Anaerobic benzene biodegradation was performed in batch experiments using Rhine River sediment as inoculum and amorphous Mn(IV) or Fe(III) as independent final electron acceptors. Benzene (4.5 μmol) was degraded in 80 and 710 days in batch experiments under Mn(IV) and Fe(III) reducing conditions, respectively. Highest benzene degradation rate, 0.07 μmol/day, was obtained under Mn (IV) reducing conditions, with soluble Mn(II) and CO₂ recoveries of 71.5% and 93% regarding to the stoichiometric values, respectively. Likewise, benzene biodegradation was performed in a continuous column coupled to the reduction of Mn(IV). Efficiency of benzene biodegradation was up to 97% under steady state operation in a sediment column operated continuously for more than 160 days. The carbon dioxide and Mn(II) recoveries were 88% and 77%, respectively, of the theoretical ratio according to the stoichiometry for benzene biodegradation.

Acute toxicity of Pb to the water flea; (Daphnia sp) and Copepod, (Cyclop sp) both important component of zooplankton diet of fish was determined by static assay. A positive relationship between percentage mortality and exposure concentration was found in all tests. Mean 24-h LC50, 48-h LC50 and 96-h LC50 values were 2.51 ± 0.0.04 mg l⁻¹, 1.88 ± 0.06 mg l⁻¹ and 1.65 ± 0.19 mg l⁻¹ for Daphnia spp and 3.11 ± 0.03 mg l⁻¹, 2.97 ± 0.05 mg l⁻¹ and 2.61 ± 0.09 mg l⁻¹ for Cyclop spp, respectively. For all tested species did the LC50 values decrease with time; the decrease was more marked for Daphnia spp. Observed symptoms include spiral movement followed by change of body colour to white and rapid disintegration of the skin. The Daphnia spp. appear to be more sensitive to Pb poison than Cyclop spp. The results showed that concentrations of Lead (Pb) in excess of 0.19 mg l⁻¹ and 0.30 mg l⁻¹ can be potentially harmful to Daphnia magna and Cyclop spp respectively.

Selection of a phytoextraction plant with high Cd accumulation potential based on compatibility with mechanized cultivation practice and local environmental conditions may provide more benefits than selection based mainly on high Cd tolerance plants. In this hydroponics study, the potential of Cd accumulation by three plant species; arum (Colocasia antiquorum), radish (Raphanus sativus L.) and water spinach (Ipomoea aquatica) were investigated. Arum (Colocasia antiquorum L.) plants were grown for 60 days in a nutrient solution with 0, 10 or 50 μM Cd, while radish and water spinach plants grew only 12 days in 0, 1.5, 2.5, 5 or 10 μM Cd. Growth of radish and water spinach plants decreased under all Cd treatments (1.5 to 10 μM), while arum growth decreased only at 50 μM Cd. At 10 μM Cd treatment, the growth of arum was similar to the control treatment indicating higher tolerance of arum for Cd than radish and water spinach. Cadmium concentrations in different plant parts of all plant species increased significantly with Cd application in the nutrient solution. Arum and water spinach retained greater proportions of Cd in their roots, while in radish, Cd concentration in leaves was higher than in other plant parts. Cadmium concentrations in arum increased from 158 to 1,060 in the dead leaves, 37 to 280 in the normal leaves, 108 to 715 in the stems, 42 to 290 in the bulbs and 1,195 to 3,840 mg kg⁻¹ in the roots, when the Cd level in the solution was raised from 10 μM Cd to 50 μM Cd. Arum accumulated (dry weight x concentration) 25 mg plant⁻¹ at 10 μM, while the corresponding values for radish and water spinach were 0.23 and 0.44 mg plant⁻¹, respectively. With no growth retardation at Cd concentrations as high as 166 mg kg⁻¹ measured in entire plant (including root) of arum at 10 μM Cd in the nutrient solution, arum could be a potential Cd accumulator plant species and could be used for phytoremediation.

