Production of Urea/Acetylated-ligninsulfonate Matrix as SRFs and Investigation the Effect of Hydrodynamic Conditions on the Release Rate Using Biot Number

Background: This study aimed to investigate the effect of the hydrodynamic condition on the release rate of urea/acetylated lignin sulfonate (Ac-LS) matrix as slow-release fertilizers (SRFs). Therefore, two models were developed using the mass transfer balance for the finite/infinite volume of fluids, solving finite integral transform/separation of a variable. In these models, the Biot number that verified the hydrodynamic condition appeared. Methods: In the experimental section, the urea/Ac-LS matrix fertilizer was produced. The morphological, thermal, chemical, and mechanical properties of the LS, Ac-LS, urea, and urea/Ac-LS matrix were analyzed using Fe-SEM, TGA, XRD, and SANTAM. Finally, the nitrogen release of the matrix fertilizer was investigated at 25°C for different impeller speeds. Results: The results showed that the thermal and mechanical resistance of urea/Ac-LS, with strong interaction, increased rather than pure urea or Ac-LS. The models were also validated using experimental data. The results further showed that in both states, the external resistance of the mass transfer decreased with increasing impeller speed, and the nitrogen release rate increased with increasing Biot number. Conclusion: It was also observed that, in a given hydrodynamic condition, initially, the release rate in the finite environment was less than the infinite; however, after a while, the type of environment did not affect the release rate

Application of Epoxy Resin for Improvement of the Banana Stem-Acoustic Panel

Background: Greener epoxidation by using vegetable oil to create an eco-friendly epoxide is being studied because it is a more cost-effective and environmentally friendly commodity that is safer than non-renewable materials. The aim of this research is to come up with low-cost solutions for banana trunk acoustic panels with kinetic modelling of epoxy-based palm oil. Method: In this study, the epoxidation of palm oleic acid was carried out by in situ performic acid to produce epoxidized palm oleic acid. Results: Banana trunk acoustic panel was successfully innovated based on the performance when the epoxy was applied. Lastly, a mathematical model was developed by using the numerical integration of the 4th order Runge-Kutta method, and the results showed that there is a good agreement between the simulation and experimental data, which validates the kinetic model. Conclusion: Overall, the peracid mechanism was effective in producing a high yield of epoxy from palm oleic acid that is useful for the improvement of acoustic panels based on the banana trunk.

Natural Organic Matter (NOM) Transformations and their Effects on Water Treatment Process: A Contemporary Review

One of the several significant concerns related to water treatment plants is the transformation of natural organic matter (NOM) concerning quality and quantity due to the changing climatic conditions. The NOM consists of heterogeneous functionalized groups. Phenolic and carboxyl groups are the dominant groups that are pH-dependent and show a stronger affinity towards the metals. Properties of natural organic matter and trace elements govern the binding kinetics, influencing cations' binding to functionalized groups at lower pH. The water treatment process mechanisms like adsorption, coagulation, membrane filtration, and ion exchange efficiencies are sturdily influenced by the presence of NOM with cations and by the natural organic matter alone. The complexation among the natural organic matter and coagulants enhances the removal of NOM from the coagulation processes. The current review illustrates detailed interactions between natural organic matter and the potential impacts of cations on NOM in the water and wastewater treatment facilities.

Application of Metal-organic Framework Materials (MOFs) in the photocatalytic CO2 Reduction：A mini review

In recent years, the effective use of CO2 has become one of the research hotspots worldwide to solve environmental pollution and energy shortage, whose excessive emission led to increasingly serious global environmental problems. Metal-organic frameworks (MOFs), with extraordinary specific surface areas, tunable surface chemistry, fast electron migration rate, large CO2 adsorption capacity, etc． are a new class of functional materials composed of metal ions/clusters and organic ligands, which have broad application potential in CO2 photocatalytic reduction. This paper systematically generalized the composition of the structure, discussed the methods of synthetics and expounded the photocatalytic properties and photocatalytic mechanism of MOFs. In addition, the application and research progress of MOFs functional materials in recent research are reviewed. The article also summarized challenges and prospects for the large-scale photocatalytic applications of MOFs catalysts. It guides the preparation of novel modified MOFs photocatalysts for high-efficiency applications in the field of CO2 reduction and photocatalytic degradation of dyes.

