A directional passive air sampler for monitoring polycyclic aromatic hydrocarbons (PAHs) in air mass

A passive air sampler was developed for collecting polycyclic aromatic hydrocarbons (PAHs) in air mass from various directions. The airflow velocity within the sampler was assessed for its responses to ambient wind speed and direction. The sampler was examined for trapped particles, evaluated quantitatively for influence of airflow velocity and temperature on PAH uptake, examined for PAH uptake kinetics, calibrated against active sampling, and finally tested in the field. The airflow volume passing the sampler was linearly proportional to ambient wind speed and sensitive to wind direction. The uptake rate for an individual PAH was a function of airflow velocity, temperature and the octanol-air partitioning coefficient of the PAH. For all PAHs with more than two rings, the passive sampler operated in a linear uptake phase for three weeks. Different PAH concentrations were obtained in air masses from different directions in the field test.     

Analysis of Environmental and Socio-economic Determinants Affecting Population Longevity Level at County Level in China

INTRODUCTIONIn recent thirty years, due to the decreasing fertility andincreasing life expectancy, China's population is aging ata very rapid pace and the elderly population size is keepingon growing. During the dramatic aging progress, the oldestold group in China is catching our eyes. More and moreold people of China are becoming the oldest old. Theextremely old population (aged 80 and above) is increasingat 5.1% annually, while the old population above 65 isincreasing at 2.9%, and the…     

Recovery of heavy metals from electroplating sludge and stainless steel pickle waste liquid by ammonia leaching method

１　ＩｎｔｒｏｄｕｃｔｉｏｎＥｌｅｃｔｒｏｐｌａｔｉｎｇｓｌｕｄｇｅ，ｃｏｎｔａｉｎｉｎｇＣｕ，Ｎｉ，Ｚｎ，Ｃｒ，Ｆｅ，ｅｔｃ．，ｉｓｈａｒｍｆｕｌｗａｓｔｅｍａｔｅｒｉａｌｐｒｏｄｕｃｅｄｂｙｇａｌｖａｎｉｚａｔｉｏｎｉｎｄｕｓｔｒｙ．Ｔｈｅｒｅｉｓｓｔｉｌｌｎｏｅｆｆｅｃｔｉｖｅｍｅｔｈｏｄｔｏｒｅｃｏｖｅｒｒｅｓｏｕｒｃｅａｎｄｃｏｎｔｒｏｌｐｏｌｌｕｔｉｏｎｂｏｔｈａｔｈｏｍｅａｎｄａｂｒｏａｄ．Ｔｈｅｍｅｔａｌｓｄｉｓｃａｒｄｅｄｂｙｇａｌｖａｎｉｚａｔｉｏｎｉｎｄｕｓｔｒｙａｍｏｕｎ…     

Electrochemical study of sulfide solution in the presence of surfactants

ｌｅｃｔｒｏｃｈｅｍｉｃａｌｓｔｕｄｙｏｆｓｕｌｆｉｄｅｓｏｌｕｔｉｏｎｉｎｔｈｅｐｒｅｓｅｎｃｅｏｆｓｕｒｆａｃｔａｎｔｓＹｉＱｉｎｇｆｅｎｇＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｃａｌＥｎｇｉｎｅｒｉｎｇ，ＸｉａｎｇｔａｎＰｏｌｙｔｅｃｈｎｉｃＵ...     

Sulfur cycle as an electron mediator between carbon and nitrate in a constructed wetland microcosm

