Comparison of sidestream treatment technologies: post aerobic digestion and Anammox

Abstract

Post aerobic digestion (PAD) and anaerobic ammonium oxidation (Anammox) are sidestream treatment technologies which are both excellent options for the reduction of nitrogen recycled back to the liquid stream without the need for supplemental carbon or alkalinity. However, the achievement of this goal is where the similarities between the two technologies end. PAD is an advanced digestion process where aerobic digestion is designed to follow anaerobic digestion. Other benefits of PAD include volatile solids reduction, odor reduction, and struvite formation reduction. Anammox harnesses a specific species of autotrophic bacteria that can help achieve partial nitritation/deammonification. Other benefits of Anammox include lower energy consumption due to requiring less oxygen compared with conventional nitrification. This manuscript describes the unique benefits and challenges of each technology. Example installations are presented with a narrative of how and why the technology was selected. A whole plant simulator is used to compare and contrast the mass balances and net present value costs on an 'apples to apples' basis. The discussion includes descriptions of conditions under which each technology would potentially be the most beneficial and cost-effective against a baseline facility without sidestream treatment.

Post aerobic digestion (PAD) is a solids sidestream nutrient removal process that utilizes native carbon: performance and key operational parameters from two full-scale PAD reactors

“…Annamox for example could be used to handle the filtrate following thermal hydrolysis that is high in N. 57 Annamox process advantages include a reduction in energy demand and volume requirements. 58…”

“…Annamox for example could be used to handle the ltrate following thermal hydrolysis that is high in N. 57 Annamox process advantages include a reduction in energy demand and volume requirements. 58 3.4 Summary of key ndings, design parameters, and other considerations for PAD Several key ndings and design parameter guidelines for PAD reactors are as follows:…”

Mass fluxes of nitrogen and phosphorus through water reclamation facilities: Case study of biological nutrient removal, aerobic sludge digestion, and sidestream recycle

“…Compounding this problem is the fact that, due to economies of scale, sludge digestion facilities are often regionalized (i.e., they handle sludge that is piped or hauled from several wastewater treatment facilities), but the sidestream is returned to the mainstream process at a single facility. Because of the recent recognition of the expense induced by recycling of nutrients, a number of technologies have been proposed to remove or recover nutrients from liquid sidestreams (Bauer, Johnson, Johnson, Oerke, & Graziano, ; WEF/ASCE, ; Woods, Sock, & Daigger, ). If nutrients can be inexpensively removed from the sidestream (or kept out of the sidestream in the first place), the sidestream can be returned to the main treatment system without re‐introducing the nutrients.…”

Techno-economic analysis of sidestream ammonia removal technologies: Biological options versus thermal stripping

“…This was also quantified by Ref. [24]; who compared an identifying annual OPEX savings of up 10%. This was much lower than frequently referenced academic papers highlighting 60% savings in aeration and 100% in chemical dosing [9].…”