Calcium spatial distribution in aerobic granules and its effects on granule structure, strength and bioactivity

Ren, Tingting; Liu, Li; Sheng, Guo‐Ping; Liu, Xianwei; Yu, Han‐Qing; Zhang, Mingchuan; Zhu, Jianzhong

doi:10.1016/j.watres.2008.04.015

Cited by 163 publications

(87 citation statements)

References 29 publications

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“…granule size and ash content had negative impact on sludge bioactivity although the influence from granule size was much serious. The bioactivity loss due to high ash content were also reported in bigger aerobic granules with a size range from 2.0 mm to 8.0mm [4] and anaerobic granules [10] The relationships between ash content and granule size, calcium content and granule size, and SOUR and granule size from different operation periods at the steady state were simulated by a modified logistic model [24] Hammes et al [9] reported that high pH, presence of carbonate at minimal concentration, concentrated source of calcium and availability of nucleation sites are four key factors for calcium carbonate precipitation. For granular sludge, it is the mixture of granules with a wide or narrow size distribution [39].…”

Section: Dependence Of Calcium and Ash Accumulations On Granule Sizementioning

confidence: 79%

“…Figure 6 shows clearly the crystals of bundles of aragonite with needle shapes embedded in some thin and amorphous extracellular polymeric substances (EPS) sheets, which has been reported to have Ca 2+ binding capacity [4]. For needles shown in Figure 6, they had around 2 μm width with 20 μm length, which are much bigger than those with a length of 1 μm observed around the suspended cell [27].…”

Section: Element Distribution In Granules With Different Sizes and MImentioning

confidence: 94%

“…The mechanism of this metal ion augmentation is not fully understood, but it has been accepted that nucleus formation of inorganic precipitates could be the main reason as metal precipitates were observed in the enhanced granular sludge. In addition, it has been evidenced that inorganic precipitates in granular sludge could improve the structure stability and strength of aerobic granules [4][5][6]. Meanwhile, however, a very high ash content in aerobic granules up to 50-84% [7,12] was reported at some circumstances, in which calcium, magnesium, or iron precipitation was observed [14][15][16].Although these metal precipitates in granules are favourable in terms of granule structure and stability, the negative impact was also reported.…”

Section: +mentioning

confidence: 99%

“…So far, there are some studies on inorganic precipitates in aerobic granules, but they mainly focused on the augmentation of aerobic granulation [1,3], identification of main inorganic precipitates in granules [16] and the relationship between inorganic precipitates with granule structure [4][5][6]. The mechanism of inorganic precipitation in granules and how granule size affects inorganic precipitation especially at steady state are still not clear.…”

Section: +mentioning

confidence: 99%

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Size-dependent calcium carbonate precipitation induced microbiologically in aerobic granules

Liu

Lan

Zeng

2016

Chemical Engineering Journal

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Calcium and ash accumulation in aerobic granules treating organic wastewater was investigated systematically in this study. It was found that ash content of granular sludge reached 43% at stable state of reactor operation with calcium carbonate precipitation as the main cause. Since granular sludge in the reactor at the steady state was the mixture of granules with different sizes, granules in the reactor on operation days 90, 120 and 150, respectively, were sorted into 10 categories by size to study the inorganic substances. It was found that calcium was selectively enriched in granules and the precipitation of calcium carbonate was just dependent on granule size instead of operation duration at the steady state. More calcium carbonate was precipitated in bigger aerobic granules, but both calcium and ash contents reached stable values when granule size was bigger than 700μm. Analysis by X-ray Diffractometer disclosed that aragonite was the only polymorph of calcium carbonate detected in aerobic granules with size bigger than 300μm. Scanning electron microscope revealed clearly for the first time that bundles of needle shaped aragonite was embedded in extracellular polymeric substances of aerobic granules. A mechanism on calcium carbonate precipitation was proposed to deepen the understanding of biomineralization.

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Section: Dependence Of Calcium and Ash Accumulations On Granule Sizementioning

confidence: 79%

Section: Element Distribution In Granules With Different Sizes and MImentioning

confidence: 94%

Section: +mentioning

confidence: 99%

Section: +mentioning

confidence: 99%

See 2 more Smart Citations

Size-dependent calcium carbonate precipitation induced microbiologically in aerobic granules

Liu

Lan

Zeng

2016

Chemical Engineering Journal

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“…are characterized by higher mechanical strength but lower bioactivity (Ren et al 2008). Another factor that determines the mechanical properties of granules is the presence of extracellular polymers (EPS) in their structure.…”

mentioning

confidence: 99%

Operation mode and external carbon dose as determining factors in elemental composition and morphology of aerobic granules

Cydzik‐Kwiatkowska

Rusanowska

Głowacka

2016

Archives of Environmental Protection

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Abstract:The elemental composition and morphology of aerobic granules in sequencing batch reactors (GSBRs) treating high-nitrogen digester supernatant was investigated. The investigation particularly focused on the effect of the number of anoxic phases (one vs. two) in the cycle and the dose of external organics loading (450 mg COD/(L·cycle) vs. 540 mg COD/(L·cycle)) on granule characteristics.Granules in all reactors were formed of many single cells of rod and spherical bacteria. Addition of the second anoxic phase in the GSBR cycle resulted in enhanced settling properties of the granules of about 10.6% and at the same time decreased granule diameter of about 19.4%. The study showed that external organics loading was the deciding factor in the elemental composition of biomass. At 540 mg COD/(L·cycle) the granules contained more weight% of C, S and N, suggesting more volatile material in the granule structure. At lower organics loadings granules had the higher diameter of granules which limited the diffusion of oxygen and favored precipitation of mineral compounds in the granule interior. In this biomass higher content of Mg, P and Ca, was observed.

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Effect of coagulant‐flocculant reagents on aerobic granular biomass

Río¹,

Morales²,

Figueroa³

et al. 2012

J of Chemical Tech & Biotech

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Calcium spatial distribution in aerobic granules and its effects on granule structure, strength and bioactivity

Cited by 163 publications

References 29 publications

Size-dependent calcium carbonate precipitation induced microbiologically in aerobic granules

Size-dependent calcium carbonate precipitation induced microbiologically in aerobic granules

Operation mode and external carbon dose as determining factors in elemental composition and morphology of aerobic granules

Effect of coagulant‐flocculant reagents on aerobic granular biomass

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