PURPOSE: Cold and hot water processes have been intensively used to recover soil organic matter, but the effect of extraction conditions on the composition of the extracts were not well investigated. Our objective was to optimize the extraction conditions (time and temperature) to increase the extracted carbon efficiency while minimizing the possible alteration of water extractable organic matter of soil (WEOM). METHOD: WEOM were extracted at 20°C, 60°C, or 80°C for 24 h, 10–60 min, and 20 min, respectively. The different processes were compared in terms of pH of suspensions, yield of organic carbon, spectroscopic properties (ultraviolet–visible absorption and fluorescence), and by chromatographic analyses. RESULTS: For extraction at 60°C, the time 30 min was optimal in terms of yield of organic carbon extracted and concentration of absorbing and fluorescent species. The comparison of WEOM 20°C, 24 h; 60°C, 30 min; and 80°C, 20 min highlighted significant differences. The content of total organic carbon, the value of specific ultraviolet absorbance (SUVA254), the absorbance ratio at 254 and 365 nm (E 2/E 3), and the humification index varied in the order: WEOM (20°C, 24 h) < WEOM (80°C, 20 min) < WEOM (60°C, 30 min). The three WEOM contained common fluorophores associated with simple aromatic structures and/or fulvic-like and common peaks of distinct polarity as detected by ultra performance liquid chromatography. CONCLUSIONS: For the soil chosen, extraction at 60°C for 30 min is the best procedure for enrichment in organic chemicals and minimal alteration of the organic matter.

BACKGROUND, AIM: The aims of the NORMACAT project are: to develop tools and unbiased standardized methods to measure the performance and to validate the safety of new materials and systems integrating photocatalysis, to develop new photocatalytic media with higher efficiency and to give recommendations aimed at improving the tested materials and systems. METHOD: To achieve this objective, it was necessary to design standardized test benches and protocols to assess photocatalytic efficiency of materials or systems used in the treatment of volatile organic compounds (VOCs) and odour under conditions close to applications. The tests are based on the validation of robust analytical methods at the parts per billion by volume level that not only follow the disappearance of the initial VOCs but also identify the secondary species and calculate the mineralization rates. RESULTS: The first results of inter-laboratory closed chamber tests, according to XP B44-013 AFNOR standard, are described. The photocatalytic degradation of mixtures of several defined pollutants under controlled conditions (temperature, relative humidity, initial concentration) was carried out in two independent laboratories with the same photocatalytic device and with various analytical procedures. Comparison of the degradation rate and of the mineralization efficiency allowed the determination of the clean air delivery rate in both cases. Formaldehyde was the only by-product detected during photocatalytic test under standardized experimental conditions. The concentration of transient formaldehyde varied according to the initial VOC concentration. Moreover the photocatalytic reaction rate of formaldehyde in mixture with other pollutants was analysed. It was concluded that formaldehyde concentration did not increase with time. CONCLUSION—PERSPECTIVE: This type of experiment should allow the comparison of the performances of different photoreactors and of photocatalytic media under controlled and reproducible conditions against mixtures of pollutants including formaldehyde.

PURPOSE: Urban waterways are impacted by diffuse stormwater runoff, yet other discharges can unintentionally contaminate them. The Okeover stream in Christchurch, New Zealand, receives air-conditioning discharge, while its ephemeral reach relies on untreated stormwater flow. Despite rehabilitation efforts, the ecosystem is still highly disturbed. It was assumed that stormwater was the sole contamination source to the stream although water quality data were sparse. We therefore investigated its water and sediment quality and compared the data with appropriate ecotoxicological thresholds from all water sources. METHODS: Concentrations of metals (Zn, Cu and Pb) in stream baseflow, stormwater runoff, air-conditioning discharge and stream-bed sediments were quantified along with flow regimes to ascertain annual contaminant loads. Metals were analysed by ICP-MS following accredited techniques. RESULTS: Zn, Cu and Pb concentrations from stormflow exceeded relevant guidelines for the protection of 90% of aquatic species by 18-, 9- and 5-fold, respectively, suggesting substantial ecotoxicity potential. Sporadic copper (Cu) inputs from roof runoff exceeded these levels up to 3,200-fold at >4,000 μg L−1 while Cu in baseflow from air-conditioning inputs exceeded them 5.4-fold. There was an 11-fold greater annual Cu load to the stream from air-conditioning discharge compared to stormwater runoff. Most Zn and Cu were dissolved species possibly enhancing metal bioavailability. Elevated metal concentrations were also found throughout the stream sediments. CONCLUSIONS: Environmental investigations revealed unsuspected contamination from air-conditioning discharge that contributed greater Cu annual loads to an urban stream compared to stormwater inputs. This discovery helped reassess treatment strategies for regaining ecological integrity in the ecosystem.

