scholarly journals Bioremediation of Aquaculture Wastewater with Algal-Bacterial Biofilm Combined with the Production of Selenium Rich Biofertilizer

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2071 ◽  
Author(s):  
Wei Han ◽  
Yufeng Mao ◽  
Yunpeng Wei ◽  
Peng Shang ◽  
Xu Zhou
Keyword(s):  
Removal Rate ◽  
Growth Period ◽  
Dry Weight ◽  
Bacterial Biofilm ◽  
Biofilm Growth ◽  
Weight Density ◽  
Removal Capacity ◽  
Batch Tests ◽  
Effective Removal ◽  
Aquaculture Wastewater

The discharge of aquaculture wastewater and the excessive selenium in aquaculture effluent caused by selenium addition to aquatic feed are posing a serious risk for the marine environment. In this study, batch tests were carried out to investigate the feasibility of utilizing algal–bacterial biofilm for the treatment of selenium-rich aquaculture wastewater. The effects of four different types of commercial biofilm carriers on the attached growth of biofilms and the contaminant removal capacity were examined. The braided cotton biofilm carrier had the best performance on biofilm growth, while in an exponential growth period the dry weight density of the biofilm was above 2.0 g L−1. By utilizing the braided cotton carrier with a hydraulic retention time (HRT) of 6 days, the removal rate of N and P from the raw aquaculture wastewater was 88.5 ± 6.2% and 99.8 ± 0.2%, respectively. After that, the effects of different initial wastewater load ratios (IWLR) and HRT on the effluent quality of the treatment process were studied. The decrease in IWLR and the extension of HRT could improve the treatment performance. The effluent N, P and Se concentrations in the group with 50% IWLR and 6-day HRT were 0.75 ± 0.10 mg L−1, 0.015 ± 0.02 mg L−1, 35.2 ± 3.2 μg L−1, respectively, indicating an effective removal of the main contaminants. The algal–bacterial biofilm harvested from the batch test was rich in N, P and Se, where the Se content was 21.8 ± 3.4 mg kg−1, which has the potential to be used as an Se-rich biofertilizer.

scholarly journals Simultaneous Adsorption and Degradation of Cr(VI) and Cd(II) Ions from Aqueous Solution by Silica-Coated Fe0Nanoparticles

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yongchao Li ◽  
Hongpu Ma ◽  
Bozhi Ren ◽  
Tielong Li
Keyword(s):  
Aqueous Solution ◽  
Active Site ◽  
Removal Rate ◽  
Core Shell ◽  
Simultaneous Removal ◽  
Stöber Method ◽  
Removal Capacity ◽  
Batch Tests ◽  
One Step ◽  
Modified Stöber Method

Core-shell silica-coated Fe0nanoparticles (Fe@SiO2) were prepared in one-step synthesis by aqueous reduction combined with modified Stöber method. The as-prepared Fe@SiO2were then used for simultaneous removal of Cr(VI) and Cd(II) from aqueous solution. Batch tests indicated that Fe@SiO2exhibited high removal capacity toward Cr(VI) and Cd(II). Cr(VI) was removed by Fe@SiO2through reduction rather than adsorption, while Cd(II) removal was mainly through adsorption. The removal rate increased with increasing initial Fe NPs dose and decreased with increasing initial Cr(VI) and Cd(II) concentrations. Cd(II) adsorption was also strengthened by Cr(VI) reduction with the release of OH−. The removals of Cr(VI) and Cd(II) were weakened in the presence of cations or humic acid, as a result of aggregation and less active site of Fe@SiO2. Overall, the simply prepared Fe@SiO2were potential material for the heavy metals removed from water.

Relations between carbon removal rates, biofilm size and density of a novel anaerobic reactor: the inverse turbulent bed

2000 ◽  
Vol 41 (4-5) ◽  
pp. 253-260 ◽  
Author(s):  
P. Buffière ◽  
R. Moletta
Keyword(s):  
Removal Rate ◽  
Removal Rates ◽  
Carbon Removal ◽  
Biofilm Growth ◽  
Loading Rates ◽  
Biomass Activity ◽  
High Turbulence ◽  
The One ◽  
High Level ◽  
Very High

An anaerobic inverse turbulent bed, in which the biogas only ensures fluidisation of floating carrier particles, was investigated for carbon removal kinetics and for biofilm growth and detachment. The range of operation of the reactor was kept within 5 and 30 kgCOD· m−3· d−1, with Hydraulic Retention Times between 0.28 and 1 day. The carbon removal efficiency remained between 70 and 85%. Biofilm size were rather low (between 5 and 30 μm) while biofilm density reached very high values (over 80 kgVS· m−3). The biofilm size and density varied with increasing carbon removal rates with opposite trends; as biofilm size increases, its density decreases. On the one hand, biomass activity within the reactor was kept at a high level, (between 0.23 and 0.75 kgTOC· kgVS· d−1, i.e. between 0.6 and 1.85 kgCOD·kgVS · d−1).This result indicates that high turbulence and shear may favour growth of thin, dense and active biofilms. It is thus an interesting tool for biomass control. On the other hand, volatile solid detachment increases quasi linearly with carbon removal rate and the total amount of solid in the reactor levels off at high OLR. This means that detachment could be a limit of the process at higher organic loading rates.

