Elevated CO2 aggravated polystyrene microplastics effects on the rice-soil system under field conditions.

Polystyrene microplastics (PS) are decomposed very slowly due to their recalcitrance and inevitably interact with the changing climate. How the interaction between PS and increasing CO2 concentration affects the plant-soil system is rarely investigated. Here, a free-air CO2 enrichment system in farm fields was used to study the impacts of PS added to soil at 10 mg kg-1 on rice and soil bacterial communities at different CO2 levels (ambient∼390 ppm and elevated∼590 ppm). Results showed that single PS interfered with Fe, Mn and Zn uptake of rice, and it increased the abundances of bacteria taxa assigned to N turnover and urease activities, leading to altered soil N transformation and availability. Elevated CO2 alone enhanced rice photosynthesis, decreased the abundances of nitrogen-fixation bacteria, and induced co-occurrence patterns between bacteria simplified and decentralized. Combined PS and elevated CO2 significantly decreased rice stomatal conductance and transpiration rate by 56.70% and 29.46%, respectively, and further inhibited elements uptake. Besides, combined exposure significantly disturbed bacterial amino acid metabolism, and stimulated the adaptative responses of resistant bacteria. Overall, this study revealed that increasing CO2 concentrations may exacerbate the impacts of PS on rice performance and soil bacterial communities, providing new insights into the interaction between microplastics and climate change.

The contribution of lignocellulosic constituents to Cr(VI) reduction capacity of biochar-supported zerovalent iron.

Biochars (BCs) derived from individual and blending lignocellulosic constituents were prepared to harbor zerovalent iron (ZVI/BC) in an effort to discriminate significance of each constituent or combination in ZVI/BC for Cr(VI) removal. BCs and ZVI/BC were characterized by TGA/GSC, XRD, Raman and BET analyses. Cellulose (BCC) and hemicellulose (BCH)-derived BCs has greater C content, H/C ratio, surface area and mass loss than BCs derived from lignin or lignin-containing biopolymer blends (BCLX). As per sorption and XPS analysis, ZVI/BC demonstrated greater Cr(VI) removal capacity than respective BCs, in which reduction accounted for over 77% Cr(VI) detoxification. Cr(VI) reduction by ZVI harbored by BCC and BCH was 19.72-16.54 g kg-1, compared to 5.97-4.26 g kg-1 for BCLX. ZVI/BC prepared by three-biopolymer blends with (12.63 g kg-1) or without (12.32 g kg-1) mineral approximated pinewood-BC (BCP) (13.02 g kg-1) for Cr(VI) reduction, suggesting minerals are not important constituent. Tafel analysis showed BCC and BCH, with lower ID/IG ratio owing to greater graphitization, were more conducible to transfer electron of ZVI in Cr(VI) reduction than BCLX. Thus, cellulose, hemicellulose and lignin can offer a good prediction of property of natural biomass, in which BCC and BCH favor electron transfer of ZVI but BCL is not electroactive.

Ultra-thin atom layer deposited alumina film enables the precise lifetime control of fully biodegradable electronic devices.

Atomic layer deposited (ALD) ultra-thin alumina film is proposed to control the operational lifetimes of fully biodegradable (FB-) surface sensitive surface acoustic wave (SAW) devices. SAW devices encapsulated with conventional thick organic materials fail to function effectively, while devices with an ultra-thin alumina encapsulation layer (AEL) function normally with high performance. After being subjected to degradation in water, a FB-SAW device with no AEL starts to degrade immediately and fails within 8 h, due to dissolution of the tungsten electrode and piezoelectric material (ZnO). The coating of an ultra-thin AEL on the surfaces prevents SAW devices from undergoing degradation in water and enables SAW devices to perform normally before the AEL is dissolved. The stable operation lifetimes of SAW devices are linearly dependent on the AEL thickness, thus allowing for the design of devices with precisely controlled operational lifetimes and degradation times. The results show that all the materials used could be degraded; also, in vitro cytotoxicity tests indicate that the encapsulated FB-SAW devices are biocompatible, and cells can adhere and proliferate on them normally, demonstrating great potential for broader biodegradable electronic device applications.

