Impacts and Solutions of Starch on Activated Sludge Treatment

Abstract Nine sets of batch experiments, each of ten to twelve days duration, were conducted in the laboratory on return-sludge samples collected from activated sludge treatment plant at Windsor. The thickened sludge samples were blended daily in a waring blender and were continuously aerated in twelve-litres capacity jars. Parallel runs were made on control sludge samples which were not blended. Amongst the parameters varied were the speed and frequency of blending and the aeration rate. The effects of these variables on progressive bio-degradation of volatile suspended solids and the settling characteristics of the sludge were determined. Blended sludge showed significant improvement in the rate of bio-degradation and its settling characteristics as compared to the control unblended sludge

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Deemulsification of Water-in-Oil Emulsion with Sludges

Water Quality Research Journal ◽

10.2166/wqrj.1987.034 ◽

1987 ◽

Vol 22 (3) ◽

pp. 437-443 ◽

Cited By ~ 5

Author(s):

N. Kosaric ◽

Z. Duvnjak

Keyword(s):

Activated Sludge ◽

Room Temperature ◽

Petroleum Refinery ◽

Treatment Plant ◽

Granular Sludge ◽

Activated Sludge Process ◽

Sludge Treatment ◽

Oil Emulsion ◽

Water In Oil Emulsion ◽

Aerobic Sludge

Abstract Aerobic sludge from a municipal activated sludge treatment plant, sludge from a conventional municipal anaerobic digester, aerobic sludge from an activated sludge process of a petroleum refinery, and granular sludge from an upflow sludge blanket reactor (USBR) were tested in the deemulsification of a water-in-oil emulsion. All sludges except the last one, showed a good deemulsification capability and could he used for a partial deemulsification of such emulsions. The rate and degree of the deemulsifications increased with an increase in sludge concentrations. The deemulsifications were faster at 85°C and required smaller amounts of sludge than in the case of the deemulsifications at room temperature. An extended stirring (up to a certain limit) in the course of the dispersion of sludge emulsion helped the deemulsification. Too vigorous agitation had an adverse effect. The deemulsification effect of sludge became less visible with an increase in the dilution of emulsion which caused an increase in its spontaneous deemulsification.

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Application of Three Step-Biological Pond with the Use of Aquatic Plant for Post Treatment of Petroleum Wastewater in Vietnam

Water Science & Technology ◽

10.2166/wst.1991.0603 ◽

1991 ◽

Vol 23 (7-9) ◽

pp. 1503-1507 ◽

Cited By ~ 2

Author(s):

L. M. Triet ◽

N. T. Viet ◽

T. V. Thinh ◽

H. D. Cuong ◽

J. C. L. van Buuren

Keyword(s):

Dissolved Oxygen ◽

Activated Sludge ◽

Residence Time ◽

Aquatic Plants ◽

Water Hyacinth ◽

Aquatic Plant ◽

Post Treatment ◽

Cod Removal ◽

Sludge Treatment ◽

Purification Efficiency

The effluent from activated sludge treatment of petroleum wastewater was treated with the aid of a ponding system using aquatic plants (Water Hyacinth, Chlorella, Reed). A good result was obtained in this study. Pilot pond system shows that the purification efficiency depends on the residence time of about 14 days. The petroleum removal waa 97-98 %, the COD removal was from 88-93 %. The dissolved oxygen amount (with Chlorella) increased from 0.7 mg/l to 9.8 mg/l and the pH increased from 6.9 to 8-8.6. The application of 3 step biological pond with the use of Water Hyacinth, Chlorella, Reeds for post treatment of petroleum wastewater is appropriate in Vietnam.

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Activated Sludge Treatment of Kraft Mill Effluents from Conventional and Oxygen Bleaching

Water Science & Technology ◽

10.2166/wst.1991.0499 ◽

1991 ◽

Vol 24 (3-4) ◽

pp. 427-430 ◽

Cited By ~ 3

Author(s):

J. Nevalainen ◽

P.-R. Rantala ◽

J. Junna ◽

R. Lammi

Keyword(s):

Activated Sludge ◽

Kraft Pulp ◽

Activated Sludge Process ◽

Chlorinated Phenols ◽

Pulp Mills ◽

Main Interest ◽

Sludge Treatment ◽

Kraft Pulp Mills ◽

Activated Sludge Processes ◽

Oxygen Bleaching

Conventional and oxygen bleaching effluents from hardwood kraft pulp mills were treated in laboratory-scale activated sludge processes. The main interest was the fate of organochlorine compounds in the activated sludge process. In the treatment of conventional bleaching wastewaters the BOD7-reduction was 80-91 % and in oxygen bleaching wastewaters 86-93 %. The respective CODCr removals were about 40 % and about 50 %. The AOX reductions were on average 22 % and 40 % in the treatment of conventional and oxygen bleaching effluents, respectively. The reductions of chlorinated phenols, guajacols and catecols were usually more than 50 % in both reactors. Very little accumulation of AOX into the sludge was observed. The stripping of AOX from aeration unit was insignificant.