INTRODUCTION: The copper bioaccumulation by the floating Lemna minor and by the completely submerged Ranunculus tricophyllus as a function of exposure time and copper concentration was studied, with the aim of proposing these species as environmental biosensors of the water pollution. RESULTS: The results show that both these aquatic angiosperms are good indicators of copper pollution because the copper uptake is the only function of metal concentration (water pollution). CONCLUSION: Uptake behavior is reported as a function of the time and concentration, based on the results of a 3-year study. Kinetic evaluations are proposed.

PURPOSE: When fossil fuels on the Earth are used up, which kind of green energy can be used to replace them? Do every bioenergy generation or crop food chain results in environmental pollution? These questions are major concerns in a world facing restricted supplies of energy and food as well as environmental pollutions. To alleviate these issues, option biogases are explored in this paper. MATERIALS AND METHODS: Two types of biogas generators were used for modifying the traditional crop food chain [viz. from atmospheric CO2 photosynthesis to crops, crop stem/husk biowastes (burnt in cropland or as home fuels), to livestock droppings (dumping away), pork and people foods, then to CO2], via turning the biowaste pollutants into green bioenergies. By analyzing the traditional food chain via observation method, the drawbacks of by-product biowastes were revealed. Also, the whole cycle chain was further analyzed to assess its “greenness,” using experimental data and other information, such as the material balance (e.g., the absorbed CO2, investment versus generated food, energy, and wastes). RESULTS AND DISCUSSION: The data show that by using the two types of biogas generators, clean renewable bioenergy, crop food, and livestock meat could be continuously produced without creating any waste to the world. The modification chain largely reduced CO2 greenhouse gas and had a low-cost investment. The raw materials for the gas generators were only the wastes of crop stems and livestock droppings. Thus, the recommended CO2 bioenergy cycle chain via the modification also greatly solved the environmental biowaste pollutions in the world. CONCLUSIONS: The described two type biogases effectively addressed the issues on energy, food, and environmental pollution. The green renewable bioenergy from the food cycle chain may be one of suitable alternatives to fossil and tree fuels for agricultural countries.

INTRODUCTION: Initial geosmin degradation was closely related to water temperature and natural geosmin concentration of sampling environment. Here, for the first time, we evaluated the biodegradation of geosmin by microorganisms in biofilm from biological treatment unit of actual potable water treatment plant. MATERIALS AND METHODS: At an initial geosmin concentration of 2,500 ng/l, efficient geosmin removal was confirmed throughout the year. Furthermore, in the presence of mixed musty odor compounds (geosmin and MIB) as carbon source, geosmin degradation was enhanced compared to sole carbon source (geosmin alone). RESULTS AND DISCUSSION: PCR-DGGE analysis revealed a rich community structure within the biofilm during rapid geosmin removal period, April. PCA revealed that the significant change in bacterial communities occurred from day 1 to day 2. Two novel geosmin-degrading bacteria were isolated from the biofilm of the biological treatment unit of Kasumigaura Water Purification, Waterworks Department, Japan. They belong to Methylobacterium sp. and Oxalobacteraceae bacterium, respectively. CONCLUSIONS: These studies provide further insights into the unknown microbiological processes that occur during the biological removal of geosmin through water treatment and could facilitate the geosmin bioremediation in contaminated habitats.

Mining activities represent a major source of environment contamination. The aim of this study was to evaluate the use of bees and ants as bioindicators to detect the heavy metal impact in post-mining areas. A biomonitoring programme involving a combination of honeybee hive matrices analysis and ant biodiversity survey was conducted over a 3-year period. The experimental design involved three monitoring stations where repeated sampling activities focused on chemical detection of cadmium (Cd), chrome (Cr) and lead (Pb) from different matrices, both from hosted beehives (foraging bees, honey and pollen) and from the surrounding environment (stream water and soil). At the same time, ant biodiversity (number and abundance of species) was determined through a monitoring programme based on the use of pitfall traps placed in different habitats inside each mining site. The heavy metal content detected in stream water from the control station was always below the analytical limit of quantification. In the case of soil, the content of Cd and Pb from the control was lower than that of mining sites. The mean heavy metal concentrations in beehive matrices from mining sites were mainly higher than the control, and as a result of regression and discriminant analysis, forager bee sampling was an efficient environmental pollution bioindicator. Ant collection and identification highlighted a wide species variety with differences among habitats mostly associated with vegetation features. A lower variability was observed in the polluted landfill characterised by lack of vegetation. Combined biomonitoring with forager bees and ants represents a reliable tool for heavy metal environmental impact studies.

