Removal of emulsified oil from water by fruiting bodies of macro-fungus (Auricularia polytricha).

The aim of this study was to investigate the feasibility of utilizing the fruiting bodies of a jelly macro-fungus Auricularia polytricha as adsorbents to remove emulsified oil from water. The effects of several factors, including temperature, initial pH, agitation speed, and adsorbent dosage, were taken into account. Results showed that the optimized conditions for adsorption of A. polytricha were a temperature of 35°C, pH of 7.5, and agitation speed of 100 rpm. The adsorption kinetics were characterized by the pseudo-first order model, which showed the adsorption to be a fast physical process. The Langmuir-Freundlich isotherm described the adsorption very well and predicted the maximum adsorption capacity of 398 mg g-1, under optimized conditions. As illustrated by scanning electron micrographs, the oil particles were adsorbed onto the hairs covering the bottom surface and could be desorbed by normal temperature volatilization. The material could be used as an emulsified oil adsorbent at least three times, retaining more than 95% of the maximum adsorption capacity. The results demonstrated that the fruiting bodies of A. polytricha can be a useful adsorbent to remove emulsified oil from water

Fitting results of the kinetic and isotherm models to adsorption data of emulsified oil by <i>A. polytricha</i>.

<p>Fitting results of the kinetic and isotherm models to adsorption data of emulsified oil by <i>A. polytricha</i>.</p

Comparison of oil adsorption capacities of <i>A. polytricha</i> and some sorbents in the literature.

<p>Comparison of oil adsorption capacities of <i>A. polytricha</i> and some sorbents in the literature.</p

Scanning electron micrographs of <i>A. polytricha</i> lower surface (A) before oil adsorption, (B) after oil adsorption, and (C) after thermal volatilization desorption; and upper suface (D) before oil adsorption, (E) after oil adsorption, and (F) after thermal volatilization desorption.

<p>Scanning electron micrographs of <i>A. polytricha</i> lower surface (A) before oil adsorption, (B) after oil adsorption, and (C) after thermal volatilization desorption; and upper suface (D) before oil adsorption, (E) after oil adsorption, and (F) after thermal volatilization desorption.</p

Kinetic models fitted with the data of adsorption conducted under the optimized conditions (i.e., 0.2 g of biomass, 1000 mg L⁻¹ of initial oil concentration, 35°C, 100 rpm of agitation speed, and 7.5 of initial pH) in a period of 90 s.

<p>The bars represent the standard errors.</p

Isotherm models fitted with the data of adsorption of emulsified oil onto <i>A. polytricha</i> from a batch experiment conducted with different initial oil concentrations ranging from 200 to 3500 mg L⁻¹ and other conditions: 0.2 g of biomass, 35°C, 100 rpm of agitation speed, and 7.5 of initial pH.

<p>The bars represent the standard errors.</p

The L₁₆(4⁵) orthogonal array for the experimental design.

a<p>Temp., Init. Conc., Agita. Speed, and Adsorp. Capacity denote the adsoption temperature, initial concentrations of emulsified oil, speed of agitation, and the adsoption capacity under the designed conditions, respectively.</p

Results of the separation factor.

<p>Results of the separation factor.</p

Results from the L₁₆ (4⁵) orthogonal array experiments.

a<p>Init. Conc. and Agita. Speed denote the initial concentrations of emulsified oil and the speed of agitation, respectively.</p>b<p><i>E_i</i> (<i>i</i> = 1, 2, 3, 4) denotes the effectiveness (mg g⁻¹) of the variables at the <i>i</i>th level.</p