The basis of the new presented method is based on the Seaboard process for natural gas sweetening, with the difference that instead of the aeration step, an anaerobic baffled reactor is used to remove sulfide. To prepare the appropriate microorganism, the sludge obtained from the activated sludge unit of urban sewage treatment, which remained anaerobically for one year, was used. This sludge was fed with thiosulphate for two weeks and then with sulphide for 15 days, which resulted in the maximum removal of sulphide in mmols-th 3.3 were observed. Microscopic studies showed that the dominant microbial population in the bioreactor is Thiobacilli species. Next, using the Taguchi method, the nutrients needed by microorganisms were optimized and the effect of each on the removal rate of sulfide and sulfur production was investigated. One of the most important advantages of this method is the removal of the disadvantages of the Seaboard process, very short initial startup time, high speed of sulfide removal, no use of pure strain, which increases the possibility of industrialization of the process, no need for aeration and very good resistance of the system in It is equal to the sudden shock of sulfide.