Application of ferrous sulfate alleviates negative impact of cadmium in rice (<i>Oryza sativa</i> L.)

Soil contamination with toxic heavy metals [such as cadmium (Cd)] is becoming a serious global problem due to rapid development of social economy. Iron (Fe), being an important element, has been found effective in enhancing plant tolerance against biotic and abiotic stresses. The present study investigated the extent to which different levels of Ferrous sulphate (FeSO₄) modulated the Cd tolerance of rice (Oryza sativa L.), when maintained in artificially Cd spiked regimes. A pot experiment was conducted under controlled conditions for 146 days, by using natural soil, mixed with different levels of CdCl₂ [0 (no Cd), 0.5 and 1 mg/kg] together with the exogenous application of FeSO₄ at [0 (no Fe), 1.5 and 3 mg/kg] levels to monitor different growth, gaseous exchange characteristics, oxidative stress, antioxidative responses, minerals accumulation, organic acid exudation patterns of O. sativa. Our results depicted that addition of Cd to the soil significantly (P < 0.05) decreased plant growth and biomass, gaseous exchange parameters, mineral uptake by the plants, sugars (soluble, reducing, and non-reducing sugar) and altered the ultrastructure of chloroplasts, plastoglobuli, mitochondria, and many other cellular organelles in Cd-stressed O. sativa compared to those plants which were grown without the addition of Cd in the soil. However, Cd toxicity boosted the production of reactive oxygen species (ROS) by increasing the contents of malondialdehyde (MDA), which is the indication of oxidative stress in O. sativa and was also manifested by hydrogen peroxide (H₂O₂) contents and electrolyte leakage to the membrane bounded organelles. Although, activities of various antioxidative enzymes like superoxidase dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX) and non-enzymatic antioxidants like phenolics, flavonoid, ascorbic acid, anthocyanin and proline contents increased up to a Cd level of 0.5 mg/kg in the soil but were significantly diminished at the highest Cd level of 1 mg/kg in the soil compared to those plants which were grown without the addition of Cd in the soil. The negative impacts of Cd injury were reduced by the application of FeSO₄ which increased plant growth and biomass, improved photosynthetic apparatus, antioxidant enzymes, minerals uptake together with diminished exudation of organic acids as well as oxidative stress indicators in roots and shoots of O. sativa by decreasing Cd retention in different plant parts. These results shed light on the effectiveness of FeSO₄ in improving the growth and upregulation of antioxidant enzyme activities of O. sativa in response to Cd stress. However, further studies at field levels are required to explore the mechanisms of FeSO₄-mediated reduction of the toxicity of not only Cd, but possibly also other heavy metals in plants.     

Experimental investigation on the invert stability of operating railway tunnels with different drainage systems using 3D printing technology

In recent years, the invert anomalies of operating railway tunnels in water-rich areas occur frequently, which greatly affect the transportation capacity of the railway lines. Tunnel drainage system is a crucial factor to ensure the invert stability by regulating the external water pressure (EWP). By means of a three-dimensional (3D) printing model, this paper experimentally investigates the deformation behavior of the invert for the tunnels with the traditional drainage system (TDS) widely used in China and its optimized drainage system (ODS) with bottom drainage function. Six test groups with a total of 110 test conditions were designed to consider the design factors and environmental factors in engineering practice, including layout of the drainage system, blockage of the drainage system and groundwater level fluctuation. It was found that there are significant differences in the water discharge, EWP and invert stability for the tunnels with the two drainage systems. Even with a dense arrangement of the external blind tubes, TDS was still difficult to eliminate the excessive EWP below the invert, which is the main cause for the invert instability. Blockage of drainage system further increased the invert uplift and aggravated the track irregularity, especially when the blockage degree is more than 50%. However, ODS can prevent these invert anomalies by reasonably controlling the EWP at tunnel bottom. Even when the groundwater level reached 60 m and the blind tubes were fully blocked, the invert stability can still be maintained and the railway track experienced a settlement of only 1.8 mm. Meanwhile, the on-site monitoring under several rainstorms further showed that the average EWP of the invert was controlled within 84 kPa, while the maximum settlement of the track slab was only 0.92 mm, which also was in good agreement with the results of model test.     

