scholarly journals Treatment of benzene vapors from contaminated air stream in a laboratory-scale compost biofilter

2009 ◽  
Vol 28 (1) ◽  
pp. 119 ◽  
Author(s):  
Eldon R. Rene ◽  
D. V. S. Murthy ◽  
T. Swaminathan
Keyword(s):  
Gas Flow ◽  
Substrate Inhibition ◽  
Laboratory Scale ◽  
Treatment Technology ◽  
Porous Support ◽  
Waste Gas ◽  
Process Waste ◽  
Air Stream ◽  
High Concentrations ◽  
Filter Bed

Biofiltration of process waste–gas streams using microorganisms attached to porous support matrix, at low concentrations and high gas flow rates, has gained importance as a versatile treatment technology ever since the Clean Air Act Amendments (1990), by the US – EPA came into existence. In this study, we evaluated the potential of a laboratory–scale biofilter, inoculated with mixed culture, to remove gas–phase benzene from a synthetic waste gas stream. Experiments were conducted in three different phases, after the acclimatization step, corresponding to empty bed residence times (EBRT) varying between 0.81–2.45 min and benzene concentrations up to 1.7 g/m3. At high concentrations, significant reduction in removal efficiency was observed, which may be due to insufficient biomass in the filter bed to utilize the substrate, or due to substrate inhibition at high concentrations. Removal efficiencies higher than 90% were achieved for inlet benzene loading rates lesser than 40 g/m3hr.

scholarly journals RESEARCH ON THE ABILITY OF HANDLING AMMONIA CONTAMINATED AIR STREAM BY ACTIVATED CARBON MATERIALS FROM COCONUT FIBER (AC-1) AND PEANUT HUSK (AC-2), IMPREGNATED WITH ZnCl2

2018 ◽  
Vol 55 (4C) ◽  
pp. 38
Author(s):  
Nguyen Thi Kim Anh
Keyword(s):  
Activated Carbon ◽  
Removal Efficiency ◽  
Gas Flow ◽  
Carbon Materials ◽  
Ammonia Removal ◽  
Ammonia Emission ◽  
Inlet Concentration ◽  
Coconut Fiber ◽  
Waste Gas ◽  
Air Stream

This research aimed to investigate the ability of handling ammonia emission from waste gas by adsorption methods. The absorbents were activated carbon materials, which were made from coconut fiber (AC-1) and peanut husk (AC-2), impregnated with ZnCl2. Both of these materials have shown their abilities to remove NH3 (over 90 % efficiency) at the concentration of about 9000 ppm, while the removal efficiency of commercial activated carbon (AC-3) was 70 %. At the inlet concentration of about 3000 ppm, the maximum ammonia removal efficiency was 96.23 % when using AC-1 and 97.74 % using AC-2. The saturation time of each activated carbon was also examined. At inlet concentration of 2800 – 3200 ppm with gas flow rate was 0.4 L.min-1 and 5 g in mass material, the ammonia removal efficiencies of AC-1 and AC-2 were maintained at 80 % lasting for 600 minutes, but the efficiency of AC-3 rapidly decreased to 30 %. In all experiments, the activated carbon that made from peanut husk (AC-2), impregnated with ZnCl2 showed higher performance than one made from coconut fiber (AC-1) and commercial activated carbon (AC-3).

scholarly journals Diseminasi Hasil Riset Anti Mikroba Alami Berbasis Pemanfaatan Limbah Kulit Buah Menjadi Hand Sanitizer Di Sentra Industri Keripik Pisang

2020 ◽  
Vol 4 (4) ◽  
pp. 655-660
Author(s):  
Dewi Sartika ◽  
Susilawati ◽  
Neti Yuliana
Keyword(s):  
Waste Treatment ◽  
Percentage Increase ◽  
Liquid Soap ◽  
Treatment Technology ◽  
Waste Products ◽  
Liquid Fertilizer ◽  
Research Results ◽  
Hand Sanitizer ◽  
Process Waste ◽  
Dissemination Of Research

The Center for Home Industry chips on Bandar Lampung. The problem of this is the waste that has not been managed properly, the chip waste IRT waste in the form of fruit peels, leaves, fruit stalks, humps has the potential to be made of high-selling value products, diversification can be in the form of hand sanitizer products. The purpose of this activity is to solve the Partner's problem by disseminating research results in the form of transfer of waste treatment technology into a hand sanitizer. The method used is lectures and discussions on the dissemination of research results, assistance in processing wastewater into hand sanitizer products. The need for partners to process waste products into products that have value in the form of making herbal solid soap, followed by liquid soap, hand sanitizer, natural anti-microbial, feed making, composting and liquid fertilizer. The percentage increase in knowledge and understanding of the material after the service activities is the utilization of waste (40%), making feed (50%), making hand sanitizer (70%).