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Behaviour of Alkylphenol Polyethoxylate Surfactants and of Nitrilotriacetate in Sewage Treatment

Water Science & Technology ◽

10.2166/wst.1987.0225 ◽

1987 ◽

Vol 19 (3-4) ◽

pp. 449-460 ◽

Cited By ~ 69

Author(s):

W. Giger ◽

M. Ahel ◽

M. Koch ◽

H. U. Laubscher ◽

C. Schaffner ◽

...

Keyword(s):

Activated Sludge ◽

Sewage Treatment ◽

Operating Conditions ◽

Municipal Sewage ◽

Sludge Treatment ◽

Loading Rates ◽

Treatment Conditions ◽

Physico Chemical ◽

Treated Sewage ◽

Removal Efficiencies

Effluents and sludges from several municipal sewage treatment plants in Switzerland were analyzed for nonylphenol polyethoxylates (NPnEO, n=3-20), nonylphenol mono- and diethoxylate (NPlEO, NP2EO), corresponding nonylphenoxy carboxylic acids (NP1EC, NP2EC) and nonylphenol (NP). These chemicals derive from nonionic surfactants of the NPnEO-type, and specific analitical techniques were used to study their behaviour during mechanical-biological sewage and subsequent sludge treatment. The parent NPnEO-surfactants, with concentrations in raw and mechanically treated sewage from 400-2200 mg/m3, were relatively efficiently removed by the activated sludge treatment. The abundances of the different metabolites varied depending on treatment conditions. The refractory nature of NPl/2EO, NP and NPl/2EC was recognized. Both biotransformations and physico-chemical processes determine the behaviour and fate of nonylphenolic substances in sewage treatment. Nitrilotriacetate (NTA) was found in primary effluents at concentrations between 430 and 1390 mg/m3. The various treatment plants showed different removal efficiencies for NTA depending on the operating conditions. Activated sludge treatment with low sludge loading rates and nitrifying conditions removed NTA with efficiencies between 95 and 99%. High sludge loading caused a decrease in NTA removal efficiencies from 70% to 39%.

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Mutagenicity in Pulp and Paper Mill Effluents and in Recipient

Water Science & Technology ◽

10.2166/wst.1988.0054 ◽

1988 ◽

Vol 20 (2) ◽

pp. 143-152 ◽

Cited By ~ 4

Author(s):

A. Langi ◽

M. Priha

Keyword(s):

Activated Sludge ◽

Mutagenic Activity ◽

Chinese Hamster Ovary Cells ◽

Chinese Hamster ◽

Paper Mill ◽

Pulp And Paper ◽

Pulp And Paper Mill ◽

Sludge Treatment ◽

Paper Mill Effluents ◽

Kraft Mill

The mutagenic properties of pulp and paper mill effluents were studied in three mills: bleached kraft mill with aerated lagoon treatment (Mill 1), bleached kraft mill with activated sludge treatment (Mill 2) and mechanical pulp/paper mill (Mill 3). Both treated and untreated effluents, process streams and molecular fractions were tested for mutagenicity (Ames test. Salmonella typhimurium TA100 and SCE sister chromatid exchange test, Chinese hamster ovary cells). To verify the potential environmental effects the mutagenic activity of concentrated recipient lake water (Mill 2) was also studied. The Ames mutagenicity of the bleached kraft mill effluent (BKME) originated from the first chlorination filtrate, SCE mutagenicity also occurred in the alkali extraction stage filtrate (Mill 1). No Ames mutagenicity was detected in the paper mill effluent, but it was SCE mutagenic. Activated sludge treatment of BKME removed both Ames and SCE mutagenicity, but the aerated lagoon treated BKME was still SCE mutagenic. No mutagenic activity was detected in the recipient water concentrates.

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