Agricultural Wastes

Abstract

This review paper provides a summary of the most recently published research activities related to agricultural wastes, including agriculture waste characterization and analysis, agricultural waste management and pollution prevention/minimization, agricultural waste reuse and recycle, as well as agricultural waste treatment. AGRICULTURAL WASTE CHARACTERIZATION AND ANALYSISThe high concentration, variation, and complexity of agricultural waste make it quite difficult to characterize. Many research efforts have been conducted on a wide range of topics, from representative sampling to physical, chemical, and biological analyses. The need for an integrated protocol, combining chemical analysis, fractionation, and biological testing to characterize the risks associated with complex mixtures was also confirmed by Cizmas et al. (2004). SamplingFor high concentrations of solids, nutrients, and organics in animal manure, Zhu et al. (2004a) investigated a procedure for producing representative samples. The results showed that representative manure samples could not be 1662 obtained without agitation, and that both vertical and horizontal agitation procedures were capable of producing representative manure samples for total solids (TS), total nitrogen (TN), and total phosphorus (TP) analysis. Solid sorption techniques based on cartridges for three categories of waste odour substances (indoles, volatile fatty acids, and methylthiol) were developed by Willig et al. (2004). It was confirmed that these techniques were comparable to fibre solid-phase micro extraction sorption techniques because of the excellent values obtained for sensitivity (lower ppb level) and repeatability (relative standard deviation <10%). Physical/Chemical/OrganicThe aggregate stability and carbon characteristics of particle-size fractions were investigated in cultivated and forested soils in semiarid Spain. It was found that the organic matter associated with the <20 µm particle-size fractions did not appear to contribute greatly to the stability of macroaggregates in semiarid soil (Caravaca et al., 2004). Urban-rural differences in polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were investigated with passive air samplers over an integrated time period. The results of this study demonstrated the feasibility of using such devices to determine air concentrations of persistent organic pollutants (POPs) and to assess the spatial distribution of these pollutants for time-integrated samples . A new technique of generating ultra-pure hydroxide eluent was proposed for carbohydrate analysis of environmental samples. This technique significantly reduced the amounts of hydroxyl ions present in the waste stream and provided faster chromatographic 1663 runs with greater sensitivity and precision for determining the monosaccharide composition of environmental samples (Martens and Loeffelmann, 2004). NutrientsFast estimation of nutrients in animal manure has been investigated by several researchers for proper land application (Higgins et al., 20...