Submitted to: Advances in Environmental Research
Publication Type: Book / Chapter
Publication Acceptance Date: 11/1/2001
Publication Date: 12/1/2002
Citation: SAJWAN, K.S., PARAMASIVAM, S., ALVA, A.K., ADRIANO, D.C. USE OF FLY ASH AND MUNICIPAL SEWAGE SLUDGE: CHALLENGES, OPPORTUNITIES, AND FUTURE. ADVANCES IN ENVIRONMENTAL RESEARCH. (In Press) 2002. Interpretive Summary: Coal combustion to generate power results in substantial amount of by-product (CCBP) called as fly ash (FA). This by-product is alkaline in reaction and contains several plant nutrients, therefore, it can be used as a soil amendment to acidic soils. FA is generally low in nitrogen and phosphorus. Another by-product of wastewater treatment is sewage sludge (SS) which is generally high in nitrogen and phosphorus. Application of FA and SS in a certain proportion can be beneficial than application of the single by-product, since the mixed amendment contains most of plant nutrients. This report reviews various aspects of using FA, SS and combined amendments applied in different rates on soil properties, plant growth response and potential leaching of metals.
Technical Abstract: Utilization of coal combustion by-products (CCBP) and municipal by-products, mainly sewage sludge (SS), as agricultural soil amendments is of considerable importance not only as an avenue to dispose these materials but also to explore the potential advantages as source of some plant nutrients and to improve soil physical and chemical properties. Fly ash (FA) is one of the important component of CCBP and alkaline in reaction with low amount N an P. On the other hand, SS contains relatively high concentrations of N and P, slightly acidic in reaction and has variable concentrations of heavy metals. Therefore, combining the FA with SS can supplement the essential plant nutrients, which are lacking in FA, and can also have high alkalinity. The case studies presented in this review address various issues related to metal leaching and plant uptake under greenhouse and field conditions and subsequent impact on groundwater quality if these by-products are applied either individually or as mixture of these by-products. These case studies covered a wide range of rates (from 0 to 1120 Mg/ha) of application of these amendments and proved that these materials could be used as agricultural land amendments up to 247 Mg/ha without affecting accumulation of metals in plant tissues, biomass production, or metal leaching if environmentally sound management practices are employed.