The Remediation in Enzyme’s Activities in Plants: Tea Waste as a Modifier to Improve the Efficiency of Growth of Helianthus annuus in Contaminated Soil

The remediation in plant enzymatic activities in Cd-contaminated soil was monitored through tea waste. Tea is an extensively used beverage worldwide with the release of a high quantity of tea waste utilized in the growing condition of Helianthus annuus on Cd metal contaminated soil. The study was a plan for the natural environmental condition in the greenhouse. For this purpose, four sets of plants were cultivated in triplicate and marked as (i) control, (ii) Cd stress plants, (iii) dry tea waste and Cd stress, and (iv) fresh tea waste and Cd stress. The improved efficiency of biochemical reactions in plants under Cd stress with tea waste treatment was the consequence of blocking Cd movement in the soil through adsorption on tea waste, showing that the tea waste effectively controls the mobility of Cd from the soil to the roots of the plants. Scan electron microscopy (SEM) validates the recovery of the leaves of the plants. The remediation of plant growth and enzyme activities such as amylase, peroxidase, nitrate reductase (NR), and nitrite reductase (NiR) under Cd metal-contaminated soil through tea waste was investigated. The source of tea waste in contaminated soil resulted in the recovery of the photosynthetic process and an improvement in amylase, NR, NiR, and peroxidase activities, thereby resulting in the recovery of pigments coupled with an increase in the biomass of the plants. It was suggested that tea waste acts as a good biosorbent of Cd and energy provider to the plants for normal enzyme activity under Cd stress and may be used by farmers in the future for safe and healthy crops as a cost-effective technology.     

Luminescent Carbon Dots from Wet Olive Pomace: Structural Insights,Photophysical Properties and Cytotoxicity

Carbon nanomaterials endowed with significant luminescence have been synthesized for the first time from an abundant, highly localized waste, the wet pomace (WP), a semi-solid by-product of industrial olive oil production. Synthetic efforts were undertaken to outshine the photoluminescence (PL) of carbon nanoparticles through a systematic search of the best reaction conditions to convert the waste biomass, mainly consisting in holocellulose, lignin and proteins, into carbon dots (CDs) by hydrothermal carbonization processes. Blue-emitting CDs with high fluorescence quantum yields were obtained. Using a comprehensive set of spectroscopic tools (FTIR, Raman, XPS, and ¹H/¹³C NMR) in combination with steady-state and time-resolved fluorescence spectroscopy, a rational depiction of WP-CDs structures and their PL properties was reached. WP-CDs show the up-conversion of PL capabilities and negligible cytotoxicity against two mammalian cell lines (L929 and HeLa). Both properties are excellent indicators for their prospective application in biological imaging, biosensing, and dynamic therapies driven by light.     

Use of Pineapple Waste as Fuel in Microbial Fuel Cell for the Generation of Bioelectricity

The excessive use of fossil sources for the generation of electrical energy and the increase in different organic wastes have caused great damage to the environment; these problems have promoted new ways of generating electricity in an eco-friendly manner using organic waste. In this sense, this research uses single-chamber microbial fuel cells with zinc and copper as electrodes and pineapple waste as fuel (substrate). Current and voltage peaks of 4.95667 ± 0.54775 mA and 0.99 ± 0.03 V were generated on days 16 and 20, respectively, with the substrate operating at an acid pH of 5.21 ± 0.18 and an electrical conductivity of 145.16 ± 9.86 mS/cm at two degrees Brix. Thus, it was also found that the internal resistance of the cells was 865.845 ± 4.726 Ω, and a maximum power density of 513.99 ± 6.54 mW/m² was generated at a current density of 6.123 A/m², and the final FTIR spectrum showed a clear decrease in the initial transmittance peaks. Finally, from the biofilm formed on the anodic electrode, it was possible to molecularly identify the yeast Wickerhamomyces anomalus with 99.82% accuracy. In this way, this research provides a method that companies exporting and importing this fruit may use to generate electrical energy from its waste.     

Preparation of a Chitosan/Coal Gasification Slag Composite Membrane and Its Adsorption and Removal of Cr (VI) and RhB in Water

At present, there are many kinds of pollutants, including dyes and heavy metal ions, in wastewater. It is very important to develop adsorbents that can simultaneously remove heavy metal ions and dyes. In this study, a renewable composite membrane material was synthesized using chitosan and treated coal gasification slag. The Cr (VI) maximum adsorption capacity of the composite membrane was 50.0 mg/L, which was 4.3~8.8% higher than that of the chitosan membrane. For the adsorption of RhB, the removal rate of the chitosan membrane was only approximately 5.0%, but this value could be improved to 95.3% by introducing coal gasification slag. The specific surface area of the chitosan membrane could also be increased 16.2 times by the introduction of coal gasification slag. This is because coal gasification slag could open the nanopores of the chitosan membrane (from 80 μm to 110 μm). Based on the adsorption kinetics and adsorption mechanism analysis, it was found that the adsorption of Cr (VI) occurred mainly through the formation of coordination bonds with the amino groups on the molecular chains of chitosan. Meanwhile, RhB adsorption occurred through the formation of hydrogen bonds with the surface of coal gasification slag. Additionally, coal gasification slag can improve the mechanical properties of the chitosan membrane by 2.2 times, which may facilitate the practical application of the composite membrane. This study provides new insight into the adsorbent design and the resource utilization of coal gasification slag.     