Chaohu Lake, one of the most eutrophicated lakes in China, has been suffering from long-term outside pollution, urban sewage, river outflows, and agricultural runoff which expectedly have been the main contributors of hydrocarbons. However, the contributions from these various sources have not been specified. The present study is aimed at identifying the potential sources of hydrocarbons in surface sediment around the whole lake and assessing the relative contributions using principal components analysis–multiple linear regression (PCA-MLR). Sixty-one surface sediments covering the whole Chaohu Lake and three main estuaries of inflowing rivers were collected, dried, extracted, and analyzed for 27 normal alkanes (n-alkanes, from C12 to C38, defined Σ27AH) and unresolved complex mixture (UCM) by GC/MS. Diagnostic ratios and PCA-MLR were utilized to apportion their sources. The concentrations of Σ27AH and UCM ranged from 434 to 3,870 ng/g and 11.9 to 325 μg/g dry weight, respectively, for all samples. The concentrations of Σ27AH in western region and estuary of Nanfei River were slightly higher but without statistical significance than those from eastern region and estuaries of Yuxi River and Hangbu River. The concentration of UCM from western region was significantly higher than that obtained from eastern region. These results reflect the importance of input of urban runoff by Nanfei River and serious eutrophication in western region. Aliphatic hydrocarbons in Chaohu Lake were mainly derived from high plant wax with mixed sources of phytoplankton and petroleum. Weak microbial decomposition of n-alkanes would be expected to occur from the low ratios of isoprenoid hydrocarbons pristine (pri) and phytane (phy) to n-C17 and n-C18, respectively. Higher plant, fossil combustion, petroleum residue, and phytoplankton were proposed as the main origines of aliphatic hydrocarbons by PCA while the contributions of individual n-alkane homologues, pri and phy from the identified sources (31 % from higher plant, 30 % from fossil combustion, 26 % from petroleum, and 19 % from phytoplankton) were well predicted using MLR. The distribution profile and corresponding diagnostic ratios of normal alkanes show the promising potential as a useful proxy for estimating the source and loading of pollutants in Chaohu Lake.

BACKGROUND, AIM AND SCOPE: The environmental presence of polybrominated diphenyl ethers (PBDEs), among which BDE-47 and BDE-99 are particularly abundant, makes toxicity data necessary to assess the hazard risk posed by PBDE to aquatic organisms. This study examines the effects of BDE-47 and BDE-99 on embryo-larval stages of the marine flatfish turbot. MATERIALS AND METHODS: The turbot embryos were exposed at nominal concentrations of BDE-47 and BDE-99 for 6 days. Selected dose levels were relevant for investigating sublethal and lethal effects. RESULTS: Both tested compounds caused lethal toxicity as well as non-lethal malformations during embryo development. We found a high toxic potency of BDE-47 compared to BDE-99 (LC50 values for embryos and larvae, respectively, BDE-47: 27.35 and 14.13 μg L−1; BDE-99: 38.28 and 29.64 μg L−1). DISCUSSION: The present study shows high sensitivity of fish early life stages (ELS) to PBDE compounds. Based on environmental concentrations of dissolved PBDEs from various aquatic ecosystems, waterborne BDE-47 and BDE-99 pose little risk of acute toxicity to marine fish at relevant environmental concentrations. CONCLUSIONS: Turbot fish ELS proved to be an excellent model for the study of ecotoxicity of contaminants in seawater. The results demonstrate harmful effects of PBDE on turbot ELS at concentrations in the range of parts per billion units. RECOMMENDATIONS AND PERSPECTIVES: In the perspective of risk assessment, ELS endpoints provide rapid, cost-effective and ecologically relevant information, and links should be sought between these short-term tests and effects of long-term exposures in more realistic scenarios.

BACKGROUND: In this study, manganese dioxide-coated multiwall carbon nanotube (MnO2/CNT) nanocomposite has been successfully synthesized. METHODS: The as-produced nanocomposite was characterized by different characteristic tools, such as X-ray diffraction, SEM, and FTIR. The MnO2/CNT nanocomposite was utilized as a fixed bed in a column system for removal of lead(II) from water. The experimental conditions were investigated and optimized. The pH range between 3 and 7 was studied; the optimum removal was found when the pH was equal to 6 and 7. The thickness of MnO2/CNT nanocomposite compact layer was also changed to find the optimum parameter for higher removal. RESULT: It was observed that the slower the flow rates of the feed solution the higher the removal because of larger contact time.