New approach to unsupported ReS2 nanorod catalyst for upgrading of heavy crude oil using methane as hydrogen source

Highly active ReS₂ nanocatalysts were prepared by CVD method and characterized by XRD, BET -BJH, Raman spectroscopy, XPS, TPR, NH₃-TPD, SEM, and HRTEM techniques. Catalytic activities were used in upgrading heavy crude oil using methane as hydrogen source. The results showed a significant increase in API and decrease in sulfur and nitrogen content of crude oil. RSM technique was used to investigate the interactive effects of temperature (200–400 °C), pressure (20–40 bar) and dosage of nanocatalyst (0.5–2 wt. %) on the performance of HDS reaction. The results represent that the maximum predicted HDS activity (74.375%) was estimated under the optimal conditions (400 °C, 20 bars, and 2 wt % of nanocatalyst). Also, the effect of reaction temperature, pressure and dosage of ReS₂ nanorods catalyst on HDN of heavy crude oil was investigated and highest efficiency in the HDN process (93%) occurred at 400 °C and 40 bar using 2 wt % ReS₂.     

云南地区滇黄精中重金属含量测定研究

目的:测定云南10个产地滇黄精药材的重金属含量,为制定滇黄精药材中重金属质量标准提供参考依据。方法:采用石墨消解法进行样品前处理,用电感耦合等离子体原子发射光谱法(ICPAES)测定铜(Cu)、镉(Cd)、铅(Pb)、锌(Zn)的含量。结果:1、7、8、9号样品分别有2种重金属含量偏高;3、10号样品分别有1种重金属含量偏高;6号样品有3种重金属含量偏高;其余均符合限量标准要求。结论:不同产地滇黄精的重金属含量存在一定差异,本研究结果可为滇黄精质量标准提供参考。     

Protein-derived nitrogen and sulfur co-doped carbon for efficient adsorptive removal of heavy metals

A nitrogen and sulfur co-doped carbon has been synthesized employing egg white as a sustainable protein-rich precursor. According to CHNS elemental analysis, N, S and O heteroatoms accounted for mass fractions of 3.66%, 2.28% and 19.29% respectively, and the types of surface functionalities were further characterized by FT-IR and XPS measurements. Although the carbon possessed a smaller surface area (815 m²·g^-1) compared to a commercial activated carbon (1100 m²·g^-1), its adsorption capacity towards Co²⁺ reached 320.3 mg·g^-1, which was over 8 times higher compared to the limited 34.0 mg·g^-1 over the activate carbon. Furthermore, the carbon was found to be an efficient adsorbent towards a series of metal ions including VO²⁺, Cr³⁺, Ni²⁺, Cu²⁺ and Cd²⁺. Combined with its environmental merits, the protein derived carbon may be a promising candidate for heavy metal pollution control.     

Effect of sintering temperature on solidification and migration of non-volatile and volatile heavy metals in glass-ceramic

Using tailings as material to prepare glass-ceramic is an excellent way to achieve the resource utilization of solid waste. However, at present, researches on the solidification and migration of heavy metals are limited. Therefore, in this study, ten groups of samples were prepared by controlling sintering temperatures. The solidification, migration, and leaching behavior of non-volatile and volatile heavy metals were studied. The research showed that, with the increase of temperature, the properties of the samples were improved. Fe participated in the phase transformation and evolved into insoluble iron pyroxenes solid solution, while Pb was homogeneously distributed in the glass matrix of glass-ceramics. The leaching concentrations of Fe and Pb in the glass-ceramics were 0.055 mg/L ～0.087 mg/L and 0.074 mg/L ～0.140 mg/L, which were far below the threshold value. The results showed that heavy metals can be effectively solidified in glass-ceramics and have good environmental benefits.     

