Anaerobic treatment of Tequila vinasses in a CSTR-type digester

Overloaded anaerobic treatment systems are characterized by high concentrations of volatile fatty acids and molecular hydrogen and poor conversion of primary substrates to methane. Previous experiments with fixed–film reactors indicated that operation with reduced headspace pressures enhanced anaerobic treatment. For these studies, four suspended culture, anaerobic reactors were operated with headspace pressures maintained between 0.5 and 1.0 atm and a solids retention time of 15 days. For lightly loaded systems (0.4 g SCOD/g VSS-day) vacuum operation provided minor treatment improvements. For shock organic loads, vacuum operation proved to be more stable and to support quicker recovery from upset conditions. Based on these studies and a companion set of bioassay tests, it was concluded that: (a) a loading rate of about 1.0 g SCOD/g VSS-day represents a practical loading limit for successful anaerobic treatment, (b) a headspace pressure of approximately 0.75 atm appears to be an optimum operating pressure for anaerobic systems and (c) simple modification to existing systems may provide relief for organically overloaded systems.

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Pond Treatment of Rettery Wastewaters

Water Science & Technology ◽

10.2166/wst.1987.0130 ◽

1987 ◽

Vol 19 (12) ◽

pp. 79-83

Author(s):

K. Bartoszewski ◽

A. Bilyk

Keyword(s):

Activated Sludge ◽

Treatment Process ◽

New Technology ◽

Treatment Plant ◽

Anaerobic Treatment ◽

Cod Removal ◽

Experimental Results ◽

Aerobic Conditions ◽

Aerobic Stabilization ◽

In Series

Rettery wastewaters were treated in anaerobic and aerobic ponds. Anaerobic treatment yielded efficiencies of BOD5 and COD removal as low as 20%. The treatment process conducted under aerobic conditions in aerated and stabilizing ponds arranged in series took from 18 to 20 days and gave efficiencies of BOD5 and COD removal amounting to 90%. The experimental results were interpreted by virtue of the Eckenfelder equation. Excess activated sludge was subjected to aerobic stabilization in a separate tank. A new technology was suggested for the existing obsolete industrial treatment plant.

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A simple design and operation for the anaerobic treatment of highly concentrated swine waste in the tropics

Water Science & Technology ◽

10.2166/wst.1995.0466 ◽

1995 ◽

Vol 32 (12) ◽

pp. 91-97 ◽

Cited By ~ 1

Author(s):

P. Y. Yang ◽

M. Kuroshima

Keyword(s):

Treatment Process ◽

Total Solid ◽

Anaerobic Treatment ◽

Solid Content ◽

Total Solid Content ◽

Treatment Processes ◽

Tropical Conditions ◽

Biological Reaction ◽

The Tropics ◽

Small Producers

In order to develop a simple operation for an anaerobic treatment process for highly concentrated pig wastewater for small producers, a three-stage anaerobic treatment process was investigated. The system provided a series of mixing, homogenization, biological reaction and final stabilization of concentrated pig waste (total solid content of 8–10%). The process provided a stable operational performance, simple operational procedure and well stabilized sludge effluent. It was also found that the system is economically feasible in Hawaii. Compared to the other treatment processes for highly concentrated pig waste, this process is considered as an appropriate alternative for the application of the small producers in land limited and tropical conditions. Also, the present treatment system can be easily developed into a prefabricated package plant which can minimize the on-site labor and building costs.

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Anaerobic Treatment of Polyethylene Terephthalate (PET) Wastewater from Lab to Full Scale

Water Science & Technology ◽

10.2166/wst.1999.0426 ◽

1999 ◽

Vol 40 (8) ◽

pp. 229-236 ◽

Cited By ~ 4

Author(s):

F. Fdz-Polanco ◽

M. D. Hidalgo ◽

M. Fdz-Polanco ◽

P. A. García Encina

Keyword(s):

Polyethylene Terephthalate ◽

Loading Rate ◽

Treatment Plant ◽

Textile Wastewater ◽

Anaerobic Treatment ◽

Cod Removal ◽

Organic Loading Rate ◽

Foam Formation ◽

Organic Loading ◽

Start Up

In the last decade Polyethylene Terephthalate (PET) production is growing. The wastewater of the “Catalana de Polimers” factory in Barcelona (Spain) has two main streams of similar flow rate, esterification (COD=30,000 mg/l) and textile (COD=4000 mg/l). In order to assess the anaerobic treatment viability, discontinuous and continuous experiments were carried out. Discontinuous biodegradability tests indicated that anaerobic biodegradability was 90 and 75% for esterification and textile wastewater. The textile stream revealed some tendency to foam formation and inhibitory effects. Nutrients, micronutrients and alkali limitations and dosage were determined. A continuous lab-scale UASB reactor was able to treat a mixture of 50% (v) esterification/textile wastewater with stable behaviour at organic loading rate larger than 12 g COD/l.d (0.3 g COD/g VSS.d) with COD removal efficiency greater than 90%. The start-up period was very short and the recuperation after overloading accidents was quite fast, in spite of the wash-out of solids. From the laboratory information an industrial treatment plant was designed and built, during the start-up period COD removal efficiencies larger than 90% and organic loading rate of 0.6 kg COD/kg VSS.d (5 kg COD/m3.d) have been reached.

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Inhibition of methanogenic activity of starch-degrading granules by aromatic pollutants

Water Science & Technology ◽

10.2166/wst.1997.0320 ◽

1997 ◽

Vol 35 (8) ◽

pp. 247-253 ◽

Cited By ~ 3

Author(s):

Herbert H. P. Fang ◽

Ivan W. C. Lau ◽

Denis W. C. Chung

Keyword(s):

Chemical Industry ◽

Functional Group ◽

Anaerobic Treatment ◽

Upflow Anaerobic Sludge Blanket ◽

Uasb Reactor ◽

Anaerobic Sludge ◽

Aromatic Pollutants ◽

Methanogenic Activity ◽

Phenolic Pollutants ◽

Ic50 Values

The effects of nine common aromatic pollutants from chemical industry on the bioactivity of anaerobic granules were examined. The granules were obtained from an upflow anaerobic sludge blanket (UASB) reactor treating wastewater containing colloidal starch. The specific methanogenic activities (SMA) of granules were measured at 37°C in serum vials using 3000 mg/l of colloidal starch as substrate, plus individual pollutants at various concentrations. The toxicity was expressed by the IR50 and IC50 values, i.e. the toxicant/biomass ratio and concentration at which levels the granules exhibited only 50% of their original bioactivities. Results showed that in general the granules exhibited mild resistance to toxicity of aromatic pollutants, probably due to the granules' layered microstructure. The toxicities, which were dependent on the nature of chemical functional group, of the aromatic pollutants were in the following descending order: cresols > phenol > hydroxyphenols/phthalate > benzoate. There was only marginal difference between the toxicity of the steric isomers. For the seven phenolic pollutants, the more hydrophobic the functional group the higher the toxicity. The granules' resistance to toxicity suggested the plausibility of anaerobic treatment of wastewater from the chemical industry.

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