scholarly journals Bioremediation of hydrocarbon-rich wastewater by aerobic granules of oil degrading bacterial strains in salinity influence

2021 ◽  
Author(s):  
Sayanti Ghosh ◽  
Saswati Chakraborty
Keyword(s):  
Suspended Solids ◽  
Extracellular Polymeric Substances ◽  
Settling Velocity ◽  
Biomass Concentration ◽  
Granule Size ◽  
Air Flow Rate ◽  
Salt Tolerant ◽  
Bacterial Strains ◽  
Nacl Concentration ◽  
Hydrocarbon Removal

Granulation of sewage and brewery sludge isolated oil degrader Brevibacterium and Staphylococcus were investigated in hydrocarbon-rich wastewater with 280 mg/L of hydrocarbon at 10-25 g/L NaCl salinity influence. Brevibacterium and Staphylococcus cultures were inoculated in aerobic granular reactors (AGRs) R1 and R2 which were operated with 24 h cycle time and 2 L/min air flow rate. Yellowish matured granules appeared within 15 days. R1 granules achieved stability till 15 g/L NaCl concentration but faced disintegration between 15-20 mg/L NaCl exposure which reduced granule size and hydrocarbon removal from 2.15-1.7 mm and 78-73%. R2 granules were more salt tolerant providing 2.5±0.5 mm granule size with 4±1 g/L volatile suspended solids (VSS) and 201±1 mg/g VSS extracellular polymeric substances (EPS) content achieving 81±0.7% hydrocarbon removal in 30 days. High granule stability and biomass concentration ensured less biomass washout from reactors. Granule settling velocity (GSV) in R1 and R2 reached 20±1 and 32±0.8 m/h which corresponded with granule size profiles. Kinetics analysis showed that at steady state, R1 and R2 were capable of 72 and 91% phenol removals in 30 and 24 h, respectively. Hence, the study provided salt tolerant oil degrading granules for refinery wastewater treatment.

Effect of Starch on the Flocculation and Settling Behaviour of Titanium Dioxide Suspensions

1974 ◽  
Vol 9 (1) ◽  
pp. 154-171
Author(s):  
S.N. Ray ◽  
C. Hsi ◽  
B.C. -Y. Lu
Keyword(s):  
Titanium Dioxide ◽  
Suspended Solids ◽  
Settling Velocity ◽  
Pollution Abatement ◽  
Paper Mills ◽  
Paper Making ◽  
Jar Test ◽  
Settling Behaviour ◽  
Dimensionless Function ◽  
Flocculation Rate

Abstract This study concerns the problem of removal of suspended solids from the effluent streams of paper mills by chemical treatment. As titanium dioxide is one of the ingredients used in paper mills and present in the effluent streams, its flocculation and settling behaviour were investigated. Jar test experiments were conducted using alum and organic polyelectrolyte as the flocculants. As starch is also used in the paper making process, its influence on the flocculation and settling behaviour of titanium dioxide was conducted with the concentration of starch varying between 0–3% of the dry solids. The experimental results on flocculation are expressed in terms of dimensionless function Gθϕ and flocculation rate constants. The fraction of solids settled is presented in terms of the settling velocity. Concentration of starch was found to have a significant influence. The amount of alum required could be reduced by 75% by using starch 0.6% of the amount of titanium dioxide in the suspension and at the same time improving the settling velocity two folds. A possible application of this finding in pollution abatement is discussed.

