Gas Washing Bottles Research Articles

Dual roles of odor cleaners and pollutant producers for chemical scrubbing and biological treatment: Evidence in a food waste anaerobic digestion plant

The odor generated during municipal solid waste and wastewater treatment is a major source of public complaints worldwide. Chemical scrubbing and biological treatment are commonly used to control the odor. However, in this study, such odor control measures were found to produce derived odorous compounds and greenhouse gases, leading to reduced efficiency or uncertainty in odor treatment. In a food waste anaerobic digestion plant, a series of site and lab investigations were conducted on the odor control performance and mechanisms, as well as secondary pollutants of chemical scrubbing and biotrickling. Methanethiol, hydrogen sulfide (H2S), propanethiol, and acetaldehyde were identified as the top four odor contributors to the gas collected in the plant. The mechanisms of acetaldehyde and propanethiol removal in the chemical scrubbers were studied using gas-washing bottles. Acetaldehyde was mainly removed via physical absorption, whereas propanethiol could be completely removed via oxidation by sodium hypochlorite (NaClO). However, acetaldehyde was desorbed from the absorption solution and generated from the oxidation of ethanol by NaClO in the chemical scrubbers, leading to low, or even negative removal efficiency. H2S, methanethiol, propanethiol, and acetaldehyde could be abated by the biotrickling filters. However, H2S, methanethiol, propanethiol, and greenhouse gases could be also produced under anaerobic conditions, particularly when the packings were compacted. Furthermore, acetaldehyde could be produced from ethanol by bacteria possessing dehydrogenase under aerobic conditions. Both chemical scrubbers and biotrickling filters demonstrated the dual roles of odor removal and pollutant production.

Experimental Investigation of SO2 Removal from Flue Gases by Cleaning with Solution of Lime Suspension and Formic Acid

The experimental investigation presented in this research was performed in order to examine the possibility of the removal of SO2 from flue gases by cleaning with a solution of lime suspension and formic acid (Ca(OH)2 and HCOOH). Research was conducted in a laboratory plant (rotary kiln) of 44 kW. The mass of the lime suspension (LS) was 400 g. The mass of the LS was homogenized (mixed) in a sample cup with 2 g (0.5%), 4 g (1%) and 8 g (2%) of 60% formic acid. The solution was placed in a gas washing bottle, where a partial flow of flue gas generated by the combustion of diesel fuel was injected. Simultaneously with the diesel fuel combustion, SO2 from a bottle was injected in a rotary kiln. The average mass concentration of SO2 in the flue gas at the entry point of the gas washing bottle was around 2900 ppm. The results indicated that the absorption of SO2 by the cleaning of flue gas with LS was 96.83%. Adding formic acid to the LS in mass ratios of 0.5% (2 g), 1% (4 g) and 2% (8 g) resulted in absorptions of 99.25%, 98.77% and 98%, respectively. The absorption of flue gases in the gas washing bottle with LS, with the addition of formic acid in the mentioned ratios, showed a reduction in sulfates and pH value, and a rise in sulfides and calcium, respectively.

Design, construction, and testing of an accurate low-cost humidistat for laboratory-scale applications

Stable and precise control of humidity is imperative for a wide variety of experiments. However, commercially available humidistats (devices that maintain a constant humidity) are often prohibitively expensive. Here, we present a simple yet effective humidistat for laboratory-scale applications that can be easily and affordably (<€250) constructed based on an Arduino Uno as microcontroller, a set of proportional miniature solenoid valves, a gas washing bottle, and a humidity sensor. The microcontroller implements a PID controller that regulates the ratio of a dry and humid airflow. The design and implementation of the device, including a custom driver circuit for the solenoids, are described in detail, and the firmware is freely available online. Finally, we demonstrate its proper operation and performance through step response and long-term stability tests, which shows settling times of approx. 30 s and an attainable relative humidity range of 10–95%

Study of the Characteristics of DC Multineedle-to-Water Plasma-Activated Water and Its Germination Inhibition Efficiency: The Effect of Discharge Mode and Gas Flow

