The toxicity of soluble oil to the aquatic environment has started to attract wide attention in recent years. In the present work, we prepare graphene according to oxidation and thermal reduction methods for the removal of soluble oil from the solution. Characterization of the as-prepared graphene are performed by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Raman spectra, Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, and contact angle analysis. The adsorption behavior of soluble oil on graphene is examined, and the obtained adsorption data are modeled using conventional theoretical models. Adsorption experiments reveal that the adsorption rate of soluble oil on graphene is notably fast, especially for the soluble diesel oil, which could reach equilibrium within 30 min, and the kinetics of adsorption is perfectly consistent with a pseudo-second-order model. Furthermore, it is determined that the adsorption isotherm of soluble diesel oil with graphene fit the Freundlich model best, and graphene has a very strong adsorption capacity for soluble diesel oil in the solution. These results demonstrate that graphene is the material that provided both good adsorptive capacity and good kinetics, implying that it could be used as a promising sorbent for soluble oil removal from wastewater.

Molecularly imprinted polymer adsorbent has been prepared to remove a group of recalcitrant and acutely hazardous (p-type) chemicals from water and wastewaters. The polymer adsorbent exhibited twofold higher adsorption capacity than the commercially used polystyrene divinylbenzene resin (XAD) and powdered activated carbon adsorbents. Higher adsorption capacity of the polymer adsorbent was explained on the basis of high specific surface area formed during molecular imprinting process. Freundlich isotherms drawn showed that the adsorption of p-type chemicals onto polymer adsorbent was kinetically faster than the other reference adsorbents. Matrix effect on adsorption of p-type chemicals was minimal, and also polymer adsorbent was amenable to regeneration by washing with water/methanol (3:1, v/v) solution. The polymer adsorbent was unaltered in its adsorption capacity up to 10 cycles of adsorption and desorption, which will be more desirable in cost reduction of treatment compared with single-time-use activated carbon.

We investigated the adsorption and decomposition of sulfamethazine (SMT), which is used as a synthetic antibacterial agent and discharged into environmental water, using high-silica Y-type zeolite (HSZ-385), titanium dioxide (TiO₂), and TiO₂–zeolite composites. By using ultrapure water and secondary effluent as solvents, we prepared SMT solutions (10 μg/L and 10 mg/L) and used them for adsorption and photocatalytic decomposition experiments. When HSZ-385 was used as an adsorbent, rapid adsorption of SMT in the secondary effluent was confirmed, and the adsorption reached equilibrium within 10 min. The photocatalytic decomposition rate using TiO₂in the secondary effluent was lower than that in ultrapure water, and we clarified the inhibitory effect of ions and organic matter contained in the secondary effluent on the reaction. We synthesized TiO₂–zeolite composites and applied them to the removal of SMT. During the treatment of 10 μg/L SMT in the secondary effluent using the composites, 76 % and more than 99 % of the SMT were decomposed within 2 and 4 h by photocatalysis. The SMT was selectively adsorbed onto high-silica Y-type zeolite in the composites. Resultantly, the inhibitory effect of the coexisting materials was reduced, and the composites could remove SMT more effectively compared with TiO₂alone in the secondary effluent.

In order to evaluate the potential adverse health effects of odor emissions from wastewater pump stations (WWPSs) to human, a health risk assessment was performed to study the odors emitted from an urban WWPS in a residential area, Tianjin (in North China). First, 15 types of volatile organic compounds in the WWPS were collected and analyzed using gas chromatography-mass spectrometry. Next, Monte Carlo probabilistic modeling was applied to evaluate the potential health effects of four odors (chlorobenzene, dichloromethane, hydrogen sulfide, and carbon disulfide), which had higher concentrations. The results revealed that the 95th percentile of the total non-carcinogenic risk was approximately 1.73, which poses a threat to human health. In addition, hydrogen sulfide had the highest non-carcinogenic risk value of the four; the hazard quotient of hydrogen sulfide was estimated to be 1.60 at the 95th percentile, higher than the upper confidence limit (1.0). The 95th percentile of the carcinogenic risk was approximately 5.47E-08, much lower than the maximum acceptable level (1.0E-06). Finally, the influence of the input variables on the output was evaluated using sensitivity analysis, and contaminant concentration, reference concentration, and inhalation unit risk were the most influential variables.

