Contaminant concentrations, sources, seasonal variation, and eco-toxicological risk of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in surface water around Beijing from summer to winter in 2015 and 2016 were investigated. The concentrations of ∑OCPs and ∑PCBs ranged from 9.81 to 32.1 ng L⁻¹ (average 15.1 ± 7.78 ng L⁻¹) and from 7.41 to 54.5 ng L⁻¹ (average 21.3 ± 1.87 ng L⁻¹), respectively. Hexachlorocyclohexane (HCHs) were the dominated contamination both in aqueous and particulate phase. For PCBs, lower chlorinated PCBs were the major contaminants. Compositions of HCHs, dichlorodiphenyltrichloroethane (DDTs), and PCBs indicated that the sources of OCPs and PCBs in water were due to historical usage in the study areas. For OCPs, there was an obvious variation among three seasons, while insignificant change was shown for PCBs. Water quality standards for China’s surface water were not exceeded in this study. Concentrations at Miyun Reservoir, the primary source of drinking water to Beijing, when compared to the USEPA’s criterion for cancer risk was below the level of risk.

The optimization of the nanofiltration (NF) concentrate backflow ratio (R cb) and the influence of the NF concentrate on the performance of membrane bioreactor-nanofiltration (MBR-NF) process treating antibiotic production wastewater were investigated on a laboratory scale. The R cb was optimized at 60 % based on the removal rates of chemical oxygen demand (COD) and NH₄ ⁺-N by MBR. Data analyses indicated that salinity brought by NF concentrate is the major driver leading to the decrease of sludge activity, especially at a high R cb. EPS analysis showed that electric conductivity (EC), proteins in soluble microbial products (SMP), and SMP brought by NF concentrate are the dominant factors causing the severe membrane fouling in MBR. Furthermore, undegradable substances including fulvic acid-like and humic acid-like compounds accumulated in NF concentrate showed significant influence on fouling of NF. MBR could well degrade small MW compounds in NF concentrate, which confirmed the enhancement of organic removal efficiency by recycling the NF concentrate to MBR. The MBR-NF process showed a relatively stable performance at the R cb of 60 % (volume reduction factor (VRF) = 5), and the NF permeate could satisfy the water quality standard for fermentation process with a water recovery rate of 90.9 %.

Sulfonamide antibiotics (SAs) have been observed to undergo direct and indirect photodegradation in natural water environments. In this study, the density functional theory (DFT) method was employed for the study of direct and indirect photodegradation mechanisms of sulfameter (SME) with excited triplet states of dissolved organic matter (³DOM*) and metal ions. SME was adopted as a representative of SAs, and SO₂ extrusion product was obtained with different energy paths in the triplet-sensitized photodegradation of the neutral (SME⁰) and the anionic (SME⁻) form of SME. The selected divalent metal ions (Ca²⁺, Mg²⁺, and Zn²⁺) promoted the triplet-sensitized photodegradation of SME⁰ but showed an inhibitory effect in triplet-sensitized photodegradation of SME⁻. The triplet-sensitized indirect photodegradation mechanism of SME was investigated with the three DOM analogues, i.e., 2-acetonaphthone (2-AN), fluorenone (FN), and thioxanthone (TN). Results indicated that the selected DOM analogues are highly responsible for the photodegradation via attacking on amine moiety of SME. According to the natural bond orbital (NBO) analysis, the triplet-sensitized photodegradation mechanism of SME⁰ with 2-AN, FN, and TN was H-transfer, and the SME⁻ was proton plus electron transfer with these DOM analogues.

The efficacies of catalyzed H₂O₂, activated persulfate, and catalyzed H₂O₂-persulfate processes for the degradation of ortho-nitrochlorobenzene (o-NCB) in soil were investigated. The application of catalyzed H₂O₂-persulfate process was promising, and after a careful adjustment of oxidants and activator doses, it demonstrated a considerable improvement in o-NCB degradation compared with activated persulfate process and catalyzed H₂O₂ process. The degradation of o-NCB in catalyzed H₂O₂-persulfate process was obviously influenced by the concentration of persulfate and H₂O₂, the molar ratio between persulfate and H₂O₂, the concentration of o-NCB, and initial pH. Degradation of o-NCB was obviously inhibited by the addition of tert-butyl alcohol, methanol, and phenol, suggesting that nitrobenzene was dominantly oxidized by HO· and SO₄ ⁻· generated in the catalyzed H₂O₂-persulfate process. The results from these studies demonstrated that the natural iron species present in soil could effectively facilitate the degradation of organic pollutants in the presence of H₂O₂ and persulfate.

This study evaluates the elemental (W, Mo, Zn, Fe, Cu, Cd, Mn, Pb, Cr, Co, B, and Bi) composition of Marrubium astracanicum Jacq. (Lamiaceae), around the abandoned tungsten mine on Uludağ Mountain, Turkey, to determine if it is an appropriate candidate for phytomonitoring and/or phytoremediation purposes. Three sample sites were selected around the mine for soil and plant sampling. Two sites approximately 500 m from the mine were assumed to be unpolluted sites. The other site was selected from a waste removal pool (WRP) and was assumed to be a polluted site. The soil and different organs (roots, leaves, and flowers) of plant samples were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) to determine the elemental content. The classic open wet digestion procedure was applied to the samples with 5 mL HNO₃ and 3 mL H₂O₂ in a borosilicate glass vessel for the roots, leaves, and the flowers of the plants. Kjeldahl digestion was used for the soil samples. The W, Zn, Fe, Cu, Cd, Mn, Pb, B, and Bi contents were found to be higher in the soil samples from the waste removal pools compared with the samples from the unpolluted sites. We also found that the elemental composition of M. astracanicum has generally been increased by the activity of the tungsten mine, and there were significant correlations between the elemental contents of the soil samples and plant parts, except for Mo and Cr. The high level of many elements in the soil samples indicates the presence of contamination related to tungsten-mining activity on Uludağ Mountain. Assessing the elemental contents of M. astracanicum, we can suggest this species as a candidate for phytoremediation purposes of W-contaminated sites due to its high W-accumulation capacity.

