Bioremediation Potential of the Macroalga Ulva lactuca (Chlorophyta) for Ammonium Removal in Elastomer Industry Wastewater

During the production of nitrile rubber, significant amounts of nitrogen in the form of ammonium are generated in the wastewater. The discharge of this high-nitrogen wastewater can lead to serious environmental issues, including eutrophication, disruption of aquatic ecosystems, and groundwater contamination. To mitigate these impacts, this research explored the bioremediation capabilities of the macroalgae Ulva lactuca (Chlorophyta) for removing nitrogen from nitrile rubber production wastewater. The study employed single-phase and Michaelis-Menten decay models based on ammonium consumption, using various dilutions of wastewater to identify the optimal concentration for treatment. The physiological state of the macroalgae was monitored by measuring the photosynthetic capacity and specific growth rate during the experiments. In the presence of U. lactuca, ammonium concentrations decreased in all treatment groups, confirming that the ammonium kinetics conformed to both applied models. Our results show that U. lactuca effectively reduces ammonium concentrations, with an approximate removal rate of 0.020 µM·g−1·min−1 across different wastewater concentrations (70%, 80%, 90%, and 100%). Notably, the treatments with 70%, 80%, and 90% wastewater strength achieved about 67% reduction in ammonium, demonstrating the alga’s capacity to treat high-nitrogen wastewater. The photosynthetic performance of U. lactuca initially declined in control conditions but stabilized across all treatments, highlighting its adaptability. The kinetic analysis using the Michaelis-Menten model indicated a Vmax of 1342 μM·g−1·DMh−1, suggesting a robust capacity for ammonium uptake when fully saturated. Our study underscores the potential of Ulva lactuca as a cost-effective and efficient agent for wastewater bioremediation, particularly in settings with high nitrogen loads.

Stationary Measures of Three-State Quantum Walks with Defect on the One-Dimension Lattice

In this paper, we focus on the space-inhomogeneous three-state on the one-dimension lattice, a one-phase model and a two-phase model include. By using the transfer matrices method by Endo et al., we calculate the stationary measure for initial state concrete eigenvalue. Finally we found the transfer matrices method is more effective for the three-state quantum walks than the method obtained by Kawai et al.

The Research on Grounding Protection for 110kV Resistance Grounding Distribution System

Using the neutral grounding method by the resistance in 110?kV system, it can limit the voltage sag and short circuit current when one-phase grounding fault occurred, but it will change the sequence of the network structure and parameters. This paper analyzes the size and distribution of zero sequence voltage and current when one-phase grounding fault occurred in the 110 kV resistance grounding system, and puts forward the grounding protection configuration setting principle of this system combining the power supplying characteristics of 110?kV distribution network. In a reforming substation as an example, the grounding protection of 110 kV lines and transformer have been set and calculated.

Comparative Investigation of Two Random Medium Models for Concrete Mesostructure

Concrete is intrinsically endowed with randomness on meso-scale due to the random distribution of aggregates,mortar,etc.In this paper,two random medium models of concrete mesostructure are developed and comparative studies are provided based on random field representation approach.In the first place,concrete is considered as a kind of one-phase random field,where stochastic harmonic function is adopted as the approach to simulate the random field.Secondly,in order to represent the stochastic distribution of the multi-phase of concrete such as aggregates and mortar,two-phase random field based on the Nataf transformation and the Hermite polynomials are introduced.Then,the proposed two random medium models are testified by the multi-scale simulation results,specifically,the mean value of the homogenized stress-strain relationship and the damage evolution curve.Meanwhile,the generalized density evolution equation is utilized to measure the consistency of these two random medium models by the probability distribution of damage.

The Research of Voltage Sag and Power Frequency Overvoltage on 110kV Resistance Grounding System

This paper researches the voltage transfer characteristics when one-phase ground fault occurred in the resistance grounding system, by using the theory of the asymmetric variable characteristics and the sequence network analysis of the -11 transformer, and concludes the scope of voltage sag and swell and the degree of power frequency overvoltage and their influencing factors in the 110 kV resistance grounding system. Accordingly this paper puts forward the resistance choosing principle: the resistance grounding coefficient must be equal to or greater than 10. So it can not only wipe out the voltage sag and voltage swell but also make sure the overvoltage is limited to electrical equipment allowing range. The method mentioned above is verified by simulation results of a 110 kV power system in ATP.

Can Electricity Be New?

A new electrical power transmission system using a single wire only is described. One hundred and twenty years on the globe, two or three wires systems work. The new method does not use the ground to transmit energy. The wire may be in air, in land, or in water. One-wire method will reduce the cost of lines several times. The global changes like these will require to change the long-established of scientific and technical approaches. Even considering that the single-wire method has tremendous economic and technical advantages, changing concepts and consciousness is always a long and painful process. In article is shown all new blocs, necessary to go to one wire method. All methods and blocks were checked by simulations and system models developing.

Blowup of the Solutions for a Reaction-Advection- Diffusion Equation with Free Boundaries

We investigate a blowup problem of a reaction-advection-diffusion equa-tion with double free boundaries and aim to use the dynamics of such a problem to describe the heat transfer and temperature change of a chemical reaction in advective environment with the free boundary representing the spreading front of the heat.We study the influence of the advection on the blowup properties of the solutions and con-clude that large advection is not favorable for blowup.Moreover,we give the decay estimates of solutions and the two free boundaries converge to a finite limit for small initial data.

Mean Velocity Estimation of Viscous Debris Flows

The mean velocity estimation of debris flows, especially viscous debris flows, is an important part in the debris flow dynamics research and in the design of control structures. In this study, theoretical equations for computing debris flow velocity with the one-phase flow assumption were reviewed and used to analyze field data of viscous debris flows. Results show that the viscous debris flow is diffficult to be classified as a Newtonian laminar flow, a Newtonian turbulent flow, a Bingham fluid, or a dilatant fluid in the strict sense. However, we can establish empirical formulas to compute its mean velocity following equations for Newtonian turbulent flows, because most viscous debris flows are tur- bulent. Factors that potentially influence debris flow velocity were chosen according to two-phase flow theories. Through correlation analysis and data fitting, two empirical formulas were proposed. In the first one, velocity is expressed as a function of clay content, flow depth and channel slope. In the second one, a coefficient representing the grain size nonuniformity is used instead of clay content. Both formulas can give reasonable estimate of the mean velocity of the viscous debris flow.