In this article, a negative dc multineedle-to-water discharge device was designed to generate plasma-activated water (PAW) with a total volume of 580 mL. The physicochemical properties of PAW were investigated. The results showed that the products concentration of PAW and its acidity were not continuously increased by adding the applied voltage. When it turned from pulse corona discharge to DC glow-like discharge (−19.5 to −20.5 kV), the corresponding value decreased with the increase of the applied voltage. This decrease was attributed to the fact that the differences in the discharge figure had an effect on the reactions of transient species with N x O y in different discharge modes. In addition, by comparing the product concentrations of PAW in different gas conditions, we discovered that the gas flow would lead to a decrease of active species in PAW and its inactivation. Although the gas flow took away the N x O y diffused in the discharge chamber and formed microbubbles in the gas-washing bottle, which benefitted for increasing the absorption area with water, this process also took away NO out of the discharge area, which decreased its reaction with transient species such as OH, O2−, and O to form HNO2 and HNO3 directly. Finally, the germination inhibition rate (GIR) of penicillium spores was calculated to estimate the inactivation efficiency of PAW. The maximum GIR was 71.5% when the applied voltage was −19.5 kV (corona discharge) and the gas flow rate was 0 L/h.

Estimation of ammonia emissions from a dairy farm using a computer program

Ammonia emission tests were carried out on a dairy cow farm (100 large production units) with a slatted-floor system. The air for the tests was collected into gas washing bottles. Ammonia emissions were modeled using Operat FB software. The enthalpy of the process and the molar mass of the oxidized substance were used to calculate the calorific value of gases on the farm. The highest ammonia concentrations on the farm were obtained in the autumn and winter and amounted to 11.2 mg/m3. The highest mass of this gas in the modelling, defined as the maximum emission, was 0.85 kg/h. The annual emission was estimated at 2.78 Mg/year. These results were the basis for estimating the amount of energy (0.85 kg/h) obtainable from ammonia on the farm. The modeling of ammonia emissions applied in the study can be used to calculate the potential degree of pollution introduced into the environment and to estimate the degree of pollutants reduction.Ammonia from the farm, together with the methane emitted, can be catalytically oxidized as a potential energy source.

Experimental Study on the Characteristics of Water Vapor Generation from Gas-washing Bottle and Injector

Gas-washing and water injection are two commonly used methods in generating certain moisture content in gas flow stream, but the control accuracy of these methods remains uncertain. The purpose of the study is to investigate the characteristic of water vapor generation of the two methods. The temperature and humidity recorder and FTIR gas analyzer have been adopted to monitor the moisture content in tests. It has been revealed that, in gas-washing process, the moisture content in gas stream is well below saturation, and long time is required before moisture content stabilized after water bath temperature or carrier gas flow rate changed. Water injection pump could directly control the amount of water injected into gas stream. However, the moisture content generated in this way is not stable but oscillates in cycles, whose frequency and magnitude are closely related to water injection amount.

Evaluation of a Simple, Small-Plot Meteorological Technique for Measurement of Ammonia Emission: Feasibility, Costs, and Recommendations

Abstract. Ammonia emission reduces the reliability and nitrogen (N) fertilizer efficiency of animal manure and mineral fertilizers applied to fields. The loss of ammonia to the atmosphere is frequently compensated for by costly over-application of N fertilizers. New technologies to reduce ammonia emission are regularly developed, and their efficacy needs to be tested using accurate methods. To date, a major obstacle to many available emission measurement techniques is the requirement of large plot sizes of homogeneous surface characteristics, which particularly is a challenge to the number of plot-level replicates that can be carried out on a field providing uniform surface characteristics throughout. The objectives of this research were to test three different methods for measuring NH3 flux when applied to small plots (&amp;lt;315 m2) by comparison with conventional micrometeorological methods and to determine the labor intensity and expenses related to the respective methods in their entirety. The integrated horizontal flux (IHF) method and the ZINST method were used with passive flux Leuning samplers as micrometeorological reference methods. As examples of conventional small-plot emission measurement techniques, wind tunnels measuring gas-phase ammonia using ALPHA passive diffusion samplers and a flux chamber method using Dräger tubes for measurements of ammonia concentration (DTM) were used. As an inexpensive alternative small-plot method, we studied the feasibility of applying ALPHA passive diffusion samplers and battery-driven cup anemometers at ZINST height on small source areas (&amp;lt;315 m2), coupled with a backward Lagrangian stochastic (bLS) dispersion model to calculate emission fluxes (referred to as the AbLS method). When exposure duration was appropriate and weather conditions were not extreme, tests showed no significant difference in NH3 emission fluxes measured with AbLS, compared to those obtained with IHF and ZINST using Leuning samplers. However, the AbLS method did not give reliable emission measurements in periods with high wind speeds and heavy rain. It was also shown that the AbLS method provided valid results when reducing the plot radius from the standard 20 m to 10 m, or even 5 m, provided that the ALPHA samplers were exposed for at least 5 or 6 h. Emission from 200 kg urea-N ha-1 was between 20 and 30 kg N ha-1 in the two trials. The cost for one study running for one week using the ZINST or bLS methodology, including equipment for four plots and eight measurement intervals, was $2785 if horizontal fluxes were measured using the ALPHA samplers, compared to $12,301 using the Leuning samplers and $13,928 using gas washing bottles. Using the DTM flux chamber method once is a little more expensive than using the AbLS method, but less expensive if the cost of purchasing the equipment is distributed over five studies in five years. Using wind tunnels is as costly as measuring emissions with the Leuning samplers or gas washing bottles using the bLS or ZINST method. Keywords: ALPHA samplers, Ammonia emission, AbLS, bLS method, DTM method, IHF method, Labor cost, Passive ammonia samplers, Wind tunnels.

