This paper comes out from the need to provide an improvement in the current oil refinery wastewater treatment plant (WWTP) aiming to generate water for reuse. The wastewater was pretreated and collected in the WWTP after the biological treatment unit (bio-disks) followed by sand filtration. Ozonation (ozone concentration from 3.0–60 mgO₃ L⁻¹), UV (power lamp from 15 to 95 W), H₂O₂ (carbon:H₂O₂ molar ratio of 1:1, 1:2, and 1:4), and two advanced oxidation processes (UV/O₃ and UV/H₂O₂) were investigated aiming to reduce the wastewater organic matter and generate water with suitable characteristics for the reverse osmosis operation and subsequent industrial reuse. Even after the biological and filtration treatments, the oil refinery wastewater still presented an appreciable amount of recalcitrant organic matter (TOC of 12–19 mgC L⁻¹) and silt density index (SDI) higher than 4, which is considered high for subsequent reverse osmosis due to membrane fouling risks. Experiments using non combined processes (O₃, H₂O₂, and UV only) showed a low degree of mineralization after 60 min of reaction, although the pretreatment with ozone had promoted the oxidation of aromatic compounds originally found in the real matrix, which suggests the formation of recalcitrant compounds. When the combined processes were applied, a considerable increase in the TOC removal was observed (max of 95 % for UV/O₃ process, 55 W, 60 mgO₃ L⁻¹), likely due the presence of higher amounts of reactive species, specially hydroxyl radicals, confirming the important role of these species on the photochemical degradation of the wastewater compounds. A zero-order kinetic model was fitted to the experimental data and the rate constant values (k, mgC L⁻¹ h⁻¹) ranged from 4.8 < k UV/O₃ < 11 ([O₃]₀ = 30–60 mg L⁻¹), and 8.6 < k UV/H₂O₂ < 11 (C:H₂O₂ from 1:1 to 1:4). The minimum and maximum electrical energy per order (E EO) required for 60 min of treatment were calculated as 5.4 and 81 Wh L⁻¹, respectively, for UV/O₃ (15 W, 60 mgO₃ L⁻¹) and UV/H₂O₂ (95 W, 1C:1H₂O₂). Good results in terms of water conditioning for reverse osmosis operation were obtained using UV/H₂O₂ process with initial molar ratio of 1 C:2 H₂O₂ (UV lamp 55 W) and 1 C:4 H₂O₂ (UV lamp 95 W), and total organic carbon (TOC) removals of 62 % (SDI₁₅ = 1.8) and 74 % (SDI₁₅ = 2.0) were achieved, respectively, after 60 min. The treated wastewater followed to the reverse osmosis system, which operated with an adequate flux of permeate, was very efficient to remove salt and generate a permeate water with the required quality for industrial reuse.

Previous studies have documented the occurrence of veterinary sulfonamide antibiotics in groundwater and rivers located far from pollution sources, although their transport and fate is relatively unknown. In mountainous agricultural fields, the transport behaviour can be influenced by climate, slope and physico-chemical properties of the sulfonamides. The objective of this research is to describe the transport behaviour of three sulfonamide antibiotics (sulfamethoxazole, sulfadimethoxine and sulfamethazine) in sloped agricultural fields located in the Haean catchment, South Korea. During dry and monsoon seasons, a solute transport experiment was conducted in two typical sandy loam agricultural fields after application of antibiotics and potassium bromide as conservative tracers. Field measurement and modelling revealed that frequency and amount of runoff generation indicate a relation between slope and rain intensity during monsoon season. Since the steepness of slope influenced partitioning of precipitation between runoff and subsurface flow, higher loss of sulfonamide antibiotics and bromide by runoff was observed at the steeper sloped field. Bromide on topsoil rapidly infiltrated at high infiltration rates. On the contrary, the sulfonamides were relatively retarded in the upper soil layer due to adsorption onto soil particles. Presence of furrows and ridges affected the distribution of sulfonamide antibiotics in the subsurface due to gradient from wetter furrows to drier ridges induced by topography. Modelling results with HydroGeoSphere matched with background studies that describe physico-chemical properties of the sulfonamides interaction between soil and the antibiotic group, solute transport through vadose zone and runoff generation by storm events.