Bifunctional Composites for Biofilms Modulation on Cervical Restorations

2021 ◽  
pp. 002203452110181
Author(s):  
A.A. Balhaddad ◽  
I.M. Garcia ◽  
L. Mokeem ◽  
M.S. Ibrahim ◽  
F.M. Collares ◽  
...  
Keyword(s):  
Free Energy ◽  
Surface Free Energy ◽  
Contact Angles ◽  
Bacterial Biofilm ◽  
Dental Composite ◽  
Log P ◽  
Rrna Gene ◽  
Cervical Lesions ◽  
Biofilm Growth ◽  
Biofilm Development

Cervical composites treating root carious and noncarious cervical lesions usually extend subgingivally. The subgingival margins of composites present poor plaque control, enhanced biofilm accumulation, and cause gingival irritation. A potential material to restore such lesions should combine agents that interfere with bacterial biofilm development and respond to acidic conditions. Here, we explore the use of new bioresponsive bifunctional dental composites against mature microcosm biofilms derived from subgingival plaque samples. The designed formulations contain 2 bioactive agents: dimethylaminohexadecyl methacrylate (DMAHDM) at 3 to 5 wt.% and 20 wt.% nanosized amorphous calcium phosphate (NACP) in a base resin. Composites with no DMAHDM and NACP were used as controls. The newly formulated 5% DMAHDM–20% NACP composite was analyzed by micro-Raman spectroscopy and transmission electron microscopy. The wettability and surface-free energy were also assessed. The inhibitory effect on the in vitro biofilm growth and the 16S rRNA gene sequencing of survival bacterial colonies derived from the composites were analyzed. Whole-biofilm metabolic activity, polysaccharide production, and live/dead images of the biofilm grown over the composites complement the microbiological assays. Overall, the designed formulations had higher contact angles with water and lower surface-free energy compared to the commercial control. The DMAHDM-NACP composites significantly inhibited the growth of total microorganisms, Porphyromonas gingivalis, Prevotella intermedia/nigrescens, Aggregatibacter actinomycetemcomitans, and Fusobacterium nucleatum by 3 to 5-log ( P < 0.001). For the colony isolates from control composites, the composition was typically dominated by the genera Veillonella, Fusobacterium, Streptococcus, Eikenella, and Leptotrichia, while Fusobacterium and Veillonella dominated the 5% DMAHDM–20% NACP composites. The DMAHDM-NACP composites contributed to over 80% of reduction in metabolic and polysaccharide activity. The suppression effect on plaque biofilms suggested that DMAHDM-NACP composites might be used as a bioactive material for cervical restorations. These results may propose an exciting path to prevent biofilm growth and improve dental composite restorations’ life span.

Coumarin Content and Physicochemical Profile of Mikania laevigata Extracts

2004 ◽  
Vol 59 (3-4) ◽  
pp. 197-200 ◽  
Author(s):  
Maique W. Biavatti ◽  
Cesar A. Koerich ◽  
Carlos H. Henck ◽  
Enderson Zucatelli ◽  
Fernanda H. Martineli ◽  
...  
Keyword(s):  
Efficient Method ◽  
Extraction Method ◽  
Dry Weight ◽  
Southern Brazil ◽  
Weight Density ◽  
Ethanol Content ◽  
Mikania Laevigata ◽  
Method Of Extraction

The ‘guaco’ lianous herb Mikania laevigata, which is widespread in Southern Brazil, is traditionally used to treat bronchitis, asthma and cough. This work investigates the influence of the extraction method, solvent:drug ratio, ethanol proportion, harvest season (summer or winter) and solvent heating on the physicochemical profile of the extracts (dry weight, density, pH) and the coumarin (1,2-benzopyrone) content determined by LC. Among the results obtained, it is observed that higher ethanol content increases the amount of coumarin in the extract. Leaves harvested in summer also produce an extract with a high coumarin yield. The most efficient method of extraction is percolation, independent of the solvent used.

