Static adsorption experiments

This section reviews static adsorption experiments which were performed by Borchardt [40] to determine the effect of olefinsulfonate chemical structure on... 

Effect of Pol3rmer. In recent years, as described previously, much attention, both experimental and theoretical, has been focused on surfactant-polymer interaction in solution. Less experimental work, however, is done on the interaction between polyelectrolyte and surfactant of similar charge at the solid-liquid interface. Static adsorption experiments from the chemical literature indicate that the polymer does not affect the adsorption of the surfactant onto solid material as long as the surfactant concentration is above the CMC, apparently owing to the availability of sufficient surface sites for adsorption of the surfactant molecules [40, 41],... 

For a bulk static adsorption experiment, a given amount of adsorbent substrate of total surface area, A, is put into a volume V of polymer solution of initial concentration, (mass/unit volume of solution). When the adsorption has reached equilibrium, the bulk solution concentration, C2, is then measured and the difference is denoted by AC (= — C2). The surface... 

In their review of static adsorption experiments with HPAM Lakatos et al. (1979) concluded that ... 

Static adsorption experiments were carried out by placing equal weights of carbonized nanofibers into each of 40 rtiL vials sealed with a septum cap and then adding aqueous solutions of monochloroacetic acid of varied initial concentratiorrs. After the vials were prepared they were placed in a shaker under mild mixing for 2 days at 25 °C. The initial and residual concentrations for each sample were meastrred after 2 days. The amount of chloroacetic acid adsorbed (mg/g) was calculated from the difference in concentrations between the initial (CJ and residual or equilibrium (C) solutions. 

RCCM showed considerable adsorption properties for citric acid [54]. Static adsorption experiments were carried out to study the adsorption kinetics and thermodynamics of citric acid on RCCM. The results indicated that the adsorption of RCCM on citric acid followed the Langmuir isotherm. The adsorption followed second-order kinetic equation. The adsorption rates of citric acid on RCCM were controlled by the intraparticle diffusion. 

FTIR can be used to screen membranes for fouling tendencies prior to the first ultrafiltration experiment. Screening can be done by means of a simple static adsorption test. Membranes showing greater static adsorption are expected to foul more during ultrafiltration and are disfavored. Figure 8 illustrates the FTIR results... 

Barrett and Thomas (10)proposed that these effects of differential monomer adsorption could be modeled by correcting homogeneous solution copolymerization reactivity ratios with the monomer s partition coefficient between the particles and the diluent. The partition coefficient is measured by static equilibrium experiments. Barrett s suggested equations are ... 

Figure 2. Apparatus used in static fissure adsorption experiments...

Results obtained previously by the authors [8] have shown that the static adsorption capacities of several commercially available ACs, conformed as monolith composites, towards o-DCB were directly related to their micro and narrow mesopore volumes. Of the original twelve ACs studied in these static adsorption measurements the four most promising materials were selected for further study in dynamic adsorption experiments. These samples... 

In order to evaluate the VOC adsorbing capacity, several small ceramic rotor (10cm diameter, 40cm length) were prepared, and the adsorption and desorption characterstics were measured using static adsorption / desorption test equipment. In the experiment, VOC laden gas was artificially made and provided by bubbling air into VOC liquid. The concentration of the VOC was adjusted between 150 ad 420 ppm, and its flow rate was from 150 to 600 liter/min. 

Zeolite impregnated ceramic rotor was put into the sample chamber of static adsorption / desorption tester, the diameter and length of which are lOqm and 40cm, respectively. Toluene, MEK, cyclohexanone were aerated by compressed air and mixed with air in a line mixer, where a required concentration of a VOC of the experiment was adjusted. As the produced VOC was supplied to the sample chamber, the concentration of the VOC after passing through adsobent was measured with total hydrocarbon analyzer (model Horiba THC-510). After the concentration of the VOC reached 40 ppmv, supply of VOC laden air was stopped, and hot air through electric heater for desorption was supplied to the adsorbent in a reverse direction compared to adsorption step, and the concentration of the VOC at the outlet of the sample chamber was measured. 

The in sim characterization of catalysts was earned out in an apparatus which included a quadiupole mass-spectrometer and a gas chromatograph for TPO and H2 chemisorption measurements. In situ coking was performed by injecting a mixture of He and n-hexane vapor over the reduced catalysts at 500 C, In TPO experiments, ihe coked sample was heated at a rate of 8 C/min in a stream of 2 voL% O2 + 98% He. The amount of CO2 produced was recorded. The chemisorption of H2 was carried out in the same appanitus by a flow method after reduction or caking. The flow rate of carrier gas (Ar) was maintained at 25 ml/min and the volume of H2 injected was 0.062 ml/pulse. Since the partial piessiire of H2 was very low in this system, the hydrogenation of coke was never observed. Isobaric H2 chemisorption measurements with fresh catalysts were carried out in a static adsorption apparatus. Dehydrogenation of n-butane was carried out in a flow micro-rcactor in H2 atmosphere at LHSV = 3 h-l and H2/HC=1. Reaction products were... 