The European Union has introduced a new bathing water directive where future classification of recreational waters will be based on the microbial parameters Escherichia coli, and intestinal enterococci. Introduction of enterococci as a new quality parameter may pose a challenge in some areas because relatively less is known about these organisms compared to E. coli. In the present study, the relative abundance of intestinal enterococci, E. coli, and ten fecal sterol and stanol biomarkers were investigated in water and sediment at two estuarine beach sites affected by fecal pollution. In the bathing water, enterococci were relatively more abundant at low E. coli concentrations. In the sediment, enterococci were generally more abundant than E. coli with surface concentrations between 1.0 × 10² and 4.5 × 10³ CFU cm⁻³. Enterococci populations were relatively similar in water and sediment, and were phenotypically different from that of nearby pollution sources. The putative human specific genetic marker esp in Enterococcus faecium was not detected in water or sediment samples despite occasional inputs of human waste from storm water overflows. Sterol and stanol profiles suggested a direct link between water and sediment pollution profiles on days with wind conditions that facilitated resuspension. Sediment resuspension may occur at wind speeds exceeding 6–8 m s⁻¹, and could contribute significantly to enterococci concentrations in the overlying water. The study emphasized that recontamination of the water column due to wind induced resuspension should be considered when evaluating indicator levels and microbial hazards in estuarine recreational waters.

This paper presents a study on the batch adsorption of a basic dye, methylene blue (MB), from aqueous solution onto ground hazelnut shell in order to explore its potential use as a low-cost adsorbent for wastewater dye removal. A contact time of 24 h was required to reach equilibrium. Batch adsorption studies were carried out by varying initial dye concentration, initial pH value (3-9), ionic strength (0.0-0.1 mol L⁻¹), particle size (0-200 μm) and temperature (25-55°C). The extent of the MB removal increased with increasing in the solution pH, ionic strength and temperature but decreased with increase in the particle size. The equilibrium data were analysed using the Langmuir and Freundlich isotherms. The characteristic parameters for each isotherm were determined. By considering the experimental results and adsorption models applied in this study, it can be concluded that equilibrium data were represented well by Langmuir isotherm equation. The maximum adsorption capacities for MB were 2.14 x 10⁻⁴, 2.17 x 10⁻⁴, 2.20 x 10⁻⁴ and 2.31 x 10⁻⁴ mol g⁻¹ at temperature of 25, 35, 45 and 55°C, respectively. Adsorption heat revealed that the adsorption of MB is endothermic in nature. The results indicated that the MB strongly interacts with the hazelnut shell powder.

Terrestrial Model Ecosystems (TMEs) are frequently used to assess the potentially harmful effects of contaminants on terrestrial organisms. Therefore we have used this tool to simulate the leaching phenomena from agricultural soils, within the drainage basin of Lake Vela (Figueira da Foz, Central Portugal), and to perform a subsequent evaluation of the toxicity of the leachates obtained, after the treatment of soil-cores with the herbicide Lasso® on non-target freshwater species. Hence, standard (algae: Pseudokirchneriella subcapitata; cladoceran: Daphnia magna) and autochthonous (algae: Aphanizomenon flos-aquae; cladoceran: Daphnia longispina) species were exposed to several dilutions of leachates obtained from the application of different treatments to soil-cores collected in an agricultural field in the Lake Vela surrounds: RW-soil-core irrigated with artificial rain water; RW+L-soil-core irrigated with artificial rain water after the application of Lasso®; GW+L-soil-core irrigated with groundwater collected in local wells, after the application of Lasso®. Chemical analysis confirmed the presence of alachlor (active ingredient of Lasso®) in the leachates RW+L and GW+L at concentrations of 88 and 16.9 μg L⁻¹ respectively. As expected, the results demonstrated that the leachate RW was not toxic for the tested species. However, leachates where the herbicide was applied, particularly the RW+L, was highly toxic to P. subcapitata (96 h-IC₅₀ = 9.7%), contrasting with the absence of toxic effects in A. flos-aquae. Notwithstanding the effects on algae, the reproduction and growth of both daphnids were not affected by the potential toxicity of leachates. Nevertheless, our results were consistent with the chemical analysis and alachlor ecotoxicity data reported in the literature. Our study confirmed that the current use of pesticides in the lands near Lake Vela, especially Lasso®, combined with the specific properties of local soils, can contribute to the contamination of surface and groundwater resources, through leaching, and could compromise the weak balance of the freshwater ecosystem by affecting one of the main trophic levels: the primary producers.

