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ARS Home » Midwest Area » Peoria, Illinois » National Center for Agricultural Utilization Research » Functional Foods Research » Research » Publications at this Location » Publication #347546
Research Project: Evaluation of the Chemical and Physical Properties of Low-Value Agricultural Crops and Products to Enhance Their Use and Value

Location: Functional Foods Research

Title: Physical and chemical properties of pyrolyzed biosolids for utilization in sand-based turfgrass rootzones

Author
item Vaughn, Steven
item DINELLI, F - North Shore Country Club
item Kenar, James - Jim
item Jackson, Michael - Mike
item Thomas, Andrew - Aj
item Peterson, Steven - Steve

Submitted to: Waste Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/6/2018
Publication Date: 4/10/2018
Citation: Vaughn, S.F., Dinelli, F.D., Kenar, J.A., Jackson, M.A., Thomas, A.J., Peterson, S.C. 2018. Physical and chemical properties of pyrolyzed biosolids for utilization in sand-based turfgrass rootzones. Waste Management. 76:98-105.

Interpretive Summary: This research shows that pyrolyzing (heating in the absence of oxygen) biosolids from the Metropolitan Water Reclamation District of Greater Chicago produces materials that have excellent potential as replacements for peat moss in sand-based root zones such as golf course greens, golf tees, and athletic fields. Peat moss is a commonly mixed with sand during the construction of new golf greens, tees and athletic fields to improve water and nutrient retention. However, peat moss decomposes, making its effectiveness less over time. Biosolids have been found to be excellent fertilizers for turfgrasses, but concerns about undesirable odors, nutrient runoff into waterways, and the presence of pathogens and chemical pollutants, such as pharmaceuticals and personal care products, have driven public opposition against their use. After pyrolysis, treated biosolids have negligible levels of organic pollutants and pathogens, and no undesirable odors. In this study we found that biosolids pyrolyzed at 300 oC were equal to untreated biosolids in promoting the growth of perennial ryegrass plants, and would produce material with excellent potential as a peat replacement for water and nutrient retention in sand-based rootzones.

Technical Abstract: Biosolids are several forms of treated sewage sludge that are intended for use as soil conditioners for horticultural, agricultural and industrial crops. The objectives of this research were to determine the chemical and physical properties of biosolids pyrolyzed at several different temperatures, and their effect on perennial ryegrass seed germination and growth. Biosolids were thermally treated in an oxygen-free (nitrogen atmosphere) retort oven at 300, 400, 500, 700 and 900 oC. As pyrolysis temperatures increased, bulk densities, total surface areas, micropore surface areas, % minerals and pH values of the pyrolyzed biosolids increased, while carbon percentage decreased compared to untreated biosolids. FTIR analysis showed decreased surface functionality as pyrolysis temperature increased. Perennial ryegrass (Lolium perenne L. ‘Nui’) plants were grown in mixtures of 10% (v/v) biosolids or 10% (v/v) of the various pyrolyzed biosolids and 90% coarse sand. Ryegrass plants grown in the biosolids and the 300 oC pyrolyzed biosolids mixture had the greatest shoot heights of any of the treatments after 4 weeks of growth. These results indicate that pyrolyzing MWRD biosolids at 300 oC would produce material with excellent potential as a peat replacement for water and nutrient retention in sand-based rootzones.