A constructed wetland microcosm was employed to investigate the sulfur cycle-mediated electron transfer between carbon and nitrate. Sulfate accepted electrons from organics at the average rate of 0.84 mol/(m³·d) through sulfate reduction, which accounted for 20.0% of the electron input rate. The remainder of the electrons derived from organics were accepted by dissolved oxygen (2.6%), nitrate (26.8%), and iron(III) (39.9%). The sulfide produced from sulfate reduction was transformed into acidvolatile sulfide, pyrite, and elemental sulfur, which were deposited in the substratum, storing electrons in the microcosm at the average rate of 0.52 mol/(m³·d). In the presence of nitrate, the acid-volatile and elemental sulfur were oxidized to sulfate, donating electrons at the average rate of 0.14 mol/(m³.d) and driving autotrophic denitrification at the average rate of 0.30 g N/(m³·d). The overall electron transfer efficiency of the sulfur cycle for autotrophic denitrification was 15.3%. A mass balance assessment indicated that approximately 50% of the input sulfur was discharged from the microcosm, and the remainder was removed through deposition (49%) and plant uptake (1%). Dominant sulfatereducing (i.e., Desulfovirga, Desulforhopalus, Desulfatitalea, and Desulfatirhabdium) and sulfuroxidizing bacteria (i.e., Thiohalobacter, Thiobacillus, Sulfuritalea, and Sulfurisoma), which jointly fulfilled a sustainable sulfur cycle, were identified. These results improved understanding of electron transfers among carbon, nitrogen, and sulfur cycles in constructed wetlands, and are of engineering significance.

一个人工湿地的缩影被用来研究硫循环介导的电子在碳和硝酸盐之间的转移。通过硫酸盐还原，硫酸盐以平均0.84 mol /（m ³ ·d）的速度从有机物中吸收电子，占电子输入率的20.0％。其余来自有机物的电子被溶解的氧气（2.6％），硝酸盐（26.8％）和铁（III）（39.9％）接受。硫酸盐还原产生的硫化物转化为酸挥发的硫化物，黄铁矿和元素硫，它们沉积在基质中，以0.52 mol /（m ³的平均速率）在微观世界中存储电子·d）。在硝酸盐的存在下，酸挥发物和元素硫被氧化为硫酸盐，以0.14 mol /（m ³ .d）的平均速率提供电子，并以0.30 g N /（m ³的平均速率）驱动自养反硝化作用·d）。自养反硝化的硫循环的总电子转移效率为15.3％。质量平衡评估表明，大约50％的输入硫已从微观世界中排出，其余的则通过沉积（49％）和植物吸收（1％）除去。主导sulfatereducing（即，Desulfovirga，Desulforhopalus，Desulfatitalea，和Desulfatirhabdium）和sulfuroxidizing细菌（即，Thiohalobacter，硫杆菌属，Sulfuritalea和Sulfurisoma共同完成了可持续的硫循环）。这些结果改善了对人工湿地中碳，氮和硫循环之间电子转移的理解，具有工程意义。