BASIC NUTRIENT CONSUMPTION AND REMOVAL WITH RAPESEED SEEDS WHEN APPLYING DIFFERENT FERTILIZER COMBINATIONS

In the context of different fertilizer combination applica-tion (urea-ammonia liquor KAS-32, liquid complex fertilizer ZhKU, and compound NPK fertilizerDiammophoska) N89P26K26S14, N70P26K26S14, N73P39K13S14, N89P39K13S14, N87P37S14and N71P37S14, we revealed increased removal of CaO to 15.6-20 kg ha as opposed to 13.8 kg ha in the con-trol; MgO to 12.3-16 kg ha compared to 10.2 kg ha in the control. Taking into account Ca and Mg removal without return, it requires the introduction of compound fertilizers containing these nutrients into the fertilizer system. Nitro-gen removal was 110.3-165.5 kg ha compared to 102.6 kg ha, and sulfur -10.9-12.8 kg ha compared to 7.8 kg ha in the control. The S/N ratio ranged from 8.9-15.4 compared to 14 in the control. For the most part, it was equal to 10.7-12.9 which was indicative of satisfactory sulfur supply to oil seed rape crops and the need to increase sulfur dose to 21-28 kg ha. The largest removal of all nutrients was found inthe variants with N73P39K13S14and N71P37S14; the highest yield was formed with N73P39K13S14with N:P:K removal ratio of 1:0.39:0.21

Glass Substrate Dust Removal Using 233 fs Laser-Generated Shockwave

Eliminating dust is gaining importance as a critical requirement in the display panel manufacturing process. The pixel resolution of display panels is increasing rapidly, which means that even small dust particles on the order of a few micrometers can affect them. Conventional surface cleaning methods such as ultrasonic cleaning (USC), CO2 cleaning, and wet cleaning may not be sufficiently efficient, economical, or environment friendly. In this study, a laser shockwave cleaning (LSC) method with a 233 fs pulsed laser was developed, which is different from the laser ablation cleaning method. To minimize thermal damage to the glass substrate, the effect of the number of pulses and the gap distance between the focused laser beam and the glass substrate were studied. The optimum number of pulses and gap distance to prevent damage to the glass substrate was inferred as 500 and 20 μm, respectively. With the optimal pulse number and gap distance, cleaning efficiency was tested at a 95% removal ratio regardless of the density of the particles. The effective cleaning area was measured using the removal ratio map and compared with the theoretical value.

Numerical Simulation on Motion Behavior of Inclusions in the Lab-Scale Electroslag Remelting Process with a Vibrating Electrode

In order to meet the requirement of high-quality ingots, the vibrating electrode technique in the electroslag remelting (ESR) process has been proposed. Non-metallic inclusions in ingots may cause serious defects and deteriorate mechanical properties of final products. Moreover, the dimension, number and distribution of non-metallic inclusions should be strictly controlled during the ESR process in order to produce high-quality ingots. A transient 2-D coupled model is established to analyze the motion behavior of inclusions in the lab-scale ESR process with a vibrating electrode, especially under the influence of the vibration frequency, current, slag layer thickness, and filling ratio, as well as type and diameter of inclusions. Simulation model of inclusions motion behavior is established based on the Euler-Lagrange approach. The continuous phase including metal and slag, is calculated based on the volume of fluid (VOF) method, and the trajectory of inclusions is tracked with the discrete phase model (DPM). The vibrating electrode is simulated by the user-defined function and dynamic mesh. The results show that when the electrode vibration frequency is 0.25 Hz or 1 Hz, the inclusions will gather on one side of the slag layer. When it increases from 0.25 Hz to 1 Hz, the removal ratio of 10 μm and 50 μm inclusions increases by 5% and 4.1%, respectively. When the current increases from 1200 A to 1800 A, the flow following property of inclusions in the slag layer becomes worse. The removal ratio of inclusions reaches the maximum value of 92% with the current of 1500 A. The thickness of slag layer mainly affects the position of inclusions entering the liquid-metal pool. As the slag layer thickens, the inclusions removal ratio increases gradually from 82.73% to 85.91%. As the filling ratio increases, the flow following property of inclusions in the slag layer is enhanced. The removal ratio of 10 μm inclusions increases from 94.82% to 97%. However, for inclusions with a diameter of 50 μm, the maximum removal ratio is 96.04% with a filling ratio of 0.46. The distribution of 50 μm inclusions is significantly different, while the distribution of 10μm inclusions is almost similar. Because of the influence of a vibrating electrode, 10 μm Al2O3 and MnO have a similar removal ratios of 81.33% and 82.81%, respectively.

