Reduced graphene oxide (rGO) can enhance the bioreduction of nitrobenzene by Shewanella oneidensis MR-1. The effects of surface modification and coexisting soluble electron shuttles on rGO-enhanced bioreduction of nitrobenzene were investigated here. The results showed that rGO enhanced the secretion of extracellular polymeric substance and the bioreduction of nitrobenzene of several folds. No inhibition effect on nitrobenzene bioreduction was observed even when the concentration of rGO was as high as 200 mg/L. The surface modification of rGO might affect the electrical conductivity which was assumed as one of the main factors that contributed to the enhancement of nitrobenzene bioreduction by rGO materials. Moreover, the coexisting electron shuttles further enhanced the rGO-mediated nitrobenzene bioreduction. After the simultaneous addition of flavin mononucleotide (10 μM) and rGO (50 mg/L), the reduction rate increased 7.8 times to 424.98 ± 7.84 mg (nitrobenzene)/(g (dry cell)∙h), which was higher than those ever reported.

Salbutamol (SAL) has been widely used as medicine both in treating asthma and in animal primary production; an increasing number of reports have detected SAL in natural waters. The photolysis kinetic and pathway of SAL in aquatic system were studied, as well as the effect of several natural water constituents, such as nitrate, dissolved oxygen (DO) and ferric ions. According to our research, the direct photolysis of SAL followed pseudo-first-order reaction kinetics. Alkaline condition could promote the degradation of SAL; the increase of solution pH would simultaneously increase the fraction of the deprotonated forms of SAL (including the deprotonated and zwitterionic species), which were easier to be excited, and result in the bathochromic shift of the UV-Vis spectrum and, finally, accelerate the degradation rate of SAL. The presence of nitrate could enhance the removal rate of SAL via generation hydroxyl radical (·OH) under irradiation. In addition, the absence of oxygen in the reaction solution could decrease the photolysis. Moreover, Fe(III) was able to chelate with SAL to form an octahedral complex, which was photochemically reactive. The octahedral complex could generate ·OH to oxidize SAL itself in turn. The pathways of SAL photolysis were also investigated by means of the solid phase extraction (SPE)-LC-MS method. The major pathways of SAL photodegradation included oxidation and side-chain cleavage.

The extensive use of parabens as preservatives in food and pharmaceuticals and personal care products results in frequent detection of their residuals in aquatic environment. In this work, the adsorption and removal of four parabens (methyl-, ethyl-, propyl-, and butyl-paraben) and two chlorinated methyl-parabens (CMPs) by periphyton were studied. Characteristics of the periphyton were identified to explore the possible relationship between paraben removal and periphyton properties. Results showed that linear adsorption coefficients (K d) vary from 554.4 to 808.6 L kg⁻¹ for the adsorption parabens and CMPs to autoclaved periphyton. The adsorption strength is positively related to the hydrophobicity of these compounds. Removal of parabens from water by periphyton was efficient with half-life (t ₁/₂) values estimated using first-order kinetic model ranging from 0.49 to 3.29 days, but CMPs were more persistent with t ₁/₂ ranging from 1.15 to 25.57 days, and t ₁/₂ increased with the chlorination degree. Higher incubation temperature accelerated the removal of all tested compounds, while a better removal of CMPs was observed in dark condition. Analysis of periphyton properties suggests that bacteria played a more important role in the removal of CMPs, but no specific relationship between periphyton properties and paraben removal ability can be established.

This study examines the impact of economic growth, corruption, health, and poverty on environmental degradation for three countries from ASEAN, namely Indonesia, Malaysia, and Thailand using annual data over the period of 1994–2014. The relationship between environmental degradation (pollution) by carbon dioxide (CO₂) emissions and economic growth is examined along with some other variables, namely health expenditure, poverty, agriculture value added growth, industrial value added growth, and corruption. The ordinary least squares (OLS) method is applied as an analytical technique for parameter estimation. The empirical results reveal that almost all variables are statistically significant at the 5% level of significance, whereby test rejects the null hypotheses of non-cointegration, indicating that all variables play an important role in affecting the environment across countries. Empirical results also indicate that economic growth has significant positive impact, while health expenditures show significantly negative impact on the environment. Corruption has significant positive effect on environment in the case of Malaysia; while in the case of Indonesia and Thailand, it has insignificant results. However, for the individual analysis across countries, the regression estimate suggests that economic growth has a significant positive relationship with environment for Indonesia, while it is found insignificantly negative and positive in the case of Malaysia and Thailand, respectively, during the period under the study. Empirical findings of the study suggest that policy-makers require to make technological-friendly environment sequentially to surmount unregulated pollution, steady population transfers from rural areas to urban areas are also important, and poverty alleviation and better health provision can also help to improve the environment.

The present study focuses on optimizing filter depth on sludge reduction in a four-stage vermifiltration during the course of treating excess sludge continuously. The results indicated that when the filter depth exceeded 75 cm, though the fourth stage can further advance the sludge reduction, its contribution for the total sludge reduction was lower than 10%, while the aerobic bacteria, especially the dominant bacteria (Proteobacteria and Bacteroidetes), kept a high similarity as the filter depth varied. Furthermore, earthworm activities attributed to aerobic bacteria being preferentially selected in the system, positively supporting the organic decomposition. As far as economic cost and process performance are concerned, a 75-cm vermifilter was recommended to efficiently and economically achieve the required standard for sewage sludge reduction and stabilization.

