Remediation of phenanthrene-contaminated soil by simultaneous persulfate chemical oxidation and biodegradation processes

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous compounds with carcinogenic and/or mutagenic potential. To address the limitations of individual remediation techniques and to achieve better PAH removal efficiencies, the combination of chemical and biological treatments can be used. The degradation of phenanthrene (chosen as a model of PAH) by persulfate in freshly contaminated soil microcosms was studied to assess its impact on the biodegradation process and on soil properties. Soil microcosms contaminated with 140 mg/kg_{DRY SOIL} of phenanthrene were treated with different persulfate (PS) concentrations 0.86–41.7 g/kg_{DRY SOIL} and incubated for 28 days. Analyses of phenanthrene and persulfate concentrations and soil pH were performed. Cultivable heterotrophic bacterial count was carried out after 28 days of treatment. Genetic diversity analysis of the soil microcosm bacterial community was performed by PCR amplification of bacterial 16S rDNA fragments followed by denaturing gradient gel electrophoresis (DGGE). The addition of PS in low concentrations could be an interesting biostimulatory strategy that managed to shorten the lag phase of the phenanthrene biological elimination, without negative effects on the physicochemical and biological soil properties, improving the remediation treatment.     

Catalytic wet air oxidation of bisphenol A solution in a batch-recycle trickle-bed reactor over titanate nanotube-based catalysts

Catalytic wet air oxidation (CWAO) is classified as an advanced oxidation process, which proved to be highly efficient for the removal of emerging organic pollutant bisphenol A (BPA) from water. In this study, BPA was successfully removed in a batch-recycle trickle-bed reactor over bare titanate nanotube-based catalysts at very short space time of 0.6 min g_CAT?g^?1. The as-prepared titanate nanotubes, which underwent heat treatment at 600 °C, showed high activity for the removal of aqueous BPA. Liquid-phase recycling (5- or 10-fold recycle) enabled complete BPA conversion already at 200 °C, together with high conversion of total organic carbon (TOC), i.e., 73 and 98 %, respectively. The catalyst was chemically stable in the given range of operating conditions for 189 h on stream.     

Removal of dichloromethane from ground and wastewater: A review

Dichloromethane (DCM) is a toxic volatile compound which is found in the ground waters and wastewaters of the pharmaceutical, chemical, textile, metal-working and petroleum industries. DCM inhibits the growth of aquatic organisms, induces cancer in animals and is potentially carcinogenic for humans. This article aims to review existing water treatments for DCM removal, focusing on recent technological advances. Air stripping, adsorption and pervaporation were found to be effective in separating DCM from water with a process efficiency of about 99%, 90% and 80% respectively. Electrocatalysis over Cu-impregnated carbon fiber electrode, photo irradiation over TiO₂ and photo-Fenton process led to the complete decomposition of DCM. Aerobic and anaerobic water treatment achieved 99% and 95% removal of DCM respectively. The maximum efficiencies observed for acoustic cavitation, radiolysis and catalytic degradation of CH₂Cl₂ were 90%, 92% and 99% respectively. Ozonation and persulfate oxidation showed lower DCM degradation efficiencies, not exceeding 20%. Further combination of different water treatment methods will further increase DCM degradation efficiency.     

An Experiment with Forced Oxygenation of the Deepwater of the Anoxic By Fjord,Western Sweden

In a 2.5-year-long environmental engineering experiment in the By Fjord, surface water was pumped into the deepwater where the frequency of deepwater renewals increased by a factor of 10. During the experiment, the deepwater became long-term oxic, and nitrate became the dominating dissolved inorganic nitrogen component. The amount of phosphate in the water column decreased by a factor of 5 due to the increase in flushing and reduction in the leakage of phosphate from the sediments when the sediment surface became oxidized. Oxygenation of the sediments did not increase the leakage of toxic metals and organic pollutants. The bacterial community was the first to show changes after the oxygenation, with aerobic bacteria also thriving in the deepwater. The earlier azoic deepwater bottom sediments were colonized by animals. No structural difference between the phytoplankton communities in the By Fjord and the adjacent Havsten Fjord, with oxygenated deepwater, could be detected during the experiment.

