Inhibitory effect of refractory organic compounds produced by activated sludge micro-organisms on microbial activity and flocculation

1985 ◽  
Vol 19 (2) ◽  
pp. 197-200 ◽  
Author(s):  
Jan Chudoba
Keyword(s):  
Activated Sludge ◽  
Microbial Activity ◽  
Organic Compounds ◽  
Inhibitory Effect ◽  
Micro Organisms

Fate of Toxic Organic Compounds in Activated Sludge and Integrated PAC Systems

1987 ◽  
Vol 19 (3-4) ◽  
pp. 471-482 ◽  
Author(s):  
W. J. Weber ◽  
B. E. Jones ◽  
L. E. Katz
Keyword(s):  
Activated Carbon ◽  
Activated Sludge ◽  
Organic Compounds ◽  
Powdered Activated Carbon ◽  
Carbon Adsorption ◽  
Powdered Carbon ◽  
Benzene Toluene ◽  
Adsorptive Properties ◽  
Carbon Concentrations ◽  
Toxic Organic Compounds

The addition of powdered activated carbon (PAC) to activated sludge treatment systems to enhance removal of specific toxic organic compounds from wastewater was evaluated. Nine organic compounds encompassing a range of solubility, volatility, biodegradability, and adsorptive properties were studied. Kate and equilibrium investigations were conducted to quantify the removal mechanisms of volatilization, biodegradation, biosorption, and carbon adsorption. Results from steady-state bioreactor studies showed that the addition of less than 100 mg/ℓ powdered activated carbon to the influent did not enhance the removal of the biodegradable target compounds investigated: benzene, toluene, ethylbenzene, o-xylene, chlorobenzene, and nitrobenzene. Significantly improved removals of the poorly degradable and non-biodegradable compounds 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, and lindane occurred at influent powdered carbon concentrations in the 12.5 to 25 mg/ℓ range. Influent powdered carbon concentrations of 100 mg/ℓ effected overall removals of greater than 90%. The addition of powdered activated carbon not only reduced effluent concentrations but also reduced the amounts of the volatile compounds stripped to the atmosphere.

Single and joint inhibitory effect of nitrophenols on activated sludge

2021 ◽  
Vol 294 ◽  
pp. 112945
Author(s):  
Zhuowei Zhang ◽  
Yin Yu ◽  
Hongbo Xi ◽  
Yuexi Zhou
Keyword(s):  
Activated Sludge ◽  
Inhibitory Effect

scholarly journals Pathogenic micro-organisms in waste waters from daiies

2000 ◽  
Vol 18 (No. 5) ◽  
pp. 170-174
Author(s):  
P. Navrátilová
Keyword(s):  
Waste Water ◽  
Listeria Monocytogenes ◽  
Activated Sludge ◽  
Cleaning Process ◽  
Waste Waters ◽  
Excess Sludge ◽  
Salmonella Spp ◽  
Potential Health ◽  
Treated Water ◽  
Micro Organisms

Waste waters from dairies were tested for the presence of bacterial pathogens – Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. The prevalence of bacteria was investigated in each stage of the cleaning process (activated sludges systems) too. Two hunder samples of raw waste water, activated sludge, returned activated sludge, excess sludge and treated water from 14 dairies were tested. The samples were all negative for Salmonella spp. From a total of 102 (51%) strains Listeria spp., Listeria inoccua 95 (47.5%) and Listeria monocytogenes 7 (3.5%) were identified. 47 samples were positive for S. aureus. L. monocytogenes were detected in raw waste water 1 (1.6%), in activated sludge 3 (5.5%), in excess sludge 1 and in treated water 2 (3.1%). S. aureus were detected in raw waste water 14 (22.6%), in activated sludge 23 (41.8%), in excess sludge 1 and in treated water 8 (12.3%). These results demonstrate a prevalence of L. monocytogenes and S. aureus in waste waters from dairies. During the cleaning process pathogenic bacteria were not devitalized. The excess sludge and treated water including pathogenic micro-organisms represent a potential health hazard.