New Efficient Configurations for Sour Wastewater Treatment-

Background: Due to the technological development, the environmental legislations on pollutant concentrations in aqueous effluents tend to tighten and increase. As a result, sour water must be handled and processed properly to provide a high quality of stripped water with insignificant traces of NH3 and H2S in it. This must be achieved within the minimum operating costs. This research investigates the stripping configurations of sour water effluents from various industries. The research also offers an insight on different scenarios and configurations to accomplish set targets satisfying the environmental law criteria. Methods: This research introduces a range of heat integration schemes for better energy savings, further vapor recompression VRC technique is opted for its ability to maximize energy savings. This research analyses the effect of operating and design variables on the stripped water quality such as feed temperature, feed location, reflux split, and steam flow rate. The option of adding new equipment is also addressed to maximize heat integration and enhance the efficiency of the process. Thus, several schemes and process configurations are explored to treat industrial sour water waste streams seeking better efficiency. These configurations differ from one another in heat integration layout and whether VRC is utilized or not. Energy efficiency and economics of the proposed configurations are considered as decisive factors in this research study. The case study adopted are based on published data taken from some iron and steel factories in South Korea named POSCO (Pohang Iron and Steel Corporation). Results: Results of the treated wastewater streams guarantee that the effluent sour water obeys standard environmental regulations, i.e., NH3 contents range from 30 to 80 ppm and H2S concentration falls below 0.1 ppm. The obtained results of the seven different scenarios are compared to the original case study. It is found that scenario 7 is the most economical solution saving 51.54 % in total annual cost when compared to the original case study, while satisfying the treated water environmental regulations with a concentration of 3.19 ppm NH3 and 0.05 ppm H2S. Scenario 7 creates its own steam unlike the original case study where steam utility is needed extensively. However, scenario 7 consumes 15 % more electricity than the original case study but still shows 56.34 % less utility cost in overall. Conclusion: The optimum process configuration can be employed for other sour water purification systems such as those from petroleum refiners. An ongoing research work is focusing on the use of internal heat integration for more energy savings and economics improvement.

Diffusion and surface reaction in porous cubical catalyst: A mathematical approach

Background: Catalysts are the most vital part of any chemical industry. Catalyst is a substance that affects the rate of reaction, but the catalyst itself does not take part in the reaction. Catalysts offer different pathways of reaction by diffusing the reactant inside it to provide a large surface area within a small volume, thus, lowering the activation energy of molecules for reaction. Most of the catalytic reactions take place in liquid-solid or gas-solid interface where catalysts are mostly porous in nature. Spherical and cubic-shaped catalyst particles are commonly used in different industries. Methods: In the first phase of the present study, the physics behind the diffusion inside the catalyst pellet has been discussed. In the second part, governing differential equations have been established at a steady-state condition. For solving the differential equation, the equation is made dimensionless. Physical boundary conditions were used to solve the diffusion equation. The assumption of writing the differential equation of the reaction is elementary. Then the Thiele modulus is derived in terms of the reaction and geometrical parameter (Length) Results and Conclusion: In the third part, the differential equation is solved for first-order reaction with some constant values of the Thiele modulus and three-dimensional plots are obtained using numerical analysis. After that, the obtained Thiele modulus and effectiveness factor plot are compared to draw the conclusion of reaction rate limited and internal diffusion limited.

Energy and Exergy Analyses of Fresh Water and Air Conditioning Production

Objective: For a combined generation of fresh water and air conditioning, the humidification-dehumidification and vapor compression refrigeration (HDH-VCR) cycle is the best option as it works at ambient pressure without handling any chemicals. Methods: The HDH cycle works on the principle of an artificially created water cycle. Air can be humidified either with heating and humidification or with the cooling and humidification process. The heating and humidification are well analyzed and the results are reported in the open literature. This work is focused on cooling and humidification for freshwater generation and air conditioning. In the current thermodynamic simulation, the identified key process conditions are evaporator temperature and ambient air conditions (temperature and relative humidity. Results: The focused results are specific desalination, specific cooling, energy performance ratio (EPR), and exergy efficiency. Conclusion: The resulted EPR for cycle and plant are 1.34 and 0.62 respectively at the evaporator temperature of -2 °C.

Research Progress on Oil Sludge Treatment in Oilfield: A Mini-Review

: A large amount of sludge produced in the processing of crude oil has brought great harm. In this paper, common flocculants are summarized. According to the treatment process of crude oil, flocculants are divided into organic flocculants, inorganic flocculants, microbial flocculants, composite flocculants, and magnetic flocculants. The mechanism and limitation of each flocculation on crude oil sludge were analyzed. Finally, it is pointed out that the flocculation process of sludge is complex, and the development of new flocculant with high efficiency, safety, and economy is the main trend of flocculant development in the future.