Methods for determining the settling velocity profiles of solids in storm sewage

1996 ◽  
Vol 33 (9) ◽  
pp. 117-125 ◽  
Author(s):  
Emmanuelle Aiguier ◽  
Ghassan Chebbo ◽  
Jean-Luc Bertrand-Krajewski ◽  
Peter Hedges ◽  
Naomi Tyack
Keyword(s):  
Suspended Solids ◽  
Settling Velocity ◽  
Test Procedure ◽  
Velocity Profiles ◽  
Test Methods ◽  
Efficient Treatment ◽  
Experimental Procedure ◽  
Comparative Tests ◽  
Settling Process ◽  
Settling Characteristics

Recently, research has shown that a settling process is an efficient treatment for the removal of suspended solids from storm sewage. In order to design settling tanks, there is a need to determine the settling velocity characteristics of these solids. Devices and test methods for measuring settling velocities of solids in storm sewage have been developed by researchers. A literature review has revealed that the settling velocity profiles obtained with some methods (Chebbo, 1992), (Michelbach and Wohrle, 1993) and (Tyack et al., 1993) are very different. In order to explain why the results are different and to quantify the influence of the experimental procedure on the settling velocity grading curves, we have compared the selected methods when tested with the same sample and we have studied the effects of the conservation of the sample before the test, of the concentration of solids in the device and of the nature of the water on the settling velocity profiles. The results of the comparative tests indicate that the settling velocities are significantly lower with both the Cergrene and Aston methods than with the UFT test procedure. Moreover, the study has shown that the settling characteristics of solids change with time, that the use of sewage liquor rather than demineralised water or drinking water can change the results of the measurement and that the higher the concentration of solids, the greater the velocity of settled particles.

Stereological assessment of extracellular polymeric substances, exo-enzymes, and specific bacterial strains in bioaggregates using fluorescence experiments

2010 ◽  
Vol 28 (2) ◽  
pp. 255-280 ◽  
Author(s):  
Sunil S. Adav ◽  
Justin Chun-Te Lin ◽  
Zhen Yang ◽  
Chris G. Whiteley ◽  
Duu-Jong Lee ◽  
...  
Keyword(s):  
Extracellular Polymeric Substances ◽  
Bacterial Strains

scholarly journals Emergence of a new salt-tolerant alien grass along roadsides? Occurrence of Diplachne fusca subsp. fascicularis (Poaceae) in Hungary

2021 ◽  
Vol 80 (2) ◽  
Author(s):  
Kristóf Süveges ◽  
Attila V. Molnár ◽  
Attila Mesterházy ◽  
Júlia Tüdősné Budai ◽  
Réka Fekete
Keyword(s):  
Salt Content ◽  
Rice Paddy ◽  
Salt Tolerant ◽  
The Road ◽  
Reproduction Strategy ◽  
Temporal And Spatial Variability ◽  
Nacl Concentration ◽  
Negative Effect ◽  
Hungarian Population ◽  
Paved Road

This paper reports the occurrence of a North American salt-tolerant taxon, Diplachne fusca subsp. fascicularis (Lam.) P.M.Peterson et N.Snow in Hungary (Central-Europe). Two earlier Hungarian observations of D. fusca were known from 1915, near Győr (West Transdanubia), later the taxon was collected by Pénzes in 1958, in downtown Budatétény (central Hungary. Both observations seem to be occasional. Recently, the taxon has started spreading in Europe, mainly on rice paddy fields, with a serious invasion potential. In North America its appearance on ruderal habitats, as well as along roads and other linear infrastructures is a well known phenomenon. The Hungarian population was found near Cegléd (Central Hungary) on the roadside of the E40 primary main road in September 2018. In July 2019 more than one thousand (mostly vegetative) individuals were detected. The salt content of the habitat shows remarkable temporal and spatial variability. At one meter distance from the edge of the paved road soil salt content was higher in spring (after the winter de-icing regime), than in autumn. Salt concentration was highest in the vicinity of the road, and decreased with increasing distance from it. Germination tests revealed a significant negative effect of NaCl concentration on germination rates, but germination occurred even on extremely saline substrates with 1.5% NaCl concentration. Considering its biology and reproduction strategy, the further spread of Diplachne fusca is highly presumable.