scholarly journals Secondary Metabolites from Saccharomyces cerevisiae Species with Anticancer Potential

2021 ◽  
Author(s):  
Muhammad Jahangeer ◽  
Areej Riasat ◽  
Zahed Mahmood ◽  
Muhammad Numan ◽  
Naveed Munir ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Secondary Metabolites ◽  
Apoptotic Cell ◽  
Inhibitory Effect ◽  
Chemotherapeutic Agents ◽  
Chemotherapeutic Drugs ◽  
Central Metabolism ◽  
Biotic Stresses ◽  
Micro Organisms ◽  
New Chemotherapeutic Agents

Chemotherapeutic agents produce from numerous sources such as animals, plants and micro-organisms are derived from the natural products. Although the existing therapeutic pipeline lacks fungal-derived metabolites, but hundreds of secondary metabolites derived from fungi are known to be possible chemotherapies. Over the past three decades, several secondary metabolites such as flavonoids, alkaloids, phenolic and polyketides have been developed by Saccharomyces cerevisiae species with exciting activities that considered valued for the growth of new chemotherapeutic agents. Many secondary metabolites are protective compounds which prevent abiotic and biotic stresses, i.e. predation, infection, drought and ultraviolet. Though not taking part in a living cell’s central metabolism, secondary metabolites play an important role in the function of an organism. Nevertheless, due to slow biomass build-up and inadequate synthesis by the natural host the yield of secondary metabolites is low by direct isolation. A detailed comprehension of biosynthetic pathways for development of secondary metabolites are necessary for S. cerevisiae biotransformation. These metabolites have higher inhibitory effect, specificity among cancer and normal cells, and the mechanism of non-apoptotic cell killing. This study shows the significance of bioactive compounds produced by S. cerevisiae species with their possible activity and value in chemotherapeutic drugs pipeline. The isolation and alteration of these natural secondary metabolites would promote the development of chemotherapeutic drugs.

scholarly journals Phytochemical Screening and Biological Studies of Shilajit (Asphaltum)

2017 ◽  
Vol 9 (1) ◽  
pp. 15
Author(s):  
Shahid Aziz ◽  
Sidra Khaliq ◽  
Habib Ur-Rehman ◽  
Kh. Shakeel Ghani ◽  
Muhammad Irshad ◽  
...  
Keyword(s):  
Microbial Activity ◽  
Cardiac Glycosides ◽  
Reducing Sugars ◽  
Phytochemical Analysis ◽  
Phytochemical Screening ◽  
Bacterial Strains ◽  
Biological Studies ◽  
Dead Plant ◽  
Micro Organisms

<p>Shilajit (asphaltum)  is produced  by the long term humification  of dead plant material  and organic vegetable matter  by different micro-organisms and has great potential for the treatment of a variety of human conditions.  This treatise reviews its origin, sources, chemical composition, biological  and  commercial importance. Phytochemical analysis was done by standard methods to evaluate  different Shilajit (asphaltum) classes of compounds in different samples of shilajit  which are responsible for their  biological activity.  Shilajit`s anti-microbial activity has been evaluated  against four different bacterial strains viz., <em>Escherichia coli, Psuedomonas aeuroginosa</em>, <em>Klebisella pneumonia</em> and <em>Staphylococcus aureus. </em>Phytochemical analysis illustrated  that shilajit contains  terpenoids, cardiac glycosides, saponins and reducing sugars. Surprisingly,  some classes of compounds are absent in shilajit  viz., alkaloids, flavonoids, tannins and anthraquinones. . Shilajit showed no response towards halophytic bacteria and  negligible activity was shown towards other strains of bacteria. Since   anti-microbial activity is based on environmental factors  its activity varied  between locations.</p>

scholarly journals Steam treatment of contaminated groundwater aquifers – development of pathogenic micro-organisms in soil

