Design Strategies for Nutrient Removal Plant

Barnard, James; Stevens, Gerry; Leslie, Patrick J.

doi:10.2166/wst.1985.0235

Cited by 37 publications

(18 citation statements)

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“…Hence, an oxygen-free environment is required for a successful EBPR process (Barnard et al, 1985;Randall et al, 1998). Hence, an oxygen-free environment is required for a successful EBPR process (Barnard et al, 1985;Randall et al, 1998).…”

Section: Factors Affecting Ebprmentioning

confidence: 99%

Biological Phosphorus Removal

Goel¹,

Motlagh²

2014

Comprehensive Water Quality and Purification

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Section: Factors Affecting Ebprmentioning

confidence: 99%

Biological Phosphorus Removal

Goel¹,

Motlagh²

2014

Comprehensive Water Quality and Purification

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“…Other areas of development may lie in plant production of easily degradable organics by fermentation of raw primary sludges (Barnard et al, 1985) and different combinations of biological and chemical phosphorus removal processes.…”

Section: Trends and Emerging Technologymentioning

confidence: 99%

Control of phosphorus discharges: present situation and trends

Balmér

Hultman

1988

Hydrobiologia

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The dominating sources of phosphorus in municipal wastewaters are excreta, 1.4 g P/(cap.d) and detergents, 0.6 -2 g P/(cap.d). Detergent phosphorus can ba substituted by nitrilotriacetic acid or zeolites, but if a substantial reduction of phosphorus in municipal waters is to be achieved, modifying the treatment process is necessary. Primary, treatment by sedimentation removes only 10-15x and secondary biological treatment 20-30 y0 of the phosphorus in waste water. If chemicals are added to the primary or secondary treatment stage or to a separate chemical stage, phosphorus can be efficiently removed. An effluent level of 0.8-1.5 g P me3 is easily achieved and with a filtration step it is possible to maintain 0.2 g P m-3 in the effluent. Different process configurations are discussed. As precipitants, ferrous and ferric salts, alum and lime are widely used. By introducing anaerobic zones in the activated sludge process, it is possible to promote the growth of bacteria which enhance biological phosphorus uptake. This makes it possible to achieve high phosphorus removal without or, al least, with very small chemical additions. Several emerging physical, chemical and biological phosphorus removal processes are discussed. The removal of phosphorus to a level of 0.8-1.5 g P m-3 increases cost lo-20% compared with conventional primary secondary treatment. Higher removal efficiencies will rapidly increase the marginal cost per marginal kg P removed.

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“…The effects of temperature on the efficiency and the kinetics of excess biological phosphorus removal (EBPR) systems have been under investigation for the past two decades, but the studies have yielded contradictory results. Early researchers (Sell, 1981;Ekama, et al 1984; Barnard et al 1985) reported that EBPR efficiency was greater at lower temperatures than at higher temperatures over the range from 5 to 24 o C. The first contradictory finding was reported by McClintock et al (1992). They showed that EBPR functions would "wash-out" of activated sludge systems before other heterotrophic functions at a temperature of 10 o C and a sludge retention time (SRT) of 5 days, whereas wash-out did not occur at 10 o C when the SRT was 15 days.…”

Section: Introductionmentioning

confidence: 97%

Effect of Temperature on Ebpr System Performance and Microbial Community

Erdal¹,

Erdal²,

Randall³

2002

proc water environ fed

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It is well known and firmly established that the rate of chemical and biochemical reactions slow down as temperature decreases. Nevertheless, several studies have reported that the efficiency of enhanced biological phosphorus removal (EBPR) improves as temperature decreases. However, several recent studies have reported that EBPR reaction rates decrease with temperature decrease in accordance with the Arrhenius relationship. This study was designed to more thoroughly investigate this controversy using two UCT plants fed with a synthetic wastewater consisting primarily of acetate as the COD form, and a small amount of supplemental yeast extract. Experiments were performed over temperatures ranging from 5 to 20 o C. The results showed that, even though the kinetic rates decrease as temperature decreases, EBPR systems perform better at colder temperatures. The reason for better system performance is apparently related to reduced competition for substrate in the non-oxic zones, which results in an increased population of PAOs and, thus, greater EBPR efficiency. The proliferation of PAOs apparently occurs because they are psychrophilic whereas their competitors are not. The experiments showed that the acclimated EBPR sludges accumulated high concentrations of both PHA and glycogen at 20 o C, but accumulated more PHA and much less glycogen at 5 o C. Although the results could be interpreted as the consequence of changes in the PAO-GAO competition, comparisons of transmission electron microscopy examinations revealed no indication of the presence of GAO population under any temperature condition. Regardless, mass balances of the glycogen data showed that the involvement of glycogen is less at cold temperature, even though PHA production and EBPR performance was greater. Unlike current EBPR models (e.g., the Mino model, 1987), the results suggest that involvement of glycogen metabolism in EBPR biochemistry is a requirement as suggested by Mino model (Mino et al. 1987) but its involvement depends on the environmental conditions. EBPR stoichiometry was presumed to be insensitive to temperature changes (Brdjanovic et al. 1997). However, this study showed that the stoichiometry of EBPR was sensitive to temperature The results also indicate that temperature not only causes selective pressure on the dominant organisms, but also may force them to use different metabolic pathways as temperature decreases.

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Design Strategies for Nutrient Removal Plant

Cited by 37 publications

References 0 publications

Biological Phosphorus Removal

Biological Phosphorus Removal

Control of phosphorus discharges: present situation and trends

Effect of Temperature on Ebpr System Performance and Microbial Community

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