Chapter 4. Fundamental biological engineering processes applicable to water treatment (84 pages)

1.General
1.1.Development of a bacterial culture
1.2.Modelling bacterial growth
1.3.Biomass activity
1.4.Aerobic cultures, anaerobic cultures
1.5.Toxicity, inhibition
1.6.Bioreactors
1.6.1.Suspended growth, attached growth processes
1.6.2.Hydraulic characteristics of biological reactors
1.7.Substrate properties
1.7.1.Carbonaceous pollution
1.7.2.Nitrogen pollution
1.7.3.Phosphorus pollution
1.8.Wastewater typology
1.8.1.Principles
1.8.2.Standard tests and typologies
1.9.Pollution and the receiver medium, the value of modelling
1.10.The outlook for biological engineering
2.Aerobic bacterial cultures
2.1.Suspended growth (activated sludge) process
2.1.1.Presentation and background
2.1.2.Basic relations used for carbonaceous pollution removal
2.1.3.Nitrogen removal
2.1.4.Biological phosphate removal
2.1.5.Modelling and its applications in UWW
2.2.Attached growth processes
2.2.1.The biological film
2.2.2.Trickling filters
2.2.3.Biological filters (or biofilters)
2.2.4.Other processes
3.Anaerobic bacterial cultures
3.1.Methanogenesis biochemistry and microbiology
3.2.Special features of methane producing bacteria
3.3.Characteristic anaerobic digestion parameters
3.3.1.Biogas
3.3.2.Sludge production
3.4.Utilisation
3.4.1.«Flocculating» suspended growth processes
3.4.2.Fixed growth processes
4.Using clarification membranes in biological wastewater treatment
4.1.The benefits of membrane bioreactors
4.2.The main membrane bioreactor families
4.2.1.External membrane bioreactors
4.2.2.Submerged membrane bioreactors
5.Extensive solutions
5.1.Different types of lagooning
5.1.1.Anaerobic lagooning (A)
5.1.2.Facultative lagooning (F)
5.1.3.Maturation lagooning (M)
5.1.4.Macrophyte lagooning (Ma)
5.1.5.Aerated lagooning (Ae)
5.1.6.Other lagooning techniques
5.2.Lagooning systems
5.3.Lagooning performances and dimensioning
5.3.1.Anaerobic lagoons
5.3.2.Facultative lagoons
5.3.3.Maturation lagoons
5.3.4.Aerated lagoons
5.3.5.General system performances
5.4.Lagoon design and maintenance
5.5.Purification through soil
6.Biological engineering applications in drinking water treatment
6.1.Background and general features
6.2.Slow filtration
6.3.The BAC (or biological activated carbon) concept
6.4.Biological iron and manganese removal
6.5.Nitrogen conversion
6.5.1.Nitrification
6.5.2.Denitrification

Introduction

Biological treatment of water makes use of a wide range of micro-organisms and, primarily, of bacteria. These micro-organisms convert the biodegradable organic matter found in wastewater into simple products, such as carbon dioxide and additional biomass. Depending of the environment, biological processes can be divided into aerobic, anaerobic or anoxic degradation processes.
These treatments that are the heart of UWW and IWW treatment plants (mainly biodegradable organic pollution), are equally important to the resulting sludge. These treatments also form the basis of many processes used in drinking water processing and which, given their specific nature, can be found in § 6. of this chapter.
Descriptions of the relevant technologies can be found in chapter 11 while systems and examples of applications have been grouped together in chapters 22 (drinking water), 23 (UWW) and 25 (IWW).