Production of plant growth–promoting bacteria inoculants from composting leachate to develop durable agricultural ecosystems

Environmental Science and Pollution Research - Composting process of residual organic material generates considerable amounts of liquid leachate which contains high organic load. This waste stream...     

Creating local ecological footprints in a North American context

Many urban areas face conflicts between economic growth and environmental limitations. The ecological footprint is popular for communicating the global impacts of local activities, and if calculated at the local level, should be useful in emphasising the impacts of local planning, engaging community members, and allowing intra-community comparisons. We compare the two dominant methods for local ecological footprints: the compound and component methods. Both fail to adequately represent local footprints in North America. We propose a hybrid component method that takes advantage of the benefits of the component method but incorporates interpolation from the compound method to address data limitations. Grounded in Montreal, Canada, a city currently facing significant conflict between environment and growth, the study applies the hybrid method and discusses its potential benefits and limitations for community activists and planners.     

NitroMAC: An instrument for the measurement of HONO and intercomparison with a long-path absorption photometer

NitroMAC (French acronym for continuous atmospheric measurements of nitrogenous compounds) is an instrument which has been developed for the semi-continuous measurement of atmospheric nitrous acid (HONO). This instrument relies on wet chemical sampling and detection using high performance liquid chromatography (HPLC)-visible absorption at 540 nm. Sampling proceeds by dissolution of gaseous HONO in a phosphate buffer solution followed by derivatization with sulfanilamide/N-(1-naphthyl)-ethylenediamine. The performance of this instrument was found to be as follows: a detection limit of around 3 ppt with measurement uncertainty of 10% over an analysis time of 10 min. Intercomparison was made between the instrument and a long-path absorption photometer (LOPAP) during two experiments in different environments. First, air was sampled in a smog chamber with concentrations up to 18 ppb of nitrous acid. NitroMAC and LOPAP measurements showed very good agreement. Then, in a second experiment, ambient air with HONO concentrations below 250 ppt was sampled. While NitroMAC showed its capability of measuring HONO in moderate and highly polluted environments, the intercomparison results in ambient air highlighted that corrections must be made for minor interferences when low concentrations are measured.     

The effect of alkaline pretreatment on the anaerobic digestion of fruit and vegetable wastes from a central food distribution market

Journal of Material Cycles and Waste Management - Anaerobic digestion of the organic fraction of municipal solid wastes is a well-established process for biogas production and various forms of...