The distribution of ambient air n-alkanes and polycyclic aromatic hydrocarbons (PAHs) associated to particles with aerodynamic diameters lesser than 10 μm (PM₁₀) into six fractions (five stages and a backup filter) was studied for the first time in Algeria. Investigation took place during September of 2007 at an urban and industrial site of Algiers. Size-resolved samples (<0.49, 0.49–0.95, 0.95–1.5, 1.5–3.0, 3.0–7.2, and7.2–10 μm) were concurrently collected at the two sampling sites using five-stage high-volume cascade impactors. Most of n-alkanes (~72 %) and PAHs (~90 %) were associated with fine particles ≤1.5 μm in both urban and industrial atmosphere. In both cases, the n-alkane contents exhibited bimodal or weakly bimodal distribution peaking at the 0.95–1.5-μm size range within the fine mode and at 7.3–10 μm in the coarse mode. Low molecular weight PAHs displayed bimodal patterns peaking at 0.49–0.95 and 7.3–10 μm, while high molecular weight PAHs exhibited mono-modal distribution with maximum in the <0.49-μm fraction. While the mass mean diameter of total n-alkanes in the urban and industrial sites was 0.70 and 0.84 μm, respectively, it did not exceed 0.49 μm for PAHs. Carbon preference index (~1.1), wax% (10.1–12.8), and the diagnostic ratios for PAHs all revealed that vehicular emission was the major source of these organic compounds in PM₁₀during the study periods and that the contribution of epicuticular waxes emitted by terrestrial plants was minor. According to benzo[a]pyrene-equivalent carcinogenic power rates, ca. 90 % of overall PAH toxicity across PM₁₀was found in particles ≤0.95 μm in diameter which could induce adverse health effects to the population living in these areas.

Adsorption of fluoranthene (FLA) in surfactant solution on activated carbon (AC) was investigated. Isotherm, thermodynamic, and kinetic attributes of FLA adsorption in the presence of the surfactant on AC were studied. Effects of AC dosage, initial concentration of TX100, initial concentration of FLA, and addition of fulvic acid on adsorption were studied. The experimental data of both TX100 and FLA fitted the Langmuir isotherm model and the pseudo-second-order kinetic model well. Positive enthalpy showed that adsorption of FLA on AC was endothermic. The efficiency of selective FLA removal generally increased with increasing initial surfactant concentration and decreasing fulvic acid concentration. The surface chemistry of AC may determine the removal of polycyclic aromatic hydrocarbons. The adsorption process may be controlled by the hydrophobic interaction between AC and the adsorbate. The microwave irradiation of AC may be a feasible method to reduce the cost of AC through its regeneration.

Korean water quality managers are required to promptly develop national assessment standards for freshwater sediment quality due to the Four Major River Restoration Project in Korea in 2009. We conducted this study to develop sediment management standards (SMSs), determining obviously and severely polluted sediment, which could have adverse impacts on water quality and aquatic ecosystem. The SMSs values were derived from the 95th percentile of concentration distribution for organic matter and nutrients in sediment quality database. For the SMSs of metals, foreign sediment quality guidelines (SQGs) were adopted. As a result, 13 % for loss on ignition (LOI), 1,600 mg/kg for total phosphorus (TP), and 5,600 mg/kg for total nitrogen (TN) were set as the SMSs for freshwater sediment in Korea. These values were higher than the range of heavily polluted sediment from USEPA Region 5 guideline derived by the similar approaches for the Great Lakes harbor sediments, and similar or lower than the severe effect level (SEL) from provincial sediment quality guideline (PSQG) of Ontario, Canada by screening level concentration (SLC) approach. However, SMSs in the present study are appropriate considering the concentration ranges and the Korean SMSs’ definition for freshwater sediments in Korea. The Puget Sound marine sediment cleanup screening level (CSL) in Washington State, USA were adopted as the Korean SMSs for As (93 mg/kg), Cd (6.7 mg/kg), Cr (270 mg/kg), Cu (390 mg/kg), Pb (530 mg/kg), and Zn (960 mg/kg) in freshwater sediments. Hg concentration (0.59 mg/kg) of CSL was too low to determine the polluted freshwater sediments in Korea, and the SEL of Ontario, Canada for mercury concentration (2 mg/kg) was selected as the SMS for Hg. These values were found reasonable through the assessment of applicability with the datasets from locations directly affected by obvious point sources. These results indicate that SMSs for organic matter, nutrient, and metals derived within the present study can successfully determine obviously and severely polluted sediment in Korea. However, the SMSs have limits to specifically determine the effects of polluted sediment on water quality and aquatic ecosystem in Korea. Thus, we will revise and specify SMSs considering those effects and further sediment quality assessment framework in the near future.

