P-nitrophenol (PNP or 4-NP) has been widely used as a biorefractory raw material in chemical industry, whereas been highly concerned for its characteristics of mutagenic/carcinogenic activity and food chain bioaccumulation. In this study, an anaerobic semi-fixed bed biofilm reactor (An-SFB-BR) was constructed and used to treat PNP wastewater which discharged from chemical industries. Experimental results revealed that the An-SFB-BR was successfully cultivated with the gradually increasing of influent PNP from 0 to 540 mg/L (gradually increased 10 mg/L every time in stage II and 30–50 mg/L for stage III), with the observation of an average removal efficiency of 98% for PNP and 80% for chemical oxygen demand (COD), also a biogas production and biogas production rate of 2.1 L/(L·d) and 0.57 m³/kg-COD, respectively. Finally, the conversion rate of P-aminophenol (PAP), the primary intermediate of PNP reached 80% after An-SFB-BR biodegradation. A relatively stable pH was maintained throughout the entire process, and insignificant VFA accumulation. The reactor exhibited a strong toxic shock resistance, and 16S rRNA sequencing results demonstrated that the dominant microbial community changed slightly with the gradually increasing of PNP concentration, which guaranteed the PNP removal efficiency.

P硝基苯酚（PNP或4-NP）已被广泛用作化学工业一个难生化原料，而受到高度关注用于诱变/致癌活性和食物链生物蓄积性其特性。在这项研究中，厌氧半固定床生物膜反应器（An-SFB-BR）被建造并用于处理从化学工业排放的PNP废水。实验结果表明，随着进水PNP从0逐渐增加到540 mg / L，成功培养了An-SFB-BR（II期每次逐渐增加10 mg / L，III期每次增加30-50 mg / L）。 ，观察到PNP的平均去除效率为98％，化学需氧量（COD）的平均去除效率为80％，沼气产量和沼气生产率分别为2.1 L /（L·d）和0.57 m ³/ kg-COD。最后，转化率P氨基苯酚（PAP），初级中间PNP的后一种-SFB-BR生物降解达到80％。在整个过程中都保持了相对稳定的pH值，并且VFA的积累微不足道。该反应器显示出较强的抗毒性冲击性，并且16S rRNA测序结果表明，随着PNP浓度的逐渐增加，优势微生物群落略有变化，从而保证了PNP的去除效率。