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Title: Soaking formulations that can soften hardened bovine manure

Author
item Ramos, Mila
item Muir, Zerlina
item Ashby, Richard - Rick
item Liu, Cheng Kung

Submitted to: Journal of American Leather Chemists Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2011
Publication Date: 7/1/2011
Citation: Ramos, M., Muir, Z.E., Ashby, R.D., Liu, C. 2011. Soaking formulations that can soften hardened bovine manure. Journal of American Leather Chemists Association. 106(7):212-218.

Interpretive Summary: Many of the problems in hides and leather industry originate from putrefaction and microbial contamination due to the presence of manure in hides. It is urgently needed to develop new washing methods that can effectively clean raw hides before preservation for their storage and while in transit during shipments. The addition of recycled crude glycerol, an abundant co-product in biodiesel production, to the biodegradable detergent are exploited in developing the eco-friendly washing formulation. Since the softening of the hardened manure is the key to its removal, the current experiments were designed to monitor the changes in the hardness of the manure balls. Among the different detergent types that were tested, the biodegradable surfactant with addition of recycled crude glycerol was observed to be more effective in softening the hardened manure samples and is worthy of further studies for “adobe” type manure removal. Employing the environmentally friendly products in these washes is preferable in order to reduce the current environmental impact of toxic effluents coming from slaughterhouses and tanneries.

Technical Abstract: Many of the damaging problems in hides and leather industry such as grain damage and weakening of the leather product, can originate from putrefaction. It is caused by microbial contamination due to the presence of adhering manure in hides. It is urgently needed to develop new washing methods using environmentally friendly products, to effectively clean raw hides for their storage and shipments. The amphiphilic property of detergents and the capability of glycerol to insert into the detergent micelles are exploited in the formulation of an ideal washing solution. Since the softening of the hardened manure is the key to its removal during the demanuring process, the initial experiments presented in this paper were designed such that the changes in hardness of the manure balls were monitored using a texture analyzer. The work needed to cause the same amount of deformation on the manure sample was measured and compared before and after soaking in the respective formulations. Different detergent types such as anionic (SDS), nonionic (Tween 20 and TritonX-114) and zwitterionic (LDAO) are represented and compared to the biodegradable surfactant, sophorolipid (SL). The biodegradable surfactant with addition of recycled crude glycerol was observed to be more effective in softening the hardened manure samples and will be further studied for “adobe” type manure removal.