Samples of Octopus vulgaris and Sepia officinalis were collected from four areas in the Gulf of Gabes, south-eastern Tunisia, and their edible tissues (mantle and arms) were analyzed for cadmium, copper, mercury, and zinc. While the concentrations of metals showed significant differences between the sampling sites, no differences were revealed between the tissues of the two species. The spatial distribution of metals analyzed showed similar pattern for both tissues of the two species, with the highest concentrations found in the central area of Gabes Gulf, and the lowest in the northern and/or southern areas. From a human health risk point of view, the highest values of estimated daily intake, target hazard quotient, and hazard index were found in the central area of Gabes Gulf. Although the results of these indices were, in general, not alarming, the health risks posed by the consumption of cephalopods on local consumers cannot be excluded.

Solidification and stabilization are well-known technologies used for treating hazardous waste. These technologies that use cementitious binder have been applied for decades as a final treatment procedure prior to the hazardous waste disposal. In the present work, hazardous waste like fly ash containing high concentrations of heavy metals such Zn (4715.56 mg/kg), Pb (1300.56 mg/kg), and Cu (534.72 mg/kg) and amounts of Ag, Cd, Co, Cr, Mn, and Ni was sampled from a city refuse incinerator facility. This fly ash was utilized in the solidification/stabilization of heavy metal sludge since fly ash has cement-like characteristics. Cement additives such as sodium sulfate, sodium carbonate, and ethylenediaminetetraacetic acid (EDTA) was incorporated to the solidified matrix in order to determine its effect on the solidification/stabilization performance. The solidified matrix was cured for 7, 14, 21, and 28 days prior for its physical and chemical characterizations. The results show that the solidified matrix containing 40% fly ash and 60% cement with heavy metal sludge was the formulation that has the highest fly ash content with a satisfactory strength. The solidified matrix was also able to immobilize the heavy metals both found in the fly ash and sludge based on the toxicity characteristic leaching procedure (TCLP) test. It also shows that the incorporation of sodium carbonate into the solidified matrix not only further improved the compressive strength from 0.36 MPa (without Na₂CO₃) to 0.54 MPa (with Na₂CO₃) but also increased its leaching resistance.

The content of selected elements: Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Sb, Si, Ti, V and Zn was determined in archaeological waterlogged oak wood from the Lednica Lake by using the inductively coupled plasma optical emission spectrometry (ICP-OES) method. The concentration of metals (especially heavy metals) in wood is typically specified to characterise this material and evaluate the possibility to use it for industrial purposes. In case of waterlogged archaeological wood intended for further research on new methods of conservation, such an analysis is important for other reasons. As it has been confirmed by numerous conservators and researchers, the presence of metal compounds is a serious problem not only due to their destructive influence on wood tissue but also from a conservation/re-conservation perspective. Metal-containing chemicals may influence conservation treatments by reacting with substances used for wood conservation and causing irreversible damage to wooden objects. Therefore, while developing new solutions for wood conservation, a broad knowledge not only on the state of wood preservation and deterioration but also on interacting chemical factors is required. The results of the research clearly show that content of minerals in waterlogged wood excavated from the bottom of the Lednica Lake considerably exceeded the average percentage of these elements in contemporary wood, which is associated with the mineralisation process. Moreover, variability in metal content was observed between waterlogged and contemporary wood. In waterlogged wood, the highest concentrations of Ca, Fe, Mg and P were observed, while in contemporary oak wood the predominant concentrations of K, Ca, Mn and Si were determined. Statistical analysis showed the variability in content of elements between different archaeological wood zones and contemporary wood. On the basis of the results obtained, it could be concluded that the studied waterlogged wood acted as an adsorbent of elements from water and sediments. High content of metal ions can be an impediment in developing new formulations for conservation, while using this wood as an experimental material. Therefore, while planning to use new chemicals as conservation agents, the possible interactions between chemicals and metals must be taken into consideration.

Abamectin is one of the most used pesticides worldwide. However, investigations about its effects on amphibian populations are rare. Thus, the present study sought to investigate possible cytotoxic effects on Lithobates catesbeianus tadpoles exposed to low abamectin concentrations diluted in water. Accordingly, four experimental groups were set: negative control, positive control (cyclophosphamide—40 mL L⁻¹), abamectin at concentrations 36 μg a.i./L (ABA36 group), and 72 μg a.i./L (ABA72 group), applied as Kraft® 36EC. The micronucleus test was conducted and other nuclear abnormalities in peripheral blood erythrocytes were checked after 24, 48, and 72 h of exposure to the treatments. The total of other nuclear abnormalities was influenced by the treatments, whereas the frequency of micronuclei was influenced by the exposure time. Such frequency was higher in the animals comprising the ABA72 group, which was assessed 72 h after the exposure had begun. The total of other nuclear abnormalities was influenced by the treatments. Animals in the positive control, ABA36, and ABA72 groups showed similar frequency of these abnormalities at 48 and 72 h. However, this frequency was statistically higher than that of animals in their respective negative control groups. Thus, the present study confirmed the hypothesis that the exposure of L. catesbeianus tadpoles to abamectin caused cytotoxic effects on them, although this exposure lasted short and the concentrations were low. It disclosed prospects for variations in the nucleus of erythrocytes circulating in amphibians, a fact that may provide an important/complementary approach for the detection of cytotoxicity caused by abamectin exposure.

This study investigates whether financial development dampens the negative impact of oil resource abundance on economic growth. Because of substantial cross-sectional dependence in our data, which contain a core sample of 63 oil-producing countries from 1980 through 2010, we use the common correlated effect mean group (CCEMG) estimator to account for the high degree of heterogeneity and drop the outlier countries. The empirical results reveal that oil resource abundance affects the growth rate in output contingent on the degree of development in financial markets. More developed financial markets can channel the revenues from oil into more productive activities and thus offset the negative effects of oil resource abundance on economic growth. Thus, better financial development can reverse resource curse or enhance resource blessing in oil-rich economies.