Study On The Treatment Of Hydrogen Sulfide Odor Air Using Modified Activated Alumina Adsorbent

Odor pollution has become a big enemy effecting the quality of human's life. Odor, which is a public hazard even in low concentration, can lead to a strong human sensory stimulation and is a serous threat to the physical and psychological health. Odor pollutants are defined as the gases that can stimulate man's olfactory organ, make people unpleasant and damage our living circumstance. Hydrogen sulfide, which is frequently encountered, is recognized to the representative of odor pollutants.The treatment technology of odor pollution is mainly physical, chemical and biological methods, such as combustion, drug treatment, adsorption and biological deodorization which are used in and out of China. Its application depends primarily on the composition and quantity of odor gases, temperature, humidity and the concentration of particulate matter as well as the local condition, covering area, economics and so on. Therefore, a combination of application methods which is the optimal efficiency, least investment, should be the best choice.Hydrogen sulfide, a colorless but toxic gas with a strong odor of rotten eggs, is produced widely from the source of coal gas in the city, petroleum processing, chemical production, sewage treatment, natural gas processing and so on. Hydrogen sulfide is a strong nerve medicament, and in a low concentration can stimulate our eyes and respiratory mucosa, the higher concentration can even affect our central nerve system and cause obvious suffocation. There will be various degrees of poisoning when hydrogen sulfide absorbed into our body.The treatment technology of hydrogen sulfide mainly contains absorption, adsorption, oxidation and biological methods.Absorption is divided into physical and chemical methods. If there is no significant chemical reaction in the process and simply dissolved gases into liquid, we call it physical absorption; otherwise, we call it chemical absorption. For example, using solid absorbents to produce chemical reaction with gas and lastly separate it from the flue.Adsorption, a purification method using proper porous materials such as zinc oxide, iron oxide and molecular sieve, is commonly used to treat with the low concentration of hydrogen sulfide. This paper introduced the adsorption principle of these materials and their advantages and disadvantages.Oxidation, generally convert hydrogen sulfide into single sulfur, occurring in gas phase is called dry oxidation, in liquid phase is named wet oxidation. The first method is always used to deal with lower concentration of hydrogen sulfide, in particular for fine desulfurization. However, it is usually needed to replace desulfurizer and couldn't do continuous operation. The second method is effective to convert hydrogen sulfide into single sulfur, no secondary pollution, can operate not only at room temperature but also increased pressure. Most desulfurizers are renewable and cost less.Biological deodorization, including biological filter, biological trickling filtration and biological absorption, has a simple operation, little investment, low power consumption, and high efficiency. It is used since mid-1980s and increasingly arouses people's attention, so has a broad application prospects. Among them, biological filtration is widely used.Sulfur pollution containing hydrogen sulfide is more and more serious in our country. There are many methods of treating hydrogen sulfide, but some costs too much money, or gets unsatisfactory results, or causes secondary pollution. In the light of above problems, here research a new method using modified solid absorbent, which is made by activated alumina as a carrier impregnated into an active solution, to absorb hydrogen sulfide emission. When the initial concentration of absorbent changes, absorption results and changing law is what we want to know. The experiments confirmed under certain condition of quality of modified absorbents, the higher concentration of initial hydrogen sulfide, the better treatment results and the higher efficiency. However, in a certain reaction time, the efficiency will be up to a certain peak, then will decline somewhat. This shows the capacity of modified activated alumina adsorbents is certain.In this paper, we measured the removal efficiency of hydrogen sulfide by the non-modified and modified activated alumina absorption, the first is 60.50%-67.67%, and the second is 96.78%-97.98%. Through the compare, we obviously concluded that modified activated alumina absorption is effective to absorb hydrogen sulfide. In addition, compared to commonly used absorbents, such as activated carbon ,5A-molecular sieve, the initial concentration of sulfur hydrogen is certain, the effects of modified activated alumina is the best, and 5A-molecular sieve is the worst.