Self-driven electrochemical system for struvite and energy recovery from digested wastewater: Device optimization strategy and long-term operation.

A self-driven electrochemical system (SDES) was utilized to treat anaerobic digestate wastewater, aiming to achieve wastewater resource utilization and energy generation. The efficiencies of pollutant removal, resource recovery, and energy production were enhanced by adjusting device parameters (anode area, external resistance, and electrode spacing). The high pollutant removal rates and struvite purity were achieved with the magnesium anode area of 15 cm, external resistance of 10 Ω, and electrode spacing of 10 cm.

Optimization Design of Submerged-Entry-Nozzle Structure Using NSGA-II Genetic Algorithm in Ultra-Large Beam-Blank Continuous-Casting Molds.

To achieve uniform cooling and effective homogenization control in ultra-large beam-blank molds necessitates the optimization of submerged-entry-nozzle (SEN) structures. This study employed computational fluid dynamic (CFD) modeling to investigate the impact of two-port and three-port SEN configurations on fluid flow characteristics, free-surface velocities, temperature fields, and solidification behaviors. Subsequently, integrating numerical simulations with the non-dominated sorting genetic algorithm II (NSGA-II) and metallurgical quality-control expertise facilitated the multi-objective optimization of a three-port SEN structure suitable for beam-blank molds.

Condition optimization of iron-air fuel cell to treat phosphate-containing wastewater regarding sustainable development.

Increasing use of phosphorus products and excessive exploitation of phosphorus resources become two major problems in perspective of phosphorus sustainable development. Phosphorus recovery is the shortcut to solve this dilemma. Combining electrochemistry, an iron-air fuel cell was adopted to recover phosphate and electricity from phosphate-containing wastewater in our previous studies.

A Stochastic Filling and Modeling Algorithm of Non-Equal Diameter Particles with Specified Probability Density for Porous Permeable Materials.

In this paper, a model generation algorithm for non-equal diameter particles with a specified probability density distribution is proposed. Based on considering the randomness of the size and distribution of the particles, the compact stacking of the particles is realized by the compactness algorithm, and then the spatial distribution of the tightly compacted particles is made to meet the random distribution of the specified probability density and the specified volume fraction by the filtering algorithm. The computational efficiency and effectiveness of the algorithm are verified, and the effects of the particle size and volume fraction on the distribution are analyzed.

Application of a blast furnace slag carrier catalyst in flue gas denitration and sulfur resistance.

It is an urgent need to develop a new catalyst with high efficiency and low cost. In the present study, we successfully prepared bimetallic-supported denitration catalysts using the blast furnace slag as the main material and calcium bentonite as the binder. The as-prepared catalyst was characterized X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM).

Aggregation enhances the activity and growth rate of anammox bacteria and its mechanisms.

The aggregation of anaerobic ammonium oxidation (anammox) bacteria is important for the start-up and biomass retention of anammox processes. However, it is unclear whether it is beneficial to the activity, growth and reproduction of anammox bacteria. In this study, four reactor systems were developed to explore the effects of aggregation on anammox activity, growth and reproduction, after excluding the contribution of aggregation to sludge settling and retention.

Ultrasonication-Assisted Preparation of a Mn-Based Blast Furnace Slag Catalyst: Effects on the Low-Temperature Selective Catalytic Reduction Denitration Process.

Reducing costs and improving performance have always been hotspots in the field of catalyst research. In order to control the NO in the low-temperature flue gas of nonpower industries, this paper studies the denitration performance of the ultrasonication-assisted preparation of Mn-based blast furnace slag selective catalytic reduction (SCR) low-temperature denitration catalysts. The catalyst was characterized by FT-IR, XRD, and SEM.

Study on Denitration Performance of Solid Waste Blast Furnace Slag Catalysts under Different Preparation Processes.

In this article, blast furnace slag, a high-yield industrial solid waste, was taken as the research object and it was used as the main material. Bentonite was used as the binder, and water was added to shape the blast furnace slag into a small column. The denitration catalyst was prepared using different methods, its denitration performances were compared and analyzed, and the best preparation method and process parameters were screened.

