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Abstract: This study was to investigate effects of digested chicken manure filtrate (DCMF) supplementation on cells growth and lipid production in heterotrophic culture Chlorella protothecoides. Higher nitrogen DCMF favored cells growth but retarded lipid accumulation and vice versa for lower nitrogen DCMF. Accordingly, a two-step DCMF supplementation method of feeding higher nitrogen DCMF at cell growth phase and lower one at the stationary phase was adopted to enhance lipid production. Moreover, based on the phenomenon that feeding glucose at the stationary phase can further enhance lipid production, the strategies of DCMF supplementation coupled with adenosine triphosphate (ATP) regeneration from glucose feeding were developed. As a result, total lipid yield of 5.28g/L was achieved after 200h cultivation, increased by 74.8% and 21.1% respectively, compared to the control and the one without glucose addition. It was suggested that application of DCMF combined with glucose feeding as being feasible for lipid overproduction. [Copyright &y& Elsevier]

Abstract: Effects of two acidophiles on metals recovery in printed circuit boards (PCBs) were investigated. Based on the phenomenon that PCBs addition times and amounts adversely inhibited bacterial growth and thus lowered metals bioleaching capacity, novel strategies of multiple PCBs additions (4g/l at 48h, 6g/l at 96h and 8g/l at 144h) were developed in separated culture of Acidithiobacillus thiooxidans and Acidithiobacillus ferrooxidans. As a result, percentages of Cu, Ni, Zn and Pb leached by A. thiooxidans were 78, 73, 75 and 71%, and corresponding values were 80, 73, 76 and 72% by A. ferrooxidans after 240h cultivation. Further applying the strategies to mixed culture of two acidophiles, extraction percentages of Cu, Ni, Zn and Pb were 94, 89, 90 and 86%, respectively. Moreover, increased redox potential and lowered pH in filtrate were observed, suggesting the mechanism involved in enhancing metals recovery in mixed culture. [ABSTRACT FROM AUTHOR]

Abstract: Uniform rod-like Sr2−x Dy x CeO4 nano-phosphors with orthorhombic structure were prepared via a hydrothermal method, in the absence of any surfactant or template. The structure, morphology, particle size, and tunable luminescence properties of the samples were investigated by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), UV–vis absorption and photoluminescence spectrum, respectively. The as-prepared phase-pure Sr2−x Dy x CeO4 nanorods had the length of 50–150nm and width of 80nm. The Dy3+ ions emission in Sr2−x Dy x CeO4 could be effectively excited through the energy absorbed by Sr2CeO4 host. The tunable photoluminescence has been observed from Sr2CeO4 doped with Dy3+ ions. Emission color of Sr2−x Dy x CeO4 phosphor could be regulated from blue-white to white to yellow by adjusting the Dy3+ doping content in Sr2CeO4 host, which originated from energy transfer between two different emission centers. [Copyright &y& Elsevier]

Modification of the environmentally-friendly non-metallic polymer semiconductor graphite carbon nitride (g-C 3 N 4) has been a research hotspot in the field of photocatalysis, and is regarded as a pivotal solution to energy problems. Nevertheless, the bottlenecks of a slow carrier separation rate, limited visible light absorption and weak water reduction driving force have not been effectively solved due to uneven mass and heat transfers during high-temperature calcination; therefore, no carbon nitride photocatalysts with excellent properties can be provided. Recently, optimizing the modification with multiple methods has become an important research direction. To generate better photocatalysts, we propose a facile copolymerization strategy by combining doping and pore formation to inhibit the agglomeration and efficiently optimize the surface properties and external structure of the catalyst, thereby improving its photocatalytic performances. The amended g-C 3 N 4 produces a broadened visible-light response, a larger surface area, and reformative separate efficiency of charge carriers. Thus, the effectively-modified g-C 3 N 4 has enhanced H 2 production, which is 6.3-fold greater than that of pristine carbon nitride. [ABSTRACT FROM AUTHOR]

• A one-pot approach was developed to prepare carbon doped WO 3-x ultrathin nanosheets. • The sample exhibits excellent photocatalytic activity toward the aerobic oxidation of amines. • Possible mechanisms are proposed. It is an important chemical transformation for oxidation of amines to imines, on account of very important versatile applications of imines in organic synthesis. Here, we develop a convenient way to synthesize carbon doped WO 3−x ultrathin nanosheets via an acid-assisted one-pot process. The carbon doped WO 3−x ultrathin nanosheets exhibit excellent photocatalytic activity in the aerobic oxidation of amines to corresponding imines under visible light irradiation at room temperature. The high catalytic performance is attributed to remarkable visible light absorption ability and effective absorption of molecular oxygen and substrates. Rich oxygen-vacancies existing in the carbon doped WO 3-x ultrathin nanosheets may play an important role, because oxygen-vacancies not only change the band structure but also act as catalytic sites to activate molecular oxygen by photoproduct electrons to generate superoxide radicals. Both photoproduct holes and superoxide radicals play important role for the oxidation of amines. [ABSTRACT FROM AUTHOR]