Adenoviruses are emerging pathogens which may represent new indicators of microbial water quality. In the present study, environmental samples of seawater, estuarine water, and influents of sewage treatment plants underwent both standard bacteriological and viral analyses (adenovirus identification, typing and quantification) in order to evaluate the role of surface water contamination as a possible vehicle for the transmission of adenovirus, and the relevance of adenoviruses as an additional tool in water quality assessment. Qualitative PCR methods were used for the detection and typing of adenoviruses. This was done through the sequencing and phylogenetic analysis of segments of the hexon- and fiber-coding regions of the viral genome. Subsequently, quantitative PCR assays based on TaqMan probe hydrolysis technology were used to assess virus concentrations in environmental samples. Results showed a widespread presence of adenovirus in the environment, even in the absence of bacterial indicators, confirming the relevance of evaluating these viruses as possible indicators of viral contamination of water.

In the daily and final landfill cover barrier system, the hydraulic properties of compacted soil liners and the strength of soil can be adversely affected by desiccation cracking, resulting in the loss of effectiveness and integrity of the containment system as a barrier. Recently, there is an interest of using fiber additive to overcome the desiccation cracking problem. In this study, the desiccation crack test was conducted to investigate the effect of fiber additive on suppressing desiccation cracks in compacted Akaboku soils. Polypropylene (C₃H₆) fiber was used as an additive material for soil sample. The percentages of fiber used were varied as 0.0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0% and 1.2% (by dry weight of samples). The soil specimens were compacted under the conditions of maximum dry density and optimum water content. The surficial cracking area was measured to determine the crack intensity factor (CIF) of the soil samples. The desiccation crack test results indicated that the percentage of volume change of the compacted soil specimen decreased with addition of fiber. The change in the soil surface area decreased with increasing in the fiber content (FC), and consequently, the volumetric shrinkage strain decreased. The CIF for the soil without fiber (FC = 0.0%) were significantly higher than the soil with fiber additive. The CIF of soil at FC = 0.0% decreased from 2.75% to 0.6% for the soil at FC = 0.2%. It was also found that the maximum crack depth reaches almost 50% of the thickness of the soil without fiber additive. This study suggests the potential application of the fiber additives to soils as an available method to suppress desiccation cracks encountered in landfill cover barriers.

During the seasons 2003/04, 2004/05 and 2005/06, a study was made of the evolution of runoff as well as soil and available P and K losses in the sediment carried away in a conventional till system--that most used at the present time--and in a no till system with added pruning remains in an olive grove of the picual variety located in Torredonjimeno (Jaén, Spain). A group of microplots for sediment collection in a randomized complete block design was established. The samples were collected in the field after each storm. In the study period, a total of 21 storms were recorded, with a precipitation of 450 mm in 2003/04, 179 mm in 2004/05 and 388 mm in 2005/06. The erosivity of the rainfall was characterized and the cover percentage in the plots throughout the time was determined. The establishment of pruning remains reduced soil loss with respect to conventional tillage (CT) in the 3 years (72%). Likewise, the available P loss greatly declined in the study (46.4%) under conservation agriculture. The reduction in available K loss (72.4%) was much greater than that of available P. The close relationship between both variables and sediment production also stands out. Runoff was the parameter on which the pruning remains had the least influence with only an 11% average reduction.

We investigated the coupling of abundance of bacteria, phytoplankton and ciliates with hydrocarbons in the surface water and sediments of five interconnected ponds in the arid Sfax solar salterns. This study aimed at determining the potential sources of hydrocarbons and the effects of salinity gradients on microorganism metabolism. Hydrocarbon analysis was performed by gas chromatography (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The GC-FID allowed the detection of aliphatic hydrocarbons and n-alkanes ranging from n-C₁₃ to n-C₃₀. Total aliphatic hydrocarbon concentrations varied from 92.5 mg. l-¹ in the first pond (having marine characteristics) to 661.1 mg. l-¹ in the last pond (crystallizer) (316.8 ± 120.1 mg. l-¹) for water samples and from 26.7 to 127.8 μg. g-¹ dry weight for sediment samples. The GC-MS enabled us to detect halogenated hydrocarbons (bromoalkanes and chloroalkanes) and n-alkenes. The distribution of n-alkanes indices coupled to several environmental factors suggests that a major fraction of hydrocarbons resulted from both prokaryotic (bacteria) and eukaryotic (protists) developments. A low hydrocarbon fraction might be petrogenic.