RESUMO
Anaerobic digestion is an established method for the biological conversion of waste feedstocks to biogas and biomethane. While anaerobic digestion is an excellent waste management technique, it can be susceptible to toxins and pollutants from contaminated feedstocks, which may have a detrimental impact on a digester's efficiency and productivity. Ethylene glycol (EG) is readily used in the heat-transfer loops of anaerobic digestion facilities to maintain reactor temperature. Failure of the structural integrity of these heat transfer loops can cause EG to leak into the digester, potentially causing a decrease in the resultant gas yields. Batch fermentations were incubated with 0, 10, 100 and 500 ppm (parts per million) of EG, and analysis showed that the EG was completely metabolised by the digester microbiome. The concentrations of EG tested showed significant increases in gas yields, however there were no significant changes to the digester microbiome.
Assuntos
Metagenoma , Microbiota , Anaerobiose , Biocombustíveis , EtilenoglicóisRESUMO
On 16 April 2007, a deeply disturbed Virginia Tech student murdered thirty-two fellow students and faculty and then shot himself. Less than one year later, the Virginia legislature improved the emergency evaluation process, modified the criteria for involuntary commitment, tightened procedures for mandatory outpatient treatment, and increased state funding for community mental health services. The unanswered question, however, is whether the necessary political momentum can be sustained for the long-term investment in community services and the fundamental legal changes needed to transform a system focused on managing access to scarce hospital beds to a community-based system of accessible voluntary services.