Characterization of immobilized cells in biodegradation of ABS resin manufacturing waste-water

1996 ◽  
Vol 34 (10) ◽  
pp. 51-58 ◽  
Author(s):  
Chen Wen-Chin ◽  
Cheng Sheng-Shung

Because of the presence of refractory and biologically inhibitory organic compounds in ABS resin wastewater, which would retard the bioactivity of the autotrophic nitrifier and make the efficiency of nitrification process unstable, the application of cell immobilization for ABS wastewater treatment has been investigated by immobilizing the enrichment culture of nitrifying bacteria with alginate. The characterization of the immobilized cells in various alignate concentrations was conducted by a series of biodegradability studies with electrolytic respirometry and compared with the differences from the dispersed cells. Results clearly indicated that immobilized cells achieved higher efficiency of COD and TKN removal than that of the dispersed cells during the period of high initial concentration of wastewater. Meanwhile, high concentration of cells were growing near the gel surface and reduced the effects of diffusional restriction. No remarkable difference was found while the concentration of alginate ranged from 3% to 5%. According to mass balance of total nitrogen, more than 25% of total nitrogen was removed in the batch system of the immobilized cell. Simultaneous nitrification and denitrification could occur due to the oxygen gradient throughout the gel matrix. Compared with the complete mixing system of the dispersed cell, the approach for the immobilized-cell system provided a more effective method for treating the special wastewater with high strength of nitrogenous and inhibitory compounds.

Biologia ◽  
2012 ◽  
Vol 67 (5) ◽  
Author(s):  
Maegala Nallapan Maniyam ◽  
Fridelina Sjahrir ◽  
Abdul Ibrahim ◽  
Anthony Cass

AbstractAnthropogenic sources contribute to the bulk presence of cyanide, which causes substantial health and environmental concerns. A petroleum-contaminated soil isolate, Rhodococcus UKMP-5M has been verified to efficiently degrade high concentration of cyanide in the form of KCN in our previous study. In order to enhance the cyanide-degrading ability of this bacterium, different encapsulation matrices were screened to immobilize cells of Rhodococcus UKMP-5M for degradation of cyanide. It was revealed that the biocatalyst activity and bead mechanical strength improved significantly when calcium alginate encapsulation technique was employed as compared to free cells. The results also indicated that the immobilized cell system could tolerate a higher level of KCN concentration and were able to support a higher biomass density. In addition, the embedded cells retained almost 96% of their initial cyanide removal efficiency during the first five batches and the entrapped cell system maintained 64% of its initial activity after eight successive batches. The encapsulated beads could be easily recovered from the production medium and reused for up to five batches without significant losses of cyanide-degrading ability, which proved to be advantageous from an economic point of view. From this study, it could be inferred that the novel Rhodococcus UKMP-5M strain demonstrated high cyanide-degrading ability and the optimized calcium alginate immobilization technique provided a promising alternative for practical application of large scale remediation of cyanide-bearing wastewaters.


2005 ◽  
Vol 71 (1) ◽  
pp. 276-281 ◽  
Author(s):  
Fuli Li ◽  
Ping Xu ◽  
Jinhui Feng ◽  
Ling Meng ◽  
Yuan Zheng ◽  
...  

ABSTRACT Mycobacterium goodii X7B, which had been primarily isolated as a bacterial strain capable of desulfurizing dibenzothiophene to produce 2-hydroxybiphenyl via the 4S pathway, was also found to desulfurize benzothiophene. The desulfurization product was identified as o-hydroxystyrene by gas chromatography (GC)-mass spectrometry analysis. This strain appeared to have the ability to remove organic sulfur from a broad range of sulfur species in gasoline. When Dushanzi straight-run gasoline (DSRG227) containing various organic sulfur compounds was treated with immobilized cells of strain X7B for 24 h, the total sulfur content significantly decreased, from 227 to 71 ppm at 40�C. GC flame ionization detection and GC atomic emission detection analysis were used to qualitatively evaluate the effects of M. goodii X7B treatment on the contents of gasoline. In addition, when immobilized cells were incubated at 40�C with DSRG275, the sulfur content decreased from 275 to 54 ppm in two consecutive reactions. With this excellent efficiency, strain X7B is considered a good potential candidate for industrial applications for the biodesulfurization of gasoline.


2000 ◽  
Vol 66 (3) ◽  
pp. 1190-1194 ◽  
Author(s):  
M. Martín ◽  
G. Mengs ◽  
E. Plaza ◽  
C. Garbi ◽  
M. Sánchez ◽  
...  

ABSTRACT A bacterial strain capable of growing on propachlor (2-chloro-N-isopropylacetanilide) was isolated from soil by using enrichment and isolation techniques. The strain isolated, designated GCH1, was classified as a member of the genusPseudomonas. Washed-cell suspensions of strain GCH1 accumulated N-isopropylacetanilide, acetanilide, acetamide, and catechol. Pseudomonas strain GCH1 grew on propachlor with a generation time of 4.2 h and a rate of substrate utilization of 1.75 ± 0.15 μmol h−1. Gene expression did not require induction but was subject to catabolite expression. Acetanilide was a growth substrate with a yield of 0.56 ± 0.02 mg of protein μmol−1. GCH1 strain cells were immobilized by adsorption onto a ceramic support and were used as biocatalysts in an immobilized cell system. Propachlor elimination reached 98%, with a retention time of 3 h and an initial organic load of 0.5 mM propachlor. The viability of immobilized cells increased 34-fold after 120 days of bioreactor operation.


