Background, aim and scope A newly developed fine bubble aeration system, by which air is transferred under supercavitation conditions, shows a clearly better performance than traditional, well-known aerators that rely on the jet-pump principle and its performance can be compared to oxygen transfer rates achieved in membrane and foil plate aerators. Materials and method A prototype supercavitation aerator installed at a sewage treatment plant revealed an air input rate, which was about one third lower than that of the jet-pump system, which it replaced. Results In spite of this low air input rate, the daily demand of pure oxygen for the additionally installed membrane aeration system went down by approximately 49%, from the original level of about 1,200 m³/day to about 600 m³/day—and this over a test period of more than 7 months. Conclusions and discussion The observed high oxygen transfer rates cannot be explained by traditional mass transfer mechanisms. It is assumed that a large amount of water being transferred into the gas phase by supercavitation contacting directly oxygen also in the gas phase and thereby overcoming mass transfer hindrances which might be favoured by hydroxyl radicals. With this new aerator, during the first 3 months of test phase, already more than 10,000 Euros had been saved because of the reduced pure oxygen demand.

Background The Atacama Desert in Northern Chile is one of the most arid places on earth. However, fog occurs regularly at the coastal mountain range and can be collected at different sites in Chile to supply settlements at the coast with freshwater. This is also planned in the fog oasis Alto Patache (20°49′S, 70°09′W). For this pilot study, we collected fog water samples in July and August 2008 for chemical analysis to find indications for its suitability for domestic use. Methods Fog water samples were taken with a cylindrical scientific fog collector and from the net and the storage tank of a Large Fog Collector (LFC). Results The pHs of advective fog, originating from the stratus cloud deck over the Eastern Pacific, varied between 2.9 and 3.5. Orographic fog, which was formed locally, exhibited a pH of 2.5. About 50% of the total ionic concentration was due to sea salt. High percentages of sulfate and very high enrichment factors (versus sea salt) of heavy metals were found. Both backward trajectories and the enrichment factors indicate that the high concentrations of ions and heavy metals in fog were influenced by anthropogenic activities along the Chilean Pacific Coast such as power plants, mining, and steel industry. Conclusions We found no direct indication for the importance of other sources such as the emission of dimethyl sulfide from the ocean and subsequent atmospheric oxidation for acidity and sulfate or soil erosion for heavy metal concentrations. When fog water was collected by the LFC, it apparently picked up large amounts of dry deposition which accumulated on the nets during fog-free periods. This material is rinsed off the collector shortly after the onset of a fog event with the water collected first. During the first flush, some concentrations of acidity, nitrate, As, and Se, largely exceeded the Chilean drinking water limits. Before any use of fog water for domestic purpose, its quality should be checked on a regular basis. Strategies to mitigate fog water pollution are given.

Purpose To protect the environmental quality of soil, groundwater, and surface water near the landfill site, it is necessary to make an accurate assessment of the heavy metal mobility. This study aims to present the bio-immobilization behavior of heavy metals in landfill and provide some reference suggestion for the manipulation of heavy metal pollution control after closure. Materials and methods Two simulated bioreactor landfill system loaded with real municipal solid waste (MSW), namely, conventional bioreactor landfill (CL) and leachate recirculated bioreactor landfill (RL), were operated. Cu and Zn, the two conventional heavy metals with the highest contents in MSW, were chosen to track the heavy metal bio-immobilization behavior in landfill. Results The MSW in landfill is a great threat to environment because much of the heavy metal is “hidden” in different components. The weight ratio of Cu and Zn in landfill amounts to 0.00427% and 0.00437%, respectively. The accumulated effluent masses of Cu and Zn in CL increased all along, while they still kept at a stable level after day 105 in RL. Conclusions The microbes like sulfate-reducing bacteria mediate the behavior of Cu and Zn in bioreactor landfill system. Cu and Zn can be bio-immobilized in bioreactor landfill system with leachate recirculation like RL.

