Experiment and Coupling Analysis of Municipal Solid Waste Degradation Under Multiple Influencing Factors

<p>The increase in municipal solid waste (MSW) in northwest China has been substantial, with a significant portion primarily treated in landfills. This rapid growth in waste generation presents considerable challenges for landfill management and treatment. The factors affecting MSW degradation are diverse and complex. This study prepares MSW samples based on on-site measured data and conducts a 190-day degradation experiment to analyze the leachate characteristics. By determining the pH, conductivity, and salinity values of the leachate, the effects of temperature (10~65℃), organic matter content (15~75%), moisture content (30~230%), and time (15~190 d) on degradation characteristics which plays a crucial role in understanding the degradation dynamics of MSW under real-world conditions. Throughout the experiment, pH was observed to peak at 7.91 on day 15 and decrease to a low of 5.33 by day 40. Meanwhile, conductivity and salinity showed a steady increase, with values ranging from 1.17 dS/m to 41.65 dS/m and 0.03 ppt to 29.67 ppt, respectively.  Generally, the pH value is higher at 65 ℃, while the salinity and conductivity are higher between 35 ℃ and 45 ℃. Coupling analysis shows that temperature, time, and moisture content are positively correlated with salinity, Organic matter has a negative impact on salinity. Therefore, by adjusting the parameters of MSW, its degradation characteristics can be regulated and can be used as backfill material in construction works. A multiple linear regression equation and automatic linear modeling (ALM) were proposed for predicting pH, conductivity, and salinity values.</p>