Pilot-scale Process Research Articles

Pellet layering: scale-up considerations using different kinds of processing equipment

Objective: In this study an aqueous suspension of poorly water-soluble HCT (hydrochlorothiazide) was layered on small spherical starter cores with a drug content in the final pellets of 30%. The aim was to compare different kinds of processing equipment (Wurster fluid-bed, CPS rotor fluid-bed and drum coater) in view of process efficiency, process duration and feasibility to scale-up.Results: In a pilot scale drum coater, it was possible to achieve the desired LE (layering efficiency) and yield specifications (both >95%), but the process duration was at least 202 min. In the small scale Wurster fluid-bed machine, it was possible to reduce the process time for an optimized process from 67 min to 41 min. However, the acceleration of the process led to an increase of agglomerates and the same process took at least 114 min in the scale-up experiments. A small scale CPS rotor processor with a cone-shaped disc was superior to the conventional planar rotor disc design, regarding yield and agglomerates. This rotor process was both, fast and highly efficient (yield: 98.4%; LE: 99.3%). The high quality of the process was also observed for the pilot scale batches, in which neither considerable losses of drug (LE ≥ 98.6%) nor formation of agglomerates occurred. The absolute spray rate in this pilot scale process was 85 kg/h.Conclusion: Best results were achieved with the CPS rotor technology. With a duration of 29 min (small scale) and 44 min (pilot scale) it was the fastest option to produce layered pellets.

Evaluation of Solar Energy for Processing Aloe Secundiflora Sap into Paste Using Parabolic Solar Concentrating Technology

This paper presents an alternative method of processing Aloe secundiflora sap into paste using solar concentrat- ing technology. Local communities living in arid and semi-arid areas of Kenya and other African countries harvest A. secundiflora sap and process it into paste for export and local use by boiling using traditional 3-stone cooking stoves. Consequences of these activities have led to widespread deforestation and environmental degradation. The study focused on establishing the effectiveness of solar concentrating technology in processing A. secundiflora sap into paste and ascertaining the effect of environmental parameters on processing. Optimum processing temperature, processing time, cooker efficiency, yield and quality of the resultant paste were also investigated. Results showed that absorber and pot content temperatures and solar radiation significantly affected the heating time. It was established that optimum process- ing temperature ranged from 90-100 o C, giving an average overall heat transfer coefficient of 17.40W/m 2 K under clear sky conditions. Results demonstrated that solar concentrating technology had great potential in processing A. secundiflora sap into paste, which is a stable, portable and value added product. In the longer term, using solar energy to substitute fu- elwood energy would contribute to reduced deforestation, environmental degradation, global warming and climate change. It would also improve biodiversity conservation and reduce the burden on women and children associated with collecting and transporting fuelwood. As a follow-up to this study, an elliptical parabolic solar concentrator was installed at Kinango in the semi-arid Kinango District, Coast Province of Kenya for pilot-scale processing of A. secundiflora sap by a local women group.

Catalytic dehydration of bioethanol to ethylene: Pilot-scale studies and process simulation

Process of bioethanol dehydration to ethylene over alumina-based catalyst in tubular fixed bed reactor was studied both experimentally and numerically. Kinetic studies were carried out to determine the reaction network, to estimate the parameters of the kinetic model and to find the optimal conditions that provide the maximal ethylene yield in the reaction of bioethanol dehydration. Pilot scale studies and process simulation were carried out to determine the optimal technological regimes in a single catalyst tube as an element of a multi-tubular reactor. The optimal characteristics and process parameters of industrial tubular fixed bed reactor for ethylene production from bioethanol at capacity of 60,000 TPA have been determined.