Nitrogen, Phosphorus and Water Contents During Grain Development and Maturation in Wheat

1977 ◽  
Vol 4 (5) ◽  
pp. 799 ◽  
Author(s):  
I Sofield ◽  
IF Wardlaw ◽  
LT Evans ◽  
SY Zee
Keyword(s):  
Grain Growth ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Growth Period ◽  
Calcium Content ◽  
Dry Weight ◽  
Water Entry ◽  
Grain Development ◽  
Nitrogen And Phosphorus ◽  
Steady Rate

Plants of five cultivars of wheat were grown under controlled-environmental conditions in order to analyse the effect of cultivar and of temperature and illuminance after anthesis on the accumulation of nitrogen and phosphorus by grains in relation to dry matter. The water relations of the grain during maturation were also examined, using calcium content as an index of water entry. The nitrogen and phosphorus contents of grains increased linearly throughout the grain growth period. The percentage of nitrogen and phosphorus in grains fell sharply during the first few days after anthesis but rose progressively thereafter. The higher the temperature, and the lower the illuminance, the higher was the percentage of nitrogen in the grain of all cultivars. Such conditions also reduce final grain size, but their effects on nitrogen concentration in the grain were apparent early in grain development. No evidence was found of a flush of nitrogen or phosphorus into the grain late in its development. Water entry into the grain continued at a steady rate until maximum grain dry weight was reached, then ceased suddenly. No evidence was found of an increased rate of water loss by the grain at that stage, and the rapid fall in water content at the cessation of grain growth may have been due to blockage of the chalazal zone of entry into the grain by the deposition of lipids. Accumulation of dry matter, nitrogen and phosphorus and entry of water into the grain all ceased at the time of lipid deposition in the chalazal zone.

scholarly journals Increasing the Growth and Quality of Red Chili with Growth Hormone from Endophytic Bacteria

2019 ◽  
Vol 15 (2) ◽  
pp. 75
Author(s):  
Rafika Yuniawati ◽  
Siti Fatimah ◽  
Reni Indrayanti ◽  
Ifa Manzila ◽  
Tri Puji Priyatno ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Foliar Spray ◽  
Growth Period ◽  
Dry Weight ◽  
Positive Control ◽  
Fruit Weight ◽  
Growth Hormones ◽  
Synthetic Hormones ◽  
Potential Test

<p>Red chili is a very important horticultural commodity in Indonesia having low productivity and quality. Cultivation method needs to be improved including the use of exogenous growth hormones. The purpose of this study was to determine (1) the optimum concentration of IAA and GA growing hormones from isolate B6.2 in stimulating plant growth and improving the quality of large red chili fruit; (2) molecular identity of the B6.2 bacterial isolate. The growth hormone content of B6.2 isolates using HPLC obtained 0.49 ppm IAA and 64.53 ppm GA. The growth hormone potential test on the growth and quality of chili was carried out with a concentration of 1, 3, 5 ml/l, while water and synthetic hormones was used as negative and positive control, respectively. The experimental design used was a Complete Random Design with the foliar spray application to the plant canopy three times during the growth period. The results showed the best concentration in increasing plant height, fruit weight, shooth wet, and dry weight compared to controls at the age of 76 days after planting (dap) was a concentration of 5 ml/l, with the values of 71.7±0.9 cm , 94.7±0.3 g, 11.5±0.43 g, and 1.4±0.09 g, respectively. The molecular identification showed that B6.2 isolate was classified as Bacillus vallismortis with 100% homology. The growth hormone from isolate B6.2 has the potential to increase growth and production of red chili plants.</p>

scholarly journals Effect of electrode material on removal efficiency regarding single discharges in wire EDM

2021 ◽  
Author(s):  
Lukas Welschof ◽  
Niklas Schäfer ◽  
Tim Herrig ◽  
Andreas Klink ◽  
Thomas Bergs
Keyword(s):  
Removal Efficiency ◽  
Electrical Discharge Machining ◽  
Removal Rate ◽  
Continuous Process ◽  
Wire Edm ◽  
Procedural Understanding ◽  
Decisive Importance ◽  
Effective Removal ◽  
Coated Wires ◽  
The Individual

AbstractFor the precise machining of demanding materials, wire electrical discharge machining (WEDM) is a flexible and often irreplaceable manufacturing process. In order to enhance productivity as the main focus of the wire EDM process, the advancement of the fundamental procedural understanding is of decisive importance. In order to be able to energetically evaluate the removal process, the individual energetic contributors of the process hence the individual discharges need to be understood in terms of their contribution to material removal. In this paper, an experimental setup is presented, which permits the generation of individual discharges on a modern industrial wire EDM machine tool. For three different wire electrodes, the correlation of the discharge energy and the individual removal volume is quantitatively described, showing that coated wires achieve a significantly higher energy-specific removal. Furthermore the removal efficiency is defined as a key figure to transfer the findings to the continuous process and compare theoretical and effective removal rate.