There are large differences between the level of static adsorption of HPAM and dynamically retained level in a core or pack (Lakatos et al., 1979). These differences are the result of changes in the specific surface area of consolidated and unconsolidated packs and also the accessibility of certain portions of the pore space. These differences also depend on the extent of mechaifical retention that is present in the dynamic core flood experiment. Polymer retention in consolidated porous media cannot be determined with static bulk adsorption (batch adsorption techniques) because the process of disaggregation to obtain... 

Adsorption of NH3, C02 and H2 on the carriers and the supported Pd catalysts was carried out 1n conventional static system. The supported Pd catalysts were reduced by 13.3 kPa of H2 at 773 K for 1 h and evacuated under 10-2 Pa just before the adsorption experiments in the apparatus. The amounts of adsorbed gases were measured at 13.3 kPa for NH3 and CO2, and 1.33 kPa for H2 at r.t. The IR spectra of adsorbed pyridine on the carriers and the supported Pd catalysts were measured with an Analect fx-6200 spectrometer. The ESR spectra of adsorbed phenothiazine (TDPA) on several Pt catalysts were... 

Desorption experiments are crucial for the validation of adsorption models and in particular for confirming the estimates of the adsoihed masses. Two desorption experiments have been carried out in order to test the reliability of the two-sink model for estimating the masses in the sinks. One of the desorption tests followed dynamic adsorption of n-dodecane, the other the static adsorption of n-decane. The results showed that (1) the masses deposited into the sinks are released very slowly (2) the two-sink model estimates the masses in the sinks reasonably well therefore, this model may be considered a satisfactory tool for estimating chamber (or test material) sinks. It coherently confirmed the existence of two sinks with different saturation rates, also giving reasonable estimates of the relative parameters. 

The adsorption experiment for Cu(II) was performed using the static method and was carried out as follows. Immerging the sample membranes was carried out into CuS04 solution with a concentration of 2 ppm for 40 min at room temperature and then, the... 

The objective of the present work is to determine the static adsorption of petroleum sulfonates from microemulsions on representative reservoir solids and to define the effect of microemulsion composition, specifically its relative oil and brine content, on sulfonate adsorption. It is also of interest to determine the effect of adsorption on the microemulsion oil and brine content because of the relationship between microemulsion composition and interfacial behavior. Consequently, the adsorption of a given petroleum sulfonate was determined from a series of microemulsions where each microemulsion contained different volume fractions of the same oil and brine. The difference in microemulsion composition within such a series was effected either by using a different cosurfactant in each microemulsion or by changing the total surfactant/cosurfactant concentration. The adsorbent was carefully reproduced in each experiment in terms of sand/clay composition and total surface area. All experiments within a series were therefore carried out at constant temperature, pressure, adsorbent composition and total surface area. 

The extent of adsorption of eommereial surfaetants developed for use in reservoir recovery proeesses ean vary from near zero to as high as 2.5 mg/g. Surfactant adsorption on rock surfaces is usually measured by either static (batch) or dynamic (coreflood) experiments. The static adsorption method, employing crushed rock samples, is essentially the classical method for determining adsorption isotherms at the aqueous solution/solid interface and involves batch equilibrations of particles in solutions of different initial surfactant concentration. The dynamic coreflood method is more involved but employs a greater solid to liquid ratio and is therefore more sensitive, see references [J69-J7J]. Temperature, brine salinity and hardness, solution pH, rock type, wettability, and the presence of a residual oil phase have all been found to influence the extent of adsorption of different surfactants [116,152,172],... 

In a related study, a biomass material, bone char was investigated by Ma et al. (2008) for its feasibility as a cost-effective biosorbent for F removal from drinking water. The amorphous biosorbent powder, which is composed mainly of calcium phosphate and a small amount of carbon, was prepared by heating bone-biomass. The adsorption capacity of the hone char was shown to be better than that of activated aluminum and tourmaline (i.e., crystal horon sUicate mineral compounded with elements such as aluminum, iron, magnesium, sodium, hthium, or potassium). Removal of F was attributed to the processes of ion binding and ion exchange between bone char and F". The authors developed static and kinetic models which provided a satisfactory prediction of F concentration after adsorption. Experiments with fixed-bed columns... 

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