Introduction From the metallurgic industry zone of Dambovita County, we harvested and analyzed seven herbaceous plants species (Lolium perenne, Festuca pratensis, Stipa capillata, Agrostis alba, Cynodon dactylon, Luzula campestris, and Agrostis tenuis) to establish the heavy metal accumulation levels in these species. Materials and method The heavy metal contents (for Cr, Mn, Zn, Sr, Cu, Ba, and Sn) were determined by analyzing the dry matter with an inductively coupled plasma-atomic emission spectrometer. This method has detection limits of 0.4-0.6 mg/kg for the analyzed metals. The heavy metal concentrations in plants harvested from the industrial area are in milligram per kilogram of dry matter and ranged from 10.03 to 191.98 mg/kg of dry matter for Cr, 165.89 to 1,103.92 mg/kg of dry matter for Mn, 62.09 to 921.67 mg/kg of dry matter for Zn, 29.21 to 50.12 mg/kg of dry matter for Sr, 0.99 to 113.83 mg/kg of dry matter for Cu, 58.66 to 133.51 mg/kg of dry matter for Ba, and 8.38 to 276.44 mg/kg of dry matter for Sn. The heavy metal accumulation levels in the studied species of plants were calculated by the rapport between the concentration level of the metal in plant samples and the level of the same metal in the soil, near the radicular system for each species of plants. Results The highest accumulation levels were found in A. alba for Cr (267.69%); in L. perenne for Mn (51.45%), Sr (114.35%), and Ba (60.81%); and in C. dactylon for Zn (136.62%), Cu (97.65%), and F. pratensis for Sn (704.00%).

Background, aim and scope Chlormequat (Cq) is a plant growth regulator used throughout the world. Despite indications of possible effects of Cq on mammalian health and fertility, little is known about its fate and transport in subsurface environments. The aim of this study was to determine the fate of Cq in three Danish subsurface environments, in particular with respect to retardation of Cq in the A and B horizons and the risk of leaching to the aquatic environment. The study combines laboratory fate studies of Cq sorption and dissipation with field scale monitoring of the concentration of Cq in the subsurface environment, including artificial drains. Materials and methods For the laboratory studies, soil was sampled from the A and B horizons at three Danish field research stations—two clayey till sites and one coarse sandy site. Adsorption and desorption were described by means of the distribution coefficient (K d) and the Freundlich adsorption coefficient (K F,ads). The dissipation rate was estimated using soil sampled from the A horizon at the three sites. Half life (DT₅₀) was calculated by approximation to first-order kinetics. A total of 282 water samples were collected at the sites under the field monitoring study— groundwater from shallow monitoring screens located 1.5-4.5 m b.g.s. at all three sites as well as drainage water from the two clayey sites and porewater from suction cups at the sandy site, in both cases from 1 m b.g.s. The samples were analysed using LC-MS/MS. The field monitoring study was supported by hydrological modelling, which provided an overall water balance and a description of soil water dynamics in the vadose zone. Results The DT₅₀ of Cq from the A horizon ranged from 21 to 61 days. The Cq concentration-dependant distribution coefficient (K d) ranged from 2 to 566 cm³/g (median 18 cm³/g), and was lowest in the sandy soil (both the A and B horizons). The K F,ads ranged from 3 to 23 (µg¹ ⁻ ¹/n (cm³)¹/n g⁻¹) with the exponent (1/n) ranging from 0.44 to 0.87, and was lowest in the soil from the sandy site. Desorption of Cq was very low for the soil types investigated (<10%w). Cq in concentrations exceeding the detection limit (0.01 µg/L) was only found in two of the 282 water samples, the highest concentration being 0.017 µg/L. Discussion That sorption was highest in the clayey till soils is attributable to the composition of the soil, the soil clay and iron content being the main determinant of Cq sorption in both the A and B horizons of the subsurface environment. Cq was not detected in concentrations exceeding the detection limit in either the groundwater or the porewater at the sandy site. The only two samples in which Cq was detected were drainage water samples from the two clayey till sites. The presence of Cq here was probably attributable to the hydrogeological setting as water flow at the two clayey till sites is dominated by macropore flow and less by the flow in the low permeability matrix. In contrast, water flow at the sandy site is dominated by matrix flow in the high permeability matrix, with negligible macropore flow. Given the characteristics of these field sites, Cq adsorption and desorption can be expected to be controlled by the clay composition and content and the iron content. Combining these observations with the findings of the sorption and dissipation studies indicates that the key determinant of Cq retardation and fate in the soil is sorption characteristics and bioavailability. Conclusions The leaching risk of Cq was negligible at the clayey till and sandy sites investigated. The adsorption and desorption experiments indicated that absorption of Cq was high at all three sites, in particular at the clayey till sites, and that desorption was generally very limited. The study indicates that leaching of Cq to the groundwater is hindered by sorption and dissipation. The detection of Cq in drainage water at the clayey till sites and the evidence for rapid transport through macropores indicate that heavy precipitation events may cause pulses of Cq. Recommendations and perspectives The present study is the first to indicate that the risk of Cq leaching to the groundwater and surface water is low. Prior to any generalisation of the present results, the fate of Cq needs to be studied in other soil types, application regimes and climatic conditions to determine the Cq retardation capacity of the soils. The study identifies bioavailability and heavy precipitation events as important factors when assessing the risk of Cq contamination of the aquatic environment. The possible effects of future climate change need to be considered when assessing whether or not Cq poses an environmental risk.