The achievement of environmentally sound and economically feasible disposal strategies for biosolids is a major issue in the wastewater treatment industry around the world, including Swaziland. Currently, an iron ore mine site, which is located within a wildlife sanctuary, is being considered as a suitable place where controlled disposal of biosolids may be practiced. Therefore, this study was conducted to investigate the effects of urban biosolids on iron mine soils with regard to plant metal content and ecotoxicological effects on earthworms. This was done through chemical analysis of plants grown in biosolid-amended mine soil. Earthworm behaviour, reproduction and bioaccumulation tests were also conducted on biosolid-amended mine soil. According to the results obtained, the use of biosolids led to creation of soil conditions that were generally favourable to earthworms. However, plants were found to have accumulated Zn up to 346 mg kg⁻¹ (in shoots) and 462 mg kg⁻¹ (in roots). This was more than double the normal Zn content of plants. It was concluded that while biosolids can be beneficial to mine soils and earthworms, they can also lead to elevated metal content in plant tissues, which might be a concern to plant-dependant wildlife species. Nonetheless, it was not possible to satisfactorily estimate risks to forage quality since animal feeding tests with hyperaccumulator plants have not been reported. Quite possibly, there may be no cause for alarm since the uptake of metals from soil is greater in plants grown in pots in the greenhouse than from the same soil in the field since pot studies fail to mimic field conditions where the soil is heterogeneous and where the root system possesses a complex topology. It was thought that further field trials might assist in arriving at more satisfactory conclusions.

Slightly polluted water has become one of the main sources of nitrogen contaminants in recent years, for which constructed wetlands (CW) is a typical and efficient treatment. However, the knowledge about contribution of individual nitrogen removal pathways and nitrogen balance in constructed wetlands is still limited. In this study, a stable-isotope-addition experiment was performed in laboratory-scale constructed wetlands treating slightly polluted water to determine quantitative contribution of different pathways and temporal variation of nitrogen balance using Na¹⁵NO₃ as tracer. Microbial conversion and substrate retention were found to be the dominant pathways in nitrogen removal contributing 24.4–79.9 and 8.9–70.7 %, respectively, while plant contributed only 4.6–11.1 % through direct assimilation but promoted the efficiency of other pathways. In addition, microbial conversion became the major way to remove N whereas nitrogen retained in substrate at first was gradually released to be utilized by microbes and plants over time. The findings indicated that N₂ emission representing microbial conversion was not only the major but also permanent nitrogen removal process, thus keeping a high efficiency of microbial conversion is important for stable and efficient nitrogen removal in constructed wetlands.

This study aimed to evaluate the effects of electromagnetic fields (EMF) exposure on levels of serum lipids in workers of an electric power plant. A cross-sectional study was carried out in an electric power plant in Zhejiang province, China, from August to September 2011. All participants were divided into two groups with high occupational EMF exposure and low occupational EMF exposure. The occupational EMF exposure included radiofrequency EMF and extremely low-frequency EMF. Occupational EMF exposure was associated with an increased level of low-density lipoprotein cholesterol (LDL-c; β = 0.17 mmol/L, P = 0.022). High EMF exposure group with longer employment duration, longer daily EMF exposure duration, and more mobile phone or electric fee per month had significantly higher levels of total cholesterol, LDL-c, or triglyceride than the corresponding reference group. However, significantly decreased level of high-density lipoprotein cholesterol was only observed in high EMF exposure group with more mobile phone fee per month. Similar results were also found in 544 participants with available data of serum lipids in 2010. The findings showed that chronic EMF exposure was associated with the change of serum lipid levels. EMF exposure might modulate the process of lipid metabolism.