Process Simulation and Life Cycle Assessment of Waste Plastics: A Comparison of Pyrolysis and Hydrocracking

Pyrolysis and hydrocracking of plastic waste can produce valuable products with manageable effects on the environment as compared to landfilling and incineration. This research focused on the process simulation and life cycle assessment of the pyrolysis and hydrocracking of high-density polyethylene. Aspen Plus was used as the simulator and the Peng-Robinson thermodynamic model was employed as a fluid package. Additionally, sensitivity analysis was conducted in order to optimize product distribution. Based on the simulation, the hydrocracking process produced value-added fuels, i.e., gasoline and natural gas. In contrast, pyrolysis generated a significant quantity of pyrolysis oil with a high number of cyclo-compounds and char, which are the least important to be utilized as fuels. Moreover, in the later part of the study, life cycle assessment (LCA) was adopted in order to investigate and quantify their impact upon the environment using simulation inventory data, which facilitates finding a sustainable process. Simapro was used as a tool for LCA of the processes and materials used. The results demonstrate that hydrocracking is a better process in terms of environmental impact in 10 out of the 11 impact categories. Overall, the present study proposed a promising comparison based on energy demands, product distribution, and potential environmental impacts, which will help to improve plastic waste management.     

制药废液中氨基酸的分离与测定

为测定维生素 B12 制药厂排出的废液中氨基酸量,先在所取的废液样品中加入乙酸铅使其中蛋白质及其他大分子有机物产生沉淀并用离心法分离.上层澄清液中的氨基酸通过装有强酸性阳离子交换树脂的交换柱(25 cm×2.5 cm)予以分离,用1 mol·L-1 氨水将氨基酸从柱上洗脱.在所得洗脱液中用气相色谱-质谱及傅立叶变换红外光谱法对氨基酸进行定性及定量测定.     

Upcycling waste PMMA to durable composites via a transesterification-inverse vulcanization process

Poly(methyl methacrylate) (PMMA) is an important commodity polymer having a wide range of applications. Currently, only about 10% of PMMA is recycled. Herein, a simple two-stage process for the chemical upcycling of PMMA is discussed. In this method PMMA is modified by transesterification with a bio-derived, olefin-bearing terpenoid, geraniol. In the second stage, olefin-derivatized PMMA is reacted with sulfur to form a network composite by an inverse vulcanization mechanism. Inverse vulcanization of PGMA with elemental sulfur (90 wt.%) yielded the durable composite PGMA-S . This composite was characterized by NMR spectrometry, IR spectroscopy, elemental analysis, thermogravimetric analysis, and differential scanning calorimetry. Composite water uptake, compressional strength analysis, flexural strength analysis, tensile strength analysis, and thermal recyclability are presented with comparison to current commercial structural materials. PGMA-S exhibits a similar compressive strength (17.5 MPa) to that of Portland cement. PGMA-S demonstrates an impressive flexural strength of 4.76 MPa which exceeds the flexural strength (>3 MPa) of many commercial ordinary Portland cements. This study provides a way to upcycle waste PMMA through combination with a naturally-occurring olefin and industrial waste sulfur to yield composites having mechanical properties competitive with ecologically detrimental legacy building materials.     

中国垃圾的资源化利用

垃圾处理的要求是无害化、减量化和资源化.中国垃圾具有水分高、热值低、品质差的特点.文章分析了中国垃圾无害化、减量化和资源化的状况、优缺点,指出了资源化的目标和未来的发展方向,并讨论了相关国家政策的配套支持问题.     

基于蒙卡模拟的分段γ扫描无源效率刻度方法

针对200 L核废物桶分段γ扫描（SGS）过程中的效率刻度问题,提出了一种效率刻度函数模型,采用MCNP程序计算不同基质密度和γ射线能量条件下的离散断层效率,经过多元非线性回归获取函数参数,从而建立效率刻度函数,实现核废物桶SGS断层效率刻度。对核废物桶样品进行实验分析,结果表明：对于桶内基质分别为密度0.310 g·cm⁻³的硅酸铝、密度0.595 g·cm⁻³的木质纤维,桶内核素分别为活度3.110×10⁵ Bq的点源¹³⁷Cs、活度1.371×10⁵ Bq的点源⁶⁰Co,在桶内仅有单个点源存在的核素分布极端不均匀情况下,桶内核素活度重建误差在−37.68%～31.52%范围内。本文的方法能够准确有效实现核废物桶SGS断层效率矩阵计算,并确定核废物桶内放射性核素活度,满足实际检测要求。     

毛细管等离子体射流技术研究现状及应用前景

毛细管放电等离子体是近年来发展起来的一种新型脉冲高能粒子源,可以产生高温、高密和高速等离子体射流,具有推进、发射、加速等功能,可以加热或引燃化学工质,具有广泛的应用前景。介绍了毛细管等离子体的基本原理和特点,综述了国内外研究现状,对毛细管等离子体应用前景进行了展望,以期引起我国对这一技术研究的重视,促进毛细管等离子体技术的发展。