Biomedical subjects

Hideo Maruyama

Publications and source records attributed to Hideo Maruyama.

7 recordsLinked to original sources

PubMed2006

Batch foam separation of a soluble protein.

Removal of protein dissolved in water by batch foam separation was conducted with using ovalbumin (OA) as a model protein in the light of wastewater treatment reducing organic loading. The removal efficiency had a maximum value near the i.e.p. of OA (pH 4.6); thus, most experiments were conducted at pH 4.6. Typical experimental conditions; superficial gas velocity, U(g): 1.97 x 10(-2)-5.37 x 10(-2)cm/s; initial bulk concentration of OA, C(i): ca. 0.05-0.25 g/L; liquid volume, V: 600 cm(3). A model estimating bulk concentration profile was proposed by taking into account a mass balance of the present system. The model predicted that OA could be removed perfectly, however, was not all removed experimentally. The residual OA concentration of the bulk liquid within the column reached plateau value, which correspond to ca. 18% of the initial OA concentration. The plateau value of the bulk concentration was attained for ca. 100-500 min with U(g)=1.97 x 10(-2)-5.37 x 10(-2)cm/s. Foaming ability test revealed that the foaming limit concentration of OA at pH 4.6 was 9.72 x 10(-3)g/L. These results suggested that OA molecules could be damaged by interaction of bubble surface in the dispersed phase, since there were the residual OA concentrations over the limit concentration. To take account of this phenomena and correct the model, average surface density, X(d), which should convert protein molecule into the denatured protein molecule, was introduced. The corrected model could explain well the time profile of OA bulk concentration.

Hydrogen-Ion Concentration↗

PubMed2006

Variation of saturated surface density of ovalbumin on bubble surface in continuous foam separation.

The adsorption of ovalbumin (OA) onto the bubble surfaces was studied with various pHs (3.5, 4.6, 6.0 and 8.0) by a continuous foam separation technique. From the value of the saturated surface density of adsorbed OA, the variation of effective diameter (D) of an OA molecule on the bubble surface was estimated for various pHs (3.5, 4.6, 6.0 and 8.0) of the OA solutions, assuming that the cross section of the OA molecules be circular and that the OA molecules adsorb on the bubble surface in a closest packing structure. The estimated variation of D with pH was attempted to explain based on a model modified from that proposed by Pujar and Zydney. The modified model could well reproduce the variation of the effective diameter with pH; the values of D calculated on the basis of the modified model almost agreed with that estimated from the saturated surface density in the present experimental pH range. From these, conclusion was drawn that the modified model presented in this study can express the variation in the effective diameter with pH.

Adsorption↗

PubMed2005

Biosorption of chromium(VI) and arsenic(V) onto methylated yeast biomass.

Yeast biomass was methylated in a 0.1 M HCl methyl alcohol solution at room temperature and the methylated yeast (MeYE) was applied to the adsorptive separation of Cr(VI) and As(V) anions from aqueous solutions. At near-neutral pH, while Cr(VI) and As(V) anions were scarcely adsorbed onto unmethylated yeast biomass, the amounts adsorbed increased with increasing methylation degree. The amount of Cr(VI) adsorbed onto MeYE was almost constant at pH 4-6 and decreased with increasing pH above pH 6. The amount of As(V) adsorbed onto MeYE was rather lower than that of Cr(VI) and it had a peak at about pH 7. A metal-binding model was used to describe the adsorption characteristics of Cr(VI) and As(V) on MeYE. The results showed that MeYE has two different types of adsorption sites. The saturated amount of Cr(VI) and As(V) adsorbed onto MeYE having methylation degree 0.94 was 0.55 mmol g(-1).

Adsorption↗

PubMed2004

Flocculation of diatomite by methylated milk casein in seawater.

