Chlorination of bisphenol A in aqueous media: formation of chlorinated bisphenol A congeners and degradation to chlorinated phenolic compounds

The chlorination of bisphenol A (BPA) in aqueous media was investigated in order to describe the degradation profile of this compound and the formation of chlorinated products. Aqueous solutions of BPA (approx. 1 mg/l) were chlorinated by sodium hypochlorite solution at room temperature and under weakly alkaline conditions. Chlorinated compounds were extracted with dichloromethane and determined by gas chromatography/mass spectrometry (GC/MS). BPA was consumed completely within 5 min of chlorination, when the initial chlorine concentration was 10.24 mg/l (molar ratio to BPA, 58.7). On the other hand, when the initial chlorine concentration was 1.03 mg/l (molar ratio, 6.56), 9.3% of BPA still remained after 60 min chlorination. Five chlorinated BPA congeners, 2-chlorobisphenol A (MCBPA), 2,6-dichlorobisphenol A (2,6-D2CBPA), 2,2'-dichlorobisphenol A (2,2'-D2CBPA), 2,2',6-trichlorobisphenol A (T3CBPA) and 2,2', 6,6'-tetrachlorobisphenol A (T4CBPA) were formed in the earlier stages of chlorination. Several chlorinated phenolic compounds, 2,4,6-trichlorophenol (T3CP), 2,6-dichloro-1,4-benzoquinone (D2CBQ), 2,6-dichloro-1,4-hydroquinone (D2CHQ), C9H10Cl2O2, C9H8Cl2O and C10H12Cl2O2, were also formed by further chlorination.     

Negatively-charged air conditions and responses of the human psycho-neuro-endocrino-immune network

BACKGROUND: Against increasing environmental adverse effects on human health such as those associated with water and ground pollution, as well as out- and indoor air conditions, trials were conducted to support and promote human health by improving the indoor air atmosphere. This study was performed to estimate the effect of negatively-charged air conditions on human biological markers related to the psycho-neuro-endocrino-immune (PNEI) network. OBJECTIVES: After construction of negatively-charged experimental rooms (NCRs), healthy volunteers were admitted to these rooms and control rooms (CTRs) and various biological responses were analyzed. METHODS: NCRs were constructed using a fine charcoal coating and applying an electric voltage (72 V) between the backside of walls and the ground. Various biological markers were monitored that related to general conditions, autonomic nervous systems, stress markers, immunological parameters and blood flow. RESULTS: Regarding the indoor environment, only negatively-charged air resulted in the difference between the CTR and NCR groups. The well-controlled experimental model-room to examine the biological effects of negatively-charged air was therefore established. Among the various parameters, IL-2, IL-4, the mean RR interval of the heart rate, and blood viscosity differed significantly between the CTR and NCR groups. In addition, the following formula was used to detect NCR-biological responses: Biological Response Value (BRV)=0.498+0.0005 [salivary cortisol]+0.072 [IL-2]+0.003 [HRM-SD]-0.013 [blood viscosity]-0.009 [blood sugar]+0.017 [pulse rate]. CONCLUSIONS: Negatively-charged air conditions activated the immune system slightly, smoothened blood flow and stabilized the autonomic nervous system. Although this is the first report to analyze negatively-charged air conditions on human biological responses, the long-term effects should be analyzed for the general use of these artificial atmospheres.     

Bioavailability of pollutants sets risk of exposure to biota and human population in reservoirs from Iguaçu River (Southern Brazil)

Environmental Science and Pollution Research - The Iguaçu River, located at the Southern part of Brazil, has a great socioeconomic and environmental importance due to its high endemic fish...     

Application of a tri-capital community resilience framework for assessing the social–ecological system sustainability of community-based forest management in the Philippines

This study proposes and empirically tests a framework that integrates the concepts of community resilience and social–ecological system (SES) resilience through community forestry case studies. The framework provides a possible approach for assessing community resilience based on the development and allocation of socio-cultural, economic, and natural capital of individual households within a given forest community. Furthermore, aspects of SES resilience and system dynamics are used to define the potential state thresholds of community resilience. This exploratory attempt to quantify community resilience, using the proposed framework, aims to advance understanding of the conceptual overlaps of SES and community resilience as applied to forestry management. We consider community forestry groups as SES examples in which the community is an important stakeholder in managing natural forest capital. We selected pioneer communities under the community-based forest management (CBFM) Program in the Philippines as our case studies. We found that, on average, CBFM group members demonstrated moderate levels of resilience according to their acquired levels of capital. Although economic capital remained the weakest capital, the CBFM program had a positive effect in increasing the socio-cultural and natural capital of an entire community.     

