Entrapped Mixed Microbial Cell Process for Combined Secondary and Tertiary Wastewater Treatment

2002 ◽  
Vol 74 (3) ◽  
pp. 226-234 ◽  
Author(s):  
P.Y. Yang ◽  
K. Cao ◽  
S.J. Kim
Keyword(s):  
Wastewater Treatment ◽  
Microbial Cell ◽  
Cell Process ◽  
Entrapped Mixed Microbial Cell

Packed-Entrapped-Mixed Microbial Cells for Small Wastewater Treatment

1990 ◽  
Vol 22 (3-4) ◽  
pp. 343-350 ◽  
Author(s):  
P. Y. Yang ◽  
M. L. Wang
Keyword(s):  
Wastewater Treatment ◽  
Calcium Alginate ◽  
Loading Rate ◽  
Cellulose Triacetate ◽  
Microbial Cell ◽  
Synthetic Wastewater ◽  
Cell Process ◽  
Suspended Solid Concentration ◽  
Sludge Recycling ◽  
Entrapped Mixed Microbial Cell

The primary goal of the research is to develop and evaluate a biological treatment system in which mixed microbial populations are physically immobilized by entrapment. The immobilized system was evaluated initially for its ability to remove simple benzene-based compounds from a synthetic wastewater as a model for treating pesticide-containing waters. Cellulose triacetate was used as the preparation of monocarrier and combined cellulose triacetate and calcium alginate were used for the preparation of bi-carrier. Phenol was used as substrate to test the entrapped mixed microbial cell process. Process performance including steady state, shock load and comparison of entrapped microbial cell process with and without entrapped microbial cell was investigated. It was concluded that the critical loading rate for phenol synthetic wastewater appeared to be 9 g COD/L/day. The COD removal efficiency could be maintained higher than 90%. Because of the low effluent suspended solid concentration, conventional-secondary-settling tanks could be eliminated. Also, the process could take both concentration and hydraulic shock loads of phenol synthetic wastewater successfully without the need of external sludge recycling. The equalization and external sludge recycling facilities equipped in the conventional wastewater treatment plant could be eliminated. When the process is operated only at low COD loading rate (less than 1.3 g/L/day), entrapped cells might not be required. However, when operated at higher loading rate, combined adsorbed and entrapped cells appeared to remove phenol more efficiently. For the application, mono-carrier (cellulose triacetate) is preferable to bi-carrier (cellulose triacetate and calcium alginate), since it is easier to prepare and the operational performance is better. Therefore, the application of packed-entrapped mixed microbial cell process for treatment of small-toxic-organic wastewater holds great potential.

Two-stage entrapped mixed microbial cell process for simultaneous removal of organics and nitrogen for rural domestic sewage application

2004 ◽  
Vol 49 (5-6) ◽  
pp. 281-288 ◽  
Author(s):  
S.J. Kim ◽  
P.Y. Yang
Keyword(s):  
Removal Efficiency ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Microbial Cell ◽  
Two Stage ◽  
Rate Limiting Step ◽  
Soluble Chemical Oxygen Demand ◽  
Removal Efficiencies ◽  
Entrapped Mixed Microbial Cell

A two-stage entrapped mixed microbial cell (2SEMMC) process which separates nitrification and denitrification phases by the installation of the anoxic and oxic EMMC reactors packed with EMMC carriers was operated with 6, 4, 3, and 2 hours of hydraulic retention time (HRT) using simulated domestic wastewater. The activated sludge was immobilized using cellulose acetate for the EMMC carriers. Similar soluble chemical oxygen demand (SCOD) removal efficiencies of 90-97% were observed for all HRTs (SCOD loading rate of 0.84-2.30 g/L/d) applied. In order to achieve more than 80 % of TN removal efficiency, the HRT should be maintained higher than 4 hours (less than 0.24 g/L/d of TN loading rate). Denitrification was a rate-limiting step which controlled overall TN removal efficiency at TN loading rate of 0.15-0.31 g/L/d although nitrification efficiencies achieved 97-99 %. The effluent TSS of less than 25 mg/L in the 2SEMMC process was maintained at the SCOD loading rate of less than 1.23 g/L/d with back-washing intervals of 5 and 10 days in the anoxic and oxic EMMC reactors, respectively. The minimum HRT of 4 hours is required for high removal efficiencies of organics (average 95.6 %) and nitrogen (average 80.5 %) in the 2SEMMC process with 3 times of recirculation ratio.

Applying entrapped mixed microbial cell techniques for biological wastewater treatment

1994 ◽  
Vol 29 (10-11) ◽  
pp. 487-495 ◽  
Author(s):  
P. Y. Yang ◽  
T. Ma ◽  
T. S. See ◽  
N. Nitisoravut
Keyword(s):  
Wastewater Treatment ◽  
Cellulose Triacetate ◽  
Suspended Solid ◽  
Microbial Cell ◽  
Biological Wastewater Treatment ◽  
Water And Wastewater Treatment ◽  
Biological Water ◽  
Suspended Solid Concentration ◽  
The University ◽  
Strength And Durability

The entrapment of mixed microbial cell was accomplished by using a porous material, such as cellulose triacetate, to confine the migration of microorganism. Synthetic glucose, phenol, carbaryl and nitrate wastewater was used as substrate to evaluate this process. Applying entrapped microbial cell techniques for biological water/wastewater treatment was previously investigated mainly by using the pure culture system. For the past six years, the University of Hawaii has investigated this technology for biological wastewater treatment by using a mixed culture approach. It was found that the developed carrier, using cellulose triacetate, is the most suitable for providing the necessary mechanical strength and durability under both the aerobic and anaerobic conditions. It also provides many advantages, such as a short start-up period, high effluent quality in terms of COD, NO3-N concentrations and removal efficiency, low effluent suspended solid concentration, and high SRT with low HRT. The process has potential to replace or upgrade the existing biological processes for water and wastewater treatment. A pre-engineered and packaged plant can be easily developed for a small wastewater treatment system for toxic or hazardous wastewater.

Modeling organics biodegradation and ammonia nitrification by entrapped mixed microbial cell carriers

2013 ◽  
Vol 52 (22-24) ◽  
pp. 4462-4468 ◽  
Author(s):  
Chug-Chun Liu ◽  
Kok-Kwang Ng ◽  
Chien-Ju Wu ◽  
Cheng-Fang Lin ◽  
Pui-Kwan Andy Hong ◽  
...  
Keyword(s):  
Microbial Cell ◽  
Cell Carriers ◽  
Entrapped Mixed Microbial Cell
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