Electronic supplementary material

The online version of this article (doi:10.1007/s13280-014-0524-9) contains supplementary material, which is available to authorized users.     

‘End to end’ planktonic trophic web and its implications for the mussel farms in the Mar Piccolo of Taranto (Ionian Sea,Italy)

The Mar Piccolo is a semi-enclosed basin subject to different natural and anthropogenic stressors. In order to better understand plankton dynamics and preferential carbon pathways within the planktonic trophic web, an integrated approach was adopted for the first time by examining all trophic levels (virioplankton, the heterotrophic and phototrophic fractions of pico-, nano- and microplankton, as well as mesozooplankton). Plankton abundance and biomass were investigated during four surveys in the period 2013–2014. Beside unveiling the dynamics of different plankton groups in the Mar Piccolo, the study revealed that high portion of the plankton carbon (C) pool was constituted by small-sized (<2 μm) planktonic fractions. The prevalence of small-sized species within micro- and mesozooplankton communities was observed as well. The succession of planktonic communities was clearly driven by the seasonality, i.e. by the nutrient availability and physical features of the water column. Our hypothesis is that beside the ‘bottom-up’ control and the grazing pressure, inferred from the C pools of different plankton groups, the presence of mussel farms in the Mar Piccolo exerts a profound impact on plankton communities, not only due to the important sequestration of the plankton biomass but also by strongly influencing its structure.     

Mortality of the scleractinian coral <Emphasis Type="Italic">Cladocora caespitosa</Emphasis> during a warming event in the Levantine Sea (Cyprus)

A mortality event of Cladocora caespitosa corals and the extent of bleaching, necrosis and pigmented areas in the colonies were studied at the southeastern coast of Cyprus during a prolonged period of higher than average sea temperature anomalies (summer/autumn 2012). With the use of scuba diving and image analysis software, we monitored the extent of mortality of 29 colonies of C. caespitosa by measuring and comparing the area percentage of healthy tissue, affected tissue (bleached, necrotic) and older mortality events (encrusted skeleton). In September 2012, on average, 24 % of the colonies surface area was affected (bleaching and/or necrosis). In October 2012, C. caespitosa showed on average 26.3 % of the colony surface area affected, evidence of continuing deterioration. At the same time, 10 % (3 of 29) of the colonies showed an increase in the pigmentation of previously bleached polyps in small and marginal areas (6–8 %). Irrespective of the amount, the regaining of pigments recorded is considered an important find. Corals and marine organisms in general in the Levantine Sea are affected greatly by warming events, to the extent where a very small percentage of polyps/colonies show resilience under thermal stress. Natural bleaching of C. caespitosa, even though limited to a few colonies and very small portions of tissue/polyps, was documented for the first time in the Levantine Sea. We conclude that temperature anomalies are associated with the mortality event. Whether prolonged higher temperature is the direct cause, or whether it acts synergistically with other factors should be the subject of further investigations.     

BIOAMBIENT.ES study protocol: rationale and design of a cross-sectional human biomonitoring survey in Spain

Human biomonitoring (HBM), defined as the measurement of concentrations of chemicals or of their metabolites in human biological matrices, is considered the method of choice for determining internal exposures in individuals. HBM is part of environmental exposure surveillance systems in several countries. In 2007, the Ministry of Agriculture, Food and Environment promoted BIOAMBIENT.ES project, a national-level HBM study on environmental pollutants carried out in Spain to estimate levels of heavy metals, persistent organic pollutants, and other substances on the Spanish active workforce. BIOAMBIENT.ES is a nationwide cross-sectional study, with a stratified cluster sampling designed to cover all geographical areas, sex and occupational sectors, and aimed to obtain a representative sample of the Spanish workforce. Participants were recruited among people residing in Spain for 5 years or more, which underwent their annual occupational medical check-up in the health facilities of the Societies for Prevention of IBERMUTUAMUR, MUTUALIA, MC-PREVENCIÓN, MUGATRA, UNIMAT PREVENCIÓN, and PREVIMAC (March 2009–July 2010). A total of 1,892 subjects fulfilled the criteria for inclusion, donated biological samples (1,880 blood, 1,770 urine, and 577 hair) and completed a short self-administrated epidemiological questionnaire on environmental and lifestyle-related exposures. Additionally, clinical information from participant’s health exams was obtained. This project will provide a first overview of the body burden of selected pollutants in a representative sample of the Spanish-occupied population. This information will be useful to establish reference values of the studied population and, eventually, to evaluate temporal trends and the effectiveness of environmental and health policies.     