Broiler genetic strain and sex effects on meat characteristics

A randomized complete block design within a factorial arrangement of treatments was used to evaluate the effect of strain and sex on carcass characteristics, meat quality, and sensory acceptability. Two broiler strains were reared: a commercially available strain (strain A) and a strain currently in the test phase (strain B) that has been genetically selected to maximize breast yield. Broilers were harvested in a pilot scale processing plant using commercial prototype equipment at 42 d of age. Carcasses were deboned at 4 h postmortem. The left half of each breast was evaluated for pH, color, cooking loss, shear force, and proximate analysis. The right side of each breast was used for consumer acceptability testing. Thigh meat was evaluated for proximate composition. No interactions were observed throughout the study. Male broilers had a higher (P < 0.05) live BW, carcass weight, and breast weight and lower (P < 0.05) dressing percentage and breast meat yield when compared with females. Broilers from strain B presented a higher (P < 0.05) breast yield and dressing percentage than those broilers corresponding to the commercially available broiler strain. At 24 h postmortem, female broilers presented a lower ultimate pH and higher Commission internationale de l'éclairage yellowness values (ventral side of the pectoralis major) when compared with male broilers. On average, no differences existed (P > 0.05) among treatments with respect to pH decline, cooking loss, shear values, and proximate composition. In addition, no differences (P > 0.05) existed among breast meat from the different strains with respect to consumer acceptability of appearance, texture, flavor, and overall acceptability, but breast meat from strain B was slightly preferred (P < 0.05) over that of strain A with respect to aroma. However, breast meat from both strains received scores in the range of “like slightly to like moderately.” Overall data suggest that all treatments yielded high quality breast and thigh meat and strain cross did not present variability in terms of consumer acceptability.

Bayesian methods for control loop diagnosis in the presence of temporal dependent evidences

Conventional Bayesian methods commonly assume that the evidences are temporally independent. This condition, however, does not hold for most engineering problems. With the evidence transition information being considered, the temporal information can be synthesized within the Bayesian framework to improve diagnosis performance. In this paper, the important evidence dependency problem is solved by a data-driven Bayesian approach with consideration of evidence transition probability. The applications in a simulated distillation column and a pilot scale process are presented to demonstrate the data dependency handling ability of the proposed control loop performance diagnosis approach.

Pilot-Scale MBR and RO Process for COD, Nitrogen and Phosphorus Removals of Mixed Domestic – Industrial Wastewater at 30°C in Singapore

Pilot-Scale MBR and RO Process for COD, Nitrogen and Phosphorus Removals of Mixed Domestic – Industrial Wastewater at 30°C in Singapore

Simultaneous capture and mineralization of coal combustion flue gas carbon dioxide (CO2 )

Abstract The mineral carbonation, a process of converting CO 2 into stable minerals (mineralization), has been studied extensively to capture and store CO 2 . However, most of the mineral carbonation studies have been largely investigated at lab scale. Preliminary and pilot scale studies for accelerated mineral carbonation (AMC) were conducted at one of the largest coal-fired power plants (2120 MW) in the USA by reacting flue gas with fly ash particles in a fluidized bed reactor. In the preliminary experiments, flue gas CO 2 and SO 2 concentrations decreased from 13.0 to 9.6% and from 107.8 to 15.1 ppmv, respectively during the first 2 min. of reaction. The flue gas treatment increased mercury (Hg) concentration in fly ash (0.1 to 0.22 mg/kg) suggesting that fly ash particles also mineralized flue gas Hg. From these results, we designed and developed pilot scale process skid consisting — a moisture reducing drum (MRD) ( 0.9 m Φ × 1.8 m ), a heater/humidifier ( 0.9 m Φ × 1.8 m ), and a fluidized bed reactor (FBR) ( 0.9 – 1.2 m Φ × 3.7 m ) to capture and mineralize flue gas CO 2 . Flue gas was withdrawn from the stack and was fed to the MRD at about 0.094 m 3 /s. The MRD and the heater/humidifier pretreat flue gas before it enters the FBR. The MRD captures droplets of water entrained in the flue gas to protect the blower placed between the MRD and the heater/humidifier. The heater/humidifier enables control of flue gas moisture and temperature. Approximately 100–300 kg of fresh fly ash was collected from the electrostatic precipitator through ash hopper and placed in the fluidized-bed reactor. The fly ash particles were fluidized by flow of flue gas through a distributor plate in the FBR. The pilot scale studies were conducted at a controlled pressure (115.1 kPa) by controlling the flue gas moisture content. The flue gas was continuously monitored to measure flue gas CO 2 , SO 2 and NO x concentrations by an industrial grade gas analyzer, while the fresh and spent fly ashes were analyzed for calcium carbonate (CaCO 3 ), sulfur (S), and mercury (Hg) content. The pilot scale study results suggest that an appreciable amount of flue gas CO 2 and significant amounts of SO 2 and Hg can be directly captured (without separation) and mineralized by the fly ash particles.

