Influence of Coagulant Species on Sulfur Oxide (SOx) Emission from the Textile Sewage Sludge Combustion

Abstract

Abstract-Simulation of textile sewage sludge combustion to investigate the typical flue gas generation was carried out by Material-oriented Little Thermodynamic (MALT) software simulation. Textile sewage sludge was modeled on the basis of loadings of effluents, daily usage of dyeing material, heavy chemical for wastewater treatment and daily production of activated sludge. Combustion temperature was set in the range of 500 °C to 1100 °C. In this research the influence of coagulant species used in wastewater treatment on flue gas especially on sulfur oxide (SO x ) generation was investigated. The replacement of conventional coagulant FeSO 4 and Al 2 (SO 4 ) 3 to FeCl 3 gave the result of more than 18% reduction of SO x at the combustion temperature of 850 °C and 19% at the temperature not less than 950 °C. The distribution ratio of sulfur element indicated that SO x especially in the form of SO 2 was generated at the combustion temperature of 700 °C and the concentration increased with a rise in combustion temperature.Index Terms-Textile sewage sludge, coagulant, sulfur oxide (SO x ), MALT. I. INTRODUCTIONTextile sewage sludge as a by-product from textile wastewater treatment causes a serious problem to be faced in textile industry due to its large amount of production and toxicity characteristic. As an illustration, a textile industry common effluent treatment plant (CETP) in Tripur India generated 200 ton of textile sewage sludge everyday [1]. Even in Leuwi Gajah Indonesia, one of textile industry produces sludge at a rate of 5 ton/day [2]. In order to reduce the volume of sludge, an incineration process by combustion is often carried out. This process is advantageous to eliminating the toxicity problem by heat treatment [3]. Another merit of the process is energy recovery from the result of waste burning in an incinerator [4]. Apart from the beneficial role, the combustion process has a disadvantage of releasing various types of gas, volatile organic compound, dioxin, furan and particulates matter [4]. The flue gas generation is another problem due to the difficulty of keeping emission regulation standards. Sulfur oxide (SO x ) in the form of SO 2 and SO 3 is one of major pollutant releasing from combustion treatment. SO x has a corrosive characteristic and plays a significant role for occurrence of acid rain when react Manuscript received April 15, 2013; revised June 13, 2013 with water to form sulfuric acid (H 2 SO 4 ) in the atmosphere. In sewage sludge combustion, the generation of SO x is coming from oxidation of sulfur compounds belong to material constituent of sludge. Generally the emission derived from the combustion treatment depends on the combustion design, the operational condition and the characteristic of waste [4].This research tried to investigate the emission characteristic from the material constituent of sludge point of view. In textile industry, the chemical composition of textile sewage sludge depends on heavy chemicals used in textile processing and textile wastewater treatment process. ...

Release of K and Cl and Emissions of NOx and SO2 during Reed Black Liquor Combustion in a Fluidized Bed

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