scholarly journals Biosynthesis of Zinc Sulfide Quantum Dots Using Waste Off-Gas from Metal Bioremediation Process

2015 ◽  
Vol 1130 ◽  
pp. 555-559
Author(s):  
Jimmy Roussel ◽  
A.J. Murray ◽  
John Rolley ◽  
D. Barrie Johnson ◽  
L.E. Macaskie
Keyword(s):  
Quantum Dots ◽  
Zinc Sulfide ◽  
Mine Drainage ◽  
Electronic Band ◽  
Light Emitting ◽  
Waste Gas ◽  
Sulfate Reducing ◽  
Relaxation Phase ◽  
Process Waste ◽  
Reducing Bacteria

Dissimilatory reduction of sulfate, mediated by various species of sulfate-reducing bacteria (SRB), can be used to remediate acid mine drainage (AMD). Hydrogen sulfide (H2S/HS-) generated by SRB can be used to remove toxic metals from AMD as sulfide biominerals. For this, SRB are usually housed in separate reactor vessels to those where metal sulfides are generated; H2S is delivered to AMD-containing vessels in solution or as a gas. This allows more controlled separation of metal precipitation and facilitates enhanced process control. Industries such as optoelectronics use quantum dots (QDs) in, for example, light emitting diodes and solar photovoltaics. QDs are nanocrystals with semiconductor bands that allow them to absorb light and re-emit it intensely at specific wavelength couples. Small nanoparticles have the possibility to get electrons shifted to a higher energy and then emit light during the relaxation phase. The QD elemental composition and the presence of doping agent determines its electronic band gaps and can be used to tune the QD to desired emission wavelengths. Traditional QD production at scale is costly and/or complex. Waste H2S gas from growth of SRB has been used to make zinc sulfide QDs which are indistinguishable from ’classically’ prepared counterparts with respect to their physical and optical properties. Clean recycling of minewater bioremediation process waste gas into high value QD product is described.

scholarly journals Removal of High Concentrations of Ammonium from Groundwater in a Pilot-Scale System through Aeration at the Bottom Layer of a Chemical Catalytic Oxidation Filter

2019 ◽  
Vol 16 (20) ◽  
pp. 3989 ◽  
Author(s):  
Zhang ◽  
Zhang ◽  
Yang ◽  
Huang ◽  
Wen
Keyword(s):  
Catalytic Oxidation ◽  
Bottom Layer ◽  
Pilot Scale ◽  
Compressed Air ◽  
Pure Oxygen ◽  
Limiting Factor ◽  
Ammonium Removal ◽  
Catalytic Filter ◽  
High Concentrations ◽  
Filter Bed

To remove high concentrations of ammonium from groundwater, pure oxygen and compressed air were fed into a chemical catalytic filter and the ammonium removal efficiency was investigated. The experimental results showed that the oxygen content is the critical limiting factor for ammonium removal. Aeration with 40 mL/min pure oxygen or 100 mL/min compressed air from the bottom of the filter supplied adequate oxygen and approximately 4.2 mg/L of ammonium was removed in this process. Moreover, when the aeration device was moved to 1/3 of the height of the filter bed, the required flow rates of pure oxygen and compressed air decreased further and the turbidity removal was improved. Pouring ozone gas into the filter system, which can inactivate bacteria effectively, can also obtain the remarkable ammonium removal, indicating that ammonium removal was mainly due to the chemical catalytic oxidation in this process rather than the biodegradation. This study provides a novel method for removing high concentrations of ammonium from groundwater.

scholarly journals Influence of Pressure on Gas/Liquid Interfacial Area in a Tray Column

2020 ◽  
Vol 10 (13) ◽  
pp. 4617
Author(s):  
Adel Almoslh ◽  
Falah Alobaid ◽  
Christian Heinze ◽  
Bernd Epple
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Volumetric Flow Rate ◽  
Interfacial Area ◽  
Gas Flow Rate ◽  
Test Rig ◽  
Flow Rates ◽  
Waste Gas ◽  
Simulated Waste ◽  
Series Of Experiments

The influence of pressure on the gas/liquid interfacial area is investigated in the pressure range of 0.2–0.3 MPa by using a tray column test rig. A simulated waste gas, which consisted of 30% CO2 and 70% air, was used in this study. Distilled water was employed as an absorbent. The temperature of the inlet water was 19 °C. The inlet volumetric flow rate of water was 0.17 m3/h. Two series of experiments were performed; the first series was performed at inlet gas flow rate 15 Nm3/h, whereas the second series was at 20 Nm3/h of inlet gas flow rate. The results showed that the gas/liquid interfacial area decreases when the total pressure is increased. The effect of pressure on the gas/liquid interfacial area at high inlet volumetric gas flow rates is more significant than at low inlet volumetric gas flow rates. The authors studied the effect of decreasing the interfacial area on the performance of a tray column for CO2 capture.

