Sulphur Dioxide Adsorption on Nickel Smelting Industry in East Luwu Using a Solution of Hydrogen Peroxide

Research on SO2 gas adsorption from emissions of nickel ore industries plant use coal in the smelting process and the production by using H2O2 as an adsorbent solution. The adsorbent used to reduce the level of SO2 in the air pollution. This study includes the adsorption of SO2 gas of 6 factory chimneys at the nickel ore industry (2 dryers, 2 kilns, and 2 furnaces). The results showed that the percentage ratio of the average absorbance between H2O2 and calcium carbonate in reducing greenhouse gas emissions of SO2 into the air that is 95.00%: 93.34%. As for the rest of SO2 gas unadsorbed fixed meet the quality standards specified (750 mg/m 3 ). Batch adsorption was conducted with respect to concentration of adsorbent, the adsorption temperature, and contact time. It was shown that the optimum concentration of adsorbent was 5%, the adsorption temperature was 20°C, and contact time was 1800 second.


Introduction
Total human population that continues to increase accompanied by increased their requirement and their activities. Diverse human activities have negative and positive impact on the environment. One of its negative effects that currently very disturbing is air pollution. According [16], air pollution is the presence of one or more physical substance, chemical, or biological in the atmosphere in an amount which can endanger the health of humans, animals and plants.
One of the substances that can cause air pollution is sulfur. Sulfur compounds in different forms has been known as a major air pollutant industrial areas as a result of burning fossil fuels, and can be derived from volcanic eruptions. In the future, an estimated amount of sulfur discharged into the atmosphere would have increased 10-fold [41]. In the form of gas, SO 2 can cause irritation to the lungs that causing hard to breathing especially for people who has asthma, children and the elderly. SO 2 is also able to react with other chemical compounds formed sulfate particles that if inhaled can accumulate in the lungs and cause breathing problems, respiratory illnesses, and even death [9].
One of the industries that produce gas emission SO 2 is smelting industry Nickel located in Sorowako, East Luwu, South Sulawesi, where the production process is done by burning the raw material in the kiln-firing with coal and produce byproduct that is SO 2 [19]. The main problem that causing gas emissions SO 2 in the industry is coal as the main fuel, even if used is coal with the best quality (low sulfur content), sulfur dioxide will formed surely and estimated gas emissions SO 2 is wasted at least able to reach 13 tons/hour.
Reducing gas emissions SO 2 can be done with a wet scrubber systems, combustion flue gas is sprayed with slurry (lime slurry), Ca(OH) 2 were able to reduce SO 2 emissions of 88.5 thousand tons/year to 4.5 thousand tons/year or absorption SO 2 gas approximately 95% [24] but this process can produce CO 2 which is also one of the air pollutants. System wet scrubber also create problems with the chimney because there is spraying a slurry of lime on the chimney wall [43] and this system is costly because the industry had to prepare the land for mining and milling limestone as well as land for waste disposal in a large capacity [48].
Based on the description above, it takes a process to reduce gas emissions SO 2 that are environmentally friendly and not damage the property industry. As it is known that the gas sulfur dioxide is a colorless, flammable and easily soluble in water, young oxidized, and can react with other compounds. Based on the chemical and physical properties, then the SO 2 can be removed by oxidation using oxidizing agent that is hydrogen peroxide and this reaction can produce sulfuric acid compound, so this research is carried out to reduce SO 2 gas emissions in the nickel industry located in the east Luwu using hydrogen peroxide.

Experimental
This research was carried out directly on the nickel smelting industry in East Luwu. This research is qualitative and quantitative research on the amount of SO 2 can react with the hydrogen peroxide. Samples emissions of SO 2 that get as laboratory scale using an instrument ( Figure 1) and there are variation on concentrations, temperature and time of hydrogen peroxide to react with SO 2 . This process is carried out at the time when the industry is operating in conditions of temperature, flow rate and pressure of maximum emissions. SO 2 concentration was measured using a UV -Vis spectrophotometer.

Results and Discussion
Sampling and adsorption exhaust gas emissionsindustry conducted for twelve days in May 2015. The sampling is done where the condition of each chimney in a state of maximum 6 industrial chimney, each on 2 chimneydryer, 2 chimney Kiln, and 2chimney furnace. The sampling technique uses a series of side tool probe, vacuum for sucking in air emissions and a series of impinger a place for adsorbent solution (hydrogen peroxide). To view the results adsorption of SO 2 gas, then conducted sample analysis in Laboratory Technical Implementation Unit of the Environment Agency of South Sulawesi province. Description of adsorption results concentration of SO 2 of each the chimney can be seen in the following chart.    Based on the test data exhaust gas of SO 2 is absorbed by the hydrogen peroxide from chimneys emissions at dryer 1 and 2; kiln 1 and 2; and furnace 1 and 2, increased concentration of maximum adsorption indicated in the treatment adsorbent solution on the condition of 20°C, with a concentration of 5% and length taking 1800 seconds. Results achieved in the adsorption capability of the accumulation of means as follows: The results showed that the higher the temperature of the solution is getting lower to adsorb exhaust gas emissions, the lower the flow rate of the exhaust gas is getting greater the ability reaction of adsorbent and the nature of the gases emitted fluctuations in temperature, pressure and flow rate as well as the turbulence also affects the absorption of gas emissions factory chimneys.
Based on data from previous research using a slurry of lime (calcium hydroxide) which is able to adsorb sulfur dioxide by 95% equal to the adsorption ability of hydrogen peroxide that is 94.85% from industrial sources of nickel.

Conclusions
This result of this study that is comparison of percentage of the average adsorption accumulation between adsorbent solution using a solution of hydrogen peroxide and calcium carbonate slurry to reduce sulfur dioxide emissions into the ambient air show results approximately equal to the lime slurry that is 95.00%: 93.34%. The adsorption concentration of SO 2 greater if conditions adsorbent greater concentration, then the lower the temperature and the longer the adsorption time. Emissions of the six chimneys that are not adsorbed, they meet the standards set. under the rules of the Governor Number 69 Year 2010 on the quality standard emissions of SO 2 750 mg/m³, means that hydrogen peroxide as a adsorbent solution viable as an alternative instead of calcium carbonate.