In this study, the efficiency of Moringa stenopetala seed extract was compared with alum and M. stenopetala-alum hybrid coagulant to remove Direct Red 23 azo dye from textile wastewater. The effects of parameters such as pH, coagulant dose, type of salt used for the extraction of coagulant and initial dye concentration on dye removal efficiency were investigated. Moreover, the existing functional groups on the structure of M. stenopetala coagulant (MSC) were determined by Fourier transform infrared spectroscopy, and the morphology of sludge produced by MSC, alum, and hybrid coagulant was characterized by scanning electron microscopy. Ninhydrin test was also used to determine the quantity of primary amines in the MSC and Moringa oleifera coagulant (MOC). According to the results, with increasing the coagulant dose and decreasing the initial dye concentration, dye removal efficiency has increased. The maximum dye removal of 98.5, 98.2, and 98.3 % were obtained by using 240, 120, and 80 mg/L MSC, alum and hybrid coagulant at pH 7, respectively. The results also showed MSC was much more effective than MOC for dye removal. The volume of sludge produced by MSC was one fourth and half of those produced by alum and hybrid coagulant, respectively. Based on the results, hybrid coagulant was the most efficient coagulant for direct dye removal from colored wastewater.

Pharmaceuticals in water are commonly found and are not efficiently removed by current treatment processes. Degradation of antiepileptic drug carbamazepine (CBZ) by UV/chlorine advanced oxidation process was systematically investigated in this study. The results showed that the UV/chlorine process was more effective at degrading CBZ than either UV or chlorination alone. The CBZ degradation followed pseudo-first order reaction kinetics, and the degradation rate constants (kₒbₛ) were affected by the chlorine dose, solution pH, and natural organic matter concentration to different degrees. Degradation of CBZ greatly increased with increasing chlorine dose and decreasing solution pH during the UV/chlorine process. Additionally, the presence of natural organic matter in the solution inhibited the degradation of CBZ. UV photolysis, chlorination, and reactive species (hydroxyl radical •OH and chlorine atoms •Cl) were identified as responsible for CBZ degradation in the UV/chlorine process. Finally, a degradation pathway for CBZ in the UV/chlorine process was proposed and the formation potentials of carbonaceous and nitrogenous disinfection by-products were evaluated. Enhanced formation of trichloroacetic acid, dichloroacetonitrile, and trichloronitromethane precursors should be considered when applying UV/chlorine advanced oxidation process to drinking water.

It has been known that outdoor temperature influences seasonal fluctuation of blood pressure and cholesterol levels, but the role of indoor temperature has been less studied. Therefore, the aim of the present study was to examine the associations between indoor temperature and biomarkers in a countrywide and population-based setting. Data was retrieved from the English Longitudinal Study of Ageing, 2012–2013. Information on demographics, room temperature and a series of biomarkers measured in the blood and lung was obtained at household interviews. t test, chi-square test and a generalized linear model were performed cross-sectionally. Of 7997 older adults with the valid indoor temperature measurements, there were 1301 (16.3 %) people who resided in cold homes (<18 °C). Age was inversely associated with people who resided in cold homes or who tended not to have blood pressure check-up. Those who resided in cold homes had higher blood pressure readings, worse handgrip, lower vitamin D levels, higher cholesterol levels, higher insulin-like growth factor levels, higher haemoglobin levels, lower level of white blood cell count and worse lung conditions. One in six older adults aged 50 and above in England resided in cold homes and had poor biomarker values. For the future research direction, studies with a longitudinal approach to systematically monitor indoor temperature, biomarkers and health and wellbeing would be suggested. From the practice and policy perspectives, increasing health knowledge on the adverse effect of low indoor temperature on risks of cardiac and respiratory conditions, affording to the heating and re-designing of residential buildings to keep warm by using efficient energy, should be kept as priority.

