Dai Qunwei

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 Reactive Light Yellow Dye Wastewater Treatment by Sewage Sludge-Based Activated Carbon

The paper is aim to discuss the dye wastewater treatment by sewage sludge-based adsorbent. The adsorbent derived from sewage sludge, which produced through phosphoric acid-microwave method, and commercia activated carbon (ACC) were tested in the process of the Reactive Light Yellow dye wastewater treatment. The effects of pH value, contact time and the adsorbents¡¯ amount on the adsorption efficiency were studied on the basis of the removal rate of CODCr, and the adsorption isotherm of the sewage sludge based activated carbon (ACSS) was discussed. The results indicated that the sewage sludge-based activated carbon was mesoporous with a surface area of 168 m2/g and an average pore diameter of 8.8nm. The optimum pH of ACSS was 10, the adsorption equilibrium time of ACSS was 40 min. When the dosage of ACSS was 5g/L, the removal rate of CODCr was92.3%, that¡¯s means the ACSS had a good adsorption performance. The Freundlich model and Langmuir model were all fit for the Reactive Light Yellow dye wastewater adsorption.

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.