• Fe(III) accepted the most electrons from organics, followed by NO₃^‒, SO₄^2‒, and O₂. • The electrons accepted by SO₄^2‒ could be stored in the solid AVS, FeS₂-S, and S⁰. • The autotrophic denitrification driven by solid S had two-phase characteristics. • A conceptual model involving electron acceptance, storage, and donation was built. • S cycle transferred electrons between organics and NO₃^‒ with an efficiency of 15%. A constructed wetland microcosm was employed to investigate the sulfur cycle-mediated electron transfer between carbon and nitrate. Sulfate accepted electrons from organics at the average rate of 0.84 mol/(m³·d) through sulfate reduction, which accounted for 20.0% of the electron input rate. The remainder of the electrons derived from organics were accepted by dissolved oxygen (2.6%), nitrate (26.8%), and iron(III) (39.9%). The sulfide produced from sulfate reduction was transformed into acid-volatile sulfide, pyrite, and elemental sulfur, which were deposited in the substratum, storing electrons in the microcosm at the average rate of 0.52 mol/(m³·d). In the presence of nitrate, the acid-volatile and elemental sulfur were oxidized to sulfate, donating electrons at the average rate of 0.14 mol/(m³·d) and driving autotrophic denitrification at the average rate of 0.30 g N/(m³·d). The overall electron transfer efficiency of the sulfur cycle for autotrophic denitrification was 15.3%. A mass balance assessment indicated that approximately 50% of the input sulfur was discharged from the microcosm, and the remainder was removed through deposition (49%) and plant uptake (1%). Dominant sulfate-reducing (i.e., Desulfovirga, Desulforhopalus, Desulfatitalea, and Desulfatirhabdium) and sulfur-oxidizing bacteria (i.e., Thiohalobacter, Thiobacillus, Sulfuritalea, and Sulfurisoma), which jointly fulfilled a sustainable sulfur cycle, were identified. These results improved understanding of electron transfers among carbon, nitrogen, and sulfur cycles in constructed wetlands, and are of engineering significance.     

Full-scale application and performance of a new multi-self-reflow decentralized Wastewater treatment device: Impact of hydraulic and pollutant loads

Decentralized treatment of wastewater in rural areas usually has several challenges, which include large fluctuations in pollutant concentration and water quantity, complicated operation and maintenance of conventional biochemical treatment equipment, resulting in poor stability and a low compliance rate of the wastewater treatment process. In order to solve the above problems, a new integration reactor is designed, which uses gravity and aeration tail gas self-reflux technology to realize the r...     

Mesoporous carbon nanomaterials induced pulmonary surfactant inhibition, cytotoxicity, inflammation and lung fibrosis

Environmental exposure and health risk upon engineered nanomaterials are increasingly concerned. The family of mesoporous carbon nanomaterials(MCNs) is a rising star in nanotechnology for multidisciplinary research with versatile applications in electronics,energy and gas storage, and biomedicine. Meanwhile, there is mounting concern on their environmental health risks due to the growing production and usage of MCNs. The lung is the primary site for particle invasion under environmental exposure to nanomaterials. Here, we studied the comprehensive toxicological profile of MCNs in the lung under the scenario of moderate environmental exposure. It was found that at a low concentration of 10 μg/mL MCNs induced biophysical inhibition of natural pulmonary surfactant. Moreover, MCNs at similar concentrations reduced viability of J774 A.1 macrophages and lung epithelial A549 cells.Incubating with nature pulmonary surfactant effectively reduced the cytotoxicity of MCNs.Regarding the pro-inflammatory responses, MCNs activated macrophages in vitro, and stimulated lung inflammation in mice after inhalation exposure, associated with lung fibrosis.Moreover, we found that the size of MCNs played a significant role in regulating cytotoxicity and pro-inflammatory potential of this nanomaterial. In general, larger MCNs induced more pronounced cytotoxic and pro-inflammatory effects than their smaller counterparts. Our results provided valuable information on the toxicological profile and environmental health risks of MCNs, and suggested that fine-tuning the size of MCNs could be a practical precautionary design strategy to increase safety and biocompatibility of this nanomaterial.     

Photocatalytic degradation of carbofuran in TiO2 aqueous solution：Kinetics using design of experiments and mechanism by HPLC/MS/MS

The photocatalytic degradation kinetics of carbofuran was optimized by central composite design based on response surface methodology for the first time. Three variables, TiO2 concentration, initial pH value and the concentration of carbofuran, were selected to determine the dependence of degradation efficiencies on independent variables. Response surface methodology modeling results indicated that the degradation efficiency of carbofuran was highly affected by the initial pH value and the concentration of carbofuran. Then nine degradation intermediates were detected by HPLC/MS/MS. The Frontier Electron Densities of carbofuran were calculated to predict the active sites on carbofuran attacked by hydroxyl radicals and photoholes. Point charges were used to elucidate the chemisorption pattern on TiO2 catalysts during the photocatalytic process. By combining the experimental results and calculation data, the photocatalytic degradation pathways of carbofuran were proposed, including the addition of hydroxyl radicals and the cleavage of the carbamate side chain.