Fatores intervenientes na geração e composição de biogás em aterro sanitário e formas de manejo para melhorar sua produção

Abstract

Sanitary landfills are of great relevance in the current scenario in Brazil, which have a high potential for generating energy and natural gas, as around half of landfilled waste has organic origin. Therefore, this work investigated factors that interfere in the production and composition of methane in ASMOC (West Caucaia Metropolitan Sanitary Landfill) and the interference of landfills in groundwater. For this, 3 upstream and 3 downstream groundwater monitoring wells were analyzed using 30 parameters in 12 collections. For transparency with biogas production and climate parameters, monthly samples of biogas were collected in monitoring wells distributed by solids from January 2019 to December 2022, totaling 48 collections. This same frequency and period was used to capture climatic parameters in the databases of the Cearense Foundation of Meteorology and Water Resources and the National Institute of Meteorology. The following were analyzed: rainfall, pressure, wind speed, temperature, air humidity, cloudiness, sunshine and evaporation. To simulate a landfill, a 1,000L reactor containing 500L of MSW was assembled according to the gravimetry of waste landfilled at ASMOC. Slurry and water were applied weekly, alternately for 91 days. The leachate application rate was 54L/m3 per week and humidity was monitored seeking to maintain 50% humidity. 25 parameters were analyzed to characterize the leachate to be irrigated. The moisture content of the MSW mass was confirmed with 5 collections during the experiment. Finally, 16 reactors of 1,000L each were assembled on a pilot scale, 4 irrigated with leachate from the old landfill cell, 4 with concentrated leachate; 4 with septic tank effluent and the other 4 did not receive leachate or septic tank effluent. 20L of leachate and effluent were inserted into the corresponding reactors every 15 days. Half of each system was irrigated every two weeks with 30L of water to simulate rainfall. MSW samples were found at 2 points in each reactor, at a height of 0.40m and 0.60m, monthly for moisture analysis and applied every six months using the parameters total carbon, total nitrogen and ammonia. The effluents inserted into the reactors and the leachate produced therein were analyzed every quarter using 22 physicochemical parameters. The measurement of the composition and flow of the biogas produced was carried out for each reactor, one point at a time, with a daily frequency for 12 months. For statistical analyses, data were tabulated in an Excel spreadsheet and JAMOVI software version 2.3 and PAST were used. It was possible