Preparation of Cellulose/Xanthan Gum Composite Films and Hydrogels Using Ionic Liquid

This paper reports the preparation of cellulose/xanthan gum composite films and hydrogels through gelation with an ionic liquid. Mixtures of cellulose and xanthan gum in desired weight ratios with an ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIMCl), were thinly placed on a Petri dish and heated at 100 °C for 9 h to obtain the solutions. Then, the solutions were left standing at room temperature for 1 day for the progress of gelation. The resulting ion gels were subjected to Soxhlet extraction with ethanol to remove BMIMCl, followed by drying under ambient conditions to obtain the composite films. The crystalline structures of the polysaccharides and the mechanical properties were evaluated by powder X-ray diffraction measurement and tensile testing of the films, respectively. The ion gels in various cellulose/xanthan gum weight ratios, which were prepared in a test tube by the same procedure, were immersed in water for the exchange of disperse media to obtain the cellulose/xanthan gum composite hydrogels. Water contents of all the materials were higher than 90 %. The mechanical properties of the hydrogels were evaluated by compressive testing.     

Potential for microbially mediated redox transformations and mobilization of arsenic in uncontaminated soils

Surface soil samples, which had no significant As contamination, were examined for As(V) reduction, As(III) oxidation and As mobilization capability. All five soil samples tested exhibited microbial As(V)-reducing activities both in aerobic and anaerobic conditions. Under aerobic conditions when As(V) reduction had almost ceased, oxidation of As(III) to As(V) occurred, whereas only As(V) reduction was observed under anaerobic conditions. In cultures incubated with As(III), As(III) was oxidized by indigenous soil microbes only under aerobic conditions. These results indicate that microbial redox transformations of As are ubiquitous in the natural environment regardless of background As levels. Mobilization through microbially mediated As(V) and Fe(III) reduction occurred both in the presence and absence of oxygen. Significant variation in dissolved As occurred depending on the Fe contents of soils, and re-immobilization of As arose in the presence of oxygen, presumably as a consequence of dissolved As(III) and Fe(II) oxidation. There was no apparent correlation between dissolved Fe(II) and As, suggesting that reductive dissolution of Fe(III) minerals does not necessarily determine the extent of As release from soils.     

Weathering patinas on the medieval (S. XIV) stained glass windows of the Pedralbes Monastery (Barcelona, Spain)

Background, aim, and scope  The first step in the restoration of a medieval stained glass window is the evaluation of its degree of degradation. This implies the study of the chemical composition of the stained glass as well as the new mineral phases developed on its surface (patinas). Patinas are clearly related to glass composition, time, environmental conditions, microenvironments developed in local zones, bioactivity, physical and chemical factors, etc. This study was carried out on patinas developed in selected Na-rich stained glass of the Santa Maria de Pedralbes Monastery (Barcelona, Spain). The location of this monument in the city (about 5 km from the shoreline and close to the Collserola hill flank) helped to determine the environmental conditions in which patinas developed. The aim of our study was to characterize the patinas formed on the surface of the selected glass of this monastery in order to understand the role of the chemical composition of the original glass (Na-rich) as well as the environmental conditions in which they developed. Materials and methods  Powdered samples of two different color-type patinas (ochre-orange and brownish) were collected in the external and internal parts of the stained glass windows of the Prebystery and Chapter House of the Pedralbes Monastery by using a precision (odontological) drill. These patinas were subsequently analyzed by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Results  XRD analyses evidenced the presence of sulfates (gypsum and thenardite), calcite, Ca-oxalates (whewellite and weddellite), and quartz forming part of the patinas. Although these mineral phases can be found in both color-type patinas, whewellite and thenardite are more common in the ochre-orange patinas. The results obtained were validated by the FTIR measurements. It has been observed, when thenardite is present, that gypsum occurs as traces. Thenardite is in most of the cases associated with whewellite and mainly occurs in the internal parts of the glass. In contrast, weddellite is limited to the absence of thenardite and whewellite and to the external parts of the stained glass. Quartz is present in all the patinas independent of their location and color. Calcite also occurs in many samples. It appears in both color-type patinas and, in some cases, is associated to the presence of weddellite but not to whewellite and/or thenardite. Discussion  Glass composition together with environmental conditions and location of the patinas (internal or external parts of the stained glass window), as well as the provenance of the glass within the monastery, are the main factors that define the development of the new mineral phases. Moreover, the action of microorganisms, when present, can also strongly influence the development of some mineral phases. For example, the formation of calcite in the external parts of the stained glass (associated with the presence of oxalates) is related to the action of microorganisms. When calcite is formed in the internal parts of the glass and it is not associated with the presence of Ca-oxalates, an inorganic origin can be invoked. The presence of weddellite requires a very humid microenvironment with very little exposure to sunlight. In fact, this mineral phase has only been observed in the external parts of some glass located in the humid and shady side of the monastery. Whewellite (which only appears in the internal parts) needs a low degree of relative humidity. It has been observed that sulfur precipitating in basically one mineral phase (thenardite or gypsum) depends on the microenvironmental conditions of the moment and the glass composition. When thenardite occurs, it can be maintained that the original glass is of Na composition. The occurrence of quartz in all samples is interpreted as being due to the deposition of atmospheric particulate matter. The color of the patinas can be originated by different processes (presence of carotenes, organic pigmentation, atmospheric contamination, etc.). Conclusions  In the case of moderately weathered stained glass windows, the combination of XRD and FTIR techniques is very useful to obtain a fast preliminary evaluation of the degree of weathering of a stained glass window. The presence of specific mineral phases in the patina (e.g., thenardite) confirms the Na composition of the original stained glass. This is important since Na-rich glass underwent a lesser degree of weathering than K- or K-Ca-rich glass. However, their absence cannot preclude other possibilities. It has been extensively evidenced through time that environmental conditions play an important role on the formation of the different mineral phases which form part of the patinas. Recommendations and perspectives  The first step in the restoration of a stained glass window is the evaluation of the degree of deterioration of the glass. This evaluation includes a chemical analysis of the glass as well as a characterization of the patinas developed on their surfaces. The obtained results will be essential in order to define the best restoration practices to be followed.     