Active moss biomonitoring of small-scale spatial distribution of airborne major and trace elements in the Belgrade urban area

In urban environments, human exposure to air pollutants is expected to be significantly increased, especially near busy traffic streets, street canyons, tunnels, etc. where urban topography and microclimate may additionally cause poor air conditions giving rise to pollution hotspots. As a practical and cost-effective approach, active moss biomonitoring survey of some major and trace element air pollution was performed in the Belgrade street canyons and city tunnel in 2011 with the aim to evaluate possibility of using Sphagnum girgensohnii moss bags for investigation of the small-scale vertical and horizontal distribution patterns of the elements. In five street canyons, the moss bags were hung at heights of about 4, 8 and 16 m, during 10 weeks, and also, for the same time, the moss bags were exposed in the tunnel, in front of and out of it. After the exposure period, the concentrations of Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Sr, V and Zn in the moss were determined by inductively coupled plasma optical emission spectrometry. According to the results, in all street canyons, the vertical distribution patterns of the moss elements concentration (Al, Ba, Co, Cr, Cu, Ni, Pb, Sr, V and Zn) showed statistically significant decrease from the first to the third heights of bags exposure. In the tunnel experiment, from inner to out of the tunnel, for Al, Ba, Cd, Co, Cr, Cu, Fe, K and Zn, decreasing trend of concentrations was obtained. Significantly higher concentration of the elements was pronounced for the tunnel in comparison with the street canyons. The results indicate that the use of S. girgensohnii moss bags is a simple, sensitive and inexpensive way to monitor the small-scale inner city spatial distribution of airborne major and trace element content.     

Strengths and weaknesses of microarray approaches to detect Pseudo-nitzschia species in the field

The planktonic diatom genus Pseudo-nitzschia contains several genetically closely related species. Some of these can produce domoic acid, a potent neurotoxin. Thus, monitoring programs are needed to screen for the presence of these toxic species. Unfortunately, many are impossible to distinguish using light microscopy. Therefore, we assessed the applicability of microarray technology for detection of toxic and non-toxic Pseudo-nitzschia species in the Gulf of Naples (Mediterranean Sea). Here, 11 species have been detected, of which at least 5 are potentially toxic. A total of 49 genus- and species-specific DNA probes were designed in silico against the nuclear LSU and SSU rRNA of 19 species, and spotted on the microarray. The microarray was tested against total RNA of monoclonal cultures of eight species. Only three of the probes designed to be species-specific were indeed so within the limits of our experimental design. To assess the effectiveness of the microarray in detecting Pseudo-nitzschia species in environmental samples, we hybridized total RNA extracted from 11 seasonal plankton samples against microarray slides and compared the observed pattern with plankton counts in light microscopy and with expected hybridization patterns obtained with monoclonal cultures of the observed species. Presence of species in field samples generally resulted in signal patterns on the microarray as observed with RNA extracted from cultures of these species, but many a-specific signals appeared as well. Possible reasons for the numerous cross reactions are discussed. Calibration curves for Pseudo-nitzschia multistriata showed linear relationship between signal strength and cell number.     

Biologic impact on the coastal belt of the province of Venice (Italy,Northern Adriatic Sea): preliminary analysis for the characterization of the bathing water profile

Background, aim and scope  

This paper presents a preliminary study of the water profile with reference to microbiological parameters, required by Directive 2006/07/EC (European Community 2006) concerning the management of bathing water quality, in the coastal belt of the Province of Venice (Italy, Northern Adriatic Sea). A historical database has been implemented with monitoring data for the period 2000–2006 (data on rivers, bathing and marine coastal waters and on the characterization of Wastewater Treatment Plant (WWTP) discharges) from the institutional activity of Veneto Regional Environmental Prevention and Protection Agency (ARPAV). An integrated areal analysis for the microbiological investigation of homogeneous stretches along the coast of the Province of Venice was performed for a preliminary characterization of the bathing water profile considering water quality status and existing pressure sources.