Composting of animal manures and chemical criteria for compost maturity assessment. A review

The threat posed by increasing amount of dyes on daily basis, especially on our ecosystem, has brought a serious search for more efficient low-cost adsorbents. Sand is mixed with cement and water to make concrete, used in the manufacture of brick, glass and other materials, and it can also be used as a medium for the filtration of water. Sand, which is ubiquitous, has been used as an adsorbent because of its enormous availability in the local environment. This review reveals that further research must be conducted to bring to the fore the expansive laboratory, industrial and environmental usage of sand materials as dye adsorbents. Consequently, the usage of different types of sand in the field of adsorption science represents a viable and powerful tool, resulting into the superior improvement in pollution control and environmental preservation.

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Adsorption of dyes using different types of clay: a review

http://www.zeolitanatural.com/docs/gasseparation2.pdf

Application of natural zeolites in the purification and separation of gases

This paper reviews the use of additives to reduce odor and ammonia (NH3) emissions from livestock wastes. Reduction of NH3 volatilization has been shown to be possible, particularly with acidifying and adsorbent additives, and potential exists to develop further practical and cost-effective additives in this area. Masking, disinfecting, and oxidizing agents can provide short-term control of malodor, but as the capacity of these additives is finite, they require frequent reapplication. Microbial-based digestive additives may offer a solution to this problem as they are regenerative, but they appear to have been developed without a thorough understanding of microbiological processes occurring in livestock wastes. Currently, their use to reduce odor or NH3 emissions cannot be recommend. If the potential of these types of additives is to be realized, research needs to shift from simply evaluating these unknown products to investigating known strains of bacteria or enzymes with known modes of action. To protect the farmers' interest, standard independent test procedures are required to evaluate efficacy. Such tests should be simple and quantify the capacity of the additive to perform as claimed. The principle use of additives needs to be identified and addressed during their development. Producers may not use effective additives in one area if they further compound other problems that they perceived to be more important. There is the potential to use additives to treat other problems associated with livestock wastes, particularly to improve handling properties, reduce pollution potential to watercourses, and reduce pathogenic bacteria. Further work is required in these areas.

J.M. Lopez-Real

Papers

Natural zeolites and sepiolite as ammonium and ammonia adsorbent materials

Application of natural zeolites for the reduction of ammonia emissions during the composting of organic wastes in a laboratory composting simulator