Some widely prescribed drugs are sparsely metabolized and end up in the environment. They can thus be a focal point of ecotoxicity, either themselves or their environmental transformation products. In this context, we present a study concerning furosemide, a diuretic, which is mainly excreted unchanged. We investigated its biotransformation by two environmental fungi, Aspergillus candidus and Cunninghamella echinulata. The assessment of its ecotoxicity and that of its metabolites was performed using the Microtox test (ISO 11348-3) with Vibrio fischeri marine bacteria. Three metabolites were identified by means of HPLC-MS and ¹H/¹³C NMR analysis: saluamine, a known pyridinium derivative and a hydroxy-ketone product, the latter having not been previously described. This hydroxy-ketone metabolite was obtained with C. echinulata and was further slowly transformed into saluamine. The pyridinium derivative was obtained in low amount with both strains. Metabolites, excepting saluamine, exhibited higher toxicity than furosemide, being the pyridinium structure the one with the most elevated toxic levels (EC₅₀ = 34.40 ± 6.84 mg L⁻¹). These results demonstrate that biotic environmental transformation products may present a higher environmental risk than the starting drug, hence highlighting the importance of boosting toxicological risk assessment related to the impact of pharmaceutical waste.

The main objective of this work concerns the coupling of biomass gasification reaction and CO₂ sorption. The study shows the feasibility to promote biomass steam gasification in a dense fluidized bed reactor with CO₂ sorption to enhance tar removal and hydrogen production. It also proves the efficiency of CaO-Ca₁₂Al₁₄O₃₃/olivine bi-functional materials to reduce heavy tar production. Experiments have been carried out in a fluidized bed gasifier using steam as the fluidizing medium to improve hydrogen production. Bed materials consisting of CaO-based oxide for CO₂ sorption (CaO-Ca₁₂Al₁₄O₃₃) deposited on olivine for tar reduction were synthesized, their structural and textural properties were characterized by Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), and temperature-programmed reduction (TPR) methods, and the determination of their sorption capacity and stability analyzed by thermogravimetric analysis (TGA). It appears that this CaO-Ca₁₂Al₁₄O₃₃/olivine sorbent/catalyst presents a good CO₂ sorption stability (for seven cycles of carbonation/decarbonation). Compared to olivine and Fe/olivine in a fixed bed reactor for steam reforming of toluene chosen as tar model compound, it shows a better hydrogen production rate and a lower CO₂ selectivity due to its sorption on the CaO phase. In the biomass steam gasification, the use of CaO-Ca₁₂Al₁₄O₃₃/olivine as bed material at 700 °C leads to a higher H₂ production than olivine at 800 °C thanks to CO₂ sorption. Similar tar concentration and lighter tar production (analyzed by HPLC/UV) are observed. At 700 °C, sorbent addition allows to halve tar content and to eliminate the heaviest tars.

The effect of irradiation with visible light-emitting diode (LED) light on the efficiency of Fenton oxidation is investigated using phenol as the target compound (100 mg/L). The H₂O₂ dose and temperature are tested as operating variables with the aim of minimizing consumption of the reagents. At 50 °C, 10 mg/L Fe²⁺, and 60 % of the stoichiometric H₂O₂ amount, phenol was completely oxidized into CO₂, H₂O, and short chain organic acids, with oxalic acid completely degraded. Up to 95 % mineralization was achieved. This high efficiency can be attributed to the effect of LED radiation on the quinones/Fe²⁺/Fe³⁺/H₂O₂ cycle, which significantly increases the reaction rate, as well as on the photodecomposition of the iron complexes formed along the oxidation process, which also enhanced mineralization.

The ingestion of plastic by seabirds has been used as an indicator of pollution in the marine environment. On Kaua‘i, HI, USA, 50.0 % of Newell’s (Puffinus newelli) and 76.9 % of wedge-tailed shearwater (Ardenna pacifica) fledglings necropsied during 2007–2014 contained plastic items in their digestive tract, while 42.1 % of adult wedge-tailed shearwaters had ingested plastic. For both species, the frequency of plastic ingestion has increased since the 1980s with some evidence that the mass and the number of items ingested per bird have also increased. The color of plastic ingested by the shearwaters was assessed relative to beach-washed plastics by using Jaccard’s index (where J = 1 complete similarity). The color (J = 0.65–0.68) of items ingested by both species, and the type ingested by wedge-tailed shearwaters (J = 0.85–0.87), overlapped with plastic available in the local environment indicating moderate selection for plastic color and type. This study has shown that the Hawaiian populations of shearwaters, like many seabird species, provide useful but worrying insights into plastic pollution and the health of our oceans.