Flow Field Simulation in Water Washing Tank of Explosion-Proof Diesel

2014 ◽  
Vol 989-994 ◽  
pp. 3456-3459
Author(s):  
Ri Sheng Long ◽  
Zi Sheng Lian ◽  
Shao Ni Sun ◽  
Qi Liang Wang
Keyword(s):  
Flow Field ◽  
Flow Condition ◽  
Gas Flow ◽  
Outlet Temperature ◽  
Flow Field Simulation ◽  
Design And Optimization ◽  
Waste Gas ◽  
Future Design ◽  
Water Washing ◽  
Field Simulation

In order to improve the cooling & purifying effect of exhaust, reducing the water-jetting phenomenon during working time, the waste-gas flow field simulation in water-washing tank of Explosion-Proof Diesel (EPD) was conducted through ANSYSCFX/Fluent. The results revealed the inner flow condition and outlet temperature of emissions in water-washing tank. It provided a reference for the future design and optimization of the water-washing tank of EPD.

Biodegradation of Styrene Vapor in a Biofilter

2013 ◽  
Vol 275-277 ◽  
pp. 2329-2332 ◽  
Author(s):  
Xian Sheng Huang ◽  
Hao Wu
Keyword(s):  
Gas Flow ◽  
Experimental Investigations ◽  
Flow Rates ◽  
Operational Conditions ◽  
New Class ◽  
Filter Materials ◽  
Air Stream ◽  
Volatile Organic ◽  
Maximum Elimination Capacity ◽  
Styrene Removal

Volatile organic compounds (VOCs) are a new class of air pollutants posing threat to the environment. Newer technologies are being developed for their control among which biofiltration seem to be most attractive. Biofiltration of styrene vapor from air stream was discussed in this study. Experimental investigations were conducted on a laboratory scale biofilter, containing mixture of compost and polystyrene inert particles as the filter materials. Mixed consortium of activated sludge was used as an inoculum. The continuous performance of biofilter for styrene removal was monitored for different concentrations and flow rates. The removal efficiencies decreased at higher concentrations and higher gas flow rates. A maximum elimination capacity of 85g/(m3•h) was achieved. The response of biofilter to upset loading operation showed that the biofilm in the biofilters was quite stable and quickly adapted to adverse operational conditions.

The type IV pilus assembly motor PilB is a robust hexameric ATPase with complex kinetics

2018 ◽  
Vol 475 (11) ◽  
pp. 1979-1993 ◽  
Author(s):  
Andreas Sukmana ◽  
Zhaomin Yang
Keyword(s):  
Atpase Activity ◽  
Enrichment Culture ◽  
Physiological State ◽  
Substrate Inhibition ◽  
Kinetic Studies ◽  
Enzyme Analysis ◽  
Type Iv Pilus ◽  
Type Iv ◽  
High Concentrations

The bacterial type IV pilus (T4P) is a versatile nanomachine that functions in pathogenesis, biofilm formation, motility, and horizontal gene transfer. T4P assembly is powered by the motor ATPase PilB which is proposed to hydrolyze ATP by a symmetrical rotary mechanism. This mechanism, which is deduced from the structure of PilB, is untested. Here, we report the first kinetic studies of the PilB ATPase, supporting co-ordination among the protomers of this hexameric enzyme. Analysis of the genome sequence of Chloracidobacterium thermophilum identified a pilB gene whose protein we then heterologously expressed. This PilB formed a hexamer in solution and exhibited highly robust ATPase activity. It displays complex steady-state kinetics with an incline followed by a decline over an ATP concentration range of physiological relevance. The incline is multiphasic and the decline signifies substrate inhibition. These observations suggest that variations in intracellular ATP concentrations may regulate T4P assembly and T4P-mediated functions in vivo in accordance with the physiological state of bacteria with unanticipated complexity. We also identified a mutant pilB gene in the genomic DNA of C. thermophilum from an enrichment culture. The mutant PilB variant, which is significantly less active, exhibited similar inhibition of its ATPase activity by high concentrations of ATP. Our findings here with the PilB ATPase from C. thermophilum provide the first line of biochemical evidence for the co-ordination among PilB protomers consistent with the symmetrical rotary model of catalysis based on structural studies.

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