Secondary Treatment Of Sewage: Ammonification, Biological Characteristics

Secondary Treatment Of Sewage: Ammonification, Biological Characteristics

INTRODUCTION

The quality of effluent provided by secondary treatment may not be always sufficient to meet discharge requirements. i.e.

When large quantities are discharged into small streams

Delicate  ecosystems  are  encountered

Further treatment may be required to remove nutrients (N, P), suspended solids, dissolved inorganic salts and refractory organics

1 Nutrient Removal

a. Nitrogen Removal

-Nitrification-denitrification

-Air Stripping

b. Phosphorus Removal

The quality of effluent provided by secondary treatment may not be always sufficient to meet discharge requirements. i.e.

When large quantities are discharged into small streams

Delicate ecosystems are encountered

Further treatment may be required to remove nutrients (N, P), suspended solids, dissolved inorganic salts and refractory organics

Nitrogen Removal using Nitrification-Denitrification

Ammonification

Nitrogen compounds results in wastewater from biological decomposition of proteins and from urea discharged in body waste.

This nitrogen is bound in complex organic molecules and is called Organic Nitrogen.

While traveling through sewer pipes, the majority of organic-nitrogen is converted to ammonia through the process of hydrolysis.

Biological Characteristics

Microorganisms may be classified according to nutrient requirements

All organisms require:

          An  Energy-for(1) maintenancesourceand (2) biosynthesis

A  Carbon-forgrowthSourceofmicrobes

Heterotrophic - these are microorganisms that uses organic compounds as BOTH a carbon source and as an energy source.

These organisms are mostly employed in WWT

Chem-Autotrophs - these are organisms that uses inorganic compounds as BOTH an energy source and a carbon source.