Heavy metals were measured by flame atomic absorption in male hair from residents in urban and rural areas in Chongqing. The median values of the Cd, Cu, Ni, Pb and Zn were 2.90, 23.9, 9.31, 39.3 and 203 μg/g in urban areas and 0.84, 13.4, 5.56, 14.5 and 169 μg/g in rural area, respectively. The levels of Cd, Ni and Pb both in urban and rural areas lie at the high end of the worldwide figures. The differences in heavy metal distribution pattern indicated that there were more sources of Cd and Pb in urban areas. The levels of Cd were increasing along with the growth of age except for the aged people in urban areas, and no significant relationship was observed between the levels of the heavy metal and the age. It is noticed that the hair of smokers exhibited more heavy metal levels than that of non-smokers both in urban and rural areas. In addition, the hair metal levels of the smokers and non-smokers in urban areas were significantly higher than those in rural area, respectively. Significant pairwise correlations (p < 0.01) were observed among Cd, Cu, Ni and Pb in rural area and only between Cu and Ni and between Pb and Ni in urban areas, indicating the elements in these two areas might originate from different sources. The elevated levels of Cd, Pb and Ni implied that the residents both in urban and rural areas might be at high risk of toxic metal exposure, especially for the children.

Low-cost catalysts with high activity and stability toward producing strongly oxidative species are extremely desirable, but their development still remains a big challenge. Here, we report a novel strategy for the synthesis of a magnetic CoFe₂O₄/C₃N₄ hybrid via a simple self-assembly method. The CoFe₂O₄/C₃N₄ was utilized as a photo-Fenton-like catalyst for degradation of organic dyes in the presence of H₂O₂ under natural indoor light irradiation, a green and energy-saving approach for environmental cleaning. It was found the CoFe₂O₄/C₃N₄ hybrid with a CoFe₂O₄: g-C₃N₄ mass ratio of 2:1 can completely degrade Rhodamine B nearly 100 % within 210 min under room-light irradiation. The effects of the amount of H₂O₂ (0.01–0.5 M), initial dye concentration (5–20 mg/L), solution pH (3.08-10.09), fulvic acid concentration (5–50 mg/L), different dyes and catalyst stability on the organic dye degradation were investigated. The introduction of CoFe₂O₄ on g-C₃N₄ produced an enhanced separation efficiency of photogenerated electron − hole pairs by a Z-scheme mechanism between the interfaces of g-C₃N₄ and CoFe₂O₄, leading to an excellent activity as compared with either g-C₃N₄ or CoFe₂O₄ and their mixture. This study demonstrates an efficient way to construct the low-cost magnetic CoFe₂O₄/C₃N₄ heterojunction as a typical Z-scheme system in environmental remediation.

Tetracycline (TC) in aqueous environment could be reductively degraded by using a hydrogen-based membrane biofilm reactor (H₂-MBfR) under denitrifying conditions as it provides an appropriate environment for the antibiotic-degrading bacteria in biofilm communities. This study evaluates the performance of H₂-MBfR for simultaneous removal of nitrate and TC, formation of degradation products of TC, and community analysis of the biofilm grown on the gas-permeable hollow fiber membranes. Hence, a H₂-MBfR receiving approximately 20 mg N/l nitrate and 0.5 mg/l TC was operated under different H₂ pressures, hydraulic retention times (HRTs), and influent TC concentrations in order to provide various nitrate and TC loadings. The results showed that H₂-MBfR accomplished successfully the degradation of TC, and it reached TC removal of 80–95 % at 10 h of HRT and 6 psi (0.41 atm) of H₂ gas pressure. TC degradation took placed at increased HRT and H₂ pressures while nitrate was the preferred electron acceptor for most of the electrons generated from H₂ oxidation used for denitrification. The transformation products of TC were found at part per billion levels through all the experiments, and the concentrations decreased with the increasing HRT regardless of H₂ pressure. Analyses from clone library showed that the microbial diversity at the optimal conditions was higher than that at the other periods. The dominant species were revealed to be Betaproteobacteria, Acidovorax caeni, and Alicycliphilus denitrificans.