Organochlorine pesticides (OCPs) are ubiquitous pollutants, and their presence in urban lakes is a concern for human and ecological health. Surface sediments in the East Lake, China, were collected in winter 2012 and summer 2013 to investigate concentrations, distribution patterns, possible sources, and potential ecological risks of OCPs in this area. The total concentrations of 14 OCPs ranged from 6.3 to 400 ng g⁻¹dry weight (dw) with an average concentration of 79 ng g⁻¹dw. The mean values of hexachlorocyclohexanes (HCHs) (α-, β-, γ-, and δ-HCH) and dichlorodiphenyltrichloroethanes (DDTs) (p,p’-DDE, p,p’-DDD, and p,p’-DDT) were 36 and 7.6 ng g⁻¹dw, accounting for 45 and 10 % of the total OCPs, respectively. The concentrations of OCPs in sediment samples collected in winter were significantly higher than those in summer, especially the HCHs, of which in winter were two times greater than summer. Composition analyses indicated that DDTs and endosulfan were mainly from historical contribution. Historical use of technical HCH and new input of lindane were probably the source of HCHs in the East Lake. Most sampling sites of HCHs and DDTs were found to have the potential ecological risk based on levels specified in the sediment quality standards.

Microorganisms play key roles in stream ecosystems, but comparatively little is known about the resilience of freshwater bacterial communities and their susceptibility to the chemical by-products of agricultural land use. Antibiotics used in the agricultural sector are of particular concern and have been detected in waterways associated with agricultural land. Despite widespread agricultural intensification globally and the sector's high antibiotic use, the effects of agricultural antibiotic by-products on stream microbial communities have yet to be characterised. We investigated the impacts of the antibiotic monensin on microbial biofilm communities in a simulated contamination event using streamside-replicated channels. A 24-h pulse experiment in flow channels precolonised by stream biofilm microbial communities contrasted the effects of monensin concentrations ranging from realistic to extreme toxicity levels (1–550 ug L⁻¹). Biofilm community composition was characterised immediately before and after the pulse for several weeks using automated ribosomal intergenic spacer analysis. Despite applying acutely toxic levels of monensin, only limited effects to biofilm community composition were detected immediately after antibiotic application, and these disappeared within 4 days. Rather, temporal factors drove biofilm differences, highlighting the overriding importance of wider, catchment-level, physiochemical hydrological influences on structuring freshwater biofilm communities, as opposed to localised and sporadic agricultural surface runoff contamination events containing antibiotics.

Battery tests serve as integral tools to decide whether a treatment process is ecotoxicologically safe or not. In the present study, a battery of toxicity tests was employed to elucidate the toxicity of the potential endocrine-disrupting pollutant bisphenol A (BPA) and its advanced oxidation products. For this purpose, BPA was subjected to Fenton treatment in the growth medium of the test organisms employed as well as in real lake water. Treatment results indicated that BPA removals were fast and complete within less than a minute, whereas total organic carbon (TOC) removals were rather incomplete, speaking for the accumulation of refractory degradation products. The presence of chloride and/or natural organic matter influenced H₂O₂ consumption rates and the treatment performance of the Fenton’s reagent as well. The sensitivity of the selected test organisms for BPA and its Fenton treatment products in different water matrices was found in the following decreasing order: the freshwater microalgae (Pseudokirchneriella subcapitata) > the freshwater cladoceran (Daphnia magna) > marine photobacteria (Vibrio fischeri).