The Physical and Chemical Properties of Hemp Fiber Prepared by Alkaline Pectinase-Xylanase System

Degumming is the vital and critical step in the preparation of hemp fiber for textile application. However, the traditional chemical degumming processes use large amounts of harmful chemicals, especially strong alkalis, which have caused severe challenges to the environment. The reaction conditions of alkaline pectinase and alkaline pectinase were studied in this research, and the alkaline pectinase-xylanase system was successfully applied to the degumming of hemp fibers at mild conditions (T=55 ℃ and pH=8.0) without strong alkali. A comparative analysis of hemp fibers treated under different conditions showed that the gum removal ratio could reach about 50% within 5.5 h of alkaline pectin-xylanase system degumming, making fiber smoother and stronger. After alkaline pectin-xylanase system treatment (0.6 g pectinase, 0.3 g xylanase, 55 ℃, pH 8.0, 5.5 h), the removal ratio of pectin and hemicellulose reached 75 % and 40 %, respectively. And linear density and tenacity of the fiber was 17.4 dtex and 5.62 cN/dtex, respectively. SEM, FT-IR and XRD analysis furthermore demonstrated the excellent effects of the proposed process. The degumming fiber had better water retention performance (513 %) and moisture sorption (8.9 %), which has more excellent application prospects in the textile industry. Moreover, the method abandons the use of acid and alkali and can provide an eco-friendly degumming process for hemp fiber.

Electrochemical degradation of chloramphenicol using Ti-based SnO2-Sb-Ni electrode

Antibiotic residues may be very harmful in aquatic environments, because of limited treatment efficiency of traditional treatment methods. An electrochemical system with Ti-based SnO2-Sb-Ni anode was developed to degrade a typical antibiotic chloramphenicol (CAP) in water. The electrode was prepared by sol-gel method. The performance of electrode materials, impact factors and dynamic characteristics were evaluated. The Ti-based SnO2-Sb-Ni electrode was compact and uniform by the characterization of SEM and XRD. The electrocatalytic oxidation of CAP was carried out in a single-chamber reactor by using Ti-based SnO2-Sb-Ni electrode. For 100 mg L−1 CAP, the CAP removal ratio of 100% and the TOC removal ratio of 60% were obtained at the current density of 20 mA cm−2 and in neutral electrolyte at 300 min. The kinetic investigation has shown that the electro-oxidation of CAP on Ti-based SnO2-Sb-Ni electrode displayed pseudo first-order kinetic model. Free radical quenching experiments presented that the oxidation of CAP on Ti-based SnO2-Sb-Ni electrode resulted from the synergistic effect of direct oxidation and indirect oxidation (·OH and ·SO4−). Doping Ni on the Ti/SnO2-Sb electrode for CAP degradation was presented in this paper, showing its great application potential in the area of antibiotic and halogenated organic pollutants degradation.

Study on Chromaticity Removal from Mineral Processing Wastewater with Salicylic Hydroxamic Acid by Granular Activated Carbon Catalyzed Ozonation

Salicylic hydroxamic acid is a novel flotation reagent used in mineral processing. However, it impacts the flotation wastewater leaving behind high chromaticity which limits its reuse and affects discharge for mining enterprises. This study researched ozonation catalyzed by the granular activated carbon (GAC) method to treat the chromaticity of the simulated mineral processing wastewater with salicylic hydroxamic acid. The effects of pH value, ozone (O3) concentration, GAC dosage, and reaction time on chromaticity and chemical oxygen demand (CODCr) removal were discussed. The results of individual ozonation experiments showed that the chromaticity removal ratio reached 79% and the effluent chromaticity exceeded the requirement of reuse and discharge when the optimal experimental conditions were pH value 3, ozone concentration 6 mg/L, and reaction time 40 min. The orthogonal experimental results of catalytic ozonation with GAC on chromaticity removal explained that the chromaticity removal ratio could reach 96.36% and the chromaticity of effluent was only 20 when the optimal level of experimental parameters was pH value 2.87, O3 concentration 6 mg/L, GAC dosage 0.06 g/L, reaction time 60 min respectively. The degradation pathway of salicylic hydroxamic acid by ozonation was also considered based on an analysis with ultraviolet absorption spectrum and high-performance liquid chromatography (HPLC).

