Annual Report 2003-2004

NRIEnergy & Environment Research CenterProject Title:Research In Pollution Abatement of Softener Clarifiers SolidWastes In Islam Abad Thermal Power PlantDepartment: Environment Protection Project Manager: S. DavariEmployer: Isfahan Regional Electric Co. Project Code: PEVBE01Project Staff: R. Riazi, A.M. Sohrabi KashaniSummary:Softener clarifiers in steam power plants with open recirculating cooling towers and ionexchangers as demin. System, have main role in water hardness, alkalinity andsuspended solids reduction. They consume large amounts of lime and produce hugeamounts of lime sludge.Accumulations of sludge in power plant area make environmental pollution as emissionof fine particles and damaging surface waters & ecosystems. So the only solutionremained, is using lime residuals in different industries as raw material and using itsprofit value. In this way, power plant problem will be reduced and raw materials inother industries will be provided.Research in pollution abatement of clarifiers solid wastes for Isfahan regional companystarted in August 2001 and finished in April 2003.In this research after evaluation of existing sludge treatment system (thickening,filtration & transporting system) the modified system was proposed.In the next step according to chemical analysis, different methods of direct & indirectapplication of residuals were specified. Through this section 18 application methodswere introduced. In third part, the information of all industries that consume limeresiduals near power plant were gathered and samples of plant residuals were sent themto be tested and obtain their permission. In the fourth & fifth steps the possibility ofresiduals consumption at different processes of industries were specified to determinewhich markets are best suited to this particular utility needs. When more than onebeneficial use markets are available and economically viable, a utility should conduct anon-economic analysis to determine which beneficial use alternative would provide thegreatest benefit separate from financial issues. The non-economic weighting parametersfor evaluation were, reliability, expandability, land requirements, flexibility operationalcomplexity, compatibility, etc.At the final section, all selected application methods were evaluated with economicalcalculations (capital cost, prime cost, turn over ratio….) and non-economicalconsiderations, in order to propose optimum method for lime residuals application.Project Results: Proposing modified system in order to optimize sludge treatment system. Manufacturing some industrial products and obtaining application permission fromreliable laboratories.59