RECIPIENT POLLUTION CAUSED BY SMALL DOMESTIC WASTEWATER TREATMENT PLANTS WITH ACTIVATED SLUDGE

Two full scale systems of oxidation ditches for domestic wastewater treatment plants (WWTP) were used as study sites: Phuket Province, southern Thailand (representative of tropical humid climates) and Plum Creek, Castle Rock, Colorado, USA (representative of cold climates). The treatment systems at both sites were designed for biological nutrient removal (BNR) fromextended activated sludge. Nitrogen is removed by nitrification-denitrification processes. The solid retention time (SRT) for both treatment plants was ≥ 10 das recommended by theory for complete nitrification in activated sludge wastewater treatment plants. Influents and effluents from these sites were compared in respect to flow rate, biochemical oxygen demand (BOD), organic nitrogen, ammonium, nitrate, total nitrogen, and phosphorus concentrations. At both sites, nutrient removal reached more than 75% because there was sufficient carbon for denitrifying and phosphate accumulating organisms. Furthermore, low dissolved oxygen concentration, long SRT, and hightemperature could be key factors to promote activity of some groups of bacteria in consuming organic matter and nutrients in wastewater in warm climates. For this reason, plant design and operating procedures for wastewater treatment in cold climates might not be always be applicable to warm climates.

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Trickling filter-activated sludge combinations for domestic wastewater treatment

10.31274/rtd-180813-4230 ◽

1972 ◽

Author(s):

Robert Frank Roskopf

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Domestic Wastewater ◽

Trickling Filter ◽

Domestic Wastewater Treatment

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Modeling of Heavy Metals Adsorption by Inorganic Particles and Activated Sludge in Domestic Wastewater Treatment Plant

Asian Journal of Chemistry ◽

10.14233/ajchem.2014.17032 ◽

2014 ◽

Vol 26 (14) ◽

pp. 4475-4480

Author(s):

Dejun Kang ◽

Danyu Xie ◽

Pengzhen Ke

Keyword(s):

Heavy Metals ◽

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plant ◽

Treatment Plant ◽

Domestic Wastewater ◽

Inorganic Particles ◽

Heavy Metals Adsorption ◽

Domestic Wastewater Treatment ◽

Metals Adsorption

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Model-based evaluation of nitrogen removal in a tannery wastewater treatment plant

Water Science & Technology ◽

10.2166/wst.2004.0383 ◽

2004 ◽

Vol 50 (6) ◽

pp. 251-260 ◽

Cited By ~ 7

Author(s):

M.S. Moussa ◽

A.R. Rojas ◽

C.M. Hooijmans ◽

H.J. Gijzen ◽

M.C.M. van Loosdrecht

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plants ◽

Computer Modelling ◽

Treatment Plant ◽

Domestic Wastewater ◽

Plant Performance ◽

Accurate Estimation ◽

Model Parameters ◽

Biological Tests

Computer modelling has been used in the last 15 years as a powerful tool for understanding the behaviour of activated sludge wastewater treatment systems. However, computer models are mainly applied for domestic wastewater treatment plants (WWTPs). Application of these types of models to industrial wastewater treatment plants requires a different model structure and an accurate estimation of the kinetics and stoichiometry of the model parameters, which may be different from the ones used for domestic wastewater. Most of these parameters are strongly dependent on the wastewater composition. In this study a modified version of the activated sludge model No. 1 (ASM 1) was used to describe a tannery WWTP. Several biological tests and complementary physical-chemical analyses were performed to characterise the wastewater and sludge composition in the context of activated sludge modelling. The proposed model was calibrated under steady-state conditions and validated under dynamic flow conditions. The model was successfully used to obtain insight into the existing plant performance, possible extension and options for process optimisation. The model illustrated the potential capacity of the plant to achieve full denitrification and to handle a higher hydraulic load. Moreover, the use of a mathematical model as an effective tool in decision making was demonstrated.

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Using metazoa to reduce sludge production

Water Science & Technology ◽

10.2166/wst.1997.0408 ◽

1997 ◽

Vol 36 (11) ◽

pp. 171-179 ◽

Cited By ~ 29

Author(s):

J. H. Rensink ◽

W. H. Rulkens

Keyword(s):

Wastewater Treatment ◽

Activated Sludge ◽

Wastewater Treatment Plants ◽

Treatment Plant ◽

Domestic Wastewater ◽

Brewery Wastewater ◽

Trickling Filters ◽

Starting Point ◽

Nitrification Process ◽

Sludge Production

Pilot plant experiments have been carried out to study the mineralization of sludge from biological wastewater treatment plants by worms such as Tubificidae. Trickling filters filled with lava slags were continuously fed with a certain quantity of excess activated sludge of a Dutch brewery wastewater treatment plant (Bavaria) by recirculation during 10 to 14 days. At the starting point of each experiment the trickling filters were inoculated with Tubificidae. Recirculation of sludge showed that use of Tubificidae resulted in a COD reduction of the sludge (mixed liquor) of 18–67–. Without worms this reduction was substantially lower. The sludge production in a pilot activated sludge system for treating settled domestic wastewater reduced from 0.40 to 0.15 g MLSS/g COD removed when Tubificidae were added to the system. The lower amounts of sludge were always accompanied by an increase of nitrate and phosphate concentration in the wastewater. There was no disturbance of the nitrification process. Application of Tubificidae or other worms may have interesting potential for practical application.

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