Disolved organic matter (DOM) removal from bio-treated coking wastewate using a new polymeric adsorbent modified with dimethylamino groups.

In the current study a new recyclable aminated hyper-cross-linked polymeric adsorbent (A-HPA) was prepared for effective removal of DOM from BTCW. Possibly benefited from its unique structure of polystyrene matrix, sufficient aminated groups and high specific surface area, A-HPA could remove DOM from BTCW through the synergetic effect of π-π interactions, acid-base interactions and micropore filling, and exhibited the highest removal efficiency than the other adsorbents. Moreover, the exhausted A-HPA was amenable to effective regeneration by using acid and alkaline solution, allowing for repeated use with a constant removal efficiency. Field application of continuous 3-year fixed-bed runs demonstrated that A-HPA is capable of effectively removing DOM from BTCW with no significant capacity loss, and the treated effluent can be partially used as recycled water in production. All the above results demonstrated that A-HPA adsoption could serve as a good choice for the advanced treatment of bio-treated sewage effluent.

Transient Resistive Switching Devices Made from Egg Albumen Dielectrics and Dissolvable Electrodes.

Egg albumen as the dielectric, and dissolvable Mg and W as the top and bottom electrodes are used to fabricate water-soluble memristors. 4 × 4 cross-bar configuration memristor devices show a bipolar resistive switching behavior with a high to low resistance ratio in the range of 1 × 10(2) to 1 × 10(4), higher than most other biomaterial-based memristors, and a retention time over 10(4) s without any sign of deterioration, demonstrating its high stability and reliability. Metal filaments accompanied by hopping conduction are believed to be responsible for the switching behavior of the memory devices. The Mg and W electrodes, and albumen film all can be dissolved in water within 72 h, showing their transient characteristics. This work demonstrates a new way to fabricate biocompatible and dissolvable electronic devices by using cheap, abundant, and 100% natural materials for the forthcoming bioelectronics era as well as for environmental sensors when the Internet of things takes off.

Determination of n-alkanes contamination in soil samples by micro gas chromatography functionalized by multi-walled carbon nanotubes.

A new method for separation of 11 n-alkanes: octane, o-nonane, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane, n-pentdecne, n-hexadecath, heptadecane, n-octadecane in soil samples was developed. Kuderna-Danish (K.D.) concentrator enrichment prior to ultrasonic extraction and the silicone chromatography column purification and with gas chromatography flame ionization detection (GC-FID) could be used for n-alkanes determination. The micro channels of open tubular column were fabricated onto a silicon wafer to replace the quartz capillary chromatographic column. The column structure and analysis parameters that affected the column separation were investigated and optimized. Under optimal conditions, the extract reagent was centrifuged and collected. A silicone chromatography column and a K.D. concentrator were used for further clean-up and enrichment. Using this method, the limits of detection (LOD) and limits of quantification (LOQ) were obtained in the range of 0.03-0.15 and 0.1-0.5 mg kg(-1) in soil samples, respectively. The relative standard deviation (RSD) was under 12%. The optimized procedure that presented good analytical performance (with recoveries ranging from 56.5% to 89.2%), was successfully applied to determine n-alkane content in farmland soil samples adjacent to a highway. The results showed that the MWCNTs-functionalized column is capable of separating the alkane contaminations with high resolution in about 3 min, which is much shorter than that of GC-MS and other conventional analytical methods, demonstrating its great potential for rapid analysis.

High resolution skin-like sensor capable of sensing and visualizing various sensations and three dimensional shape.

Human skin contains multiple receptors, and is able to sense various stimuli such as temperature, pressure, force, corrosion etc, and to feel pains and the shape of objects. The development of skin-like sensors capable of sensing these stimuli is of great importance for various applications such as robots, touch detection, temperature monitoring, strain gauges etc. Great efforts have been made to develop high performance skin-like sensors, but they are far from perfect and much inferior to human skin as most of them can only sense one stimulus with focus on pressure (strain) or temperature, and are unable to visualize sensations and shape of objects. Here we report a skin-like sensor which imitates real skin with multiple receptors, and a new concept of pain sensation. The sensor with very high resolution not only has multiple sensations for touch, pressure, temperature, but also is able to sense various pains and reproduce the three dimensional shape of an object in contact.