Abstract Cost-effectively drying of sewage sludge is the prerequisite step for further disposal, such as landfilling, incineration and pyrolysis. A novel solar drying method was developed using a thin layer sandwich-like chamber. The drying rate was optimized by adjusting the operating variables such as the thickness of sludge bed, and solar radiation intensity. Lower height of sewage sludge bed facilitates the faster drying process in thin layer sandwich-like solar drying chamber. In this experiment, the most suitable thickness of sewage sludge layer was found to be 0.5 cm for quick drying (average drying rate 6.72 g/h) under the sunlight in sandwich-like dryer. The water content in sewage sludge was decreased from 79% to 5% in 11 h drying with thickness of 0.5 cm under the solar radiation intensity of 500 W/m2. It was observed that the solar radiation influenced the drying process significantly, the drying time was reduced from 18 h to 9 h, as the solar radiation was increased from 300 W/m2 to 700 W/m2, respectively. To identify the drying kinetics of raw sewage sludge inside the sandwich-like drying chamber, eight established drying kinetics models were tried and compared the suitability of the model based on the R2, sum of square error (SSE), chi-square value, and root mean square error. Among these models, Danish model was found applicable for sewage sludge drying in this newly designed thin layer sandwich-like dryer. Based on the results obtained for solar drying of sewage sludge in thin layer sandwich-like drying chamber, it could be proposed that thin layer solar dryer may be a good choice for fast drying of sewage sludge in a cost-effective way. Graphical abstract Image 1 Highlights • A novel solar sandwich-like chamber bed was modeled for thin layer drying. • The input solar radiation intensity was optimized for effective drying of sewage sludge. • The drying kinetics of sewage sludge inside dryer was established through Danish model. • Temperature and relative humidity of the simulated solar radiation was profiled. • The mechanism of water diffusivity from sludge was established. [ABSTRACT FROM AUTHOR]

Mass concentrations and chemical compositions of submicron particles (PM 1 ) collected during July 2015 to April 2016 in Changzhou, a city in the Yangtze River Delta region, were systematically investigated for the first time. Specifically, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was employed to characterize the water-soluble organic matter (WSOM). The average concentration of PM 1 was 63.6 μg m −3 , occupying ∼60% of co-collected PM 2.5 mass. Water soluble inorganic ions (WSIIs) was the most abundant component with secondary ions (SO 4 2− , NO 3 − and NH 4 + ) as the dominant species. Organic matter (OM) accounted for 21.6% of PM 1 , with approximately 80% was water-soluble. Trace metals could constitute up to 3.0% of PM 1 mass, and Fe, Al and Zn were the three most abundant ones. PAHs were predominated by ones with 5–6 rings, occupying over half of the PAHs mass; further analyses showed that fuel and coal combustion had significant contributions to PAHs. Positive matrix factorization of the WSOM data separated four factors: a traffic-related hydrocarbon-like OA (HOA), a local OA (LOA) likely associated with cooking and coal combustion emissions, etc., a secondary nitrogen-enriched OA (NOA) and an oxygenated OA (OOA). PCA analyses showed that crustal source was likely important for PM 1 too. Back trajectory results implied that both PM 1 and PM 2.5 were mainly derived from local/regional emissions. Our findings present results regarding the PM 1 chemistry and its relationship with the PM 2.5 in Changzhou, which are valuable for the government to make effective policies to reduce the aerosol pollution in and near the city. [ABSTRACT FROM AUTHOR]

Nickel cobalt sulfide (NiCo 2 S 4 ) nanosheets were successfully grown on porous graphitic carbon nitride (g-C 3 N 4 ) nanosheets (NiCo 2 S 4 NSs/P-g-C 3 N 4 ), which was employed as supercapacitor electrode materials. The NiCo 2 S 4 NSs/P-g-C 3 N 4 electrode shows specific capacity as high as 506 C g −1 at a current density of 1 A g −1 , outstanding rate capability and cycling stability (almost no attenuation after 1500 cycles at 3 A g −1 ), which can be attributed to the unique ‘sheets on sheets’ architectures providing short ion diffusion pathways, and good ion permeability. NiCo 2 S 4 NSs/P-g-C 3 N 4 was combined with activated carbon (AC) to construct NiCo 2 S 4 NSs/P-g-C 3 N 4 //AC asymmetric supercapacitor (ASC), which offers a specific energy of 16.7 W h kg −1 at a specific power of 200 W kg −1 , and high cycling performance (about 99% retention after 5000 continuous cycles). An ASC device could power a mini-fan for about 60 s, demonstrating that NiCo 2 S 4 NSs/P-g-C 3 N 4 is a potential electrode material for energy storage. [ABSTRACT FROM AUTHOR]

