As one of toxic Volatile Organic Pollutant (TVOCs), formaldehyde has a toxic effect on microorganisms, and then inhibits the biochemical process of formaldehyde wastewater treatment. Therefore, the selective degradation of formaldehyde is of great significance to achieve formaldehyde wastewater high-efficiency and low-cost treatment. This study constructed a heterogeneous Fe-ZSM-5/H2O2 Fenton system for selective degradation to target compounds. By bonding Fe3+ onto the surface of ZSM-5 molecular sieve, Fe-ZSM-5 was prepared successfully. XRD, BET and FT-IR spectral studies shown the prepared Fe-ZSM-5 was mainly composed of micropores. The influences of different variables on formaldehyde selective heterogeneous Fenton degradation performance were studied. The 93.72% formaldehyde degradation and the 98.15% selectivity of formaldehyde compared with glucose had demonstrated in the optimized Fenton system after 360 min. Notably, the resultant selective Fenton oxidation system had a wide range of pH suitability from 3.0 to 10.0. Also, the Fe-ZSM-5 was used in 5 consecutive cycles, while the degradation efficiency of formaldehyde did not drop dramatically. Using reactive oxygen species scavengers, hydroxyl radical was the main active substance to degrade formaldehyde. Furthermore, the great degradation performance of this system to high concentration of formaldehyde was acquired, and the degrading efficiency was more than 95%.

Soil cadmium (Cd) contamination has become a serious problem in China. In this study, the goals of the field experiments were to understand how the application of nitrogen fertilizer at the full heading stage and filling stage reduced the uptake of Cd in rice by affecting the distribution of Cd in iron plaques on the root surfaces and subcellular in the root and flag leaf. The hydroponic culture experiments aimed to explore the effect of interaction or deficiency of nitrogen and cadmium on cadmium accumulation in rice at the late growth stage. The results showed that under the condition of having enough nitrogen supply during the early growth stage, applying nitrogen fertilizer during the full heading stage and filling stage resulted in a significant increase in the concentration of Fe and Cd on the root plaques at the milk stage and mature stage. Additionally, it increased the concentration and proportion of Cd in the soluble fraction of subcellular in the flag leaves at the milk stage. On the other hand, when there was a deficiency of nitrogen, the concentration of Fe in the root plaques increased significantly, while the concentration of Cd in the root plaques decreased significantly. Moreover, the proportion of Cd in the flag leaf cell walls increased significantly. Regardless of whether there was sufficient or deficient nitrogen supply during the early growth stage, applying nitrogen at the full heading stage reduced the Cd concentration in brown rice by 35.11% and 57.25%, respectively. Under hydroponic culture conditions with both Cd exposure and later-stage nitrogen supply significantly increased the Cd concentration in brown rice. However, in the absence of Cd, nitrogen supply significantly reduced the Cd concentration in brown rice. The accumulation of Cd in brown rice was significantly correlated with the accumulation of Fe and Mn at the late growth stage. Our findings indicate that when there is sufficient nitrogen nutrition during the early growth stage of rice, topdressing nitrogen fertilizer at the full heading stage combined with lime with mineral element fertilizers such as Fe and Mn is an effective approach to reduce the presence of cadmium in rice grains.