This study explores the perception and knowledge of environmental problems among students of Atatürk University, Turkey, as a developing country, by comparing their perceptions with known facts about environmental problems at local, national, and global levels. In addition, the correlation between the student groups and their knowledge levels and the differences between the student groups according to their knowledge levels when taking age and gender into account are explored. To this end, the research designed as a case study and pursued an exploratory approach revealed that major perceived environmental problems show differences at local, national, and global levels; that consensus on both major perceived problems and knowledge decreases from a local to global level; that a weak correlation exists between the age (r (205) = −.010; .002; −.071) and gender groups (r (205) = −.099; −.125; .065) in terms of their knowledge at local, national, and global level, respectively; and that the contribution of knowledge at a national level can help to explain differences among the age groups (−.304; .102; −.148) at national level and the gender groups (.131; −.205) at national and global levels.

The IARC Monographs are a series of scientific reviews that identify environmental factors that can increase the risk of cancer in humans. In its first part, the principles and procedures of the IARC Monographs evaluations are summarized. In a second part, we present the most recent IARC evaluation of polychlorinated biphenyls (PCBs) and polybrominated biphenyls (PBBs), performed in February 2013: PCBs and dioxin-like PCBs were both classified into group 1 “carcinogens,” while PBBs were evaluated as “probably carcinogenic to humans” (group 2A). Noteworthy is that the relative contributions of different PCB congeners to the carcinogenicity of PCB mixtures are not known. The use of mechanistic data for the classification into a higher category is discussed in the context of the history of the consecutive evaluations of several related polychlorinated compounds.

The photocatalytic degradation of furfural in aqueous solution was investigated using N-doped titanium dioxide nanoparticles under sunlight and ultraviolet radiation (N-TiO₂/Sun and N-TiO₂/UV) in a lab-scale batch photoreactor. The N-TiO₂ nanoparticles prepared using a sol-gel method were characterized using XRD, X-ray photoelectron spectroscopy (XPS), and SEM analyses. Using HPLC to monitor the furfural concentration, the effect of catalyst dosage, contact time, initial solution pH, initial furfural concentration, and sunlight or ultraviolet radiation on the degradation efficiency was studied. The efficiency of furfural removal was found to increase with increased reaction time, nanoparticle loading, and pH for both processes, whereas the efficiency decreased with increased furfural concentration. The maximum removal efficiencies for the N-TiO₂/UV and N-TiO₂/Sun processes were 97 and 78 %, respectively, whereas the mean removal efficiencies were 80.71 ± 2.08 % and 62.85 ± 2.41 %, respectively. In general, the degradation and elimination rate of furfural using the N-TiO₂/UV process was higher than that using the N-TiO₂/Sun process.

Moso bamboo (Phyllostachys pubescens) has great potential as phytoremediation material in soil contaminated by heavy metals. A hydroponics experiment was conducted to determine organic acid compounds of root exudates of lead- (Pb), zinc- (Zn), copper- (Cu), and cadmium (Cd)-tolerant of Moso bamboo. Plants were grown in nutrients solution which included Pb, Zn, Cu, and Cd applied as Pb(NO₃)₂ (200 μM), ZnSO₄·7H₂O (100 μM), CuSO₄·5H₂O (25 μM), and CdCl₂ (10 μM), respectively. Oxalic acid and malic acid were detected in all treatments. Lactic acid was observed in Cu, Cd, and control treatments. The oxalic was the main organic acid exudated by Moso bamboo. In the sand culture experiment, the Moso bamboo significantly activated carbonate heavy metals under activation of roots. The concentration of water-soluble metals (except Pb) in sand were significantly increased as compared with control. Organic acids (1 mM mixed) were used due to its effect on the soil adsorption of heavy metals. After adding mixed organic acids, the Cu and Zn sorption capacity in soils was decreased markedly compared with enhanced Pb and Cd sorption capacity in soils. The sorption was analyzed using Langmuir and Freundlich equations with R ² values that ranged from 0.956 to 0.999 and 0.919 to 0.997, respectively.