Abstract: Sulfur acts as an effective inhibitor of dioxins formation, and such action has been proved in laboratory studies, but few studies in actual waste incinerators are reported. To control the emission of dioxins from hazardous waste incinerator (HWI) effectively, a new pilot scale system with SO₂ recycling and fly ash thermal treatment from the bypass flue gas in an actual HWI (50 t·d^-1) was developed. An absorbent was used to realize SO₂ recycling by which SO₂ absorption was conducted by the absorbent in the flue gas and SO₂ desorption was conducted in the low-temperature thermal treatment system. The capacity of SO₂ accumulation and inhibition of dioxins synthesis of the system was studied, and it was found that the system could operate continuously. The system could maintain a high SO₂ concentration of 100 mg·m^-3 after adding a certain amount of other S-compounds and reduce more than 80% of dioxins emission factor. Therefore, the SO₂ recycling inhibition technology provides guidance for dioxin emission reduction during waste treatment, and the long-term stable operation of the system will play a key role in achieving low emission of dioxins, but some relevant parameters of the pilot system still need further optimization.

Key words: waste treatment, dioxins, synthesis, inhibition, absorption, desorption, optimization

摘要： 依托某危险废物焚烧炉(50 t·d^-1)开发了一套硫基循环抑制及飞灰低温热处置联用控制二(口恶)英排放的中试平台,研究了该系统对硫基的循环累积能力及对烟气中二(口恶)英合成的抑制能力.系统利用吸附剂吸附了烟气中SO₂,并在低温热处置装置中将吸附剂中SO₂脱附回烟气中,实现SO₂循环.试验结果表明,该系统能连续稳定运行,对烟气中的SO₂具有一定的富集累积能力,添加一定量外源硫基物质后系统中烟气SO₂能维持在100 mg·m^-3左右,对整体二(口恶)英排放因子的去除率达80%以上.可见,该硫基循环抑制技术对废物处理过程中二(口恶)英减排具有重要指导价值,且长期稳定运行对控制二(口恶)英低排放起关键作用,但该中试系统的相关参数需进一步优化.

关键词: 废物处理, 二(口恶)英, 合成, 抑制, 吸附, 脱附, 优化