Soybean and rice bran oil extraction in a continuous microwave system: From laboratory- to pilot-scale

The performance of a custom-designed, multimode 2450 MHz laboratory-scale, batch type-converted to continuous microwave-assisted extraction (CMAE) system was investigated and the optimization results obtained were used to develop and test a pilot-scale 5 kW, 915 MHz focused cavity CMAE system. Oil was extracted from soy flour and rice bran at various time–temperature combinations with an ethanol: feedstock ratio of 3:1. Both processes were optimized to minimize extraction time while maximizing the quantity of oil extracted. Extraction yields were compared to conventional (CE) and Soxhlet extraction. Yields in the laboratory-scale system for soybean oil were highest at the highest temperature (73 °C) and longest exposure time (21 min), while for rice bran oil, the highest yields were obtained at 73 °C and 17 min. Using the pilot-scale extraction system, greater than 93.0% of total recoverable oil was extracted from both feedstock at all tested flow rates and extraction times, more than the oil recovered by the laboratory-scale unit. Time of extraction and flow rate did not have a significant influence on extraction yield at tested temperatures for the pilot-scale process for soybeans. For rice bran, extraction yield decreased slightly with increasing flow rate (from 0.6 to 1.0 l/min) and extraction time also influenced oil yields. Analysis of oil quality indices (IV, AV, FFA content, wax and phospholipids) extracted by both CMAE processes indicate that the oil meets prescribed biodiesel feedstock quality standards, further justifying use of microwaves as a rapid tool for oil extraction.

Development of an Ingredient Containing Apple Peel, as a Source of Polyphenols and Dietary Fiber

Apple peel is a waste product from dried apple manufacture. The content of phenolic compounds, dietary fiber, and mineral are higher in apple peel, compared to other edible parts of this fruits. The objective of this study was to develop an ingredient from Granny Smith apple peel, using a pilot scale double drum-dryer, as drying technology. The control of all steps to maximize the retention of phenolic compounds and dietary fiber was considered. Operational conditions, such as drying temperature and time were determined, as well as important preprocessing steps like grinding and PPO inhibition. In addition, the physical-chemical characteristics, mineral and sugar content, and technological functional properties such as water retention capacity, solubility index, and dispersability among others, were analyzed. A simple, economical, and suitable pilot scale process, to produce a powder ingredient from apple peel by-product, was obtained. The drying process includes the application of ascorbic acid at 0.5% in the fresh apple peel slurry, drum-dryer operational conditions were 110 degrees C, 0.15 rpm and 0.2 mm drum clearance. The ingredient developed could be considered as a source of phenolic compounds (38.6 mg gallic acid equivalent/g dry base) and dietary fiber (39.7% dry base) in the formulation of foods. Practical Application: A method to develop an ingredient from Granny Smith apple peel using a pilot scale double drum-dryer as drying technology was developed. The method is simple, economical, feasible, and suitable and maximizes the retention of phenolic compounds and dietary fiber present in the raw matter. The ingredient could be used in the formulation of foods.

Enhancing nutrient removal efficiency by changing the internal recycling ratio and position in a pilot-scale MBR process

A study of the membrane bioreactor (MBR) equipped with anaerobic/anoxic switching tanks was conducted to investigate the effect of different internal recycling modes on nutrient removal. The system consisted of a pre-anoxic tank, a first anaerobic/anoxic switching tank, a second anaerobic/anoxic switching tank and an MBR tank. To study the effect of the change in the condition of anaerobic/anoxic switching tanks on nutrient removal, three different modes were tested. These modes were classified according to the varying operating conditions of the anaerobic/anoxic switching tanks. In mode 1, the internal recycle was introduced to the pre-anoxic tank and second anaerobic/anoxic switching tank. In mode 2, the internal recycle was introduced to the pre-anoxic tank and first anaerobic/anoxic switching tank. In mode 3, the internal recycle was introduced to the pre-anoxic tank. To investigate the effect of each mode, GPS-X was used. Subsequently, a pilot-scale experiment was conducted. At the site of this study, phosphorous loading of the influent wastewater was comparatively high; therefore after finishing the experiment, the pilot plant was operated under mode 3. The phosphorous removal efficiency increased up to 88.3% for mode 3 as the anaerobic phase increased. Also, nitrogen removal efficiency was the highest for mode 2.

