Study on the preparation and feasibility of a novel adding-type biological slow-release carbon source

• Published in: Journal of environmental management 2022-08, Vol.316, p.115236-115236, Article 115236
• Main Authors: Cui, Ying, Zhao, Bowei, Xie, Fei, Zhang, Xiao, Zhou, Aijuan, Wang, Sufang, Yue, Xiuping
• Format: Article
• Language: English
• Subjects: Cellulose degradation; Denitrification; Mixed flora screening; Slow-release carbon source
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2022.115236

The development of slow-release carbon sources is an effective biological treatment to remove nutrients from wastewater with low carbon-to-nitrogen ratio (C/N). Most filling-type slow-release carbon could not fulfil the needs of current wastewater treatment plants (WWTPs) process. And most adding-type slow-release carbon sources were prepared using some expensive chemical materials. In this study, combining the advantages of the aforementioned types, a novel adding-type wastepaper-flora (AT-WF) slow-release carbon source was proposed, aiming to realise wastepaper recycling in WWTPs. The screening and identification of the mixed flora, AT-WF carbon source release behaviour, and denitrification performance were investigated. The results showed that through the proposed screening method, a considerable proportion of cellulose-degradation-related genera was enriched, and the cellulose degradation ability and ratio of readily available carbon sources of flora T4, S4 and S5 were effectively strengthened. AT-WF had significant carbon release ability and stability, with an average total organic carbon (TOC) release of 8.82 ± 2.36 mg/g. Kinetic analysis showed that the entire carbon release process was more consistent with the first-order equation. Piecewise fitting with the Ritger-Peppas equation exhibited that the rapid-release (RR) stage was skeleton dissolution and the slow-release (SR) stage was Fick diffusion. Denitrification efficiency can achieve a high average removal efficiency of 94.17%, which could theoretically contribute 11.2% more to the total inorganic nitrogen (TIN) removal. Thus, this study indicated that AT-WF could be utilised as an alternative carbon source in WWTPs. [Display omitted] •A novel adding-type biological slow-release carbon source AT-WF was proposed.•Short-term organic nitrogen source stimulation enhanced the function of the flora.•AT-WF had great ability of carbon release and realized the stable NO3−-N removal.•The production of AT-WF provided a new way for wastepaper recycling in WWTPs.