PURPOSE: Organophosphate pesticides (OPs) are among the most used insecticides in agriculture, causing the inhibition of esterases like acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and carboxylesterase (CbE). Pesticides can reach the aquatic environment, posing risks to non-target organisms, including tadpoles. METHODS: In this work, we characterized the activities of AChE, BChE and CbE in tadpoles of the snouted treefrog Scinax fuscovarius, and verified their in vitro sensibility to different inhibitors [phenylmethane sulfonyl fluoride (PMSF), tetra-isopropylpyrophosphamide (iso-OMPA) and the OP diazinon]. In vivo effects of diazinon and esterase recovery after 2-pyridine-aldoxime (2-PAM) treatment of the protein extract were also studied in tadpoles with distinct stages of development exposed to 1 and 3 mg/l for 2 and 7 days. RESULTS: Optimal conditions were established for AChE and CbE; BChE activity was negligible. PMSF affected esterase activities and is not recommended for homogenization buffers. Iso-OMPA treatment caused no changes in AChE and CbE activities, but diazinon inhibited these enzymes in a dose-responsive manner. In vivo, CbE activity was insensitive to diazinon in younger tadpoles, but inhibited after 2 days of exposure in more developed tadpoles. AChE activity was inhibited after 2 and 7 days of exposure, in a dose-responsive manner. Esterase reactivation by 2-PAM was obtained both in vitro and in vivo. CONCLUSIONS: (1) Tadpoles can be adequate sentinel organisms in biomonitoring studies of OP contamination; (2) AChE was more sensitive than CbE to diazinon; (3) tadpoles from earlier developmental stages seems to be less responsive to OPs; (4) AChE activity was sensitive to diazinon in both development stages, being a better OP biomarker.

Background, aim and scope The climatic characteristic is a major parameter affecting on the distribution variation of organic pollutants such as polycyclic aromatic hydrocarbons (PAHs). The Tumen River is located in Northeastern of China. The winter era lasts for more than 5 months in a year, and the river water was frozen and covered by ice phase. Coal combustion is an essential heating source in the Tumen River Basin. The objective of this research is to study ice phase effect on the seasonal variation of PAHs in the Tumen River environment. Materials and methods Samples were collected from 13 sites along the River in March, July, October, and December of 2008. In addition, the ice sample, under ice water and air particulate were also collected in winter. The samples were analyzed for 16 PAHs (naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, beazo[a]anthene, chrysene, beazo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno(1,2,3-cd)pyrene, dibenz(a,h)anthracene, and benzo(ghi)perylene). The compounds were extracted from the water samples and solid samples using LLE and Soxhlet extraction technique, respectively, and it is determined by gas chromatography-mass spectrometry. Results and discussion Among 16 PAHs, fluorene, phenanthrene, and pyrene were found to be present in high concentrations and at high detection frequencies. The total concentration of PAHs in the water, particulate, sediment and ice phase ranged from 35.1-1.05 × 10³ ng L⁻¹, 25.4-817 ng L⁻¹, 117-562 ng g⁻¹and 62.8-136 ng g⁻¹, respectively. The levels of PAHs were generally higher in spring than other seasons. The ice phase in winter acts like a major reservoir of the pollutants and it is major contributor on the seasonal variation of PAHs in Tumen River. The PAHs found in water, particulate, and sediment in the Tumen River were possibly derived from similar pollution sources a proposition based on the compositions and isomer ratios of PAHs. Conclusions The distribution of PAHs was showed clear seasonal variation in the Tumen River environment, the ice phase and air pollution look like an important factor affecting on the seasonal variation. Recommendations and perspectives The ice phase as an important factor affecting on the seasonal variation of PAHs in Tumen River environment. Further studies regarding the effects of air pollution on the river and the mechanisms of migration and transformation of them in the environment are currently being conducted in our laboratory.

