%0 Journal Article
%T Use of Iron (II) Salts and Complexes for the Production of Soil Amendments from Organic Solid Wastes
%A Amerigo Beneduci
%A Ilaria Costa
%A Giuseppe Chidichimo
%J International Journal of Chemical Engineering
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/701728
%X A method to obtain rapidly stabilized composts for crops from solid organic wastes is evaluated. Here we used a laboratory scale reaction chamber where solid waste treatment was performed under strictly controlled temperature and pressure conditions. The row organic waste was mixed with acid solutions containing iron (II) ions either in the fully hydrated form or in the form of complexes with the diethylentriaminopentaacetic acid. Data from elemental analysis distribution and GC/MS analysis of the polar and non polar dissolved organic matter, clearly showed that Fe(II) ions significantly enhance organic substrate oxidation of the initial solid waste, compared to a material obtained without the addition of the Fe(II) ions to the raw organic matrix. These results suggest that Fe(II) ions might be involved in a catalytic oxidation pathway that would be activated under the experimental conditions used. The extent of the oxidation process was evaluated by the value of the C/N ratio and, qualitatively, by the molecular composition of the dissolved organic matter. After about 6 hours of incubation, dark-brown and dry organic matrices were obtained with C/N ratio as low as 12 and a high degree of oxidative decomposition into low-molecular-weight compounds at high oxidation state. 1. Introduction Solid organic waste managing, treatment, and disposal is one of the most important worldwide environmental problems. Among the various options (minimization, recycling, sanitary landfilling, incineration, and composting) composting is one of the most interesting and economically feasible. This is especially true because the produced compost can be used for soil amendment or fertilizer when the organic waste does not contain pollutants such as heavy metals. The composting process is defined as ˇ°the biological decomposition of biodegradable solid waste under controlled predominantly aerobic conditions to a state that is sufficiently stable for nuisance-free storage and handling and is satisfactorily matured for safe use in agricultureˇ± [1]. In this process, the raw organic material is progressively broken down by a succession of populations of living organism at different stages of the decomposition process (mesophilic, thermophilic, and maturation stages) [2]. Micro- and macroflora are key process factors controlling the composting process. Other key factors are temperature, pH, moisture content, and aeration as well as the chemical and physical availability of the nutrients in the organic waste, respectively, determined by the molecules vulnerability to microbes attack
%U http://www.hindawi.com/journals/ijce/2012/701728/