Aiming at disadvantages of conventional sulfur-limestone autotrophic denitrification system, such as producing stink (H₂S) and low-rate nitrogen and phosphorus removal from wastewater with low C/N, foam FeSO₄ modified limestone sulfur concrete (FFLSC) was prepared. Experimental parameters of FFLSC biofilter, such as hydraulic retention time (HRT), influent NO₃⁻-N, additional alkalinity and COD addition, were tested. For wastewater without COD, FFLSC biofilter could simultaneously remove TON (NO₃⁻-N+NO₂⁻-N) from 22.63 to 0.73 mg/L and PO₄³⁻-P from 0.98 to 0.34 mg/L, respectively, and H₂S was not detected at HRT 1 h, and obtain the highest TON removal rate 1514.88 mg/L/d at HRT 0.25 h with effluent TON 6.80 mg/L. The longer the HRT, the higher N and P removal, but the more the H₂S production. Additional alkalinity and COD addition could enhance N removal largely. But H₂S production increased with COD addition increasing. FFLSC biofilter was a sulfur-based mixotrophic denitrification reactor with non-ignorable biological sulfate reduction and hydrolysis. FeSO₄ in FFLSC accelerated N removal by providing additional Fe²⁺ and SO₃²⁻ autotrophic denitrification, prevented H₂S production by FeS formation, increased P removal by precipitation of FePO₄. FFLSC is a promising material for non-stink and high-rate nitrogen and phosphorus removal from wastewater.

中文翻译：

---

泡沫 FeSO4 改性石灰石硫混凝土，用于从废水中去除无臭和高速率的氮磷


针对常规硫-石灰石自养反硝化系统产生恶臭（H₂S）和低C/N废水脱氮脱磷等缺点，制备了泡沫FeSO₄改性石灰石硫混凝土（FFLSC）。测试了 FFLSC 生物过滤器的实验参数，如水力停留时间 （HRT）、进水 NO₃⁻-N、附加碱度和 COD 添加量。对于无 COD 的废水，FFLSC 生物过滤器可同时去除 22.63 至 0.73 mg/L 的 TON （NO₃⁻-N+NO₂⁻-N） 和 0.98 至 0.34 mg/L 的 PO₄³⁻-P，在 HRT 1 h 时未检测到 H₂S，在 HRT 0.25 h 时获得最高的 TON 去除率 1514.88 mg/L/d，出水 TON 6.80 mg/L。HRT 越长，N 和 P 去除率越高，但 H₂S 的产生越多。额外的碱度和 COD 添加可以大大提高 N 的去除率。但 H₂S 的产量随着 COD 添加量的增加而增加。FFLSC 生物过滤器是一种基于硫的混合营养脱硝反应器，具有不可忽视的生物硫酸盐还原和水解。FFLSC 中的 FeSO₄ 通过提供额外的 Fe²⁺ 和 SO₃²⁻ 自养反式反犹作用加速了 N 的去除，阻止了 FeS 形成产生的 H₂S，增加了 FePO₄ 沉淀的 P 去除。FFLSC 是一种很有前途的材料，可用于从废水中去除无臭和高速率的氮和磷。