THE EFFECT OF PROCESS CONDITIONS IN PREPARATION OF VEGETABLE BROTH AS SAVORY FLAVOR FROM MUNG BEANS (&lt;i&gt;Phaseolus radiatus&lt;/i&gt; L.) USING INOCULUM OF &lt;i&gt;Rhizopus&lt;/i&gt;-C&lt;sub&gt;1&lt;/sub&gt;

Preparation of vegetable broth from mung beans (Phaseolus radiatus L.) in semi pilot scale is an attempt development to get product of savory flavor in larger scale. The aim of this activity was to find out the effect of process multiplication on composition of vegetable broth from mung beans using inoculum of Rhizopus-C1 through brine fermentation in mixtures of inoculum, salt, and mung beans of 26, 23, and 51 %. This activity was conducted in both temperature of fermentation (room temperature and 30 °C), various time of fermentation (0, 2, 4, 6, 8, 10, and 12 weeks) and process scales, namely laboratory scale (300 g) and semi pilot scale (± 25 kg), respectively. The result of experiment indicated that fermentation temperature and time and process scales were tend to affect on composition of product. The length of fermentation time would increase concentrations of dissolved protein, N-amino and reducing sugar, decreased concentrations of fat and Volatile Reduction Substance (VRS), while concentrations of total protein, and water were tend to be constant in laboratory and semi pilot scales at the both process temperatures. Multiplication in preparation process of inoculum (7 kg) using starter of Rhizopus-C1 resulted inoculum with activities of proteolytic of 0.71 U/g, and amilolytic of 17.5 U/g at 56 h of incubation. The whole process in semi pilot scale decreased composition of products. The optimal treatment based on recovery of total protein, and the highest amino acids as N-amino in semi pilot scale was at fermentation temperature of 30 ºC for 10 weeks with concentrations of water of 44.96%, total protein of 11.77% (dry matter), dissolved protein of 8 mg/mL, N-amino of 15.4 mg/mL, reducing sugar of 582.5 mg/mL, fat of 0.26% and, VRS of 90 µeq.reduction/g. Keywords: Brine fermentation, vegetable broth, mung beans (Phaseolus radiatus L.), Rhizopus-C1, semi pilot

Removal of organic compounds of real textile dyeing wastewater by pilot scale combination process of anoxic baffled reactor-hybrid membrane bioreactor

A pilot-scale combination process of anoxic baffled reactor -hybrid membrane bioreactor for the real textile dyeing wastewater treatment was investigated. Anoxic baffled reactor as a hydrolysis process pre-treatment was performed well, which achieved 35.6 % COD removal efficiency when hydraulic retention time (HRT) was 16 h. The total COD removal efficiency of the combined process was 83.8 %. GC-MS analysis results demonstrated that the main component of raw influent was alkanes including 13 types. After hydrolysis process, the types of alkanes decreased to 5. In subsequent aerobic treatment phase, alkanes of supernatant of HMBR increased to 19, but total organic compounds category decreased to 24. New intermediate CholestaN-3β-ol production demonstrated that some complicated structures or large molecules substances in raw wastewater could be decomposed. GC-MS quantitative analysis results further showed that some toxic and hazardous substances, such as toluene, styrene, 1,2-dichlorobenzene were still in the final effluent. However toxic compounds e.g. phenols could be removed in the subsequent aerobic process. Therefore, most organic pollutants could be removed using the combined process. There were still some amounts of toxic compounds present in the final effluent.

Dietary inclusion level effects of distillers dried grains with solubles on broiler meat quality

A completely randomized design with 7 replications (n = 7, treatments = 5 with 8 subsamples per treatment) was used to evaluate the effects of feeding various levels of distillers dried grains with solubles (DDGS; 0, 6, 12, 18, and 24%) on broiler breast and thigh meat quality. Broilers were harvested in a pilot scale processing plant with commercial prototype equipment at 42 d of age. The right half of each breast was evaluated for pH, instrumental color, cooking loss, proximate analysis, and tenderness. The left half of each breast was used for consumer acceptability testing. Thigh meat was evaluated for proximate composition, fatty acid composition, and TBA reactive substances. Breast meat from broilers that were fed DDGS had a higher (P < 0.05) pH than those from the control diet. In addition, the 18 and 24% DDGS treatments yielded breast meat with higher (P < 0.05) pH values than the 6% DDGS treatment. No differences existed (P > 0.05) among breast meat from the different treatments with respect to cooking loss, instrumental color, and consumer acceptability, but breast meat from the control (0% DDGS) treatment had slightly lower (P < 0.05) shear force than breast meat from the 18 and 24% DDGS treatments. In addition, no differences (P > 0.05) existed among proximate composition of breast and thigh meat from the control and DDGS treatments. As DDGS concentration increased, there was a linear increase (P < 0.05) in linoleic and polyunsaturated fatty acids, which indicates a greater potential for lipid oxidation. The TBA reactive substances values were greater (P < 0.05) for the 18 and 24% DDGS treatments at d 5 when compared with the control and 6% DDGS treatments, which indicates increased oxidation. Overall, data suggest that all treatments yielded high-quality breast meat and that thigh meat quality was similar among treatments containing 0 to 12% DDGS, but higher inclusion levels led to thigh meat that was more susceptible to oxidation.