NH2-Fe-MILs for effective adsorption and Fenton-like degradation of imidacloprid: Removal performance and mechanism investigation

This investigation enables amino-functionalized metal–organic frameworks (MOFs) materials for the removal of imidacloprid (IMC). Two Fe-based MOF materials of NH2-MIL-88B(Fe) and NH2-MIL-101(Fe) both exhibited high adsorption capacity and Fenton-like degradation ability for IMC which were utilized to remove IMC from aqueous solution. Although the adsorption capacity of NH2-MIL-101(Fe) was higher than that of NH2-MIL-88(Fe), the degradation abilities of both MOF materials were similar. The removal efficiencies were evaluated through several basic studies, including concentrations of catalyst (0.12–0.3 g/L) and IMC (20–100 mg/L), pH of solution (3–11), and amounts of 30% H2O2 (0–2.0 μL/mL). By optimizing the above factors, the total removal ratio of IMC by NH2-MIL-88B(Fe) was as high as 93%, whereas the removal ratio of NH2-MIL-101(Fe) was 97%. Moreover, these MOF materials were proven to be stable and recyclable. The free radical quenching experiment and density functional theory calculation were applied to research the removal mechanism, and the hydroxyl radicals (·OH) was found to be the key active intermediate. The high catalytic efficiency can be attributed to the synergy of the Fe3+/Fe2+ redox cycle.

Parametric optimization of cyanobacterial coagulation at exponential and decline phases by combining polyaluminum chloride and cationic polyacrylamide

Microcystis spp. is the most common and problematic species during cyanobacterial bloom. This study employed Microcystis aeruginosa for coagulation experiments. Effects of polyaluminum chloride (PAC), cationic polyacrylamide (CPAM), and pH value on cyanobacterial removal at exponential and decline phases by coagulation were investigated by measuring chlorophyll a. A mathematical model between factors and response variables was established using response surface methodology (RSM). Results showed that factors of CPAM dosage, PAC dosage, and pH value could strongly affect the removal ratio of Microcystis at both exponential and decline phases. RSM revealed that the order of influence factors on the removal of chlorophyll a was CPAM > PAC > pH for Microcystis at the exponential phase, and these orders of CPAM > PAC > pH (PAC coagulation) and CPAM > PAC > pH (CPAM coagulation) were for Microcystis at the decline phase. It suggested that the growth phase of cyanobacteria was also quite important to optimize the coagulation process. Besides, a fitted model was developed, and it could well predict the removal ratio of chlorophyll a by coagulation with various treatments. The model recommended dosages of CPAM (3.72 mg/L) and PAC (10.23 mg/L) for Microcystis at the exponential phase with a pH value of 8.25, and dosages of CPAM (5.98 mg/L) and PAC (17.81 mg/L) were for Microcystis at the decline phase with a pH value of 8.21. Overall, these results would provide a technical guideline of combining PAC and CPAM to treat cyanobacteria at exponential and decline phases.

Removal of Suspended Solids Using Pumice Stone in Integrated Fixed Film Activated Sludge Process

Wastewater treatment plants operators prefer to make adjustments because they are more cost effective, to use the existing tank instead of building new ones. In this case an imported materials would be used as bio-loads to increase biomass and thus maintain efficiency as the next organic loading increases.In the present study, a local substance "pumice stone" was used as a biological carrier in the aeration tank, and the experiments were carried out in five stages: without biological carriers, filling ratio of 4%,10%,20%, and25% with pumice stone, the maximum organic loading at each stage (1.1884, 1.2144, 1.9432, 2.7768, 3.3141)g BOD /l.d respectively.Other experiments were carried out to determine the best filling ratio, the SS removal ratio was (67.57%, 69.5%,79.44%,89.61%,and 99.2%) when the filling ratio with pumice stone was (0, 4, 10, 20, and 25)% respectively, at organic loading 2 ± 0.0528 g BOD /l.d, so the best filling ratio of pumice stone was 25% . In this case an imported materials would be used as bio-loads to increase biomass and thus maintain efficiency as the next organic loading increases. In this research, a local substance "pumice stone" was used as a biological carrier in the aeration tank, and the experiments were carried out in five stages: without biological carriers, filling ratio of 4%,10%,20%, and25% with pumice stone, The maximum organic loading at each stage (1.1884, 1.2144, 1.9432, 2.7768, 3.3141)g BOD /l.d respectively. The SS removal ratio was when we operatio without biological carriers and with pumice stone with a filling ratio of 4% (82.86 % and 84.96 %) respectively, at organic loading 1.15 ± 0.0384 g BOD / d, the SS removal ratio when using pumice stone with a filling ratio of 4% and 10% was (80.36%, 91.59%) respectively, at organic loading 1.25 ± 0.024 g BOD /l.d The SS removal ratio when using pumice stone with a filling ratio of 10% and 20% was (79.44%, 91.23%) respectively, at organic loading 2 ± 0.0528 g BOD /l.d , and The SS removal ratio when using pumice stone with a filling ratio of 20% and 25% was (80.45 %, 92.28%) respectively, at organic loading 2.85 ± 0.0624 g BOD /l.d ,which means there is improvement in yield using pumice stone with filling ratio 4%,10%,20 and 25% by 2.1% ,11.23%,11.79% and 11.83%, respectively.