An empirical approach for simulating the infection and progress of leaf rust (caused by Puccinia triticina) during stem elongation on winter wheat was analysed for the 2000 to 2006 growing seasons. The approach was elaborated based on night weather conditions (i.e., air temperature, relative humidity and rainfall) and leaf rust occurrences. Data from three consecutive cropping seasons (2000–2002) at four representative sites of the Grand-Duchy of Luxembourg were used in the set-up phase. The capability to correctly simulate the occurrence expression of P. triticina infections on the upper leaf layers was then assessed over the 2003–2006 period. Our study revealed that the development of leaf rust required a period of at least 12 consecutive hours with air temperatures ranging between 8 and 16 °C, a relative humidity greater than 60 % (optimal values being 12–16 °C and up to 80 % for air temperatures and relative humidity, respectively) and rainfall less than 1 mm. Moreover, leaf rust occurrences and infections were satisfactorily simulated. The false alarm ratio was ranged from 0.06 to 0.20 in all the study sites. The probability of detection and critical success index for WLR infection were also close to 1 (perfect score).

The UN estimated about five million deaths every year due to water-borne diseases, accounting from four billion patients. Keeping in view, the ever increasing health issues and to undermine this statistics, a reliable and sustainable water-treatment method has been developed using visible light for water treatment. titania nanoparticles (NPs) have been synthesized successfully by a more applicable method Viz: liquid impregnation (LI) method. The bacterial death rate by photocatalysis under visible light was studied by employing a typical fluorescent source and was found to follow pseudo first-order reaction kinetics. The nanoparticles were characterized using X-ray diffraction (XRD), scanning electron microscopy, and energy-dispersive X-ray spectroscopy to deduce their size range, surface morphology, and elemental compositions, respectively. Among all the prepared grades, 1 % Ag–TiO₂was found to be a very effective photocatalytic agent against Escherichia coli. The resulted photoinactivated data were also evaluated by different empirical kinetic models for bacterial inactivation. Hom, Hom-power, Rational, and Selleck models were not able to explain the disinfection kinetics but modified-Hom model fitted best with the experimentally obtained data by producing a shoulder, log-linear, and a tail region.

The basic aim of this work is (1) to review and present practically operational requirements for a sustainability assessment of marine environment, such as describing the monitoring process, research approaches, objectives, guidelines, and indicators and (2) to illustrate how physico-chemical and biological indicators can be practically applied, to assess water and sediment quality in marine and coastal environment. These indicators should meet defined criteria for practical usefulness, e.g. they should be simple to understand and apply to managers and scientists with different educational backgrounds. This review aimed to encapsulate that variability, recognizing that meaningful guidance should be flexible enough to accommodate the widely differing characteristics of marine ecosystems.

In the present work, nanoscale zero-valent iron/activated carbon (NZVI/AC) was investigated as heterogeneous Fenton catalyst in three-dimensional (3D) electrode system for methyl orange (MO) degradation. Some important operating parameters such as cathodic potential, pH, and O₂flow rate were investigated, exhibiting good decolorization. The mineralization of MO was significantly improved by 20–35 % compared to two-dimensional (2D) AC system at the optimum conditions. Although the TOC removal of AC was higher than NZVI/AC due to its good adsorption capacity initially, heterogeneous Fenton catalysis played a more and more important roles in the following test. After eight runs, NZVI/AC still exhibited excellent catalytic properties with low iron leaching. Further, a relatively comprehensive mechanism of NZVI/AC as particle electrodes in 3D system was proposed.