Combined autotrophic nitritation and bioelectrochemical-sulfur denitrification for treatment of ammonium rich wastewater with low C/N ratio

Abstract

A novel combined autotrophic nitritation and bioelectrochemical-sulfur denitrification (CANBSD) process was developed for treatment of synthetic ammonium-rich wastewater with low carbon/nitrogen ratio. Total nitrogen removal of the CANBSD was higher than 95 %, the effluent SO₄²⁻ was lower than 1280 mg L⁻¹, and the maximum nitrogen volumetric loading rate was 1.2 kg m⁻³ day⁻¹ when (1) the influent NH₄⁺-N was lower than 1008 mg L⁻¹, (2) hydraulic retention time was between 3.7 and 32 h, (3) the DO was between 0.5 and 1.2 mg L⁻¹, (4) the pH was between 7.5 and 8.2, and (5) the temperature was between 28 and 30 °C. Both the NH₄⁺-N removal and conversion to NO₂⁻-N in the nitritation membrane reactor (NMBR) were maintained at about 50 %, and the residual NH₄⁺-N and accumulated NO₂⁻-N were subsequently treated in the bioelectrochemical-sulfur three-dimensional denitrification reactor. The CANBSD energy consumption was 0.13 and 3.4 kWh m⁻³, respectively, for influent NH₄⁺-N of 100 and 1000 mg L⁻¹. The energy consumption of CANBSD was close to that of partial nitritation-ANNMMOX.

Key findings

• ▸Autotrophic nitritation was effective in removing ammonium from wastewater with low C/N ratio.
• ▸Bioelectrochemical-sulfur denitrification showed high denitrification efficiency and stable operation.
• ▸The combined process demonstrated improved removal of nitrogen and sulfur compounds from wastewater.

Keywords

Identifiers

DOI

10.1007/s11356-015-5460-0

PubMed

26408123

Journal

Environmental Science and Pollution Research

Year

2015