Special issue : domestic wastewater treatment.Demonstration test of irregular small-scale combined disposal clarification tank with advanced treatment.

The authors have developed what we call the submerged iron contactor process as a simple and inexpensive phosphorus removal method for small-scale plants disposing of domestic wastewater and household wastewater treatment tanks. In this method iron contactors are submerged in biological treatment tanks, where phosphate anions in wastewater are combined with iron cations produced through corrosion of the contactors, and the compound thus produced is precipitated and removed together with biological sludge. In these studies, laboratory experiments were made on the contact aeration process combined with the above-mentioned method, and the following findings were obtained. (1) It is desirable to treat wastewater by making use of corrosion by sulfate-reducing bacteria instead of corrosion by oxygen dissolved in wastewater, to conduct a stable phosphorus removal by this combined method. (2) The corrosion rate of iron contactors is affected by the volumetric loading of BOD in the tanks where they are submerged. (3) Assuming that an iron contactor continues to suffer corrosion evenly all over the surface when our combined method is applied, it is estimated that the corrosion rate is about 1mm or less in 30 years.

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Evaluation of flocculation and dissolved air flotation as an advanced wastewater treatment

Water Science & Technology ◽

10.2166/wst.2001.0470 ◽

2001 ◽

Vol 43 (8) ◽

pp. 83-90 ◽

Cited By ~ 7

Author(s):

A. C. Pinto Filho ◽

C. C. Brandão

Keyword(s):

Wastewater Treatment ◽

Domestic Wastewater ◽

High Rate ◽

Advanced Treatment ◽

Dissolved Air Flotation ◽

Anaerobic Reactor ◽

Treatment Processes ◽

Domestic Wastewater Treatment ◽

Air Flotation ◽

Dissolved Air

A bench scale study was carried out in order to evaluate the applicability of dissolved air flotation (DAF) as an advanced treatment for effluents from three different domestic wastewater treatment processes, namely: (i) a tertiary activated sludge plant ; (ii) an upflow sludge blanket anaerobic reactor (UASB); and (iii) a high-rate stabilization pond.

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Advanced Treatment of Domestic Wastewater Using Sequencing Batch Reactor Activated Sludge Process

Water Science & Technology ◽

10.2166/wst.1993.0243 ◽

1993 ◽

Vol 28 (10) ◽

pp. 267-274 ◽

Cited By ~ 6

Author(s):

M. Imura ◽

E. Suzuki ◽

T. Kitao ◽

S. Iwai

Keyword(s):

Activated Sludge ◽

Sequencing Batch Reactor ◽

Batch Reactor ◽

Domestic Wastewater ◽

Experimental Period ◽

Small Scale ◽

Experimental Plant ◽

Activated Sludge Process ◽

Nitrogen And Phosphorus ◽

Experimental Apparatus

In order to apply a sequencing batch reactor activated sludge process to small scale treatment facilities, various experiments were conducted by manufacturing an experimental apparatus made of a factory-produced FRP cylinder transverse tank (Ø 2,500mm). Results of the verification test conducted for one year by leading the wastewater discharged from apartment houses into the experimental apparatus were as follows. Excellent performance was achieved without any addition of carbon source, irrespective of the organic compound concentration and the temperature of raw wastewater. Organic substances, nitrogen and phosphorus were removed simultaneously. Due to the automated operation format, stable performance was obtained with only periodic maintenance. Though water depth of the experimental plant was shallow, effective sedimentation of activated sludge was continued during the experimental period. Regarding the aerobic and anaerobic process, nitrification and denitrification occurred smoothly.

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