Polyhydroxyalkanoates

2020 ◽  
pp. 370-387 ◽  
Author(s):  
Javid A. Malik ◽  
Monika Bhadauria
Keyword(s):  
Drug Delivery ◽  
Heart Valves ◽  
Extracellular Polymeric Substances ◽  
Animal Health ◽  
Carbon Sources ◽  
Bacterial Strains ◽  
Chemical Derivatives ◽  
Recovery Processes ◽  
Heat Tolerant ◽  
Efficient Fermentation

Human dependence on number of chemicals or chemical derivatives has increased alarmingly. Among the commodity chemicals, plastics are becoming independent for our modern lifestyle, as the usage of plastics is increasing worryingly. However, these synthetic plastics are extremely persistent in nature and accumulate in the environment, thereby leading to serious ecological problems. So, to build our economy sustainably, a need of replacement is necessary. Biomaterials in terms of bioplastics are an anticipated option, being synthesized and catabolized by different organisms with myriad biotechnological applications. Polyhydroxyalkanoates (PHAs) are among such biodegradable bioplastics, which are considered as an effective alternative for conventional plastics due to their similar mechanical properties of plastics. A range of microbes under different nutrient and environmental conditions produce PHAs significantly with the help of enzymes. PHA synthases encoded by phaC genes are the key enzymes that polymerize PHA monomers. Four major classes of PHA synthases can be distinguished based on their primary structures, as well as the number of subunits and substrate specificity. PHAs can also be produced from renewable feedstock under, unlike the petrochemically derived plastics that are produced by fractional distillation of depleting fossil fuels. Polyhydroxybutyrate (PHB) is the simplest yet best known polyester of PHAs, as the PHB derived bioplastics are heat tolerant, thus used to make heat tolerant and clear packaging film. They have several medical applications such as drug delivery, suture, scaffold and heart valves, tissue engineering, targeted drug delivery, and agricultural fields. Genetic modification (GM) may be necessary to achieve adequate yields. The selections of suitable bacterial strains, inexpensive carbon sources, efficient fermentation, and recovery processes are also some aspects important aspects taken into consideration for the commercialization of PHA. PHA producers have been reported to reside at various ecological niches with few among them also produce some byproducts like extracellular polymeric substances, rhamnolipids and biohydrogen gas. So, the metabolic engineering thereafter promises to bring a feasible solution for the production of “green plastic” in order to preserve petroleum reserves and diminish the escalating human and animal health concerns environmental implications.

scholarly journals Inorganic Phosphate Solubilization by a Novel Isolated Bacterial Strain Enterobacter sp. ITCB-09 and Its Application Potential as Biofertilizer

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 383 ◽  
Author(s):  
Gustavo Enrique Mendoza-Arroyo ◽  
Manuel Jesús Chan-Bacab ◽  
Ruth Noemi Aguila-Ramírez ◽  
Benjamín Otto Ortega-Morales ◽  
René Efraín Canché Solís ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Inorganic Phosphate ◽  
Extracellular Polymeric Substances ◽  
Phosphate Solubilization ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
Habanero Pepper ◽  
Phosphate Solubilizing

The excessive use of fertilizers in agriculture is mainly due to the recognized plant requirements for soluble phosphorus. This problem has limited the implementation of sustainable agriculture. A viable alternative is to use phosphate solubilizing soil microorganisms. This work aimed to isolate inorganic phosphorus-solubilizing bacteria from the soils of agroecosystems, to select and identify, based on sequencing and phylogenetic analysis of the 16S rRNA gene, the bacterium with the highest capacity for in vitro solubilization of inorganic phosphate. Additionally, we aimed to determine its primary phosphate solubilizing mechanisms and to evaluate its effect on Habanero pepper seedlings growth. A total of 21 bacterial strains were isolated by their activity on Pikovskaya agar. Of these, strain ITCB-09 exhibited the highest ability to solubilize inorganic phosphate (865.98 µg/mL) through the production of organic acids. This strain produced extracellular polymeric substances and siderophores that have ecological implications for phosphate solubilization. 16S rRNA gene sequence analysis revealed that strain ITCB-09 belongs to the genus Enterobacter. Enterobacter sp. ITCB-09, especially when immobilized in beads, had a positive effect on Capsicum chinense Jacq. seedling growth, indicating its potential as a biofertilizer.

