Heavy metals [chromium (VI) and lead (II)] removal from water using mesoporous magnetite (Fe3O4) nanospheres

An increase of organic waste coming from different humans and productive activities is a continuous concern, and their application in soil is proposed many times as a solution to disposal problem. In agricultural soil, this practice is actually more popular because of its contribution as a fertilizer and soil enhancement. Recently, increased interest has been focused on assessing the influence of organic waste added to the soil related to pesticides behavior. The studies carried out show that addition of organic matter and nutrient mainly can affect the adsorption, movement, and biodegradation of pesticides. This review shows the factors involved, trend, and result obtained with pesticide behavior in soil amendment. Contradictory trends are reported in the literature on the pesticides' fate. These are mainly because soil type differences, pesticide characteristics, and source amendment are difficult to organize in a tendency pattern, and can significantly complicate the understanding of pesticides fate.

Influence of Organic Amendment on the Biodegradation and Movement of Pesticides

We discuss the thermodynamics of physical adsorption of gases in porous solids. The measurement of the amount of gas adsorbed in a solid requires specialized volumetric and gravimetric techniques based upon the concept of the surface excess. Excess adsorption isotherms provide thermodynamic information about the gas-solid system but are difficult to interpret at high pressure because of peculiarities such as intersecting isotherms. Quantities such as pore density and heats of adsorption are undefined for excess isotherms at high pressure. These difficulties vanish when excess isotherms are converted to absolute adsorption. Using the proper definitions, the special features of adsorption can be incorporated into a rigorous framework of solution thermodynamics. Practical applications including mixed-gas equilibria, equations for adsorption isotherms, and methods for calculating thermodynamic properties are covered. The primary limitations of the absolute adsorption formalism arise from the need to estimate pore volumes and in the application to systems with larger mesopores or macropores at high bulk pressures and temperatures where the thermodynamic properties may be dominated by contributions from the bulk fluid. Under these circumstances a rigorous treatment of the thermodynamics requires consideration of the adsorption cell and its contents (bulk gas, porous solid and confined fluid).

Physical adsorption of gases: the case for absolute adsorption as the basis for thermodynamic analysis

In this study, activated carbon (AC) based adsorbents were synthesized from biomass-derived hydro-char (HC) through modified hydrothermal carbonization (HTC) process coupled with H3PO4 (PA), ZnCl2, (ZnCl), and KOH thermochemical activation with a specific impregnation ratio of 1:3 (HC/activating agent) at 600 °C. The prepared ACs were characterized through CHN-S analyser, XRD, SEM/EDS, BET, TGA, and FTIR analysis. The modification in textural and surface morphology has been observed. Thermochemical activation results in surface modification of AC samples with a higher specific (SBET) surface area having a range of 650−1225 m2/g, large microporous volume (VμD-A, VμD–R) up to 0.624 and 0.642 cm3/g with 68–90 % micro-porosity. The CO2 adsorption capacity was examined through a high-pressure gas sorption analyser at a pressure of 0−16 bar and temperature of 15 °C, 30 °C, and 45 °C. At 15 °C of temperature, AC-PA showed the adsorption capacity of 130 and 958 mg/g, while AC-ZnCl exhibited 160 and 836 mg/g of adsorption at 1 and 16 bar of pressure respectively. Whereas AC-KOH exhibited a notable CO2 adsorption capacity of 198 and 1560 mg/g at 1 and 16 bar of pressure (15 °C). Furthermore, experimental equilibrium data of CO2 adsorption were analysed by applying Freundlich, Langmuir, Redlich-Peterson, Sips, and Toth isotherm models and validate these models by calculating the regression coefficient (R2), and standard deviation Δq (%). Finally, the thermodynamics parameters (ΔH°, ΔS°, ΔG°, and ΔHIsosteric) were evaluated and concluded that the adsorption of CO2 (adsorbate) on adsorbent is spontaneous and exothermic.

Synthesis and characterization of biomass-derived surface-modified activated carbon for enhanced CO2 adsorption

Experimental study and numerical simulation for a storehouse fire accident

Simulation of an experimental compartment fire by CFD

Dubinin-Astakhov (D-A) equation is used for determining the micropore volume and surface area of zeolite molecular sieves (ZMS) by using physisorption measurements. Likewise, Dubinin-Radushkevich (D-R) equation is used for the estimation of these parameters for carbon molecular sieves (CMS), and, unlike D-A equation it does not require the estimation of the exponent n. In this paper, surface area and micropore volume of 13X molecular sieves (MS) have been determined by using both D-A and D-R equations. The results by both equations are in very good agreement. Therefore, D-R equation may also be used for estimation of these parameters because its application is simple and easier.

/pdf/determination-of-micropore-volume-and-surface-area-of-4t9f7jkskb.pdf

Determination of micropore volume and surface area of zeolite molecular sieves by D-R and D-A equations: A comparative study

http://dzumenvis.nic.in/Biodegradation/pdf/Sensitivity%20analysis%20of%20biodegradation%20of%20soil.pdf

Sensitivity analysis of biodegradation of soil applied pesticides using a simulation model

This paper presents an algorithm for obtaining the inverse of a tridiagonal matrix numerically. The algorithm does not require diagonal dominance in the matrix and is also computationally efficient.

Shashi

Papers

Simulation of an experimental compartment fire by CFD

Determination of micropore volume and surface area of zeolite molecular sieves by D-R and D-A equations: A comparative study

Sensitivity analysis of biodegradation of soil applied pesticides using a simulation model

An algorithm for the numerical inversion of a tridiagonal matrix

A case-based analysis of the competitiveness of the North Indian sugar industry