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15 Photobiological Reactors for the Degradation of Harmful Compounds in Wastewaters

domestic wastewater tracer in environmental waters, studies are needed to confirm

the absence of nonfecal sources such as food processing plant effluent and agricul-

tural fields. Further study is required to regulate if PMMoV correlates with enteric

viruses, and the concentrations of PMMoV that agree to high human health risks in

environmental waters are polluted by tertiary-treated wastewater. The PMMoV is a

hopeful index virus to assess the microbial quality of shellfish as well as agricultural

products watered with susceptible water sources [7].

15.2.1.6

Cyanobacteria as a Bio-resource in Making of Bio-fertilizer

and Biofuel from Wastewaters

Microalgae and cyanobacteria are eco-friendly and their larger cell size and effective

biomass make them best and supportable solution for the problems connected to soil

fertility and accessible water resources. The cyanobacteria serve as supplements to

fertilizer, and micro-algal biomass yields biofuels. They act as potential candidates

for lipid production due to their fast biomass production efficiency. Integration of

cyanobacteria and microalgae into sewage and effluent treatment plants could be

very useful for wastewater treatment. Farmers can produce bio-fertilizers and biofu-

els on their own by using microalgae. The test ponds and soils should be seeded with

these bioagents, which are certain to be present in native habitats. These are used

for sustainable agriculture and also are feedstocks for eco-friendly biofuel cohort.

Microalgal and cyanobacterial arbitrated remediation could be a safe approach in

the elimination of heavy metals from municipal wastewater and a squalor of tox-

ins from the industrial wastewater. The open ponds can be cost-effective and may

be used by the local farmers for the large-scale cultivation and harvesting of locally

adapted microalgae. The microalgae let the recovery of phosphors and nitrogen from

wastewater and sequestration of CO2 produced during the wastewater treatment.

Potential species of microalgae and cyanobacteria, which could efficiently grow in

wastewater, may be exploited to fulfill the requirement of valuable bioactive com-

pounds, bio-fertilizers, and biofuel cohort for sustainable agriculture, environment,

and planet [8]. Use of cyanobacteria during the treatment of wastewater is shown in

Figure 15.2.

15.2.1.7

Bio-sorption of Copper and Lead Ions by Surplus Beer Yeast

Beer yeast, which is a by-product of brewing industry, acts as an adsorbent for

copper and lead ions from wastewater. This was observed in batch mode, and

the adsorptive quantity was resolute to be a function of the solution pH, contact

time, beer yeast concentration, salt concentration, and initial concentration of

copper and lead ions. Recent studies showing the limits of Langmuir isotherm state

that the maximum biosorption capacities of copper and lead ions onto beer yeast

were 0.0228 and 0.0277 mmol/g at 293 K, correspondingly. The negative values

of the standard free-energy change designate impulsive nature of the process.

Competitive bio-sorption of two metal ions was examined in terms of sorption

quantity. The amount of one metal ion adsorbed onto unit weight of biosorbents

was inversely proportional to the competing metal ion concentration. The binding

capacity for lead is greater than for copper, and ion exchange is perhaps one of the