As one of the typical deposits in Sichuan-Yunnan-Guizhou Pb-Zn metallogenic province, the Daliangzi Pb-Zn deposit has a close genetic relation with the structural system of “black/fracture zone” formed under the action of NWW-approx. EW strike-slip structures in the metallogenic province, but the mechanism of rock and ore-controlling action of the structural system remains unclear. Based on detailed analysis of tectonite-mineralized alteration lithofacies of R1 “black/fracture zone”, the tectonite-mineralized alteration lithofacies zones can be divided into 4 types in succession outward from the Pb-Zn mineralization center, i.e., ① brecciated and stockwork-like Pb-Zn mineralization-complex breccia facies zone, ② stockwork-like Pb-Zn mineralization-simple breccia and cataclasite facies zone, ③ veined pyrite-sulfide-dolomitic cataclasite facies zone, and ④ fine-veined calcite-black carbonized dolomite facies zone; Cl- and SO42--rich high-temperature oxidizing ore-bearing fluid mixes with reducing fluid in Zone ① while migration and precipitation occur in Zone ④. With the evolution of ore-forming fluid, the homogenization temperature decreases from Zone ① to Zone ④, the salinity increases from Zone ① to Zone ② and then decreases to Zones ③ and ④, and the fluid density has little change on the whole; the contents of Zn, Pb, Cu, Ga, Ge, Cd, Ag, and other metallogenic elements, the Zn/Pb ratio, and the CaO/MgO mole ratio decrease gradually from Zone ① to Zone ④; and REE fractionation, calcilization, silicification, and pyritization enhance gradually from Zone ① to Zone ④. This series of changes are the product of diapirism (cryptoexplosion) of strike-slip structures and “black/fracture zone”, among which the second-order structures (F5, F100, and other faults) derived from NWW-approx. EW striking dextral shear-tension faults F1 and F15 control the brecciated and stockwork-like Pb-Zn mineralized complex breccia facies zones and the stockwork-like Pb-Zn mineralized simple breccia and cataclasite facies zones. Therefore, this paper establishes the zoning mode of tectonite-mineralized alteration lithofacies of “black/fracture zone” and proposes that Zones ① and ② are important prospecting criteria. conclusions.

Our environment has been significantly impacted by man-made pollutants, primarily due to industries make substantial use of synthetic chemicals, resulting in significant environmental consequences. In this research investigation, the co-precipitation approach was employed for the synthesis of cellulose-based ferric oxide (Fe₂O₃/cellulose) and copper oxide nanoparticles (CuOx-NPs). Scanning electron microscopy (SEM) analyses were conducted to determine the properties of the newly synthesised nanoparticles. Furthermore, the synthesized nanoparticles were employed for eliminating chromium from aqueous media under various conditions, including temperature, contact time, adsorbent concentration, adsorbate concentration, and pH. Additionally, the synthesised materials were used to recover Cr(VI) ions from real samples, including tap water, seawater, and industrial water, and the adsorptive capacity of both materials evaluated under optimal conditions. The synthesis of Fe₂O₃/cellulose and CuOx-NPs proved to be effective, as indicated by the outcomes of the study.

Laser-Powder Directed Energy Deposition (DED-LB/Powder) is an additive manufacturing process that is gaining popularity in the manufacturing industry due to its numerous advantages, particularly in repairing operations. However, its application is often limited to case studies due to some critical issues that need to be addressed, such as the degree of internal porosity. This paper investigates the effect of the most relevant process parameters of the DED-LB/Powder process on the level and distribution of porosity. Results indicate that, among the process parameters examined, porosity is less affected by travel speed and more influenced by powder mass flow rate and laser power. Additionally, a three-dimensional finite element transient model was introduced, which was able to predict the development and location of lack-of-fusion pores along the building direction.

Bone drilling is a common procedure used to create pilot holes for inserting screws to secure implants for fracture fixation. However, dis process can increase bone temperature, teh excessive heat can lead to cell death and thermal osteonecrosis, potentially causing early fixation failure or complications. We conducted a three-dimensional dynamic elastoplastic finite element model to evaluate teh propagation and distribution of heat during bone drilling and assess teh thermally TEMPeffected zone (TAZ) dat may lead to thermal necrosis. dis model investigates teh parameters influencing bone temperature during bone drilling, including drill diameter, rotational speed, feed force, and predrilled hole. Teh results indicate dat our FE model is sufficiently accurate in predicting teh temperature rise TEMPeffect during bone drilling. Teh maximum temperature decreases exponentially wif radial distance. When teh feed forces are 40 and 60 N, teh maximum temperature does not exceed 45 °C. However, wif feed forces of 10 and 20 N, both teh maximum temperature exceeds 45 °C wifin a radial distance of 0.2 mm, indicating a high-risk zone for potential thermal osteonecrosis. Wif teh two-stage drilling procedure, where a 2.5 mm pilot hole is pre-drilled, teh maximum temperature can be reduced by 14 °C. dis suggests dat higher feed force and rotational speed and/or using a two-stage drilling process could mitigate bone temperature elevation and reduce teh risk of thermal osteonecrosis during bone drilling.