@article{patil_sharara_shah_kulesza_classen_2023, title={Impacts of utilizing swine lagoon sludge as a composting ingredient}, volume={327}, ISSN={0301-4797}, url={http://dx.doi.org/10.1016/j.jenvman.2022.116840}, DOI={10.1016/j.jenvman.2022.116840}, abstractNote={Lagoon sludge, a byproduct of swine operations in the Southeast United States, poses a management challenge due to its high mineral and metal content. Composting is a low-cost, scalable technology for manure management. However, limited information is available on composting swine lagoon sludge in terms of recipes, greenhouse gas emissions and end-product quality. Moreover, due to its high Zn and Cu content, high inclusion of sludge in composting recipes can potentially inhibit the process. To address these knowledge gaps, in-vessel aerated composting (0.4 m3each) was carried out to evaluate impacts of sludge inclusion, at 10% (Low Sludge, LS-Recipe) and 20% (High sludge, HS-Recipe) wet mass-basis, on composting process and end-product quality. Comparable maximum temperatures (74 ± 2.7 °C, 74.9 ± 2.9 °C), and organic matter loss were observed in both recipes. Similarly, sludge inclusion ratio had no significant impact on cumulative GHG emissions. The global warming potential (20-year GWP) for swine lagoon sludge composting using LS and HS recipes was observed to be 241.9 (±13.3) and 229.9 (±8.7) kg CO2-e/tDM respectively. Both recipes lost 24–28% of initial carbon (C) and 4–15% of nitrogen (N) respectively. Composting and curing did not change water-extractable (WE) phosphorus (P) concentrations while WE Zn and Cu concentrations decreased by 67–74% and 55–59% respectively in both recipes. End compost was stable (respiration rates <2 mgCO2-C/g OM/day) with germination index >93 for both recipes.}, journal={Journal of Environmental Management}, publisher={Elsevier BV}, author={Patil, Piyush and Sharara, Mahmoud and Shah, Sanjay and Kulesza, Stephanie and Classen, John}, year={2023}, month={Feb}, pages={116840} }
 @article{patil_sharara_2022, title={Impacts of sonication on biomethane potential (BMP) and degradation kinetics of pig lagoon sludge}, volume={223}, ISSN={["1537-5129"]}, url={https://doi.org/10.1016/j.biosystemseng.2022.08.008}, DOI={10.1016/j.biosystemseng.2022.08.008}, abstractNote={Lagoon sludge is a by-product of pig production in North Carolina. Sludge contains nutrients, minerals, and cellular biomass. Sustainable management of sludge is crucial to avoid accumulation impacts on lagoon performance. This study investigated sonication as a potential pre-treatment for sludge. The impact of sonication on sludge bio-methane potential and degradation kinetics was evaluated. At sonication energy dosage of 20,400 kJ.kgTS−1, the dissolved total carbon (DOC) and soluble chemical oxygen demand (SCOD) increased from 446 to 1055 mg L−1 and from 2297 to 9239 mgO2L−1, respectively. In the bio-methane potential (BMP) study, cumulative biogas and bio-methane yield increased from 21.0 to 28.4 mLbiogas.gVS−1 and from 15.0 to 21.3 mLCH4.gVS−1 due to sonication. Sonicated sludge reached 95% of its experimental biomethane yield more than 10 days earlier compared to raw sludge. The first order kinetics equation showed the highest co-efficient of determination (R2) and least root mean square error (RMSE) when fitted to raw sludge bio-methane production, while transference model was the best fit for sonicated sludge bio-methane production. The transference model substantially overestimated the maximum gas production rate for sonicated sludge. A significantly higher hydrolysis constant (p-value < 0.05) was observed for sonicated sludge (0.6 day−1) in comparison to raw sludge (0.08 day−1). Findings suggest sonication is a promising tool to aid organic matter and nutrient fractionation, and energy recovery pathway but the high energy inputs are still a barrier.}, journal={BIOSYSTEMS ENGINEERING}, author={Patil, Piyush S. and Sharara, Mahmoud A.}, year={2022}, month={Nov}, pages={129–137} }