Advantages of sulphate reducing bacteria in wastewater treatment

Tessa van den Brand, Kees Roest, Guang Hao Chen, Damir Brdjanovic and Mark van Loosdrecht

2Watercycle Research Institute

Water shortage

We do have freshwater shortage! Only ~0.1% of global water reserves is easily accessible freshwater.

Desalination techniques in order to deliver enough freshwater costs a lot of energy

Potable water is used for waste transport. Each person uses ~37L = 30% of total usage, potable water per day for toilet flushing.

Replace by seawater!

3Watercycle Research Institute

SANI-process

Sulphate reduction,

Autotrophic denitrification

Nitrification

Integrated

Lau 2006, WS&T, 53(3), 227-235

CH3COOH + SO42- HS- + 2HCO3

-

NO3- + 0.63HS- + 0.38 H+ 0.63SO4

2- + 0.5N2 + 0.5H2O

NH4+ + 2O2 H2O + 2H+ + NO3

-

1g COD : 1.5 g SO42-

4Watercycle Research Institute

Advantages of SANI

• Major fresh water savings

• Major reduction in oxygen demand at WWTP• Electricity for aeration is biggest environmental footprint of WWTP

• Major reduction in sludge production• Essentially only unbiodegradable sewer particulates

• Applicable in coastal regions• Most populated

5Watercycle Research Institute

Additional advantage of SRB

• COD removal with a low sludge yield

• Removal or recovery of heavy metals

• Significant reduction of pathogens in wastewater

• Sulphate removal

6Watercycle Research Institute

Current Research

• Inhibitory effect of sulphide

• COD composition and amount

• Robustness analyses

• The effect of seawater (sulphate and salt also separately)

• The presence of SRBs in conventional WWTPs

7Watercycle Research Institute

Saline project team