Phosphorus recycle as a highly fertile fertilizer from acid solution of broiler litter ash for composting exhaust deodorization

2019 Fiscal Year Final Research Report

• Project/Area Number: 16K07954
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Agricultural environmental engineering/Agricultural information engineering
• Research Institution: Iwate University
• Principal Investigator: MAEDA Takeki 岩手大学, 農学部, 准教授 (40333760)
• Co-Investigator(Kenkyū-buntansha): 立石 貴浩 岩手大学, 農学部, 准教授 (00359499)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 生物系廃棄物 / 家畜排せつ物 / 堆肥化 / 脱臭 / リン資源

Outline of Final Research Achievements

An experiment was conducted in which chicken manure was dissolved in multiple concentrations of sulfuric acid and hydrochloric acid. It was found that sulfuric acid forms gypsum during dissolution, which hinders the recovery of the solution, and that addition of MgCl2 promotes precipitation by NH3. An experiment was conducted by combining a composting apparatus capable of laboratory experiments with a deodorizing unit using the acid solution. Although 100% of NH3 in the compost exhaust gas could be removed by the acid solution, the amount of N recovered as a precipitate remained at a low value of 13%. It is considered that the recovery rate of nitrogen was low because the percentage of MAP in the precipitate was not high. As a result of Komatsuna cultivation in a pot using the precipitate obtained by adding ammonia to the acid solution, the fertilizer effect of P and N in the precipitate was equivalent to that of chemical fertilizer.

Free Research Field

農業環境工学（生物資源循環工学）

Academic Significance and Societal Importance of the Research Achievements

燃焼灰からのリン回収は，下水汚泥焼却灰を対象とした事例がみられるものの，鶏ふん灰を対象とした事例は少ない。酸に溶解させたリンを結晶化するために必要なアルカリ源として，石灰に代えて堆肥化施設から大量に放出されているアンモニアを用いようとする点が，本研究の独創的な点である。この方法により，鶏ふん灰に含まれるリン成分を窒素成分も同時に含む形態の塩として分離・回収できれば，得られる塩は肥料効果が高いものと考えられる。本研究により期待される成果は，リンと窒素の循環利用と畜産環境問題の改善に貢献するにとどまらず，廃棄物を利用した農畜業の6次産業化につながる実用技術の1つとしても期待される。