Effect of light Sphagnum peat on odour formation in the early stages of biowaste composting

In the present study, we investigated the effects of two bulking materials, Sphagnum peat and pine wood chips, on the early stages of biowaste composting in two pilot-scale processes. Emphasis was placed on studying the formation conditions of malodorous compost gases in the initial phases of the processes. The results showed that gas emission leaving an open windrow and a closed drum composting system contained elevated concentrations of fermentative microbial metabolites when acid Sphagnum peat (pH 3.2) was used as a bulking material. Moreover, the gas emission of the peat amended drum composter contained a high concentration of odour (up to 450,000 ou m −3 of air). The highest odour values in the outlet gas of peat amended composts coincided with the elevated concentrations of volatile organic compounds such as acetoin and buthanedion. We conclude that the acidifying qualities of composting substrates or bulking material may intensify odour emission from biowaste composts and prolong the early stages of the composting process.

Pilot scale processing technology for extraction of Cliv-92: A combination of three coumarinolignoids cleomiscosins A, B and C from Cleome viscosa

The paper reports an improved pilot scale process technology for the extraction of Cliv-92: a combination of three hepatoprotective coumarinolignoids, cleomiscosins A, B and C from the seeds of Cleome viscosa. The method involved the extraction of the defatted seeds with methanol, which on concentration gave a viscous residue. Trituration of the residue with methanol and keeping it at a low temperature resulted in the precipitation of Cliv-92 which was separated by filtration. Almost half of total yield of Cliv-92 was obtained from the methanolic extract simply by the trituration method. The filtrate obtained was concentrated and adsorbed on celite. The adsorbed material was then partitioned with toluene, ethyl acetate and methanol successively. The fractions obtained from partitioning methods were concentrated and Cliv-92 was isolated from the above fractions by passing through a bed of silica gel. The novelty of the improved process included application of an extrusion device to expel out the fixed oil before extraction, adopting trituration technique to effectively crystallize the coumarinolignoids and using solid-matrix partitioning technique thereby avoiding the use of water for partitioning to isolate the coumarinolignoids. The yield of Cliv-92 obtained was 1.13% carried out at a scale of 100 kg/batch level which was about 10 times higher in comparison to previous bench scale process.

Characteristics and Microbial Succession in Co-Composting of Oil Palm Empty Fruit Bunch and Partially Treated Palm Oil Mill Effluent

Microbial communities and cellulolytic enzymes activities were analyzed during the co-composting of empty fruit bunch (EFB) and partially treated palm oil mill effluent (POME) in pilot scale. The physicochemical parameters were also measured during the composting. The diversity of the bacterial community was investigated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results indicated that the composting process of EFB with partially treated POME was dominated by uncultured bacteria species. The dominant bacterial group changed from the phylum proteobacteria in the thermophilic stage to the phylum chloroflexi in the maturing stage. Scanning electron microscope (SEM) analysis exhibited the significant degradation of EFB structure during the composting process. The maximum cellulase activity for carboxymethylcellulase (CMCase), filter paperase (FPase) and β-glucosidase were 13.6, 4.1 and 20.3 U/g of dry substrate, respectively at day 30 of composting. The results of this study significantly contributed to a better understanding of mechanisms involved in co-composting process in pilot scale.

Decolorization/deodorization of zein via activated carbons and molecular sieves

Commercially available corn zeins from co-products of the corn ethanol industry possess yellow color and off-odors that deter their usage in food, medical, pharmaceutical and cosmetic industries. A pilot-scale process (patent pending) was developed to purify those products. Our objective is to investigate a series of activated carbons and zeolites, clay-based particles acting as molecular sieves, as potential column media for that process. A batch process was used to evaluate each of five different activated carbons and zeolites to determine the adsorption characteristics of protein and the color and off-odor components. Adsorptive properties of those media were performed by spectral analyses at wavelengths 280 nm for the protein component and 325 nm for the contaminants. Statistical evaluation of the batch adsorption data from each series demonstrated that activated carbon generated from coconut hulls and zeolite 5 A (5 angstrom pore size) adsorbed the least amount of protein relative to contaminant adsorptions. Our selection of column media for the pilot-scale process was based on these findings.

