The aim of this study was to investigate the performances of polyamide nanofiltration membranes during water reclamation. The study was conducted using nanofiltration concentrates obtained from two different nanofiltration drinking water treatment plants placed in the northern part of Serbia (Kikinda and Zrenjanin). Used nanofiltration concentrates contained high concentrations of arsenic (45 and 451 μg/L) and natural organic matter (43.1 and 224.40 mgKMnO₄/L). Performances of polyamide nanofiltration membranes during water reclamation were investigated under various fluxes and transmembrane pressures in order to obtain drinking water from nanofiltration concentrates and, therefore, reduce the amount of produced concentrates and minimize the waste that has to be discharged in the environment. Applied polyamide nanofiltration membranes showed better removal efficiency during water reclamation when the concentrate with higher content of arsenic and natural organic matter was used while the obtained permeates were in accordance with European regulations. This study showed that total concentrate yield can be reduced to ~5 % of the optimum flux value, in both experiments. The obtained result for concentrate yield under the optimum flux presents considerable amount of reclaimed drinking water and valuable reduced quantity of produced wastewater.

The effect of sewage sludge on the mobility and the bioavailability of trace metals in plant-soil systems have aroused wide interested and been widely explored. Based on a wheat-cultivating experiment, the effect of municipal sludge compost (MSC) on the mobility and bioavailability of Cd in a soil-wheat system was studied. With the application of MSC, soil organic matter (SOM), total nitrogen (TN), and total phosphorus (TP) in the soil increased significantly, while concentrations of trace metals (Cu, Zn, Ni, Pb, Cd) were below the China’s minimum thresholds. The application of MSC could improve wheat growth. The application of MSC at the rate of 0.5 % had no significant effect on the chemical fraction distribution of Cd in soil. In two soil treatments, Cd mainly existed in the labile chemical fractions (exchangeable chemical fraction (EXCF) and carbonate chemical fraction (CABF)). However, the application of MSC could reduce accumulation of Cd by wheat. Cd contents in each part of the MSC-applied wheat were significantly less than that of non-MSC-applied wheat. In the tested soils, the extractable concentrations decreased in the order: EDTA > MgCl₂ ≈ NH₄OAc > DTPA. There were no significant differences between soil treatments in the amounts of extractable Cd when the extraction was done under neutral conditions, although significant differences were observed when the extraction was done under alkaline conditions. In this study, the DTPA extraction procedure provided a good indication of Cd bioavailability. Our results suggest that, in the short term at least, amending soils with MSC may benefit crop dry matter production while not increasing the risk of human exposure to Cd through consumption of wheat grown on MSC-amended soils.

This study aimed to investigate and discuss the occurrence and accumulation of mercury in the fruiting bodies of wild-growing fungi (Macromycetes) collected from montane forests in two regions of southwestern China with differences in soil geochemistry, climate and geographical conditions. Fungal mycelia in soils of the subalpine region of the Minya Konka (Gongga Mountain) in Sichuan and in the highlands of Yunnan efficiently accumulated mercury in fruiting bodies (mushrooms). The examined sites in Yunnan with highly mineralized red and yellow soils showed Hg contents ranging from 0.066 to 0.28 mg kg⁻¹ dry biomass (db) which is roughly similar to the results obtained for samples collected from sites with dark soils relatively rich in organic matter from a remote, the subalpine region of Minya Konka. Due to the remoteness of the subalpine section of Minya Konka, as well as its elevation and climate, airborne mercury from long-range transport could be deposited preferentially on the topsoil and the Hg levels determined in soil samples taken beneath the fruiting bodies were up to 0.48 mg kg⁻¹ dry matter. In Yunnan, with polymetallic soils (Circum-Pacific Mercuriferous Belt), Amanita mushrooms showed mercury in caps of fruiting bodies of up to 7.3 mg kg⁻¹ dry biomass. Geogenic Hg from the mercuriferous belt seems to be the overriding source of mercury accumulated in mushrooms foraged in the regions of Yunnan, while long-range atmospheric transport and subsequent deposition are the mercury sources for specimens foraged in the region of Minya Konka.

In the present work, the toxicity of three forms of graphene: pristine graphene (pG), graphene oxide (GO), and reduced graphene oxide (rGO) was investigated using a chicken embryo model. Fertilized chicken eggs were divided into the control group and groups administered with pG, GO, and rGO, in concentrations of 50, 500, and 5000 μg/ml. The experimental solutions were injected in ovo into the eggs, and at day 18 of incubation, the embryo survival, body and organ weights, the ultrastructure of liver samples, and the concentration of 8-hydroxy-2′-deoxyguanosine (8-OHdG) in the livers were measured. Survival of embryos decreased significantly after treatment with all types of graphene, but not in a dose-dependent manner. The body weights were only slightly affected by the highest doses of graphene, while the organ weights were not different among treatment groups. In all experimental groups, atypical hepatocyte ultrastructure and mitochondrial damage were observed. The concentration of the marker of DNA damage 8-OHdG in the liver significantly decreased after pG and rGO treatments. Further in vivo studies with different animal models are necessary to clarify the level of toxicity of different types of graphene and to estimate the concentrations appropriate to evaluate their biomedical applications and environmental hazard.

