Characterization of Poultry Manure Biochars

The obtained poultry-manure-derived biochars were subjected to the analyses of physico-chemical and physical properties. pH was measured in distilled water; ash was determined according to the standard PN-EN ISO 18122:2016-01 Polish version [43 ], Solid biofuels—Determination of ash content; bulk density (BD) was determined according to the PN-EN 1236 standard [44 ] on fertilizers; and water holding capacity (WHC, % w/w) was determined from the difference in mass between dry and saturated biochar according to ASTM D2216-10 [45 ]. Selected elements including P, K, Ca, Mg, Hg, Pb, Cd, Cr, Cu, Ni, and Zn were determined in the investigated biochars with the use of ICP-OES according to the standard PB-186/ICP. Detailed methods for analyzing biochars are provided in our previous works [30 (link),31 ,41 (link)]. Total carbon (TC) was determined by Multi N/C, Analytykjena—the high-temperature incineration with detection IR according to PN-ISO 10694:2002 [46 ]—Soil quality—Determination of organic carbon content and total carbon content after dry combustion (elemental analysis). The elemental analysis of CHNS was performed according to the standards CSN ISO 29541 [47 ], CSN EN ISO 16994 [48 ], CSN EN ISO 16948 [49 ], CSN EN 15407 [50 ], CSN ISO 19579 [51 ], CSN EN 15408 [52 ], and CSN ISO 10694 [53 ]. BET surface area was determined by nitrogen sorption by the ASAP2020 Plus analyzer (Micromeritics, Atlanta, GA, USA). The investigated poultry-manure-derived biochars were tested for the presence of dioxins and furans: US EPA 1613B [54 ] and CSN EN 16190 [55 ], and polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs): US EPA 8270D [56 ], US EPA 8082A [57 ], CSN EN 15527 [58 ], ISO 18287 [59 ], ISO 10382 [60 ], CSN EN 15308 [61 ], and US EPA 3546 [62 ].