Lagoons aerated

Fig. 15. Aerated lagoon types (a) aerobic (b) facultative (c) settling.

Aerated lagoons are employed for the treatment of nontoxic or nonha2ardous wastewaters such as food processing and pulp and paper. Retention time varies from 3 to 12 d, so a large land area is usually required. 

The BPT is defined as the level of treatment that has been proven to be successful for a specific industrial category and that is currendy in fuU-scale operation. Sufficient data exist for this level of treatment so that it can be designed and operated to achieve a level of treatment consistendy and with rehabUity. For example, in the pulp and paper industry, BPT has been defined as biological treatment using the aerated lagoon or the activated sludge process with appropriate pretreatment. 

The four most common aerobic biological treatment processes are stabilization ponds, aerated lagoons, trickling filters, and activated sludge (see... 

Aerated Lagoons. Aerated lagoons are 2—5 mhquid depth depending on the aeration system and detention times are 2—10 days. They are mainly used because of their efficiency in removing BOD from textile effluents (2). 

Anaerobic lagoons do not produce a high-quahty effluent but are able to reduce the BOD load oy 80 to 90 percent with a minimum of effort. Since anaerobic lagoons work best on strong organic wastes, their effluent must be treated by either aerated lagoons or facultative... 

Belly RT, JJ Lauff, CT Goodhue (1975) Degradation of ethylenediaminetetraacetic acid by microbial populations from an aerated lagoon. Appl Microbiol 29 787-794. 

The aerobic biofilter used in the study had a capacity of 10 L. The reactor was packed to 60% of the empty bed volume with Cosmo ball media. The biofilter was seeded with active innoculum taken from an active aerated lagoon of a nearby landfill leachate treatment. Fresh raw leachate was used as feed to the reactor at a rate of 5 L/d over 24h. The loading rates applied to the bioreactor were between 1.6 and 22.2 kg COD/m3d. Initial studies were conducted as a batch process lasting for a period of 24 d. Thereafter, the biofilter was fed continuously for a total period of 240 d. 

Dewatered sludge LOD-212 22 18 Activated sludge or aerated lagoon Canada [53]... 

Yu ZT, Mohn WW (2001) Bacterial diversity and community structure in an aerated lagoon revealed by ribosomal intergenic spacer analyses and 16S ribosomal DNA sequencing. Appl Environ Microbiol 67 1565-1574... 

Moura A, Tacao M, Henriques I et al (2009) Characterization of bacterial diversity in two aerated lagoons of a waste water treatment plant using PCR-DGGE analysis. Microbiol Res 164(5) 560-569... 

The performance studies of aerated lagoons carried out by many researchers [14,51] have demonstrated that lagoons are capable of successfully treating wastewater containing diversified fine chemicals and pharmaceutical intermediates. 

A laboratory-scale study of aUcaline and condensate waste streams from a synthetic drug factory at Hyderabad demonstrated that an aerated lagoon is capable of treating the wastewater from this industry [14]. The BOD removal rate K of the system was found to be 0.18/day and 0.155/day based on the soluble and total BOD, respectively. Based on the laboratory studies, a flow sheet (Fig. 2) for the treatment of waste was developed and recommended to the factory. 

An aerated lagoon is to be designed to treat 15,000 GPD of spent stream generated from a biological production plant. The depth of the lagoon is restricted to 3.3 m and the HRT of the... 

The temperature of the aerated lagoon of more than 38°C has been reported to decrease the system efficiency. At this high temperature nitrifiers cannot survive. Hence, a heat exchanger on the influent line must be provided to reduce the high temperature of the raw wastewater. 

Design a flow-through aerated lagoon to treat 0.575 MGD of composite wastewater generated from a pharmaceutical plant. Assume that the following conditions and requirements apply. 

A) Determine the size of the aerated lagoon based on 9 (solid retention time) ... 

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