Dong Faqin

The Biosorption Effect and Mechanism of Pb(II) on Waste Beer Yeast

The biosorption of Pb(II) ions on dried wasted beer yeast was investigated with respect to the adsorption conditions. The results of this study indicated that different variables, such as contact time, adsorbent dose, solution pH and initial heavy metal ions concentration influenced the adsorptive quantity. The best adsorption parameters and quantitative analysis of Pb2+ by dried waste beer yeast revealed that at optimum conditions (pH = 4.5; Pb2+ initial concentration = 1.0 mmol/L; biomass dose = 4.0 g/L; contact time = 90 min), the highest metal uptake values obtained above 60 mg/g and the adsorptive efficiency was above 93%. The SEM analysis showed that the interactions between Pb(II) ions and functional groups on the cell wall surface of dried waste beer yeast. Consequently, dried waste beer yeast is an inexpensive, readily available adsorbent for metals and especially has a high adsorption capacity for Pb(II) ions.

The Surface Groups and Active Site of Fibrous Mineral Materials

The exposed and transformed groups of fibrous brucite, wollastonite, chrysotile asbestos, sepiolite, palygorskite, clinoptilolite, crocidolite and diatomaceous earth mineral materials are analyzed by IR spectra after acid and alikali etching, strong mechanical and polarity molecular interaction. The results show the active sites concentrate on the ends in stick mineral materials and on the defect or hole edge in pipe mineral materials. The inside active site of mineral materials plays a main role in small molecular substance. The shape of minerals influence their distribution and density of active site. The strong mechanical impulsion and weak chemical force change the active site feature of minerals, the powder process enables minerals exposed more surface group and more combined types. The surface processing with the small polarity molecular or the brand of middle molecular may produce ionation and new coordinate bond, and change the active properties and level of original mineral materials.

The Kinetics of Biosorption and Desorption to Pb2+ on Beer Yeast

The kinetics of biosorption and desorption to lead ions on dried and wet wasted beer yeast were investigated with the instruments of AAS and SEM. In order to enhance the experimental results reliability and practice application value, the sorption solution system was gone on ¡°L¡±-degree dosage level in the whole experimental process. The results showed that the biosorption and desorption process were fast to Pb2+ on dried and wet beer yeast. There were very good biosorption or desorption effect in the first 30 min, and in this time, the desorption efficiency was 91.70% and 82.93% to dried and wet beer yeast, respectively. In the first biosorption process, wet beer yeast had better biosorption effect than dried beer yeast. In addition, desorbent of 0.1 mol/L HNO3 was considered that it couldn¡¯t use as the best desorption condition. The other desorption conditions were need research or the beer wasted beer yeast is only used for single-time biosorbent.

The Reciprocity between Atmosphere Dusts and S. epidernidis

In order to compare the chemical compositions and physical characteristics of different atmosphere dusts on S. epidernidis, chemical compositions of five kinds of atmosphere natural dropping dusts have been analyzed and the changes of pH value, glucose (GLU), electrolyte before and after the dusts reacted with S. epidernidis have been measured. The SEM analysis has been used to study the bacterial surface morphology and interface action status in the course of reaction between dusts and bacteria. The results illustrated that Major chemical composition of atmosphere dusts and dissolution quantity of ions after the aced with S. epidernidis were different. The atmosphere dusts containing high Ca2+ or Mg2+ could increase the number of S. epidernidis and the use quantity of GLU. The dust granules’ adhered degree is increasing with the granularity’s decreasing, and the abnormity figure could increase the adhering degree between the bacterial membranes and dust surfaces.