Mixed sulfur–iron particles packed reactor for simultaneous advanced removal of nitrogen and phosphorus from secondary effluent

Abstract

A mixed sulfur-iron particles packed reactor (SFe reactor) was developed to simultaneously remove total nitrogen (TN) and total phosphorus (TP) of the secondary effluent from municipal wastewater treatment plants. Low effluent TN (<1.5 mg/L) and TP (<0.3 mg/L) concentrations were simultaneously obtained, and high TN removal rate [1.03 g N/(L·d)] and TP removal rate [0.29 g P/(L·d)] were achieved at the hydraulic retention time (HRT) of 0.13 h. Kinetic models describing denitrification were experimentally obtained, which predicted a higher denitrification rate [1.98 g N/(L·d)] of SFe reactor than that [1.58 g N/(L·d)] of sulfur alone packed reactor due to the mutual enhancement between sulfur-based autotrophic denitrification and iron-based chemical denitrification. A high TP removal obtained in SFe reactor was attributed to chemical precipitation of iron particles. Microbial community analysis based on 16S rRNA revealed that autotrophic denitrifying bacteria Thiobacillus and Sulfuricella were the dominant genus, indicating that autotrophic denitrification played important role in nitrate removal. These results indicate that sulfur and iron particles can be packed together in a single reactor to effectively remove nitrate and phosphorus.

A modified BAF system configuring synergistic denitrification and chemical phosphorus precipitation: Examination on pollutants removal and clogging development

“…For compensating the loss of carbon source, the addition of external carbon sources in the denitrification process are often required, and therefore operation cost increases. To address the issue of carbon source shortage of removing phosphorus and nitrogen from wastewater with a low C/N ratio, combined chemical phosphorus precipitation and denitrification (through heterotrophic or autotrophic pathways) were proposed (Wang et al, 2006(Wang et al, , 2015. Nevertheless, pre-treatment of suspended solids (SS) in the influent was not fully addressed in these previous researches, which is however crucial for successful operation of BAF.…”

Performance and mechanism of synchronous nitrate and phosphorus removal in constructed pyrite-based mixotrophic denitrification system from secondary effluent

“…Eutrophication caused by excessive nitrogen (N) and phosphorus (P) contaminants is an environmental issue of high concern nowadays (Boonchai and Seo 2015;Wang et al 2015). The discharge of secondary effluent from municipal wastewater treatment plants (WWTPs) is one of the major anthropogenic sources of N and P contaminants (Wang et al 2015).…”

“…Eutrophication caused by excessive nitrogen (N) and phosphorus (P) contaminants is an environmental issue of high concern nowadays (Boonchai and Seo 2015;Wang et al 2015). The discharge of secondary effluent from municipal wastewater treatment plants (WWTPs) is one of the major anthropogenic sources of N and P contaminants (Wang et al 2015). Total N (TN) and total P (TP) concentrations in secondary effluent are ranging from 5 to 30 mg L −1 and 0.2 to 3 mg L −1 , respectively (Shi et al 2015;Wu et al 2014), far exceeding the reporting levels of 1.2 mg L −1 and 0.03 mg L −1 for eutrophication controlling (Chambers et al 2012).…”

“…Autotrophic denitrification process is recently considered an attractive approach for nitrate removal from oligotrophic secondary effluent (Li et al 2016a;Lv et al 2017;Wan et al 2014;Wang et al 2015). Considering the explosive nature of hydrogen, autotrophic denitrification using elemental sulfur or sulfide as electron donors is more feasible and cost-effective (Sahinkaya and Dursun 2012).…”

Sulfurirhabdus autotrophica gen. nov., sp. nov., isolated from a freshwater lake

“…The type strain of Sulfuricella denitrificans was isolated from a cold anoxic hypolimnion of a freshwater lake, and was characterized as a psychrotolerant sulfur oxidizer (Watanabe et al, 2012). Based on nucleotide sequences, its close relatives have been found in freshwater lake sediments (Nelson et al, 2007;Song et al, 2012;Watanabe et al, 2013), Thioploca samples from two freshwater lakes (Nemoto et al, 2011), drinking water distribution systems (Li et al, 2010;Sun et al, 2014a, b), the sediment of a drinking water reservoir (Cheng et al, 2014), soil (Field et al, 2010), a bioreactor (Wang et al, 2015), subglacial sediment (Boyd et al, 2014), wetland sediment (Liu et al, 2014), a limestone aquifer (Herrmann et al, 2015), groundwater (Hong et al, 2013), black shale (Li et al, 2014), a horizontal subsurface flow system constructed in wetlands (Zhong et al, 2015) and the freshwater layer of a meromictic lake (Kubo et al, 2014). Members of the genus Sulfuricella are likely to contribute to sulfur cycling in a wide range of freshwater ecosystems, but only two cultured strains of the genus Sulfuricella have, so far, been described (Watanabe et al, 2015b).…”