Phycoremediation by High-Rate Algal Ponds (HRAPs) - Biotechnological Applications of Microalgae - page 181

cost-effective reactors for liquid waste management and capture of solar energy, and the
capture of atmospheric carbon dioxide, and are used in the treatment of animal wastes
(Narkthon, 1996). HRAP wastewater treatment can be highly efficient in reducing bac-
teria, biological oxygen demand (BOD), and nutrient levels by integrated approaches to
recycling wastes. Phycoremediation can be used in the process as a second step after
initial anaerobic treatment of high organic wastewater to yield a significant reduction
in influent organic matter, such as nitrogen and phosphorus. Harvested microalgae are
rich in nutrients such as nitrogen, potassium, and phosphorus, which can be used for
animal feed, etc. (Ogbonna et al . , 2000; Olguın, 2003; Rawat et al . , 2011). Therefore,
HRAPs are very appropriate for sanitation in small rural communities because of their
simplicity of operation in comparison to conventional technologies such as the acti-
vated sludge process. This chapter critically evaluates phycoremediation HRAPs for
removal of high organic strength nutrients by means of enriched microalgae.

12.2 WASTEWATER CHARACTERISTICS
Wastewater is one of the main sources of increasing water pollutant levels glob-
ally (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

Wa stewater

1. Household 1. Industry:

a) Chemical processing
b) Leather processing
c) Petrochemical
d) Pharmaceutical

2. Hospital

3. Animal
4. Drainage water

2. Agricultural and food
processing:
a) Sugar refinery
b) Confectionery
c) Diary
d) Yeast fermentation

3. Aquaculture:
a) Shrimp production
b) Fish production
c) Salmon trout production
d) Trout production

FIGURE 12.1 Types of domestic and industrial wastewater.