Preparation of Gypsum Retarding Material and Activated Carbon from Waste Mycelium

A clean and safe process of utilizing waste penicillin mycelium (WPM) was proposed in this paper. We treated WPM by soaking it in aqueous alkaline solution, to produce retarders for hemihydrate gypsum (the protein hydrolysate) by filtration. The filter cake was used to produce activated carbon, while the waste water can be reused for soaking process. This retarder can effectively prolong the setting time of gypsum with less drop in mechanical strength of gypsum plaster. The activated carbon produced with 674 mg/g of Iodine value, which meets the requirements of general industrial applications.

Research Progress for Gypsum Retarder

Gypsum retarder is an important additive of building materials. Commercial gypsum retarders are mainly composed of four types: organic acids, phosphates, protein and composite retarder. Although the effects of organic acids and phosphates have better retarding performances, there is still obvious a shortcoming that the mechanical strength reduces largely with time going by. Protein based retarders prolong the setting time of hemihydrates with less strength loss and higher costs. The gypsum retarder from waste mycelium, a protein-rich raw material, solved the problem of the disposal of waste mycelium from anti-biotic plants, while producing high-quality retarder for gypsum, shows potential for future.

Waste Mycelium Processing and Resource Utilization

The waste mycelium containing a certain amount of antibiotic is a byproduct of the fermentation industry. If not handled properly, it would cause environmental pollution and result abuse of antibiotics. This paper introduces the treatment and resource utilization technologies of waste mycelium, including extraction of chitosan and ergosterol from waste mycelium, preparation of activated carbon, and preparation of gypsum retarder with waste mycelium. The integrated process of waste mycelium utilization was proposed.

Screening of Lincomycin-Degrading Bacteria by Silica Gel Plate and Visible Spectrophotometry

Due to the existence of antibiotic residues, waste mycelium of lincomycin was difficult to be treated and used as resources, which had become a major problem in the production enterprise. So it is very necessary to isolate and screen lincomycin - degrading bacteria to biodegrade the waste mycelium. In this paper, Box-Behnken Experimental Scheme was performed to optimize the experimental conditions for the treatment of silica gel plates, and the visible spectrophotometry was used to determine the concentration of lincomycin in the silica gel plates to indicate the degradation capacity. The results showed that the optimal conditions were to add 4 ml of water to a silica gel plate, and immerse for 40min, and repeat this process for four times. Under these conditions, the linear correlation between the lincomycin concentration and absorbance was satisfactory in the calibration standards at the range of 0-5mg/ml (r=0.99976). The method precision values (RSD=0.1126%), accuracy values (RSD=0.2358%), reproducibility values (RSD=0.2358%), stability values (RSD=0.1129%) and recovery values (98.1318%) of lincomycin in silica gel aqueous solution were adequate. Application of this method to 1311 strain showed the lincomycin - degradation rate was of 35.81±2%. Taken together, we have established a simple, convenient, rapid and valid visible spectrophotometry method to detect lincomycin in silica gel plates for screening lincomycin - degrading bacteria.

Hexavalent chromium removal by waste mycelium of Aspergillus awamori

In this study, the Cr(VI) removal potential of waste mycelium from the industrial xylanase-producing strain Aspergillus awamori was evaluated. It was determined by FTIR analysis that amino groups from the major fungal wall constituents, chitin and chitosan, played a key role in the metal binding process. The effect of pH, initial ion concentration, temperature and amount of biomass on the removal was also studied. The removal efficiency increased with decreasing pH and increasing temperature and amount of biomass. The mechanism of Cr(VI) removal by A. awamori can be explained by a two-stage process involving an initial adsorption stage followed by a reducing stage. The removal process was described by a second-order polynomial and the optimal process parameters for attaining Rmax 94.4 % in 48 h were predicted, i.e., pH 1.5 and T 40?C. From both economic and ecological points of view, a promising possibility for the utilization of waste industrial mycelium of A. awamori as a low-cost Cr(VI) removal agent was proposed.