Background, aim, and scope In the Water Framework Directive 2000/60/EC, environmental objectives for the proper quality of inland, surface, transitional, coastal, and ground waters have been set. Member states are required to identify chemical pollutants of significance in the water bodies, to establish emission control measures, and to achieve quality standards. A specific category of pollutants are the compounds that may possess endocrine-related functions known as endocrine disrupting compounds (EDCs). This means that member states have the obligation to take action in order to prevent human exposure to these compounds via aquatic environment. The objective of this research was to study the occurrence and distribution of phenolic and steroid EDCs in inland waters and wastewaters discharged in the area of Thermaikos Gulf, Thessaloniki, Northern Greece. Materials and methods Samples were collected from three rivers, four streams, and four municipal and industrial wastewaters from the area of Thessaloniki, Northern Greece, during the period 2005-2006. The samples were analyzed for 14 EDCs (nonylphenol, octylphenol, their mono- and di-ethoxylate oligomers, bisphenol A, estrone, 17α-estradiol, 17β-estradiol, estriol, mestranol, and 17α-ethynylestradiol). The compounds were recovered by solid phase extraction and ultrasonic extraction from the dissolved phase and particulate phase, respectively, and determined by employing gas chromatography-mass spectrometry. Results Results revealed the presence of phenolic EDCs (NP, NP1EO, NP2EO, tOP, OP1EO, OP2EO, and BPA) in all water and wastewater samples. Steroid EDCs were not found at detectable concentrations. The relationships between field partition coefficients of EDCs and concentration of total suspended solids, dissolved, and particulate organic carbon were investigated. Discussion Rivers exhibited concentrations of EDCs similar to minimally impacted surface waters worldwide. The concentrations of NP and OP occasionally exceeded the environmental quality criteria proposed for inland waters. The concentrations of EDCs in streams exhibited wide variations due to low flow rate in these systems and the impact of wastewaters from various pollution sources. Wastewater from tannery activities showed extremely high concentrations of NP, whereas relatively high concentrations of EDCs were determined in effluents from the industrial wastewater treatment plant. Field partition coefficients of EDCs are negatively correlated with concentrations of total suspended solids and dissolved organic carbon and positively correlated with particulate organic carbon. Conclusions The examined rivers (Aliakmon, Axios, and Loudias) exhibited concentrations of EDCs similar to minimally impacted surface waters worldwide. However, special attention should be paid to these systems since the concentrations for NP and OP occasionally were above the proposed quality standards, revealing the impact of urban, industrial, and agricultural activities. High concentrations of EDCs were determined in streams, urban, and industrial wastewater posing significant risk to the aquatic environment they discharged. Recommendations and perspectives The occurrence of EDCs in inland waters and wastewaters discharged to Thermaikos Gulf results in an increased risk to the marine environment. Thus, these systems should be regularly monitored, especially for NP, OP, and BPA that are considered as priority hazardous compounds in the Water Framework Directive.