Abstract: Ultrathin Bi2MO6 (M=W, Mo) nanoplates were synthesized by a simple hydrothermal method. SEM, EDS and XRD were used to investigate the morphologies and compositions of the samples from BiONO3 nanoplates along with some nanoparticles, to precursory Bi2WO6 nanoplates and Bi2MoO6 nanoparticles, and to final Bi2MO6 nanoplates. The possible formation mechanism of products was proposed. The experimental results exhibited that Bi2MO6 nanoplates had stronger light adsorption in ultraviolet–visible range. Bi2MO6 nanoplates were useful host for rare earth ions, Eu3+was successfully doped in Bi2MO6 nanoplates and an energy efficiently transferred from Bi3+ to Eu3+, displaying intense red color under ultraviolet (UV) light excitation. The morphologies of products kept constant after doping. It is suggested that Bi2MO6:Eu nanoplates have promising application in fluorescent mark. [Copyright &y& Elsevier]

Abstract: Binary Fe2O3/SiO2-coated aluminum pigments were prepared by chemical liquid deposition method using tetraethyl silicate (TEOS) and FeCl3 as the precursors of SiO2 and Fe2O3, respectively. The chemical structure and the evolution mechanism of the binary Fe2O3/SiO2 coating layers were investigated by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, powder X-ray diffraction, and scanning electron microscopy techniques. The binary Fe2O3/SiO2 coating layers were anchored at aluminum flake surfaces via Sih name="sbnd" />Al and Feh name="sbnd" />Si bonds. The anticorrosive performance of the SiO2-coated aluminum flakes was significantly improved as compared with the naked aluminum flakes, indicating that SiO2 coating layers were densely and tightly formed on the surfaces of aluminum flakes. The pigmentary performances of the binary Fe2O3/SiO2-coated aluminum samples were analyzed by CIE, showing that yellow and red colored aluminum-based pigments were achieved by varying the Fe2O3 loading on SiO2-coated aluminum flake substrates. [Copyright &y& Elsevier]

• HCN fabricated by H 2 O 2 -assisted fast surface thermal processing. • HCN exhibits much higher photocatalytc activity than that of UCN. • The improvement of surface properties accelerates charge transfer and separation. Graphite carbon nitride (g-C 3 N 4) is a fascinating 2D photocatalyst, but preparing ultrathin g-C 3 N 4 with outstanding surface properties by a green and facile method is still a tremendous challenge. In this research, g-C 3 N 4 nanosheets were modified through H 2 O 2 -assisted rapid thermal surface treatment. The rapid decomposition of H 2 O 2 molecules on the surface greatly optimized the surface properties of the catalyst. Thus, the modified g-C 3 N 4 nanosheets had more interfacial active sites and broader visible light absorption and showed the largest hydrogen evolution rate of 894.9 μmol g−1 h−1. Photoluminescence and electron spin resonance (ESR) assays showed that the modified photocatalyst accelerated charge transfer and thereby attained higher photocatalytic H 2 generation efficiency. This research offers a new strategy to develop g-C 3 N 4 -based 2D photocatalysts for H 2 preparation. [ABSTRACT FROM AUTHOR]

Particulate toxic species, such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals may have significant health risks. This study investigated characteristics, sources and health risks of all three classes of toxic species in PM 2.5 (particles with aerodynamic diameter ≤2.5 μm) samples collected at an industrial area in Changzhou, a big city in the Yangtze Delta region of China. Fourteen heavy metals altogether constituted 2.87% of PM 2.5 mass, with Fe, Al and Zn as the major elements. Principal component analysis (PCA) suggested that heavy metals came from four sources: vehicles, industry, crustal dust, mixed coal combustion and industrial process. The daily average concentration of 18 PAHs was 235.29 ng/m3, accounting for 0.21% of PM 2.5 mass. The dominant PAHs were high molecular weight ones, contributing 73.5% to the total PAHs. Diagnostic analyses indicated that sources of PAHs included vehicle/coal combustion and petroleum emissions, wherein diesel emission played a more important role than gasoline emission. PCA showed that the largest contributor of PAHs was vehicle exhaust mixed with coal combustion, followed by three industry-related sources. Total concentration of 17 PCDD/Fs varied between 3.14 and 37.07 pg/m3, with an average of 14.58 pg/m3. The 10 PCDFs accounted for 70.5% of total concentration of 17 PCDD/Fs. Health risk assessments showed that the carcinogenic risk of heavy metals was acceptable, while risks from PAHs and PCDD/Fs cannot be ignored. Back trajectory analysis indicated that local/regional transported air masses from northern China was the major source areas of the toxic species. Image 10631 • Concentrations and sources of toxic species including heavy metals, PAHs and PCDD/Fs were determined. • Diagnostic ratio of PAHs revealed diesel emission contributes more than gasoline emission. • PAHs and PCDD/Fs are assessed to have high health risks to residents in this area. [ABSTRACT FROM AUTHOR]