A new biodegradable flocculant was prepared from a common and inexpensive protein. Milk casein was methylated in a 0.05 M HCl methyl alcohol solution at room temperature. The methylated milk casein (MeCS), having a methylation degree of 81%, was applied to the separation or flocculation of diatomite in seawater (pH 8.1+/-0.1) at room temperature (18-23 degrees C). The flocculating ability of MeCS was evaluated by a sedimentation balance method (cumulative measurement method). The diatomite suspension was effectively flocculated by the addition of a small amount of MeCS (0.25 wt% of the diatomite weight). The results of sedimentation analysis showed that the size-frequency curve had a very sharp and high peak; thus the diatomite floc formed by MeCS had a rather uniform size. The settling velocity of diatomite floc at the appropriate MeCS dosages (0.25-2 wt% of diatomite) was about 3 x 10(-3) ms(-1).

Animals↗

PubMed2004

Adsorption of egg albumin onto methylated yeast biomass.

A new biosorbent, methylated yeast (MeYE), was prepared for the adsorptive separation of proteins from aqueous solutions. Yeast was methylated in a 0.1 M HCl methyl alcohol solution at room temperature. About 80% of the carboxylic groups of yeast could be methylated within 9 h. The adsorption of egg albumin onto MeYE was studied to evaluate the protein adsorption ability of MeYE. At near neutral pH, egg albumin was scarcely adsorbed onto unmethylated yeast and the adsorbed amount of egg albumin increased with increasing methylation degree. The amount of egg albumin adsorbed onto MeYE increased with increasing pH from 4 to 7 and steeply decreased above pH 7. The Langmuir isotherm was applied to determine the apparent adsorption constant and the saturated adsorbed amount of egg albumin on MeYE. Both the apparent adsorption constant and the saturated adsorbed amount increased with the degree of methylation. The saturated adsorbed amount of egg albumin onto MeYE having methylation degree 77% was 8.41 x 10(-6) mol g(-1) or 0.378 gg(-1) at near neutral pH.

Adsorption↗

PubMed2002

Selective foam separation of binary protein solution by SDS complexation method.

A fundamental study about the selective foam separation of protein mixture was carried out. A solution containing two proteins, ovalbumin (OA) and lysozyme (LZ), and an anionic surfactant, sodium dodecyl sulfate (SDS), was adjusted to pH 6.0, which referred to an intermediate state between the isoelectric points of the proteins. The solution was processed by continuous foam separation. The results showed that a proper addition of SDS greatly improved the selective recovery of LZ to OA. The experimental data were well explained by a simple model that most of cationic protein molecules (LZ) are associated with SDS and the adsorption of all the species including LZ-SDS complexes are subjected to Langmuir adsorption isotherm. The results also showed that one of the Langmuir parameters, which means a kind of lyophillic property of adsorbed material, of LZ-SDS complexes was extremely large as compared with that of primary protein.

Absorption↗

PubMed2001

Influence of Liquid Properties and Operating Variables on Enrichment Ratio in Nonfoaming and Foaming Adsorptive Bubble Separation Techniques.

The influence of the liquid properties and the operating variables on the intrinsic volumetric flow rate, q(0), of the droplets at the liquid-atmosphere interface in nonfoaming adsorptive bubble separation and that, W(f0), of the liquid in foam at the liquid-foam interface in foam separation was studied to estimate the enrichment ratio of surface-active substance in the two techniques. Each intrinsic flow rate was determined by the extrapolation method, which the authors proposed previously, and was mainly influenced by superficial gas velocity, liquid viscosity, and surface tension. Although the changes in the surface tension and the liquid viscosity were small, they greatly affected the intrinsic flow rates for both the droplets and the liquid in foam. The experimental results were applied to a dimensional analysis. Dimensionless volumetric flow rates, q(0)/Q and W(f0)/Q, were successfully correlated with a dimensionless number (Ohnesorge number, Z=&mgr;(L)/(rho(L)sigmad(b))(0.5)). q(0)/Q=6.66 Z(1.46) and W(f0)/Q=2.53Z(0.533) were obtained for the nonfoaming and the foaming regions within errors of 30 and 35%, respectively. The enrichment ratio of surface-active substance in the droplets and the liquid in foam to the bulk liquid was derived by using these correlations for the nonfoaming and the foaming regions, respectively. A good agreement of the experimental enrichment ratio and the calculated ones was obtained by using the correlations for nonfoaming and foaming. Copyright 2001 Academic Press.

Journal Article↗