Data-driven Control Loop Diagnosis: Dealing with Temporal Dependency in Bayesian Methods

Abstract Abstract Conventional Bayesian methods commonly assume that the evidences are temporally independent. This condition does not hold for most practical engineering problems. With evidence transition information being considered, the temporal domain information can be synthesized within the Bayesian framework to improve the diagnosis performance. A data-driven algorithm is developed to estimate the evidence transition probabilities. The application in a pilot scale process is presented to demonstrate the data dependency handling ability of the proposed approach.

Microbial ecology and performance of ammonia oxidizing bacteria (AOB) in biological processes treating petrochemical wastewater with high strength of ammonia: effect of Na2CO3 addition

This study evaluated nitrification performance and microbial ecology of AOB in a full-scale biological process, powder activated carbon treatment (PACT), and a pilot-scale biological process, moving bed biofilm reactor (MBBR), treating wastewater collected from a petrochemical industry park. The petrochemical influent wastewater characteristics showed a relative low carbon to nitrogen ratio around 1 with average COD and ammonia concentrations of 310 mg/L and 325 mg-N/L, respectively. The average nitrification efficiency of the full-scale PACT process was around 11% during this study. For the pilot-scale MBBR, the average nitrification efficiency was 24% during the Run I operation mode, which provided a slightly better performance in nitrification than that of the PACT process. During the Run II operation, the pH control mode was switched from addition of NaOH to Na(2)CO(3), leading to a significant improvement in nitrification efficiency of 51%. In addition to a dramatic change in nitrification performance, the microbial ecology of AOB, monitored with the terminal restriction fragment length polymorphism (T-RFLP) molecular methodology, was found to be different between Runs I and II. The amoA-based TRFLP results indicated that Nitrosomonas europaea lineage was the dominant AOB population during Run I operation, while Nitrosospira-like AOB was dominant during Run II operation. To confirm the effects of Na(2)CO(3) addition on the nitrification performance and AOB microbial ecology observed in the MBBR process, batch experiments were conducted. The results suggest that addition of Na(2)CO(3) as a pH control strategy can improve nitrification performance and also influence AOB microbial ecology as well. Although the exact mechanisms are not clear at this time, the results showing the effects of adding different buffering chemicals such as NaOH or Na(2)CO(3) on AOB populations have never been demonstrated until this study.

Investigation on laboratory and pilot-scale airlift sulfide oxidation reactor under varying sulfide loading rate

Airlift bioreactor was established for recovering sulfur from synthetic sulfide wastewater under controlled dissolved oxygen condition. The maximum recovered sulfur was 14.49 g/day when sulfide loading rate, dissolved oxygen (DO) and pH values were 2.97 kgHS−/m3-day, 0.2–1.0 mg/L and 7.2–7.8, respectively. On the other hand, the increase in recovered sulfur reduced the contact surface of sulfide oxidizing bacteria which affects the recovery process. This effect caused to reduce the conversion of sulfide to sulfur. More recovered sulfur was produced at high sulfide loading rate due to the change of metabolic pathway of sulfide-oxidizing bacteria which prevented the toxicity of sulfide in the culture. The maximum activity in this system was recorded to be about 3.28 kgS/kgVSS-day. The recovered sulfur contained organic compounds which were confirmed by the results from XRD and CHN analyzer. Afterwards, by annealing the recovered sulfur at 120°C for 24 hrs under ambient Argon, the percentage of carbon reduced from 4.44% to 0.30%. Furthermore, the percentage of nitrogen and hydrogen decreased from 0.79% and 0.48% to 0.00% and 0.14%, respectively. This result showed the success in increasing the purity of recovered sulfur by using the annealing technique. The pilot-scale biological sulfide oxidation process was carried out using real wastewater from Thai Rayon Industry in Thailand. The airlift reactor successfully removed sulfide more than 90% of the influent sulfide at DO concentration of less than 0.1 mg/L, whereas the elementary sulfur production was 2.37 kgS/m3-day at sulfide loading rate of 2.14 kgHS−/m3-day. The sulfur production was still increasing as the reactor had not yet reached its maximum sulfide loading rate.