Comparison of Bioleaching Kinetics of Spent Catalyst by Adapted and Unadapted Iron & Sulfur Oxidizing Bacteria - Effect of Pulp Density; Particle Size; Temperature

2011 ◽  
Vol 49 (12) ◽  
Keyword(s):  
Particle Size ◽  
Pulp Density ◽  
Spent Catalyst ◽  
Iron Sulfur ◽  
Sulfur Oxidizing ◽  
Kinetics Of ◽  
Sulfur Oxidizing Bacteria

Bacterial Kinetics of Sulfur Oxidizing Bacteria and Their Biodeterioration Rates of Concrete Sewer Pipe Samples

2010 ◽  
Vol 136 (7) ◽  
pp. 731-738 ◽  
Author(s):  
Angela Bielefeldt ◽  
Ma. Guadalupe D. Gutierrez-Padilla ◽  
Serguei Ovtchinnikov ◽  
Joann Silverstein ◽  
Mark Hernandez
Keyword(s):  
Sewer Pipe ◽  
Sulfur Oxidizing ◽  
Kinetics Of ◽  
Sulfur Oxidizing Bacteria

scholarly journals Accelerated Biodegradation of Cement by Sulfur-Oxidizing Bacteria as a Bioassay for Evaluating Immobilization of Low-Level Radioactive Waste

2004 ◽  
Vol 70 (10) ◽  
pp. 6031-6036 ◽  
Author(s):  
Orli Aviam ◽  
Gabi Bar-Nes ◽  
Yehuda Zeiri ◽  
Alex Sivan
Keyword(s):  
Weight Loss ◽  
Sulfuric Acid ◽  
Radioactive Waste ◽  
Cement Matrix ◽  
Leaching Kinetics ◽  
Low Level ◽  
Sulfur Oxidizing ◽  
Kinetics Of ◽  
Low Level Radioactive Waste ◽  
Sulfur Oxidizing Bacteria

ABSTRACT Disposal of low-level radioactive waste by immobilization in cement is being evaluated worldwide. The stability of cement in the environment may be impaired by sulfur-oxidizing bacteria that corrode the cement by producing sulfuric acid. Since this process is so slow that it is not possible to perform studies of the degradation kinetics and to test cement mixtures with increased durability, procedures that accelerate the biodegradation are required. Semicontinuous cultures of Halothiobacillus neapolitanus and Thiomonas intermedia containing thiosulfate as the sole energy source were employed to accelerate the biodegradation of cement samples. This resulted in a weight loss of up to 16% after 39 days, compared with a weight loss of 0.8% in noninoculated controls. Scanning electron microscopy of the degraded cement samples revealed deep cracks, which could be associated with the formation of low-density corrosion products in the interior of the cement. Accelerated biodegradation was also evident from the leaching rates of Ca2+ and Si2+, the major constituents of the cement matrix, and Ca exhibited the highest rate (up to 20 times greater than the control rate) due to the reaction between free lime and the biogenic sulfuric acid. Leaching of Sr2+ and Cs+, which were added to the cement to simulate immobilization of the corresponding radioisotopes, was also monitored. In contrast to the linear leaching kinetics of calcium, silicon, and strontium, the leaching pattern of cesium produced a saturation curve similar to the control curve. Presumably, the leaching of cesium is governed by the diffusion process, whereas the leaching kinetics of the other three ions seems to governed by dissolution of the cement.

Bioleaching of Valuable Metals from Spent Catalyst Using Metabolic Citiric Acid by Aspergillus niger

2020 ◽  
Vol 898 ◽  
pp. 23-28
Author(s):  
Himawan Tri Bayu Murti Petrus ◽  
Hotden Manurung ◽  
Rivky Juarsa Aditya ◽  
Rifani Amanda ◽  
Widi Astuti
Keyword(s):  
Particle Size ◽  
Aspergillus Niger ◽  
Metal Recovery ◽  
Pulp Density ◽  
Spent Catalyst ◽  
Valuable Metal ◽  
Weak Organic Acid ◽  
Valuable Metals ◽  
Calcium Iron ◽  
Leaching Efficiency

Spent catalyst is listed as one of the hazardous wastes. Based on the toxicity characteristic shows that spent catalyst contains some heavy metals at concentration above the regulations limits. This situattion becomes an important issue in nowadays. In this research, fungus Aspergillus niger was investigated to produce weak organic acid (citric acid). Batch experiments were performed to compare the leaching efficiency from spent catalyst of pulp density (2% and 4%) and particle size (212 µm, 150 µm and 75 µm). Result showed that after direct bioleaching process, maximum recovery of valuable metal 24.94%, 7.42%, 1.09%, 3.51%, 4.87% and 1.66% were achieved for aluminum, calcium, iron, copper, silver and platinum respectively at 2% pulp density. Overall data shows that metal recovery at pulp density 2% are higher than 4% pulp density. The maximum recovery based on particle size shows that the smaller particle (75 µm) the higher metal recovery (Al, Ag and Pt) and for some metals was different such as Fe, Cu and Ca.

