Comparison between two anammox fiber fillers under load impact and the effect of HCO3− concentration

Based on the establishment of a stable anaerobic ammonia oxidation treatment system in 100 days, the impact resistances of two different anammox fiber fillers (the curtain filler: R1 and the bundle filler: BR) were compared.

Irrigation with Activated Water Promotes Root Growth and Improves Water Use of Winter Wheat

Magnetic or oxidation treatment of irrigation water can promote the transport of water and nutrients by the root system, improve the efficiency of water and fertilizer use and potentially increase yields. Hydroponic and field experiments were conducted to explore how irrigation with magnetized and/or oxidized water affects grain yield and water-use efficiency (WUE) in winter wheat with an emphasis on physiological changes in the root system. Hydroponic cultivation of winter wheat with pure groundwater and brackish water included the following treatments: control group (CK−G, CK−B); magnetization (GM, BM); oxidation (GO, BO); and the combination of magnetization and oxidation (G(M+O), B(M+O), G(O+M), B(O+M)). Field experiments only tested irrigation with various types of groundwater, including the control group (IG), magnetization treatment (IGM), oxidation treatment (IGO), and the combination of the two treatment methods (IG(M+O), IG(O+M)). Hydroponic cultivation revealed that the magnetic treatment and oxidation of both groundwater and brackish water can significantly improve the root vigor of winter wheat, i.e., improvements of 100.5–253.7% and 100.4–213.9% were seen in the groundwater and brackish treatment groups, respectively, relative to the control group. The root length density (RLD) of wheat increased by 67.6% (GM), 79.4% (GO), 7.5% (BM), and 40.0% (BO) relative to the respective control groups (CK−G and CK−B). Moreover, the root weight density (RWD) for BO and B(O+M) treatments improved significantly (66.7% and 55.4%, respectively) relative to CK−B. The maximal increases in root surface area density (RSD) were observed in treatments GO and B(O+M), which showed values 125% and 100%, respectively, higher than what was measured for the control groups. The root/shoot ratios of the GO and G(O+M) treatments improved significantly (by 75.3% and 62.0%, respectively) relative to CK−G. The results of field experiments showed that wheat in the IGO and IG(O+M) plots absorbed more water from the soil than wheat in the of IG plots (increases of 13.9% and 16.9%, respectively). Furthermore, the IGO and IG(O+M) treatments produced significantly higher grain yields and WUE than the IG plots, with IGO producing the maximum yield (11.7 × 103 kg ha−1) and IG(O+M) the highest observed WUE (30.3 kg ha−1 mm−1). Hence, the research provides clear evidence that the irrigation of winter wheat with magnetized and/or oxidized water can increase grain yields and WUE.

Selective Laser Melting of High Relative Density and High Strength Parts Made of Minor Surface Oxidation Treated Pure Copper Powder

Pure Copper (Cu) is very difficult to prepare using selective laser melting (SLM) technology. This work successfully prepared the pure Cu with high relative density and high strength by the SLM technology using a surface oxidation treatment. The gas-atomized pure Cu powder was used as the feedstock in this work. Before the SLM process, the pure Cu powder was initially handled using the surface oxidation treatment to coat the powder with an extremely thin layer of Cu2O. The SLMed highly dense specimens contain α-Cu and nano-Cu2O phases. A relationship between the processing parameters (laser power (LP), scanning speed (SS), and hatch space (HS)) and density of Cu alloy in SLM was also investigated. The microstructure of SLMed Cu consists of fine grains with grain sizes ranging from 0.5 to ~30 μm. Tensile testing and detailed microstructural characterization were performed on specimens in the as-SLMed and pure copper state specimens. The mechanical property experiments showed that the specimens prepared by SLM technology containing nano-oxide phases had higher yield strength and tensile strength than that of other SLM-built pure copper. However, the elongation was remarkably decreased compared to other SLM-built pure copper, due to the fine grains and the nano-oxides.

Removal of cephalexin from aqueous solutions using the fenton photocatalytic process

This paper aims to study the degradation and oxidation/mineralization process of cephalexin in model systems using Fenton’s reagent for UV irradiation (λ = 254 nm). The effect of pH (2-11), concentration of H2O2 (0,3434 mg/L) and concentration of Fe(II) (0-28 mg/L) on the degradation of 50 mg/L CPX were investigated. It has been determined optimum conditions for photocatalytic oxidation of CPX. Increasing the amount of H2O2 plays an inhibitory role in the production of hydroxyl radicals and reduces the process efficiency. This can be attributed to the reaction of excess peroxide with •OH and the formation of HO2 •, which has less oxidizing power compared to free hydroxyl radical. And as the concentration of the catalyst increases to the optimum, the excess of Fe(II) ions reacts with the hydroxyl radical and, therefore, the efficiency of the process also is reduced. Accordingly, the optimum degradation efficiency of 88 % and 83% for COD was obtained under the following conditions: pH 2,5, H2O2 concentration – 3,4 mg/L, Fe(II) ions concentration – 5,6 mg/L, cephalexin concentration – 50 mg/L, and reaction time – 60 min. Thus, the current study demonstrated that the photo-Fenton reactor can be used effectively as an advanced oxidation treatment unit for degradation of cephalexin under optimized environmental conditions.