Background, aim, and scope Lead, a major contaminant, is highly used in paint manufacturing due to its anticorrosive properties. Recent reports indicated high lead content among Indian paints used for commercial purposes. Painters are continuously exposed to these lead containing paints during painting of both commercial as well as residential buildings. Lead is well-known for its genotoxicty in occupational workers; however, in Indian painters the genotoxic effects of lead have not been reported to date. Therefore we aimed to study the genotoxic end points in painters due to their long-term exposure to these high lead-containing Indian paints. Materials and methods Study group selection was made after a questionnaire administration, which included questions about lifestyle and medical history to exclude exposure to the other potential sources of genotoxics. Blood and buccal cell samples were obtained from 30 male painters and from a similar number of age-matched controls of same location with no occupational exposure to lead. Blood lead levels (Pb-B) were measured in painters and controls. Micronucleus (MN) frequencies and nuclear changes, i.e., karyorrhexis, karyolysis, broken egg, and binucleated, were investigated in buccal epithelial cells. Results Painters had significantly (P < 0.01) greater lead levels in blood than the control group. MN frequencies and nuclear changes in buccal epithelial cells were also significantly (P < 0.01) elevated in painters as compared with control subjects. Regression analysis also revealed significant (P < 0.01) association of Pb-B with all the genotoxic endpoints in painters. Cytogenetic damage was significantly associated with Pb-B as no other co-founding factors (smoking, alcohols) showed significant difference between both groups. Discussion Lead is widely used in paints which may serve as potential source of exposure among painters due to their long-term engagement with paints. Our results clearly demonstrated genotoxicity among the exposed population as evident from increase micronucleus frequencies, frequent nuclear changes, and apoptosis. Many studies had previously related nuclear change events in buccal epithelial cells with the progression of different carcinomas. Furthermore in-depth investigations with larger sample size are needed to provide evidence to this effect. Conclusions Here, we report cytogenetic toxicity to the exposed population by the high lead containing paints from India for the first time. Frequent, high and unregulated use of lead in paints may cause genetic mutation and may accelerate cytogenetic damage which may further lead to different carcinomas in painters. These findings need to be considered and necessary steps should be taken to protect the occupational workers engaged with these high lead-containing paints. Recommendations The use of lead in paints is completely unregulated in India and routine surveillance of paints for lead content is still lacking. These paints are readily available in markets and are also used in other products (jewelry, miniblinds) which could be exported to other countries including United States and Europe. Serious consideration should be given to the inclusion of regulations and bans on the use of lead in paints. Moreover, attention should also be paid towards the use of various protective measures (face-masks, hand gloves, and separate clothes) by the workers as safe work practices during working periods.

Purpose The aim of this study was to compare the level of metal contamination in two bays in the middle part of the Eastern Adriatic coastal zone in Croatia using the gills of mussels Mytilus galloprovincialis as indicator tissue. Despite the existing sources of contamination, previous studies with caged mussels only indicated moderate metal contamination of the Kaštela Bay, contrary to the Trogir Bay in which marina and shipyard present a probable source of Cu- and Zn-contamination. Methods The measurements of metallothioneins (MTs) and metals that induce MT synthesis (Cu, Zn, and Cd) were performed in the heat-treated gill cytosol and total proteins (TPs) in the untreated gill cytosol. MTs were determined by differential pulse voltammetry, Cu and Zn by flame atomic absorption spectrometry (AAS), Cd by graphite furnace AAS, and TPs by Bradford spectrophotometric procedure. Results The results collected in four sampling campaigns (autumn periods from 2001 to 2004) indicated that MT levels in mussel gills (expressed on dry mass basis 2.3 ± 0.3 mg g⁻¹) were comparable with basal levels reported in the literature (2.5 ± 0.8 mg g⁻¹). Observed interindividual, temporal, and spatial MT variability could be associated with different confounding factors, such as the time of sampling, total protein concentration, and mussel size rather than cytosolic levels of Cu and Zn. Metal levels, expressed on wet mass basis, in the heat-treated gill cytosol ranged from 1.33 to 11.31 μg g⁻¹ for Zn, from 0.72 to 2.96 μg g⁻¹ for Cu, and from 0.036 to 0.100 μg g⁻¹ for Cd. The highest Zn level was measured at Vranjic (Kaštela Bay)—the site influenced by untreated domestic wastewater, while somewhat increased Zn and the highest Cu levels were found at marina and shipyard locations (Trogir Bay). The highest Cd level was measured at Inavinil (Kaštela Bay). Conclusions The observed association of gill MT levels with several biotic and abiotic factors limits its use as the biomarker of low-level metal exposure. Therefore, the use of the metal concentrations in the heat-treated gill cytosol of Mediterranean mussels should be considered for the assessment of the low-level metal contamination of coastal marine areas.