Evaluation of river pollution of neonicotinoids in Osaka City (Japan) by LC/MS with dopant-assisted photoionisation

An atmospheric pressure photoionisation (APPI) source for liquid chromatography/mass spectrometry (LC/MS) was applied to determine neonicotinoid pesticides in the aquatic environment. Dopant-assisted APPI was very effective in the ionisation of neonicotinoids. Neonicotinoids generated protonated molecules in APPI with high sensitivity, while adduct ions, such as sodiated molecules, were predominantly generated in conventional electrospray ionisation. The ionisation of neonicotinoids was confirmed by ultra-high-resolution MS. An analytical method coupled with solid phase extraction was developed for acetamiprid, clothianidin, dinotefuran, imidacloprid, nitenpyram, and thiamethoxam. Method detection limits were 0.47 to 2.1 ng L(-1) for six neonicotinoids. Dinotefuran was the most frequent and highest among the neonicotinoids examined in the aquatic environment in Osaka, Japan. The maximum concentration of dinotefuran was 220 ng L(-1). Given the toxicity of neonicotinoids for aquatic creatures, the concentrations observed here were substantially low. The change in concentrations was temporally coincident with the period of the neonicotinoid application. Although rapid photodegradation and some degradation products have been elucidated, the degradation products in the aquatic environment were not identified in the present study.     

Preparation of Cationic/Anionic Chitin Nanofiber Composite Materials

In this study, we investigated the preparation of cationic/anionic chitin nanofiber (CNF) composite materials by electrostatic interaction. An aqueous dispersion of amidinium CNF was prepared by a top-down approach, and a maleylated CNF film was obtained by a bottom-up approach from a chitin ion gel in an ionic liquid with subsequent maleylation on the CNFs. The resulting film was dispersed in ammonia (aq), which was then mixed with the aqueous cationic CNF dispersion to give the composite film. The composition of the two CNFs was evaluated by scanning electron microscopy and X-ray diffraction measurements. Tensile testing results indicated that the mechanical properties of the composites were enhanced with increasing degrees of substitution of the cationic and anionic groups on CNFs, and also when the molar ratio of these groups approached 1:1. The dissociation of the two kinds of CNFs by alkaline treatment of the composite film was achieved, suggesting the presence of an electrostatic interaction among the interactions between them.     

Evaluation of pressurized liquid extraction for the analysis of four pesticides in unpolished rice

The aim of to evaluate efficiency of this study was extraction pressurized liquid extraction (PLE) for the analysis of four pesticides, fthalide, etofenprox, fenitrothion, and isoprothiolane, in unpolished rice by comparing with homogenization as a reference technique. The concentrations of four selected pesticides obtained by PLE with acetonitrile at 130 degrees C for 10 min x 2 cycles were comparable to those by homogenization with water-soaking. The repeatability of the analysis, represented as relative standard deviations (RSDs), were 1.4-3.6% (n = 3) for PLE at 130 degrees C and 1.2-3.8% (n = 3) for homogenization with water-soaking. Recovery yields of surrogates were 75-88% and 87-109% for PLE at 130 degrees C and homogenization with water-soaking, respectively, and these were satisfactory according to the method of positive list. This study suggested that PLE can be applied for the analysis of selected four pesticides in unpolished rice as well as homogenization with water-soaking.