Biofiltration of NH₃ and H₂S with different packing media, biodehydration stage compost (BSC), and curing stage compost (CSC) was studied. Meanwhile, fluorescence excitation–emission matrix (EEM) spectroscopy was used to characterize the conversion mechanisms of organic matter during these biofiltration processes. Both biofilters were effective for the simultaneous removal of NH₃ and H₂S when inlet concentrations of NH₃ and H₂S were 0–50 and 50–250 mg/m³, respectively. An abrupt increase in the inlet gas concentrations of NH₃ and H₂S to 100–150 and 200–250 mg/m³, respectively, caused the decrease in the removal efficiencies (REs) of NH₃ and H₂S in the BSC biofilter, followed by a slow upturn. By contrast, relatively steady REs of both NH₃ and H₂S were observed in the CSC biofilter. After 60 days of operation, the average REs of NH₃ and H₂S were more than 95 % in the CSC biofilter. During the operation of CSC, nitrate and nitrite peaked around the 30th day, whereas sulfate showed a steady increase. The excitation–emission matrix fluorescence and parallel factor analysis (EEM-PARAFAC) indicated that the simultaneous inlet of NH₃ and H₂S facilitated the degradation of protein-like substances, whereas humic-like substances played an important role in the packing filters for the treatment of the two odorous pollutants.

Technological innovation is one of the potential engines to mitigate environmental pollution. However, the implementation of new technologies sometimes fails owing to socioeconomic constraints from different stakeholders. Thus, it is essential to analyze constraints of environmental technologies in order to build a pathway for their implementation. In this study, taking three technologies on rural sewage treatment in Hangzhou, China as a case study, i.e., wastewater treatment plant (WTP), constructed wetland (CW), and biogas system, we analyzed how socioeconomic constraints affect the technological choices. Results showed that socioeconomic constraints play a key role through changing the relative opportunity cost of inputs from government as compared to that of residents to deliver the public good—sewage treatment—under different economic levels. Economic level determines the technological choice, and the preferred sewage treatment technologies change from biogas system to CW and further to WTP along with the increase of economic level. Mismatch of technological choice and economic level results in failures of rural sewage treatment, e.g., the CW only work well in moderately developed regions in Hangzhou. This finding expands the environmental Kuznets law by introducing the coproduction theory into analysis (i.e., inputs from both government and residents are essential for the delivery of public goods and services such as good environmental quality). A match between technology and socioeconomic conditions is essential to the environmental governance.

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 relative potencies of non-ortho-substituted coplanar polychlorinated biphenyl (PCB) congeners to activate the aryl hydrocarbon receptor (AhR) and to cause the AhR-dependent toxic events are essential for their risk assessment. Since some studies suggested that abundant non-dioxin-like PCB congeners (NDL-PCBs) may alter the AhR activation by PCB mixtures and possibly cause non-additive effects, we evaluated potential suppressive effects of NDL-PCBs on AhR activation, using a series of 24 highly purified NDL-PCBs. We investigated their impact on the model AhR agonist-induced luciferase reporter gene expression in rat hepatoma cells and on induction of CYP1A1/1B1 mRNAs and deregulation of AhR-dependent cell proliferation in rat liver epithelial cells. PCBs 128, 138, and 170 significantly suppressed AhR activation (with IC₅₀ values from 1.4 to 5.6 μM), followed by PCBs 28, 47, 52, and 180; additionally, PCBs 122, 153, and 168 showed low but still significant potency to reduce luciferase activity. Detection of CYP1A1 mRNA levels in liver epithelial cells largely confirmed these results for the most abundant NDL-PCBs, whereas the other AhR-dependent events (CYP1B1 mRNA expression, induction of cell proliferation in confluent cells) were less sensitive to NDL-PCBs, thus indicating a more complex regulation of these endpoints. The present data suggest that some NDL-PCBs could modulate overall dioxin-like effects in complex mixtures.

Guánica Bay, located in southwestern Puerto Rico, has suffered oil spills and other pollution discharges since the 1960s. Previous research showed elevated concentrations of polychlorinated biphenyls (PCBs) in coral reef and sediment. This research examined PCB concentrations in sediment and fish. Sediment and fish sampling in the bay was facilitated by community members. This study identified the second highest reported PCB level (129,300 ng/g) in sediment in the USA. Fish samples also showed elevated concentrations (1623 to 3768 ng/g), which were higher than the thresholds of safe levels of PCBs in fish for human consumption. The alarmingly high concentration of PCBs calls for proactive community engagement to bring awareness about contamination of the bay and more extensive sampling to test for the concentration of PCBs in seafood and the people of Guánica. This study also underscores the value of the involvement of local communities during sampling design aimed at identifying hot spots of contaminants.

This study evaluates the efficacy of a sanitary sewage treatment system, proposing post-treatment of the effluent generated by the upflow anaerobic sludge blanket UASB reactor, through a Fenton coagulation/oxidation ((ferric chloride (FC) or ferrous sulfate (FS) and peracetic acid (PAA)), followed by a double filtration system, composed of a gravel ascending drainage filter and a sand descending filter. Following the assessment of treatability, the system efficiency was evaluated using physicochemical and microbiological parameters. In all treatments performed in the pilot unit, total suspended solids (TSS) were completely removed, leading to a decrease in turbidity greater than 90 % and close to 100 % removal of total phosphorous. In the FC and PAA combination, the effluent was oxygenated prior to filtration, enabling a more significant removal of biochemical oxygen demand (BOD), which characterizes aerobic degradation even in a quick sand filter. The treatments carried out in the presence of the PAA oxidizing agent showed a more significant bleaching of the effluent. Concerning the microbiological parameters, the simultaneous use of PAA and FC contributed to the partial inactivation of the assessed microorganisms. A 65 % recovery of the effluent was obtained with the proposed treatment system, considering the volume employed in filter backwashing.