Freshwater Shortage Brings Need for Wastewater Treatment

CHAPTER 1

INTRODUCTION

Despite the fact that the world is two-thirds water, most of it is not potable. Population expansion and industrial development has deteriorated the quality of freshwater reservoirs around the world and has caused freshwater shortages in certain areas. To meet the growing population’s demand for freshwater, wastewater treatment techniques aimed at remediating municipal wastewater and industrial wastewater should be employed. Municipal wastewater mainly consists of domestic wastewaters originated from households, sewer overflows and partially (or pre-) treated industrial wastewaters. Different industries produce various kinds of industrial wastewater based on their own specific combination of pollutants. Among those, metal working industry serves as an important pollution distributor discharging heavy metal waste (toxic waste) such as nickel, lead, chromium, cadmium, zinc and iron contaminated wastewater into the environment. This indiscriminate disposal of industrial and domestic wastes leads to heavy pollution of water, threatening all kinds of inhabiting organisms [1]. Therefore, it is necessary to focus on the treatment techniques and ways to partially remove contaminants (nitrates, phosphates and heavy metals) from wastewater before discharging them into waterways.

1.1 Conventional Wastewater Treatment

Most of wastewater treatment plants employ conventional wastewater treatment method to reduce the contaminants and improve the quality of wastewater effluent before it

discharges to groundwater and re-enters water bodies [2]. This method is employed for treating municipal wastewater and is not designed and equipped for handling toxic waste. Toxic waste is pretreated at the source of generation (ind...

... middle of paper ...

...ovides potential advantages for biofuel production, carbon dioxide mitigation, wastewater treatment, food production and so on. Typically, algae are grown in inorganic nutrient media but the increasing cost of inorganic fertilizers and emergence of serious problems of pollution during the production of such fertilizers [27] has led researchers to search for an alternative source, i.e. the use of organic materials of different origin. Animal wastes have a long history that shows their use as a source of phosphorus, nitrogen and carbon for microalgal growth and the production of natural food [28].

To provide an alternative method to the conventional wastewater treatment techniques, the present study focuses on the potential of algae to treat wastewater; removal of heavy metals ions from wastewater and also evaluates the usage of animal manure for algal cultivation.