Application of biogenic iron precipitation by strain H117 for tetracycline removal: mechanism of adsorption and activation

A number of groundwater heat pump systems have been investigated to determine the extent of problems caused by the chemistry of the groundwater used. The main purpose was to investigate sites using iron rich groundwater. Fifteen facilities were studied regularly for three years. Ten of these facilities had some kind of problem caused by iron precipitation. Four of the sites were rebuilt because of severe plugging due to iron sludge in wells, pumps and pipes. In all facilities with severe problems, iron bacteria were found. Low redox potential, indicated by hydrogen sulphide in the groundwater, seems to protect from iron bacteria. In some of the systems using groundwater with H2S the problems were corrosion and sludge formation caused by sulphur oxidizing bacteria. Rapid clogging was caused by aeration of the groundwater due to improper design of the system. Knowledge of the water composition, design of the systems to minimize aeration, and control of clogging turned out to be important factors to maintain operation safety.

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Pilot-plant experiments for improvement of polluted canal/klong water by rock-bed filtration

Water Science & Technology ◽

10.2166/wst.1997.0300 ◽

1997 ◽

Vol 35 (8) ◽

pp. 83-90

Author(s):

Shigeo Fujii ◽

Chiaki Niwa ◽

Mitsuo Mouri ◽

Ranjna Jindal

Keyword(s):

Organic Matter ◽

Pilot Plant ◽

Horizontal Flow ◽

Removal Mechanism ◽

Soluble Organic Matter ◽

Filter Media ◽

Canal Water ◽

Rock Bed ◽

One Year ◽

Filtration Technique

Applicability of the rock-bed filtration technique was investigated through pilot-plant experiments in Bangkok, Thailand. Polluted canal water was used as horizontal flow influent to two reactor channels filled with rocks. During one year operation, HRT, filter media, and aeration mode, were changed in several runs. The results showed that 1) the rock-bed filtration with aeration and the HRT more than 6 h can successfully improve polluted klong water by reducing the pollutants (e.g. 60-120mg/L of SS to 20-40 mg/L and 15-30 mg/L of BOD to 5-20 mg/L); 2) main removal mechanism seems to be the sedimentation resulting from the settleability enhanced by aeration, and the biofilm attached onto rocks also works in the reduction of soluble organic matter; 3) a combination of three rock sizes arranged in descending order showed best results; 4) longer HRT (13 h) produces better effluent but is not so effective if it exceeds 9 hours; 5) 60-70% of sediment IL was decomposed in a year, and porosity in rock beds reduced approximately 16%.

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Nitrogen removal from wastewater treatment lagoons

Water Science & Technology ◽

10.2166/wst.1999.0296 ◽

1999 ◽

Vol 39 (6) ◽

pp. 191-198 ◽

Cited By ~ 8

Author(s):

Timothy J. Hurse ◽

Michael A. Connor

Keyword(s):

Wastewater Treatment ◽

Nitrogen Removal ◽

Treatment Plant ◽

Ammonia Removal ◽

Contour Plot ◽

Removal Mechanism ◽

Dissolved Oxygen Concentration ◽

Physical Processes ◽

Contour Plots ◽

Removal Processes

In an attempt to gain a better understanding of ammonia and nitrogen removal processes in multi-pond wastewater treatment lagoons, an analysis was carried out of data obtained during regular monitoring of Lagoon 115E at the Western Treatment Plant in Melbourne. To do this, a contour plot approach was developed that enables the data to be displayed as a function of pond number and date. Superimposition of contour plots for different parameters enabled the dependence of ammonia and nitrogen removal rates on various lagoon characteristics to be readily assessed. The importance of nitrification as an ammonia removal mechanism was confirmed. Temperature, dissolved oxygen concentration and algal concentration all had a significant influence on whether or not sizeable nitrifier populations developed and persisted in lagoon waters. The analysis made it evident that a better understanding of microbial, chemical and physical processes in lagoons is needed before their nitrogen removal capabilities can be predicted with confidence.

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