A surface- and vertical subsurface-flow-constructed wetland were designed to study the response of chlorophyll and antioxidant enzymes to elevated UV radiation in three types of wetland plants (Canna indica, Phragmites austrail, and Typha augustifolia). Results showed that (1) chlorophyll content of C. indica, P. austrail, and T. augustifolia in the constructed wetland was significantly lower where UV radiation was increased by 10 and 20 % above ambient solar level than in treatment with ambient solar UV radiation (p < 0.05). (2) The malondialdehyde (MDA) content, guaiacol peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities of wetland plants increased with elevated UV radiation intensity. (3) The increased rate of MDA, SOD, POD, and CAT activities of C. indica, P. australis, and T. angustifolia by elevated UV radiation of 10 % was higher in vertical subsurface-flow-constructed wetland than in surface-flow-constructed wetland. The sensitivity of MDA, SOD, POD, and CAT activities of C. indica, P. austrail, and T. augustifolia to the elevated UV radiation was lower in surface-flow-constructed wetland than in the vertical subsurface-flow-constructed wetland, which was related to a reduction in UV radiation intensity through the dissolved organic carbon and suspended matter in the water. C. indica had the highest SOD and POD activities, which implied it is more sensitive to enhanced UV radiation. Therefore, different wetland plants had different antioxidant enzymes by elevated UV radiation, which were more sensitive in vertical subsurface-flow-constructed wetland than in surface-flow-constructed wetland.

Field monitoring was conducted to develop a polycyclic aromatic hydrocarbon (PAH) emission inventory for the magnesium (Mg) metallurgy industry in China. PAH emissions in stack gas and fly/bottom ash samples from different smelting units of a typical Mg smelter were measured and compared. Large variations of concentrations, congener patterns, and emission factors of PAHs during the oxidation and reduction stages in the Mg smelter were observed. The measured average emission factor (166,487 μg/t Mg) was significantly higher than those of other industrial sources. Annual emission from Mg metallurgy in 2012 in China was estimated at 116 kg (514 g BaPeq) for PAHs. The results of this study suggest that PAH emission from Mg industries should be considered by local government agencies. These data may be helpful for understanding PAH levels produced by the Mg industry and in developing a PAH inventory.

The present study explores the tolerance and metal removal response of a well-developed 2-week-old Phormidium mat after long-term exposure to Cu²⁺-enriched medium. Cu²⁺enrichment inhibited increase in mat biomass in a concentration-dependent manner. Mat area and the number of entrapped air bubbles decreased as Cu²⁺concentration increased in the medium. Decrease in number of air bubbles obviously reflects the adverse effect of Cu²⁺on photosynthetic performance of the mat. Metal enrichment did not substantially alter the amount of pigments, such as chlorophyll a, chlorophyll b, carotenoids, and phycocyanin, in the mat. Enhancement of Cu²⁺concentration in the medium led to changes in species composition of the test mat; however, Phormidium bigranulatum always remained the dominant organism. Relative share of green algae and some cyanobacterial taxa, namely, Lyngbya sp. and Oscillatoria tenuis, in the mat were increased by Cu²⁺enrichment. The mat successfully removed 80 to 94 % Cu²⁺from the growth medium containing 10 to 100 μM Cu²⁺. Extracellular polysaccharides, whose share increased in the mat community after metal addition, seem to have contributed substantially to metal binding by the mat biomass.

Land use has obvious influence on surface water quality; thus, it is important to understand the effects of land use patterns on surface water quality. This study explored the relationships between land use patterns and stream nutrient levels, including ammonium-N (NH₄⁺-N), nitrate-N (NO₃⁻-N), total N (TN), dissolved P (DP), and total P (TP) concentrations, in one forest and 12 agricultural catchments in subtropical central China. The results indicated that the TN concentrations ranged between 0.90 and 6.50 mg L⁻¹and the TP concentrations ranged between 0.08 and 0.53 mg L⁻¹, showing that moderate nutrient pollution occurred in the catchments. The proportional areal coverages of forests, paddy fields, tea fields, residential areas, and water had distinct effects on stream nutrient levels. Except for the forest, all studied land use types had a potential to increase stream nutrient levels in the catchments. The land use pattern indices at the landscape level were significantly correlated to N nutrients but rarely correlated to P nutrients in stream water, whereas the influence of the land use pattern indices at the class level on stream water quality differentiated among the land use types and nutrient species. Multiple regression analysis suggested that land use pattern indices at the class level, including patch density (PD), largest patch index (LPI), mean shape index (SHMN), and mean Euclidian nearest neighbor distance (ENNMN), played an intrinsic role in influencing stream nutrient quality, and these four indices explained 35.08 % of the variability of stream nutrient levels in the catchments (p<0.001). Therefore, this research provides useful ideas and insights for land use planners and managers interested in controlling stream nutrient pollution in subtropical central China.

