Adsorption Beds: The Significance of Thermodynamic Properties and Particle Size on System-Level Heat Pump Performance

The performance of an adsorption heat pump is a function of the equilibrium uptake and diffusion resistances of a particular system, which determine the refrigerant throughput during a cycle. Previous studies have sought improved sorption bed performance by increasing heat transfer; however, some of the proposed heat exchanger enhancements represent costly alterations to the system. This work instead investigates a method for optimizing sorption bed mass transfer, which can be implemented as a low-cost alternative to heat transfer enhancement or in addition to it. The objective is to balance the intra-particle diffusion resistance, which increases with adsorbent particle diameter, with the inter-particle pressure drop, which decreases with adsorbent particle diameter. A silica gel-water system model is used to show that the optimal particle geometry in a packed bed yields a 48% improvement in cooling duty and over 50% increase in COP compared with larger particles (dp = 1.42 mm).

INVESTIGATION OF THE INFLUENCE OF PARTICLE SIZE OF RICE HUSK ASH AS ADSORBENT FOR MERCURY IN COLUMN ADSORPTION SYSTEM

The presence of heavy metal mercury (Hg2+) in liquid waste has caused serious problems to environmental pollution. One of the most effective method to reduce the levels of heavy metals mercury (Hg2+) in liquid waste is adsorption. Rice husk ash is highly potential to adsorb heavy metals in water because it is a porous material with a high silica content. Therefore, rice husk ash can be used as an adsorbent for heavy metals in liquid waste. The purpose of this study was to determine the level of mercury (Hg2+) that can be adsorbed from the column adsorption process using adsorbent of rice husk ash and to determine the optimum mass of rice husk ash as an adsorbent. The research was conducted using a series of simple adsorption column tools with a circulation time of 120 minutes. While the independent variables were adsorbent particle size of 50, 100, and 200 mesh. Measurement of mercury (Hg2+) levels was carried out on samples before and after treatment with Atomic Absorption Spectrophotometer (AAS). The results showed a significant decrease in Hg2+ levels with the optimum adsorbent particle size of 200 mesh. The value of the adsorbed Hg2+ ion content reached 101.670 mg/L in the adsorption process using adsorbent with 200 mesh particle size .

Thermodynamic Studies of The Removal of Lead From Synthetic Wastewater Using Cyperus Rotundus

This research wasaccomplished to appraise the performance of Cyperus Rotundus Stalk (CRS) in adsorption of lead heavy metalofaquatic environments. For this purpose, the batch system was used for review the effect pH, Mixing time, adsorbent particle size and temperature for Pb(II) removal on the CRS. The highest lead removal efficacy was achieved in pH=6 and it was considered as the optimum pH. The result indicated the maximum Pb(II) adsorption at the contact time of 90 min which implies that increase in contact time lead to a higher lead uptake.The amount of R2using the pseudo-second-order are greater than compare with others models.Influence of temperature was determined byusing thermodynamic parameters and the results showedremoval of lead on the CRS was endothermic, spontaneousandfeasible.

UTILIZATION OF ZEOLITS FOR WATER FILING

<p>This study aims to obtain zeolite powder from Sarulla natural zeolite as an adsorbent, particle size of zeolite powder, and water analysis before and after water purification. The benefit is to increase the benefits of zeolite to a higher economic value.The method used is the grinding mill method to smooth the zeolite chunks. Whereas the water purification process uses a screening process.The results of this study were zeolite produced at 200 mesh or 74 microns, and the purification was successfully carried out.The conclusion of this study is that zeolite powder obtained from Sarulla natural zeolite as an adsorbent, obtained zeolite particles namely 200 mesh or 74 microns, and the water purification process was successfully carried out.</p>

Elimination of Lead Ions from Aqueous Environment by Waste Tires Rubber

The investigation goes through paper to taking away of lead ions from aqueous medium by waste tire rubber granules(WTRG). The effect of various operational parameters like period of time, original metal concentration, size of adsorbent particles, adsorbent dose, and PH of medium on the adsorption ability of WTRG was evaluated. The kinetic of the adsorption process was relatively fast with approximately one hour of equilibrium time. A tiny adsorbent particle size (0.04 mm), PH medium (5-6) preferential the adsorption process. Data of isotherm studies exposed that adsorption of Pb(II) was well expressed by the Langmuir isotherm formula (R2=0.993). The study demonstrated the ability of WTRG to remove lead from aqueous environment as a cheap and available material. The use of WTRG exhibited the safe disposal of solid waste. Hence its with double benefit for environment.

Zinc (Zn) Removal from Textile Wastewater by Saw Dust Fixed Bed Column

The textile industry has been recognized as one of the industries that produces high dischargedrate of wastewater with high volume and composition of contaminants to the environment. Zinc(Zn) is one of the contaminant that commonly found in textile wastewater. An investigation onthe capability of saw dust to remove Zn in the textile wastewater was done. The abundance of sawdust produced from the saw mill will bring adverse effects on the environment. In this study, aninvestigation of Zn removal was carried out by using saw dust fixed bed column. The effect oftypes of sawdust, adsorbent dosage and adsorbent particle size to the Zn removal was studied. Theresults showed that the carbonized sawdust with 15g of adsorbent dosage and 150?m of adsorbentparticle size gives the highest percentage of Zn removal with lowest time taken. This studyindicates that sawdust has the potential to be employed as an adsorbent for Zn removal in textilewastewater.

Using Phragmites australis(Iraqi plant) to remove the Lead (II) Ions form Aqueous solution.

Lead remediation was achieved using simple cost, effective and eco-friendly way from industrial wastewater. Phragmitesaustralis (P.a) (Iraqi plant), was used as anovel biomaterial to remove lead ions from synthesized waste water. Different parameters which affected on adsorption processes were investigated like adsorbent dose, pH, contact time, and adsorbent particle size, to reach the optimized conditions (maximum adsorption). The adsorption of Pb (?) on (P.a) involved fast and slow process as a mechanism steps according to obey two theoretical adsorption isotherms; Langmuir and Freundlich. The thermos dynamic adsorption parameters were evaluated also. The (?H) obtained positive value that meanes adsorption of lead ions was an endothermic processwhile (?G)values were negative which means that adsorption of lead ions was a spontaneous process and the decrease in (?G) with temperature increasing revealed that lead ions adsorption on (P.a) became favorable with temperature increasing

Adsorpsi Logam Tembaga (Cu), Mangan (Mn) dan Nikel (Ni) dalam Artificial Limbah Cair dengan Menggunakan Nanopartikel Magnetit (Fe3O4)

<p>Magnetite (Fe3O4) nanoparticles have been successfully synthesized using co-precipitation method and have been used for removing Cu, Mn and Ni metals ions from artificial wastewater. Ability of removing metal ions with Fe3O4 against pH, adsorbent particle size, readsorption and by addition of Polyethylene Glycol (PEG-4000) as coating agent of adsorbent have been studied. The adsorption process was found to be pH-dependent. Maximum adsorption at pH 12 for most of the metal ions with percent of sorption Cu 99.79%, Ni 69.83% and Mn 44.53%. Using adsorbent with 12 nm of particles size, readsorption process and by addition of Polyethylene Glycol (PEG-4000) as coating agent of adsorbent also made the ability of removing metals ions increasing. Preliminary results indicate that magnetite nanoparticles may be used as an adsorbent for removal of Cu, Mn and Ni from wastewater.</p>