Under natural conditions, some of the sulfur compounds in the oil refinery wastewater and tar contaminated soil will be degraded because of the presence of bacteria in nature. Fungus desulfurization (MDS) is a kind of metabolic process using bacteria under mild conditions, which is suitable for oil desulfurization. In chemical process, desulfurizer can be recycled or replenished by itself. In the desulfurization operation, hydrocarbon is still the carbon source of organic sulfur molecules, rather than selective or specific sulfur excretion. The water-soluble organic sulfur compounds are water-soluble, and then separated from petroleum, but some valuable carbon argon compounds are also lost. MDS such as organic sulfur compounds with mercaptans, sulfides and other small molecular weights are more effective. For aromatic compounds with bowl heterocycles, it has been reported that only a few strains have been able to excrete them into water-soluble compounds, such as Pseudomonas and palcaligens, with mild odor, which limits the commercial value of fungus desulfurization.
在菌类脱硫方法的基础上，90年代国外迅速发展起来了石油的生物脱硫( Bio De Sulfurization，BDS)技术。BDS技术是通过微生物的酶催化产生特定的C-S裂解反应，释放可溶性硫，碳氬化合物的酶催化反应，不损害石油烃链的基本骨架。BDS和加氢脱硫相比、具有以下优点:
On the basis of bacteria desulfurization method, bio de sulfurization (BDS) technology for petroleum was developed rapidly abroad in 1990s. BDS technology is a specific C-S cracking reaction, which releases soluble sulfur and carbon argon compounds by enzyme catalysis of microorganisms, without damaging the basic skeleton of petroleum hydrocarbon chain. Compared with hydrodesulfurization, BDS has the following advantages:
1. It can operate at low temperature and low pressure;
2. Compared with HDS, biological desulfurization has less investment and 50% lower operating cost of 10 ~ 15%;
3. Good flexibility, can handle all kinds of oil, such as petroleum, gasoline, intermediate gasoline, FCC gasoline, residual fuel oil;
4. No need of gas, saving energy, reducing carbon dioxide emissions, beneficial to environmental protection;
5. It is very difficult to remove sulfur compounds effectively in HDS unit, which is more difficult to solve with traditional HDS desulfurization technology. Therefore, the biological desulfurization method is very promising.