Human serum samples (n = 113) from Bizerte, northern Tunisia, collected between 2011 and 2012 were analyzed for 8 organochlorine pesticides (OCPs) including p,p′-dichlorodiphenyltrichloroethane (DDT) and its metabolites, hexachlorobenzene (HCB), hexachlorocyclohexane isomers, dieldrin, and heptachlor and 12 polychlorinated biphenyls (PCBs) congeners. Concentrations of these residues in serum were determined by gas chromatography with electron capture detector and total cholesterol (CHOL) and triglycerides (TG) levels were evaluated by enzymatic colorimetric method. HCB, p,p′-DDE, PCB-138, PCB-153, and PCB-180, were the most abundant organochlorine compounds (OCs) detected in >95 % of the study subjects. The mean levels of p,p′-DDE and HCB in serum were 168.8 and 49.1 ng g⁻¹lipid, respectively. The sum PCBs concentrations ranged from 37.5 to 284.6 ng g⁻¹lipid in the samples, with mean and median value of 136.1 and 123.2 ng g⁻¹lipid, respectively. The PCB profile consisted of persistent congeners, such as PCB-138, PCB-153, and PCB-180 which contributed for approximately 82.7 % to the ∑PCBs. Statistical analysis showed that most OCs correlated significantly with age, considering all samples together or with gender differentiation. The present study shows that the levels of p,p′-DDE and ∑DDTs were significantly higher in females than in males (p < 0.05), while PCBs levels were significantly higher in male (p < 0.05) than in females. No statistically significant association was found between body mass index and concentration of any organochlorine pesticide or PCB congeners 153, 138, 180, or ∑PCBs.

Sorption and biodegradation are the main mechanisms for the removal of endocrine disruptor compounds (EDs) from both solid and liquid matrices. There are recent evidences about the capacity of white-rot fungi to decontaminate water systems from phenolic EDs by means of their ligninolytic enzymes. Most of the available studies report the removal of EDs by biodegradation or adsorption separately. This study assessed the simultaneous removal of five EDs—the xenoestrogens bisphenol A (BPA), ethynilestradiol (EE2), and 4-n-nonylphenol (NP), and the herbicide linuron and the insecticide dimethoate—from a municipal landfill leachate (MLL) using a combined sorption/bioremoval approach. The adsorption matrices used were potato dextrose agar alone or added with each of the following adsorbent materials: ground almond shells, a coffee compost, a coconut fiber, and a river sediment. These matrices were either not inoculated or inoculated with the fungus Pleurotus ostreatus and superimposed on the MLL. The residual amount of each ED in the MLL was quantified after 4, 7, 12, and 20 days by HPLC analysis and UV detection. Preliminary experiments showed that (1) all EDs did not degrade significantly in the untreated MLL for at least 28 days, (2) the mycelial growth of P. ostreatus was largely stimulated by components of the MLL, and (3) the enrichment of potato dextrose agar with any adsorbent material favored the fungal growth for 8 days after inoculation. A prompt relevant disappearance of EDs in the MLL occurred both without and, especially, with fungal activity, with the only exception of the very water soluble dimethoate that was poorly adsorbed and possibly degraded only during the first few days of experiments. An almost complete removal of phenolic EDs, especially EE2 and NP, occurred after 20 days or much earlier and was generally enhanced by the adsorbent materials used. Data obtained indicated that both adsorption and biodegradation mechanisms contribute significantly to MLL decontamination from the EDs studied and that the efficacy of the methodology adopted is directly related to the hydrophobicity of the contaminant.