Flow modeling of high-viscosity fluids in pipeline infrastructure of oil and gas enterprises

Today, the issues related to solving the problem of finding an effective distribution of oil flows through the system of oil pipelines in order to reduce the total energy consumption are relevant. The solution to this problem is connected with selection of rational pumping modes for various technological sections of oil pipelines using modern methods of mathematical programming or new techniques for improving the energy and transport characteristics of oil.Reducing energy consumption during pumping of crude through oil trunk pipelines can be achieved by various methods. Numerous investigations in this direction are mainly carried out to save energy on separate single-line pipelines. However, due to the development of the network of trunk oil pipelines in the world over the past decades, the issues of energy efficient management of oil flows throughout the entire oil pipeline system of oil and gas enterprises become urgent.This paper analyses parameters for pipeline transport of high-viscosity and heavy oils. The article proposes a method for assessing the rheological properties of oil for further planning of pumping taking into account the preservation of oil quality and an increase in energy and transport characteristics. The proposed solutions and tasks for predicting changes in the viscosity-temperature characteristics of the flow for blends of different oil types are especially relevant in the current conditions of an increase in the share of oil production with complex rheological characteristics. Results of the presented investigations may be used for planning the measures of efficient transportation of high-viscosity and heavy oils.     

列车贮藏方式对生猪肉原料新鲜度的影响研究

探究夏季高温期某铁路局集团公司旅客列车贮藏条件下生猪肉原料的品质变化,为改善餐车生猪肉保存及取用方式、保障旅客列车食品安全提供可靠依据。在实验室条件下模拟该列车餐车实际条件下生猪肉贮藏及取用方式:将生猪肉分别在4℃(冷藏)和-10℃(冷冻)两种条件下贮藏,再解冻,使用,再贮藏。通过猪肉的色泽、气味、组织状态感官指标以及挥发性盐基氮(TVB-N)、硫化氢、球蛋白沉淀理化指标的变化为依据,来评价猪肉的新鲜度。结果表明:夏季高温期间,该铁路局集团公司列车生猪肉原料,在4℃冷藏贮存条件下,有2d保质期,在-10℃冷冻贮藏条件下,10d内猪肉品质能够保持新鲜,满足铁路运输的时限要求。该铁路公司列车贮藏和使用生猪肉符合规范,用肉时限在保质期范围内,能够保证全年时段肉质新鲜安全。为保障铁路旅客的食品安全,生猪肉原料应贮存在制冷效果良好的冷冻冰箱内,取用肉类置于冷藏保存的,应在2d内使用完毕。     

Melatonin and its protective role against male reproductive toxicity induced by heavy metals,environmental pollutants,and chemotherapy: A review

Melatonin, as a ubiquitous indoleamine hormone, is synthesized primarily by the pineal gland. It has diverse biological effects through quite complex mechanisms. More recently, studies have focused on the mechanism of melatonin in anti-reproductive toxicity/damage. Since melatonin possesses strong antioxidant and anti-apoptotic properties, researchers have examined its potential role in protecting against male reproductive toxicity/damage, which may be induced by chemotherapy or environmental toxicants and can lead to male infertility. In this article, recent progress regarding the protective effects of melatonin on male reproductive toxicity/damage is reviewed.     

Al2O3/Yttria‐Stabilized Zirconia Hollow‐Fiber Membrane Incorporated with Iron Oxide for Pb(II) Removal

Removal by absorptive ceramic membranes can simultaneously absorb and separate metal ions from water. Alumina/yttria‐stabilized zirconia (Al₂O₃/YSZ) hollow‐fiber membranes, fabricated using phase inversion and sintering process, were deposited with iron oxide by an in‐situ hydrothermal process. The results showed that α‐Fe₂O₃ was produced and incorporated across the membranes. A reduction in flux was recorded with the deposition of α‐Fe₂O_3. However, it improved the adsorption capacity for heavy metal adsorption. The adsorption‐separation test demonstrated that the optimized membrane is able to completely remove Pb(II) ions after two hours.