2005 ◽  
Vol 7 ◽  
pp. 37-40
Author(s):  
Carsten Suhr Jacobsen ◽  
Susanne Elmholt ◽  
Carsten Bagge Jensen ◽  
Pia Bach Jakobsen ◽  
Mikkel Bender
Keyword(s):  
Microbial Community ◽  
Microbial Activity ◽  
Environmental Protection Agency ◽  
Steam Injection ◽  
Vapour Phase ◽  
Steam Treatment ◽  
Deep Aquifer ◽  
Vacuum Suction ◽  
Water Saturated ◽  
Micro Organisms

Steam treatment of contaminated soil and aquifer sediment is a promising method of cleaning soil. The treatment is based on steam injection into a water saturated porous aquifer (Gudbjerg et al. 2004), by which the heat transfers the contaminants into the vapour phase, allowing entrapment in an active carbon filter connected to a large vacuum suction device. The treatment is effective against several important groundwater contaminants, including pentachlorophenole and perchloroethylene, typically found in association with industrial processes or dry cleaning facilities. Furthermore, as an example of removal of non-aqueous phase liquids (NAPLs) large amounts of creosote have been recovered after steam injection in a deep aquifer (Kuhlmann 2002; Tse & Lo 2002). Steam treatment is dependent on the complete heating of the soil volume under treatment. The steam has a strongly adverse impact on trees and other plants with deep root systems within the soil, but no other visible effects have been reported. The aim of the activities undertaken during collaborative projects carried out by the Geological Survey of Denmark and Greenland (GEUS) and the Danish Institute of Agricultural Sciences (DJF) for the Danish Environmental Protection Agency and the local authorities in Copenhagen (Københavns Amt) was to establish to what extent the microbial community was affected by the steam treatment of the soil. A few results from the literature indicate that the microbial activity increases in steam treated soil (Richardson et al. 2002), probably due to microbial degradation of the soil contaminants in combination with microbial utilisation of heatkilled organisms. It is, however, not known whether this increased microbial activity is associated with the development of pathogenic micro-organisms; these are typically able to grow at higher temperatures than the general microbial community in soil.

Factors affecting nitrogen removal from domestic wastewater using immobilized bacteria

1998 ◽  
Vol 38 (1) ◽  
pp. 193-202 ◽  
Author(s):  
Vasanthadevi Aravinthan ◽  
Satoshi Takizawa ◽  
Kenji Fujita ◽  
Kazuya Komatsu
Keyword(s):  
Activated Sludge ◽  
Nitrogen Removal ◽  
Nitrate Nitrogen ◽  
Domestic Wastewater ◽  
Nitrification Rate ◽  
Factors Affecting ◽  
Immobilized Bacteria ◽  
Bulk Oxygen ◽  
Micro Organisms ◽  
Nitrogen Loadings

The parameters affecting the nitrogen removal process by the immobilized bacteria in the anoxic-oxic process have been studied by investigating two bench scale Runs A and B. The hollow polypropylene pellets have been dosed into the anoxic reactor in Run A and into the oxic reactors of both Runs up to 24% of volume. Run B was operated with no pellets in the anoxic reactor as a control. The maximum nitrification rate of 0.4 kg NH4-N/m3d was achieved in sufficient DO (6.5 mg/l) at 15°C in the reactor with both activated sludge and immobilized micro-organisms. The volumetric nitrification rate was found to be greatly dependent on bulk oxygen concentration especially when the DO was maintained below 4 mg/l. A mathematical model developed successfully simulated the experimental results showing the variation of nitrification rate with DO. In the case of denitrification, the contribution of immobilized bacteria was prominent when lesser concentration of MLSS was present in the activated sludge in the combined immobilized and activated sludge system. The presence of immobilized bacteria in the anoxic reactor will be effective when higher nitrate nitrogen loadings are expected and the maintenance of higher MLSS than 2 g/l in an activated sludge facility is not feasible.

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