scholarly journals Vanadium removal from spent sulfuric acid plant catalyst using citric acid and Acidithiobacillus thiooxidans

2020 ◽  
Vol 20 (4) ◽  
Author(s):  
Bartosz Mikoda ◽  
Anna Potysz ◽  
Harry Kucha ◽  
Ewa Kmiecik
Keyword(s):  
Particle Size ◽  
Sulfuric Acid ◽  
Citric Acid ◽  
Acid Leaching ◽  
Copper Smelter ◽  
Pulp Density ◽  
Acidithiobacillus Thiooxidans ◽  
Acid Plant ◽  
Spent Catalyst ◽  
Sulfuric Acid Plant

Abstract Spent catalysts being considered hazardous wastes exhibit a high metal content in mobile forms. In addition, growing demand for circular economy policy applications requires proper utilization of these wastes. This study aimed at the assessment of vanadium leaching from spent desulfurization catalyst derived from sulfuric acid plant dump located nearby a copper smelter. Chemical and phase composition of the catalyst has been characterized. The extraction has been performed using chemical (0.1-M and 1-M citric acid) and biological (biotic solution with Acidithiobacillus thiooxidans) methods, using different experimental parameters (pulp density, particle size, leaching time) to observe V leaching behavior and kinetics. The results revealed that both citric acid and bacteria carried out the extraction process well. The optimal parameters for acid leaching were < 0.2-mm particle size and 2% pulp density, which allowed to leach out 95% of V from spent catalyst within 48 h. The bacterially mediated extraction resulted in 93% V leached out within 21 days with 2% pulp density. The experiments showed that V present in the catalyst is susceptible to bioleaching and organic acid leaching with the latter being a quicker process.

Flotation Desulfurization of High-Sulfur Bauxite with Ethyl Thio Carbamate as Collector

2011 ◽  
Vol 239-242 ◽  
pp. 1515-1519 ◽  
Author(s):  
Xiao Min Wang ◽  
Ting An Zhang
Keyword(s):  
Particle Size ◽  
Sulfur Content ◽  
Ph Value ◽  
Experimental Results ◽  
Pulp Density ◽  
Flotation Kinetics ◽  
Flotation Process ◽  
Flotation Agent ◽  
Kinetics Of

The desulfurization of high-sulfur diasporic bauxite （from China） with flotation process and ethyl thio carbamate as collector was studied, and the effects of flotation time, pulp density, pH value and particle size of ores were examined. The experimental results indicate that the sulfur in bauxite was successfully decreased through flotation. The sulfur content of bauxite was lowed to 0.66% under the condition of pH value 4, the dose of flotation agent ethyl thio carbamate 0.5kg/t, frother 20g/t, flotation time 15 minutes, pulp density 10%, the particle size of ores ≦0.09 mm, and the reclamation of Al2O3is 90.16% as well. The flotation kinetics of flotation desulfurization was also studied.

Effects of activated carbon on treatment of photo-processing waste by sulfur-oxidizing bacteria

1997 ◽  
Vol 35 (7) ◽  
pp. 187-195 ◽  
Author(s):  
Binle Lin ◽  
K. Futono ◽  
A. Yokoi ◽  
M. Hosomi ◽  
A. Murakami
Keyword(s):  
Activated Carbon ◽  
Treatment Effectiveness ◽  
Environmental Concern ◽  
Type Systems ◽  
Continuous Treatment ◽  
Processing Waste ◽  
Treatment Technology ◽  
Adsorption Effect ◽  
Sulfur Oxidizing ◽  
Sulfur Oxidizing Bacteria

Establishing economic treatment technology for safe disposal of photo-processing waste (PW) has most recently become an urgent environmental concern. This paper describes a new biological treatment process for PW using sulfur-oxidizing bacteria (SOB) in conjunction with activated carbon (AC). Batch-type acclimation and adsorption experiments using SOB/PAC, SOB/PNAC, and SOB reactor type systems demonstrated that AC effectively adsorbs the toxic/refractory compounds which inhibit thiosulfate oxidization of SOB in PW. Thus, to further clarify the effect of AC, we performed a long-term (≈ 160 d) continuous-treatment experiment on 4- to 8-times dilution of PW using a SOB/GAC system which simulated a typical wastewater treatment system based on an aerobic activated sludge process that primarily uses acclimated SOB. The thiosulfate load and hydraulic retention time (HRT) were fixed during treatment such that they ranged from 0.8-3.7 kg S2O32-/l/d and 7.7-1.9 d, respectively. As expected, continuous treatment led to breakthrough of the adsorption effect of GAC. Renewing the GAC and continuing treatment for about 10 d demonstrated good treatment effectiveness.

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