2008 ◽  
Vol 58 (11) ◽  
pp. 2155-2163 ◽  
Author(s):  
Sumana Siripattanakul ◽  
Wanpen Wirojanagud ◽  
John M. McEvoy ◽  
Francis X. M. Casey ◽  
Eakalak Khan

Bench-scale sand column breakthrough experiments were conducted to examine atrazine remediation in agricultural infiltrate by Agrobacterium radiobacter J14a (J14a) immobilized in phosphorylated-polyvinyl alcohol compared to free J14a cells. The effects of cell loading and infiltration rate on atrazine degradation and the loss of J14a were investigated. Four sets of experiments, i) tracers, ii) immobilized dead cells, iii) immobilized cells, and iv) free cells, were performed. The atrazine bioremediation at the cell loadings of 300, 600, and 900 mg dry cells l−1 and the infiltration rates of 1, 3, and 6 cm d−1 were tested for 5 column pore volumes (PV). The atrazine breakthrough results indicated that the immobilized dead cells significantly retarded atrazine transport. The atrazine removal efficiencies at the infiltration rates of 1, 3, and 6 cm d−1 were 100%, 80–97%, and 50–70% respectively. Atrazine remediation capacity for the immobilized cells was not significantly different from the free cells. Both infiltration rate and cell loading significantly affected atrazine removal for both cell systems. The bacterial loss from the immobilized cell system was 10 to 100 times less than that from the free cell system. For long-term tests at 50 PV, the immobilized cell system provided consistent atrazine removal efficiency while the atrazine removal by the free cells declined gradually because of the cell loss.


2020 ◽  
Author(s):  
Kehinde Sowunmi ◽  
Suliat Morenike Shoga ◽  
Oluwabukola Mabel Adewunmi ◽  
Adewale Felix Oriyomi ◽  
Lukman Sowunmi

AbstractPesticides are the substances for preventing, destroying, repelling any pest. Due to bulk handling or accidental release, they are accumulated in soil which leads to occasional entry into ecosystem that shows lethal effect on living system. An enrichment culture technique was used to isolate bacterial strains from organophosphate soil degrading high concentration of the selected pesticides. Five pure bacterial cultures were isolated. All five isolates were characterized on the basis of molecular and biochemical features like biodegradation test and substrate specificity, phosphate solubilization and screened for pesticide residue, pH, and extraction of DNA, quantity and quality check and salt tolerance. The organophosphate isolates were also tested for quantitative production. The screening of pesticide tolerance was done at for fungicides and insecticides.


Author(s):  
G. N. Shapovalenko ◽  
S. N. Radionov ◽  
V. V. Gorbunov ◽  
V. A. Khazhiev ◽  
V. Yu. Zalyadnov ◽  
...  

Chernogosky open pit mine integrates truck-and-shovel system of mining with overburden rehandling to internal dump with a set of walking excavators for rehandling of overburden to mined-out area of the pit. It is possible to improve efficiency of stripping in the conditions of Chernogorsky OPM by reducing percentage of stripping with more expensive handling system. The relevant research and solutions to this effect are presented in this article. Comparative characterization of mining conditions and parameters of mining systems applied is given for open pit mines Chernogorsky, Turnui, Nazarovsky, Vostochno-Beisky and Izykh. The comparative analysis points at the need to account for difficulty of mining and process sites in comparison of equipment productivity. High concentration of mining machines, which is conditioned by narrow mining front and simultaneous operation of five faces, as well as blasting operation implemented every 1-2 days, are recognized as the main constraints of excavator capacity in mining with direct dumping in Chernogorsky open pit mine. The management and engineering solutions implemented in the mine and resulted in higher efficiency of draglines are described.


1998 ◽  
Vol 37 (4-5) ◽  
pp. 95-98 ◽  
Author(s):  
Nancy G. Love ◽  
Mary E. Rust ◽  
Kathy C. Terlesky

An anaerobic enrichment culture was developed from an anoxic/anaerobic/aerobic activated sludge sequencing batch reactor using methyl ethyl ketoxime (MEKO), a potent nitrification inhibitor, as the sole carbon and energy source in the absence of molecular oxygen and nitrate. The enrichment culture was gradually fed decreasing amounts of biogenic organic compounds and increasing concentrations of MEKO over 23 days until the cultures metabolized the oxime as the sole carbon source; the cultures were maintained for an additional 41 days on MEKO alone. Turbidity stabilized at approximately 100 mg/l total suspended solids. Growth on selective media plates confirmed that the microorganisms were utilizing the MEKO as the sole carbon and energy source. The time frame required for growth indicated that the kinetics for MEKO degradation are slow. A batch test indicated that dissolved organic carbon decreased at a rate comparable to MEKO consumption, while sulfate was not consumed. The nature of the electron acceptor in anaerobic MEKO metabolism is unclear, but it is hypothesized that the MEKO is hydrolyzed intracellularly to form methyl ethyl ketone and hydroxylamine which serve as electron donor and electron acceptor, respectively.


1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.


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