods, we have obtained the concentration levels of these kinds of pollutants in milligrams per day in busk dust samples and micrograms per cubic meter in TSP. Due to the fact that the corrosivity of these pollutants fundamentally depends on their compositions, the study has been completed with a mineralogical and chemical characterisation. By X-ray diffraction and scanning electron microscopy, we have analysed the particles of the two kinds of samples. The chemical analysis was carried out by inductively coupled plasma-atomic spectroscopy and inductively coupled plasma-mass spectrometry (multielement analysis techniques) in TSP samples and in the soluble fraction of the depositing particulate matter. The results have shown as main compounds: clay minerals, calcite, and carbonaceous matter coming from non-perfect combustion of vehicles. The chemical analysis indicates a high Ca/S ratio and high levels of concentration in chemical elements associated to this representative industrial cluster of ceramics industry in Europe.

A study was conducted to determine nitrogen budget and ammonia volatilization in Japanese paddy fields supplemented with liquid cattle waste (LCW). A series of four, 2 x 10 m experimental plots was established in a paddy field with silty clay soil planted with forage rice (Oryza sativa L.). In addition to 195 kg N ha⁻¹ of chemical or compost-based basal fertilizer, LCW was applied as an additional fertilizer at total nitrogen rates of 0, 255, 255, and 405 kg N ha⁻¹ to the four plots C195, T450-1, T450-2, and T600, respectively. The mass balance showed that after application of LCW, 32-39% of total input nitrogen was assimilated into aboveground parts of rice plants, 11-15% leached downward, 2.5-4.0% was lost via ammonia volatilization, 1.6-5.1% was retained in roots or was adsorbed onto soil, and approximately 30-40% was lost via denitrification. Compared to animal waste slurries applied to unsaturated soils, nitrogen loss via ammonia volatilization was relatively lower, probably due to the dilution effect of floodwater. Nitrogen loss via denitrification was markedly higher in areas where LCW was applied compared to areas without LCW application. On the other hand, nitrogen leaching downwards represented a substantial loss and may be an environmental concern. However, after LCW application only, the ammonium ion was detected, at a maximum nitrogen concentration of 11.4 mg L⁻¹. In this system, therefore, nitrogen has a different fate to that in animal waste slurries applied to unsaturated soil. In that situation, the major nitrogen form in leaching water is nitrate nitrogen, which moves readily into groundwater.

Quantitative structural activity relationship (QSAR) models are receiving wide use because of new regulations and public scrutiny regarding new compounds entered into commerce. Accordingly, the US Department of Defense (DoD) supported this study to evaluate QSAR modeling for energetic compounds. Four compounds proposed to replace ammonium perchlorate were examined: ammonium di(nitramido)amine (ADNA); 1,3,5,5-tetranitrohexahydropyrimidine (DNNC); 1,3,3,5,7,7-hexanitro-1,5-diazacyclooctane (HCO); and diammonium di(nitramido)dinitroethylene (ADNDNE). Currently used compounds were evaluated as analogues for those under development. Ammonium dinitramide (ADN) was the analogue for ADNA; hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) for DNNC; octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) for HCO; and 1,1-diamino-2,2-dinitroethene (FOX-7) for ADNDNE. QSAR analysis was performed with the US Environmental Protection Agency's Estimation Program Interface (EPI) Suite[trade mark sign]. The comparison of model estimates to literature values ranged from good-to-poor. Results suggested the proposed replacement compounds have low aquatic toxicities and little potential to bioaccummulate, but the uncertainty in the predictions indicates QSAR modeling with EPI Suite[trade mark sign] is only useful for qualitative assessments of these proposed energetic compounds.

In this work we studied the phenol sorption from contaminated water onto modified clay mineral vermiculite and bentonite by insertion of hexadecyltrimethylammonium in the interlayer of clays. The non modified clays showed negligible interaction with phenol. The experimental data were treated using the Freunlich equation which had a good fit. The removal percentages were higher than 35% for modified vermiculite and for modified bentonite, 30%. Vermiculite and bentonite were compared for the removal of phenol from an aqueous solution based on the maximum adsorption capacity of each adsorbent, and no significant difference was found. The adsorption mechanism for both is the same, according to the results. Although, there is a lack of studies using vermiculite for this purpose, it can be concluded that hydrophobic modified vermiculite is very effective for removing phenol from water. Hydrophobic modified bentonite also remove phenol, but in lower proportions.

Sampling was conducted at seven sites on, and at varying distances adjacent to, the Island of Montréal (Québec, Canada), and as far as 1,100 km away in Northern Québec, to explore the hazard potential of snowpacks in remote, rural, and urban environments. Ecotoxic effects of melted snow were ascertained with a suite of small-scale bioassays representing several aquatic taxonomic groups (bacteria, micro-algae, micro-invertebrates, fish liver cells) as well as with biomarker measurements determined with a rainbow trout primary hepatocyte (RTPH) assay. Bioassays undertaken with the cnidarian Hydra attenuata and RTPH cell assays, and to a lesser extent with the micro-alga Pseudokirchneriella subcapitata, proved particularly sensitive to infer the presence of bio-available pollutants in snow samples collected from all sites, thereby suggesting their contamination (at least) via atmospheric sources. Furthermore, biomarker responses indicated that snow samples presumably included metals (free Zn biomarker), organics (CYP 1A1 biomarker), estrogens (alkali-labile phosphate biomarker) as well as chemicals capable of causing oxidative stress (LPO biomarker), depending on the site being considered. Overall, effects data acquired during this preliminary investigation on the ecotoxicity of snowpacks submit that adverse impact toward aquatic biota is conceivable at some sites during spring meltdown. Because snow has a recognized affinity for sequestering solids and contaminants of atmospheric origin, future studies aimed at identifying sources and chemicals implicated in observed effects are legitimate endeavors.

Chemical remediation of soil and groundwater containing hexavalent chromium (Cr(VI)) was carried out under batch and semi-batch conditions using different iron species: (Fe(II) (sulphate solution); Fe⁰ G (granulated elemental iron); ZVIne (non-stabilized zerovalent iron) and ZVIcol (colloidal zerovalent iron). ZVIcol was synthesized using different experimental conditions with carboxymethyl cellulose (CMC) and ultra-sound. Chemical analysis revealed that the contaminated soil (frank clay sandy texture) presented an average Cr(VI) concentration of 456 ± 35 mg kg⁻¹. Remediation studies carried out under batch conditions indicated that 1.00 g of ZVIcol leads to a chemical reduction of ~280 mg of Cr(VI). Considering the fractions of Cr(VI) present in soil (labile, exchangeable and insoluble), it was noted that after treatment with ZVIcol (semi-batch conditions and pH 5) only 2.5% of these species were not reduced. A comparative study using iron species was carried out in order to evaluate the reduction potentialities exhibited by ZVIcol. Results obtained under batch and semi-batch conditions indicate that application of ZVIcol for the “in situ” remediation of soil and groundwater containing Cr(VI) constitutes a promising technology.