The conversion of CO₂ into useful raw materials for fuels and chemicals by solar energy is described using a plasmonic photocatalyst comprised of Ag supported on Ag₂SO₃ (Ag/Ag₂SO₃) fabricated by a facile solid-state ion-exchange method and subsequent reduction with hydrazine hydrate. The optimum molar ratio of Ag⁰/Ag⁺ was 5 %. Visible light irradiation (>400 nm) of the Ag/Ag₂SO₃ powder in the presence of CO₂ and water vapor led to the formation of CH₄ and CO with a quantum yield of 0.126 %, and an energy returned on energy invested of 0.156 %. The Ag/Ag₂SO₃ retained high catalytic activity after ten successive experimental cycles. The catalysts were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy with energy-dispersive X-ray analysis, UV/Vis absorption spectroscopy, and Brunauer-Emmett-Teller analyses, as well as photocurrent action spectroscopy. It is proposed that the photocatalytic activity of the catalysts is initiated by energy conversion from incident photons to localized surface plasmon resonance oscillations of silver nanoparticles. This plasmonic energy is transferred to the Ag₂SO₃ by direct electron transfer and/or resonant energy transfer, causing the separation of photogenerated electron/hole pairs.

The Waste Framework Directive 2000/98 (WFD) contains specific requirements to define end-of-waste criteria (EWC). The main goal of EWC is to remove and eliminate the administrative loads of waste legislation for safe and high-quality waste materials, thereby facilitating and assisting recycling. The target is to produce effective with high quality of recyclables materials, promoting product standardization and quality and safety assurance, and improving harmonization and legal certainty in the recyclable material markets. At the same time, those objectives aim to develop a plan in order to improve the development and wider use of environmental technologies, which reduce pressure on environment and at the same time address the three dimensions of the Lisbon strategy: growth, jobs and environment. This paper presents the importance of EWC, and the approach of setting EWC as EWC affect several management systems as well as sustainable and clean technologies.

The Shaggy Ink Cap (Coprinus comatus), which is a common in wild in northern hemisphere was examined in field for potential to be used as possible bio-extractor of Hg from polluted grounds but also as possible bioindicator of urban soils (roadside, barren lands, lawns) pollution with Hg. The contents of Hg in caps and stipes of C. comatus from the grounds examined in this study correlated positively with the levels of soil contamination. Analysis of sets of data available worldwide on Hg in C. comatus and soils beneath-fruiting bodies showed on a positive correlation between degree of soil and mushroom contamination. Hence, C. comatus could be considered as a sensitive species and with bioindication and bioremediation potency for soils polluted with Hg in further studies. Young-fruiting bodies of C. comatus are edible and considered excellent if consumed soon after pick-up. Eating them when foraged from the urban places can provide to a consumer Hg at relatively high dose, while unresolved question is absorption rate of Hg compounds contained in ingested mushroom meal.

Portable photocatalytic air cleaners were investigated in 24 and 48 m³ emission test chambers with regard to efficiency and by-product generation. For this purpose, formaldehyde, decane, 1,2-dichlorobenzene, toluene, α-pinene and heptanal were doped at sub-ppm concentration levels into the chambers individually and in mixtures. By way of specified test protocols, efficiencies could be distinguished but were strongly dependant on the choice of test compounds, especially on whether single or multi compound dosing was used, and on long-term effects. Initial clean air delivery rates (CADRs) up to 137 m³/h were measured. Typical by-products were found in significant concentrations. The main ones were formaldehyde up to 50 ppb (62 μg/m³) and acetone up to 80 ppb (190 μg/m³). Other aldehydes were also found, but at smaller levels. The detection of chloroacetone, a strong irritating compound, at concentrations up to 15 ppb (57 μg/m³) strengthens the importance of such investigations especially in cases were chloro-organic compounds are involved.

The concentration of TBBPA in dust samples from automobiles (n = 14), computer laboratories (n = 8), homes (n = 7), and offices (n = 7), and, also, PBDE concentrations in the indoor dust of 19 personal and previously owned automobiles in Durban, South Africa, were determined. Gas chromatography coupled with mass spectrometry was applied for the separation, identification, and quantitation of TBBPA and PBDEs. The median concentrations of TBBPA were 1156, 269, 120, and 492 ng g⁻¹ in automobiles, computer laboratories, homes, and offices, respectively. The ∑ ₙ ₌ ₈ PBDE in 19 automobile samples ranged from 573 to 11,833 ng g⁻¹. BDE-209 accounted for approximately 42 % of ∑ ₙ ₌ ₈ PBDE in the samples. Household characteristics influenced the distribution of TBBPA in the various microenvironments. By assuming an average dust ingestion rate, and a median TBBPA concentration, the ∑DED (in ng kg⁻¹ bw day⁻¹) of TBBPA is 0.08, 0.08, and 0.60, for an adult, teenager, and toddler, respectively. These doses are similar to dust ingestion intakes reported for Asian countries where there is a high demand for TBBPA as a flame retardant. Similarly, automobiles provide ample opportunity for human exposure to PBDEs via dust ingestion, particularly for toddlers and occupationally exposed adults.