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dc.contributor.advisorEvans Changamu Ogwagwaen_US
dc.contributor.advisorDickson Andalaen_US
dc.contributor.authorMakhanu, Mutenyo Maxmilla
dc.date.accessioned2021-09-20T12:40:48Z
dc.date.available2021-09-20T12:40:48Z
dc.date.issued2021
dc.identifier.urihttp://ir-library.ku.ac.ke/handle/123456789/22538
dc.descriptionA Thesis Submitted in Fulfilment of the Requirements for the Award of the Degree of Doctor of Philosophy (Chemistry) in the School of Pure and Applied Sciences, Kenyatta University, February, 2021en_US
dc.description.abstractobtained from finite rock phosphate is one of the essential elements for food production and modern agriculture. Therefore, for sustainability of food supply and development in agriculture, management of phosphorus is key. The estimated periods within which the finite rocks might be depleted range from 30 to 300 years. There is a general agreement that there is a decrease in accessible reserves of phosphorus. Among the alternatives to rock phosphorus are animal bones disposed as waste from abattoirs in large cities and towns. Animal bones have a high concentration of phosphate that can be harvested and used in fertilizer production but they take many years to decompose and release the phosphate. The objective of this was to prepare bone-phosphate enriched phosphoric acid from discarded animal bones and use it to prepare DAP fertilizer and determine its efficacy in tomato growing in a greenhouse. Animal bones (predominantly cattle bones) were collected from Kachok Municipal dump site, Kisumu West District, Kenya. They were washed, dried and crashed to smaller particles using a hammer after which they were ground in a mill. The ground bones were extracted with 0.275M H3PO4 to give a 4.58 M bone phosphate-enriched phosphoric acid solution. Nitrogen was extracted from air by passing the air over heated copper filings and reacted with lithium to form lithium nitride. The lithium nitride was later hydrolysed to form ammonia which was reacted with the bone-phosphate enriched phosphoric acid to generate the diammonium phosphate (NH4)2HPO4) fertilizer. Lithum metal was recycled by electrolysis of LiCl using electricity generated by a hybrid solar – wind system in a cell fabricated at Kenyatta University‟s Engineering Workshop. The percent composition of nitrogen (Kjeldahl) in the diammonium phosphate was found to be 17.14 % N while that of the phosphate was found to be 44.58 % P2O5. The process realized 98.87 % N2 separation from air, 94.74 % lithium conversion to lithium nitride and 94.75% lithium nitride conversion to ammonia. The percentage yield of (NH4)2HPO4) obtained from the reaction of ammonia with 4.58 M H3PO4 was 48.06 %. The efficacy of diammonium phosphate in the growing of tomatoes in a greenhouse was determined with the commercially obtained diammonium phosphate as the positive control and no fertilizer as the negative control. Growth parameters of the tomatoes including plant heights, leaf length, leaf width and root length were obtained over a period of twelve weeks. The results showed that the growth parameters recorded for tomato plants grown with synthesized fertilizer were not significantly different from those recorded for tomato plants grown with commercial fertilizer (p-values = 0.000 <0.05). However, growth parameters of tomato plants grown without any fertilizer were significantly different (lower in value) from those grown with fertilizer. Based on the results obtained, it can be concluded that the bone phosphate based fertilizer prepared in this study was as efficacious as the commercial fertilizer.this is a significant finding in that it shows that it shows that animal bones can be converted into readily available phosphatic fertilizer. A pilot study on production of the same is recommendeden_US
dc.description.sponsorshipKenyatta Universityen_US
dc.language.isoenen_US
dc.publisherKenyatta Universityen_US
dc.subjectAmmonium Phosphate Fertilizeren_US
dc.subjectBone–Phosphateen_US
dc.subjectEnriched Phosphoric Aciden_US
dc.subjectAmmoniaen_US
dc.subjectLithium Nitrideen_US
dc.subjectEfficacyen_US
dc.subjectTomato Growingen_US
dc.titleAmmonium Phosphate Fertilizer from Bone–Phosphate Enriched Phosphoric Acid and Ammonia from Lithium Nitride and its Efficacy in Tomato Growingen_US
dc.typeThesisen_US


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