Martial recycling from renewable landfill and associated risks: A review.

Landfill is the dominant disposal choice for the non-classified waste, which results in the stockpile of materials after a long term stabilization process. A novel landfill, namely renewable landfill (RL), is developed and applied as a strategy to recycle the residual materials and reuse the land occupation, aim to reduce the inherent problems of large land occupied, materials wasted and long-term pollutants released in the conventional landfill. The principle means of RL is to accelerate the waste biodegradation process in the initial period, recover the various material resources disposal and extend the landfill volume for waste re-landfilling after waste stabilized. The residual material available and risk assessment, the methodology of landfill excavation, the potential utilization routes for different materials, and the reclamation options for the unsanitary landfill are proposed, and the integrated beneficial impacts are identified finally from the economic, social and environmental perspectives. RL could be draw as the future reservoirs for resource extraction.

Study on Increasing the Protein Expression of Cells by Specific Nutrient Compensation and Metabolism Control Strategy / 中国生物工程杂志

To increase the productivity and yield of recombinant protein in continual perfusion processing, Every amino acid consumption rate in continual perfusion culture of engineering CHO cell line which expressed recombinant TNFRp75: Fc fusion protein were analyzed. Then rational amino acids were accordingly added to improve its comprehensive utilizing. At the same time, glucose supply was controlled to make the concentration of glucose below 0.5 g/L for ameliorating the toxicity of lactate accumulation in order to decrease the perfusion rate. The result showed that the productivity of recombinant protein was 3.1 times (388mg/L) and the total yield was 4. 7 times (244. 4g) that of control cultures after nutrient compensation and metabolism control in 30 liter working volume, and the fermentation period was prolonged one week longer. The sialic acid content and bioactivity in vitro of recombinant TNFRp75: Fc were not changed after nutrient compensation and glucose control supply. Nutrient compensating and metabolic control in continual perfusion fermentation could significantly increase the productivity and yield of recombinant TNFRp75:Fc, and thus reduced relative industrialization costs.

A comparison of refuse attenuation in laboratory and field scale lysimeters.

For this study, small and middle scale laboratory lysimeters, and a large scale field lysimeter in situ in Shanghai Refuse Landfill, with refuse weights of 187,600 and 10,800,000 kg, respectively, were created. These lysimeters are compared in terms of leachate quality (pH, concentrations of COD, BOD and NH3-N), refuse composition (biodegradable matter and volatile solid) and surface settlement for a monitoring period of 0-300 days. The objectives of this study were to explore both the similarities and disparities between laboratory and field scale lysimeters, and to compare degradation behaviors of refuse at the intensive reaction phase in the different scale lysimeters. Quantitative relationships of leachate quality and refuse composition with placement time show that degradation behaviors of refuse seem to depend heavily on the scales of the lysimeters and the parameters of concern, especially in the starting period of 0-6 months. However, some similarities exist between laboratory and field lysimeters after 4-6 months of placement because COD and BOD concentrations in leachate in the field lysimeter decrease regularly in a parallel pattern with those in the laboratory lysimeters. NH3-N, volatile solid (VS) and biodegradable matter (BDM) also gradually decrease in parallel in this intensive reaction phase for all scale lysimeters as refuse ages. Though the concrete data are different among the different scale lysimeters, it may be considered that laboratory lysimeters with sufficient scale are basically applicable for a rough simulation of a real landfill, especially for illustrating the degradation pattern and mechanism. Settlement of refuse surface is roughly proportional to the initial refuse height.