Reclamation of treated urban water

Dissolved organic nitrogen

Diana Norton Brandão

Promotor: Jules van LierCo-supervision: Sigrid Scherrenberg

29th May 2012

Contents

I. What is DON?

II. Relevance

III. Research objectives

IV. Methodology and results

V. Further research

What is DON Relevance Objectives Meth. & Results Further research

I. What is DON?

- 65% of the dissolved nitrogen in effluents from conventional WWTP

- Free aminoacids

- Combined aminoacids

- Proteins

- Low-molecular-weight aliphatic amines such as methylamine, dimethylamine, piperidine and pyrroline

- Nitrogen containing synthetic chelating agents

What is DON Relevance Objectives Meth. & Results Further research

II. Relevance

- European surface water criteria: Total N concentrations < 2,2 mg/L

- DON and inorganic N may have different potential for eutrophication (bioavailability of DON is uncertain)

- DON may form variety of nitrogenous disinfection by-products with much stronger carcinogenicity than that of regulated DBPs

- Little knowledge about DON

What is DON Relevance Objectives Meth. & Results Further research

III. Research objectives

- Understand DON occurrence and composition in wastewater

- Determine DON bioavailability

What is DON Relevance Objectives Meth. & Results Further research

IV. Methodology and results

1) DON along tertiary filtration

DON Phobic

DON Philic

Persulfate digestion

Ion cromatography

HL

XAD treatment

Collection, filtration

What is DON Relevance Objectives Meth. & Results Further research

6 sampling points, fractionation in Phi and Pho

SBBR filtration removes DON

SamplesP1 - HF 3,68P1 - HB 0,75P2 - HF 2,78P2 - HB 0,31P3 - HF 3,20P3 - HB 0,29P4 - HF 1,93P4 - HB 0,46P5 - HF 1,32P5 - HB 0,09P6 - HF 0,96P6 - HB 0,20

DON

1,16

4,42

3,09

3,50

2,39

1,41

IV. Methodology and results

1) DON along tertiary filtration

What is DON Relevance Objectives Meth. & Results Further research

IV. Methodology and results

2) Bioavailability tests: test mediums

- Effluent + Algae + full nutrients

- Effluent + Algae + full nutrients except NO3

- Effluent + Algae + no nutrients

Effluent: untreated, philic fraction, phobic fraction

What is DON Relevance Objectives Meth. & Results Further research

IV. Methodology and results

2) Bioavailability tests: preparation

What is DON Relevance Objectives Meth. & Results Further research

1. Effluent filtration

2. Fraccionation philic/phobic

3. Bacterial inoculum

4. Algae inoculum

5. Nutrient addition

6. Incubation at half dark light cycle

7. Monitoring of Chl-a, TN, NO3, NO2, NH4 and DON

IV. Methodology and results

2) Bioavailability tests: Chl-a development

Chl-a development

-100

0

100

200

300

400

500

600

0 1 2 3 4 5 6 7 8 9 10

Time (days)

Ch

la c

on

c (

µg

/L)

Eff full nutEff full nut except NO3Phi full nutPhi no nut

HNP effluent with addition of nutrients except NO3 allowed algal growing

What is DON Relevance Objectives Meth. & Results Further research

V. Further research

- Quantification of DON bioavailability

- Relation between DON concentration profile and backwash phase

- How to remove DON

What is DON Relevance Objectives Meth. & Results Further research

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