A METHOD AND A SYSTEM FOR ADJUSTING S/NA -BALANCE OF A PULP MILL

The invention relates to a method and a system for adjusting S/Na -balance of a pulp mill， wherein an aqueous pulp mill liquor containing sulphides is diverted into a bioreactor and oxidized by means of sulphur-oxidizing microbes， thereby producing an aqueous suspension from which elemental sulphur can be separated as a precipitate and the residual solution may be directed to causticizing. Optionally， prior to oxidation in the bioreactor， the aqueous pulp mill liquor may be first stripped to obtain a gas stream containing H2S which is then scrubbed with a scrubbing solution to obtain an aqueous spent scrubbing solution containing sulphides， in which case the residual solution can be used to replenish the scrubbing solution. The invention relates to a method and a system for adjusting S/Na -balance of a pulp mill， wherein an aqueous pulp mill liquor containing sulphides is diverted into a bioreactor and oxidized by means of sulphur-oxidizing microbes， thereby producing an aqueous suspension from which elemental sulphur can be separated as a precipitate and the residual solution may be directed to causticizing. Optionally， prior to oxidation in the bioreactor， the aqueous pulp mill liquor may be first stripped to obtain a gas stream containing H2S which is then scrubbed with a scrubbing solution to obtain an aqueous spent scrubbing solution containing sulphides， in which case the residual solution can be used to replenish the scrubbing solution.本发明涉及一种用于调节纸浆厂S/Na平衡的方法与系统：将含硫化物的水性纸浆厂废液引入生物反应器（bioreactor），通过硫氧化微生物（sulphur-oxidizing microbes）进行氧化反应，生成水性悬浮液，可从该悬浮液中分离出作为沉淀物的单质硫（elemental sulphur），剩余溶液可送入苛化工序。可选地，在生物反应器中进行氧化反应前，可先对该水性纸浆厂废液进行汽提，得到含硫化氢（H₂S）的气流，随后用洗涤液（scrubbing solution）对该气流进行洗涤，获得含硫化物的废弃水性洗涤液；在此情况下，剩余溶液可用于补充洗涤液。本发明涉及一种用于调节纸浆厂S/Na平衡的方法与系统：将含硫化物的水性纸浆厂废液引入生物反应器（bioreactor），通过硫氧化微生物（sulphur-oxidizing microbes）进行氧化反应，生成水性悬浮液，可从该悬浮液中分离出作为沉淀物的单质硫（elemental sulphur），剩余溶液可送入苛化工序。可选地，在生物反应器中进行氧化反应前，可先对该水性纸浆厂废液进行汽提，得到含硫化氢（H₂S）的气流，随后用洗涤液（scrubbing solution）对该气流进行洗涤，获得含硫化物的废弃水性洗涤液；在此情况下，剩余溶液可用于补充洗涤液。