Biosorption of Pb(II) and Cu(II) by activated sludge in batch and continuous-flow stirred reactors

The paper evaluates biodegradation characteristics of wastewaters generated from acrylic fibre-based carpet processing and manufacturing. It involves detailed characterisation, respirometric modelling and kinetic description of dyeing and softening wastewater streams and the composite effluent. The wastewaters exhibit different COD content and fractionation. The resulting composite effluent has a total COD of 775 mgL−1, predominantly soluble and with a biodegradable fraction of 86%. In respirometric studies, the OUR profiles can only be calibrated with a dual hydrolysis model with rates significantly slower compared to domestic sewage and other textile plant effluents. Kinetic information derived from the experiments is applied for the conceptual evaluation of the treatability of the composite wastewater using two different continuous-flow activated sludge configurations.

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Evaluation of ozonation and cryptic growth for biosolids management in wastewater treatment

Water Science & Technology ◽

10.2166/wst.1999.0646 ◽

1999 ◽

Vol 39 (10-11) ◽

pp. 155-158 ◽

Cited By ~ 6

Author(s):

E. Egemen ◽

J. Corpening ◽

J. Padilla ◽

R. Brennan ◽

N. Nirmalakhandan

Keyword(s):

Activated Sludge ◽

Continuous Flow ◽

Growth Conditions ◽

Aeration Tank ◽

Biomass Growth ◽

Waste Sludge ◽

Process Configuration ◽

Activated Sludge System ◽

Expensive Problems ◽

Cryptic Growth

The ultimate disposal of biosolids has been and continues to be one of the most expensive problems faced by wastewater utilities. The objective of this research is to develop a process configuration for reducing the waste sludge generation in an activated sludge plant by promoting cryptic growth conditions (i.e., biomass growth on intracellular products). For this purpose, excess biosolids from a continuous flow activated sludge system were solubilized using ozone as the cell lysis agent, and then returned to the aeration tank. It is hypothesized that growth under such cryptic conditions will result in low net microbial yields, and hence, minimal net solids wastage. The results of these preliminary studies indicate that the proposed process configuration has the potential to reduce the waste sludge production by 40% to 60%.

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A general solution for the transient response of heterogeneous continuous-flow stirred reactors

The Canadian Journal of Chemical Engineering ◽

10.1002/cjce.5450660425 ◽

1988 ◽

Vol 66 (4) ◽

pp. 691-693

Author(s):

Ravindra Datta

Keyword(s):

General Solution ◽

Transient Response ◽

Continuous Flow ◽

Stirred Reactors

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Conditions Favoring Proliferation of Glycogen Accumulating Organisms for Excess Biological Carbon Removal in Treating Nutrient Deficient Wastewater

Periodica Polytechnica Chemical Engineering ◽

10.3311/ppch.10078 ◽

2017 ◽

Vol 61 (3) ◽

pp. 149 ◽

Cited By ~ 1

Author(s):

Andrea Jobbágy ◽

Bernadett Kiss ◽

Vince Bakos

Keyword(s):

Activated Sludge ◽

Continuous Flow ◽

The Other ◽

N Availability ◽

Filamentous Bacteria ◽

Severe Deficiency ◽

And Performance ◽

Experimental Stage ◽

Activated Sludge Systems ◽

P Sources

Impact of marginal availability and severe deficiency of nitrogen on the growth of glycogen accumulating organisms (GAOs) and performance of anaerobic/aerobic activated sludge systems treating nutrient deficient wastewater was investigated at marginal availability and severe deficiency of phosphorus. Two continuous-flow lab-scale systems were operated simultaneously fed by model winery wastewater, one with marginal availability and the other one at severe deficiency of nitrogen. In the second experimental stage, marginal availability of P was converted into severe deficiency by interrupting external dosing.Common practice of dosing N- and P-sources to marginal availability caused enhanced proliferation of filamentous bacteria leading to poor biomass settling and instable operation. At marginal N-availability accumulation of GAOs started when conditions became deficient for phosphorus. In severe lack of nitrogen GAOs overgrew filaments, and outcompeted phosphorous accumulating organisms (PAOs) initially present in the seed. Stable and good performance could be maintained even after withdrawal of phosphorous dosing.

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