Study on denitration and sulfur removal performance of Mn-Ce supported fly ash catalyst.

Nitrogen oxides (NOx) are the main pollutants of air, which mainly come from the combustion of coal and fossil fuels. In this paper, with fly ash used as the catalyst carrier, the effects on the denitration and sulfur resistance of Mn-Ce loading sequence and molar ratio were studied. The catalyst was characterized and analyzed by XRD, XPS, SEM.

Gas-Modified Pyrolysis Coke for in Situ Catalytic Cracking of Coal Tar.

Modified pyrolysis coke can be used as a catalyst for tar cracking. In this paper, pyrolysis coke was used as a carrier for modification by using gases (HO, CO, and NH), and the optimal modified gas was selected. On the basis of this, pyrolysis coke with different modified flow rates, temperatures, and times were prepared to catalyze the cracking of tar.

MnOx-CuOx cordierite catalyst for selective catalytic oxidation of the NO at low temperature.

Low-value solid waste cordierite honeycomb ceramics were used as carrier of SCO denitration catalyst, and the active component was supported by the impregnation method to improve the performance of the catalyst. Firstly, the effect of calcination conditions on the denitration performance of the Mn-loaded cordierite catalyst was studied for the cordierite-loaded active component MnO. Secondly, the preferred catalyst was reloaded with another active component to further improve its denitration performance; the bimetal ratios were affected by the denitration performance, which was, finally, characterized by XRD, XPS, and SEM.

Study on the Pressure Bearing Capability of Folded Multi-Port Flat Tube.

The pressure bearing capability of a folded multi-port flat tube (MPFT), which has the advantage of retaining the corrosion property of corrosion resistant materials, was investigated in this study with both a burst pressure test and finite element simulation. Results show that the folded tube's failure is mainly caused by the breaking of the inner ribs. Instead of detecting inner pressure, the bulging ratio, which is supposed to be small under service pressure, rises rapidly before failure.

Preparation and mechanism research of Ni-Co supported catalyst on hydrogen production from coal pyrolysis.

The combustible gas produced by coal pyrolysis can be used as a clean fuel to reduce environmental pollution caused by coal combustion. In order to improve the efficiency of coal pyrolysis to prepare flammable gases, Ni-Co supported pyrolysis catalysts were prepared by equal volume impregnation method using the pyrolysis coke of different pyrolysis final temperatures as the carrier in this study. The effects of different pyrolysis final temperatures and different metal loadings on pyrolysis products were studied.

Application of Plasma Treatment in Preparation of Soybean Oil Factory Sludge Catalyst and Its Application in Selective Catalytic Oxidation (SCO) Denitration.

At present, the most commonly used denitration process is the selective catalytic reduction (SCR) method. However, in the SCR method, the service life of the catalyst is short, and the industrial operation cost is high. The selective catalytic oxidation absorption (SCO) method can be used in a low temperature environment, which greatly reduces energy consumption and cost.

Study on the Preparation of Plasma-Modified Fly Ash Catalyst and Its De⁻NO Mechanism.

Fly ash and bentonite were mixed in a certain proportion as raw materials to prepare a denitration catalyst. In previous studies, it has been concluded that fly ash-type catalysts can provide significant catalytic activity for denitrification after being modified with oxygen. In this study, the effect of plasma conditions on the denitration performance of the catalyst was investigated from the aspects of plasma modification power, modification time, and the flow rate of the gas.

Study on the NO removal efficiency of the lignite pyrolysis coke catalyst by selective catalytic oxidation method.

Selective catalytic oxidation (SCO) method is commonly used in wet denitration technology; NO after the catalytic oxidation can be removed with SO2 together by wet method. Among the SCO denitration catalysts, pyrolysis coke is favored by the advantages of low cost and high catalytic activity. In this paper, SCO method combined with pyrolysis coke catalyst was used to remove NO from flue gas.