Biological treatment characteristics of benzene and toluene in a biofilter packed with cylindrical activated carbon

2002 ◽  
Vol 46 (11-12) ◽  
pp. 51-56 ◽  
Author(s):  
G.-W. Li ◽  
H.-Y. Hu ◽  
J.-M. Hao ◽  
H.-Q. Zhang
Keyword(s):  
Carbon Dioxide ◽  
Activated Carbon ◽  
Gas Flow ◽  
Removal Rate ◽  
Carbon Dioxide Concentration ◽  
Organic Load ◽  
Filler Materials ◽  
Removal Capacity ◽  
Bacillus Spore ◽  
Maximum Removal

The biodegradation of toluene and benzene in a biofilter using cylindrical activated carbon as the filler materials was studied. Three gas flow rates, i.e. 0.25, 0.50 and 0.75 m3/h, corresponding to empty bed gas residence of 75, 37.5 and 25 s, respectively, and total organic load lower than 400 g/m3.h were tested. The biofilter proved to be highly efficient in biodegradation of toluene and benzene, and toluene was more easily degraded than benzene. When each inlet load was lower than 150 g/m3.h, removal rate increased with inlet load and reached a maximum, which was 150 and 120 g/m−3.h for toluene and benzene, respectively. For inlet load higher than the maximum removal capacity conditions, the removal rate decreased with inlet load. Carbon dioxide concentration profile through the biofilter revealed that the mass ratios of carbon dioxide produced to the toluene and benzene removed were 2.15 g(CO2)/g(toluene) and 1.67 g(CO2)/g(benzene), which furthermore, confirmed the biodegradation performance in biofilter. The observation of biotic community demonstrated that the microbes consisted of bacillus, spore bacillus and fungi, of which the spore bacillus was dominant.

scholarly journals Bioremoval of Different Heavy Metals by the Resistant Fungal StrainAspergillus niger

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Ismael Acosta-Rodríguez ◽  
Juan F. Cárdenas-González ◽  
Adriana S. Rodríguez Pérez ◽  
Juana Tovar Oviedo ◽  
Víctor M. Martínez-Juárez
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Aspergillus Niger ◽  
Fungal Biomass ◽  
Dry Weight ◽  
Removal Capacity ◽  
Removal Of Heavy Metals ◽  
The Ideal

The objective of this work was to study the resistance and removal capacity of heavy metals by the fungusAspergillus niger. We analyzed the resistance to some heavy metals by dry weight and plate: the fungus grew in 2000 ppm of zinc, lead, and mercury, 1200 and 1000 ppm of arsenic (III) and (VI), 800 ppm of fluor and cobalt, and least in cadmium (400 ppm). With respect to their potential of removal of heavy metals, this removal was achieved for zinc (100%), mercury (83.2%), fluor (83%), cobalt (71.4%), fairly silver (48%), and copper (37%). The ideal conditions for the removal of 100 mg/L of the heavy metals were 28°C, pH between 4.0 and 5.5, 100 ppm of heavy metal, and 1 g of fungal biomass.

scholarly journals Oral streptococci growth on aging and non-aging esthetic restorations after radiotherapy

2010 ◽  
Vol 21 (4) ◽  
pp. 346-350 ◽  
Author(s):  
Adriana D. da Cruz ◽  
Karina Cogo ◽  
Cristiane de C. Bergamaschi ◽  
Frab N. Bóscolo ◽  
Francisco C. Groppo ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Bacterial Biofilm ◽  
Oral Streptococci ◽  
Restorative Material ◽  
Biofilm Growth ◽  
Aged Group ◽  
Dental Resins ◽  
Colony Forming Units ◽  
Therapeutic Doses ◽  
Therapeutic Irradiation

The aim of this study was to examine Streptococcus mutans biofilm growth on both aged and non-aged restorative dental resins, which were submitted to therapeutic irradiation. Sixty-four disks of an esthetic restorative material (Filtek Supreme) were divided into 2 groups: aged group (AG) and a non-aged group (NAG). Each group was subdivided into 4 subgroups: non-irradiated and irradiated with 10Gy, 35Gy, and 70Gy. The biofilms were produced by Streptococcus mutans UA159 growing on both AG and NAG surfaces. The colony-forming units per mL (CFU/mL) were evaluated by the ANOVA and the Tukey LSD tests (α=0.05). AG presented smaller amounts of CFU/mL than the NAG before irradiation and after 10Gy of irradiation (p<0.05). AG irradiated with 35 and 70Gy showed increased amount of bacterial biofilm when compared to non-irradiated and 10Gy-irradiated disks (p<0.05). The exposure to ionizing radiation at therapeutic doses promoted changes in bacterial adherence of aged dental restorative material.

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