scholarly journals Diseño de un medio para la producción de un co-cultivo de bacterias fosfato solubilizadoras con actividad fosfatasa

2012 ◽  
Vol 17 (1) ◽  
pp. 43 ◽  
Author(s):  
Jimena Paola Angulo-Cortés ◽  
Anamaría García-Díaz ◽  
Aura Marina Pedroza ◽  
María Mercedes Martínez-Salgado ◽  
Viviana Gutiérrez-Romero
Keyword(s):  
Phosphatase Activity ◽  
Microbial Growth ◽  
Culture Media ◽  
Biomass Concentration ◽  
Soil Samples ◽  
Phosphate Solubilizing Bacteria ◽  
Bacterial Strains ◽  
Box Behnken Design ◽  
Phosphate Solubilizing ◽  
Complex Culture

<strong>Objective</strong>. To design a complex culture media for the production of biomass and acid phosphatases from phosphate-solubilizing bacteria isolated from soil. <strong>Materials</strong> <strong>and methods</strong>. Phosphate-solubilizing bacteria were isolated from oil palm crop soil samples and selected on SMRS1 agar, which were then assessed with antagonism tests to verify their aptitude to form a co-culture. A Box-Behnken experimental design was applied to<br />evaluate the effect of each one of the culture media components on the production of biomass and phosphatase enzymes at a laboratory scale. Finally, microbial growth and enzyme production curves were carried out in order to determine their production times. <strong>Results</strong>. Five phosphate-solubilizing bacterial strains were isolated and three of them were selected based on their solubilization indices.These Gram negative strains with bacillus morphology were identified as A, B and C; their solubilization indices were 2.03, 2.12, and 2.83, respectively. According to the ANOVA analyses for the Box-Behnken design, the only factor which had a significant effect on the phosphatase activity (p&lt;0.01) was hydrolyzed yeast, and the formulation that generated the highest biomass concentration and phosphatase activity (p&lt;0.01) contained 10, 15 and 2.5 gL-1 of phosphoric rock, sucrose and hydrolyzed yeast, respectively. After 24 hours of incubation at 100 rpm, the highest values of biomass and phosphatase activity were obtained: 11.8 logarithmic units of CFU and 12.9 phosphatase units. <strong>Conclusion</strong>. We determined that the culture media based on phosphoric rock 10 gL-1, hydrolyzed yeast 2.5 gL-1 and commercial sucrose 15 gL-1 was ideal for the production of biomass and phosphatases by the strains evaluated; likewise, we proved that the hydrolyzed yeast was the only factor significantly influential for the production of phosphatases.<br /><br /><strong>Key words</strong>: bio-inoculants, phosphate solubilizing microorganisms, phosphatase activity, Box Behnken design.

Some observations on the effects of accumulated benthic sludge on the behaviour of waste stabilisation ponds

2005 ◽  
Vol 51 (12) ◽  
pp. 217-226
Author(s):  
C.J. Banks ◽  
S. Heaven ◽  
E.A. Zotova
Keyword(s):  
Light Intensity ◽  
Dissolved Oxygen ◽  
Water Column ◽  
Suspended Solids ◽  
Biomass Concentration ◽  
Pilot Scale ◽  
Controlling Factor ◽  
Waste Stabilisation Ponds ◽  
Nutrient Levels ◽  
Complex Mechanisms

The effect of accumulated bottom sludge on water column characteristics was studied in two pilot-scale ponds. Parameters measured were ammonia, nitrate, phosphate, COD, suspended solids, dissolved oxygen (DO), temperature and light intensity. The de-sludged pond showed a stronger correlation between DO, light intensity, nutrients and suspended solids with the controlling factor being availability of nitrogen. This was less apparent in the pond with sludge where nutrient levels were higher and more complex mechanisms controlled biomass concentration. Water column characteristics in the two ponds converged rapidly in 7–10 weeks, however, due to accumulation of fresh sludge.

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