Enhanced Denitrification of Integrated Sewage Treatment System by Supplementing Denitrifying Carbon Source

Abstract

Integrated sewage treatment system (ISTY) is a new technology for rural domestic sewage treatment. In the ISTY, the carbon source in the denitrification stage is often insufficient, affecting the denitrification efficiency. In order to improve the denitrification efficiency, several commonly available agricultural wastes, peanut shell (PS), sawdust (SD), peat (PT), and their mixtures (MT), were selected as supplementary carbon sources in the denitrification stage of ISTY to study the denitrification efficiency. Results show that PS exhibited a high carbon release capacity. PS released an enormous amount of carbon in 144 h, and the cumulative total organic carbon was 41.99 ± 0.7 mg/(g·L). The optimum carbon source dosage was 3 g/L, the nitrate removal rates of PS exceeded 95% after 48 h, and the denitrification rates were 9.35 mg/(g·L), which were 63.92% higher than that of the control group. After running the ISTY for 120 h, and with PS as supplementary carbon sources, the removal rate of TN increased from 29.76% to 83.86%. At the genus level, the dominant denitrifying bacteria in ISTY, after adding PS, were Pseudomonas and Cupriavidus, accounting for 78.68%, an increase of 72.90% compared with the control group. This evidence suggested that PS can obviously enhance the denitrification efficiency of the ISTY as a supplementary carbon source.

Systematic review: External carbon source for biological denitrification for wastewater

“…Nitrogen and phosphorus removal with biological methods by a (phosphorus accumulating) bacteria “ Acinetobacter sp. strain C‐13” with the capacity of heterotrophic nitrification–aerobic denitrification shows better results (Chen, Chen, et al, 2021). High removal efficiency has been noticed while evaluating of microbial community and biological denitrification in an anoxic sequencing batch biofilm reactor, focused on nitrous oxide emission, performance evaluation, and microbial community (Ding et al, 2019).…”

“…Removal of nitrogen and phosphorus (biologically) by a phosphorus‐accumulating bacteria Acinetobacter sp. strain C‐13 with the capability of heterotrophic nitrification–aerobic denitrification demonstrated good results (Chen, Chen, et al, 2021). Another study (Ding et al, 2019) evaluating microbial community, where Lysobacter, Thauera , and Tolumonas were the main genera, representing the coexistence of autotrophic and heterotrophic denitrifiers in ASBBR showing better results (Ding et al, 2019).…”

“…Waste management process and benefits for water treatment process with low cost will be acknowledged. with the capability of heterotrophic nitrification-aerobic denitrification demonstrated good results (Chen, Chen, et al, 2021).…”

“…In addition, an evaluation of published review papers relevant to denitrification, removal of nitrogen, carbon source (Chen, Chen, et al, 2021;Dhamole et al, 2015;Hang et al, 2016;Ji et al, 2015;Kuypers et al, 2018;Martínez-Espinosa et al, 2021;Pang & Wang, 2021;Rajta et al, 2020;Scheer et al, 2020;Shi et al, 2020;Tian & Yu, 2020;Wang, Chen, et al, 2021;Wang, Gao, et al, 2021;J. Yang et al, 2020;You et al, 2020;Zhang et al, 2020;Zhang et al, 2021), their keywords and search strings were carried out.…”

“…In addition, an evaluation of published review papers relevant to denitrification, removal of nitrogen, carbon source (Chen, Chen, et al, 2021; Dhamole et al, 2015; Hang et al, 2016; Ji et al, 2015; Kuypers et al, 2018; Martínez‐Espinosa et al, 2021; Pang & Wang, 2021; Rajta et al, 2020; Scheer et al, 2020; Shi et al, 2020; Tian & Yu, 2020; Wang, Chen, et al, 2021; Wang, Gao, et al, 2021; J. Yang et al, 2020; You et al, 2020; Zhang et al, 2020; Zhang et al, 2021), their keywords and search strings were carried out. SD and the WoS database resulted different article types including review articles (625), research articles (3084), encyclopedia (58), book chapters (461), conference abstracts (14), discussion (1), editorials (4), mini reviews (6), news (1), Short communications (45), and other (46) in total since 2015 to 2021.…”