03.08.2015   Biotechnological Applications of Microalgae

WASTEWATER CHARACTERISTICS

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Wastewater is one of the main sources of increasing water pollutant levels glob­ally (Gomec, 2010). An understanding of wastewater characteristics is essential in the design and operational processes of wastewater treatment and deserves ample research efforts. Wastewater is divided into two types: (1) municipal wastewater and (2) industrial wastewater. Wastewater is generally a combination of household and industrial waste, depending on the treatment collection system. These are generated during different human activities and are mixed together. Figure 12.1 provides a few

Подпись: 4. Drainage water2. Agricultural and food processing:

a) Sugar refinery

b) Confectionery

c) Diary

d) Yeast fermentation

a) Подпись: 3. Aquaculture:Shrimp production

b) Fish production

c) Salmon trout production

d) Trout production

FIGURE 12.1 Types of domestic and industrial wastewater.

TABLE 12.1

Chemical Composition and Characteristics of Untreated Wastewater

Подпись: Concentration Unit Weak Medium Strong (TS) mg L-1 350 720 1,200 (TDS) mg L-1 250 500 850 mg L-1 145 300 525 mg L-1 105 200 325 mg L-1 100 220 350 mg L-1 20 55 75 mg L-1 80 165 275 mg L-1 5 10 20 mg L-1 110 220 400 mg L-1 80 160 290 mg L-1 250 500 1,000 mg L-1 20 40 85 mg L-1 8 15 35 mg L-1 12 25 50 mg L-1 0 0 0 mg L-1 0 0 0 mg L-1 4 8 15 mg L-1 1 3 5 mg L-1 3 5 10 mg L-1 30 50 100 mg L-1 20 30 50 mg L-1 50 100 200 mg L-1 50 100 150 No./100 mL 106-107 107-108 107-109 g L-1 <100 100-400 >400 Contaminants

Total solids

Total dissolved solids

Fixed

Volatile

Suspended solids

Fixed

Volatile

Settleable solids BOD5, 20°C TOC COD

Nitrogen (total as N)

Organic

Free ammonia

Nitrites

Nitrates

Phosphorus (total as P)

Organic

Inorganic

Chlorides

Sulfate

Alkalinity (as CaCO3) Grease

Total coliforms

Volatile organic compounds

Source: From Rawat et al. (2011).

examples of municipal and industrial wastewater types. Municipal and industrial wastewater treatment by socio-economic biological treatment is a highly efficient technology (Metcalf and Eddy, 1991), and reclaimed wastewater can be used for various purposes. Table 12.1 shows the evaluation of weak, medium, and strong typical composition levels of domestic wastewater. A complete assessment of waste­water quality can be broadly classified into three main characteristics by its physical, chemical, and biological constituents and their sources (Figure 12.2).