Mathematical modeling of ferrous sulfate oxidation in presence of air

In the present paper we studied the oxidation of ferrous sulfate salt with oxygen. ferric ammonium sulfate and ferrous sulfate were used to prepare standard solutions of Fe(III) and Fe(II) solutions. Oxidation experiments were carried out by mixing FeSO4·7 H2O in H2O. Air was supplied using a gas washing bottle in which air entered the bottle through the center tube, and exited into the bottom of the bottle. Samples were taken periodically and analyzed in the UV-Vis spectrophotometer. We consider that basic Fe(III) sulfate was one of the main compounds produced during the reaction and proposed a model to describe the process. We found solution to the differential equations that described the profile of FeSO4 and FwOHSO4 concentration in time and observed agreement between the experimental results and data predicted by the model. Moreover, we determined values of rate constants using the model and confirmed the determined values by means of experiments. This suggests that basic ferric sulfate was generated after aeration of ferrous sulfate solution.

The potency of monoethanolamine in biogas purification and upgrading

Biogas has been exploited as one of the alternative sources of renewable energy having the potential to replace fossil fuels. It contains impurities when raw, as it consists of 50–70% methane (CH4), 30–50% carbon dioxide (CO2) and trace gases such as hydrogen sulfide (H2S). Chemical absorption is often a preferred purification technique in industrial applications because it has high efficiencies, removes H2S completely, operates at low pressures, and has higher reaction rates. The focus of this study is on amines as they are widely used worldwide to purify biogas. A continuous system was used where 1 L digester was used for biogas production which was bubbled through an absorbent in 500 mL gas washing bottle. The gas exiting the absorption column was analyzed using Gas Chromatography. The methane yield obtained in this study was higher because MEA is a good absorbent. The biomethane potential was found to be 0.40 m3 CH4/kg VS (volatile solids). An increase in concentration resulted in increased co2 absorption capacity and rate, an average of 76%, 78%, and 84% vol from an initial concentration of 52% vol were achieved for the respective concentrations. The CH4 content of the purified biogas improved with increasing temperature. The removal efficiency of carbon dioxide increased from 66% at room temperature to 77% at 40 °C. Temperature of the solvent increased the absorption capacity and carbon dioxide removal efficiency of the process.

Nicotine delivery, retention and pharmacokinetics from various electronic cigarettes.

To measure the systemic retention of nicotine, propylene glycol (PG) and vegetable glycerin (VG) in electronic cigarette (e-cigarette) users, and assess the abuse liability of e-cigarettes by characterizing nicotine pharmacokinetics. E-cigarette users recruited over the internet participated in a 1-day research ward study. Subjects took 15 puffs from their usual brand of e-cigarette. Exhaled breath was trapped in gas-washing bottles and blood was sampled before and several times after use. San Francisco, California, USA. Thirteen healthy, experienced adult e-cigarette users (six females and seven males). Plasma nicotine was analyzed by gas chromatography-mass spectrometry (GC-MS/MS) and nicotine, VG and PG in e-liquids and gas traps were analyzed by LC-MS/MS. Heart rate changes and subjective effects were assessed. E-cigarettes delivered an average of 1.33 (0.87-1.79) mg [mean and 95% confidence interval (CI)] of nicotine, and 93.8% of the inhaled dose, 1.22 (0.80-1.66) was systemically retained. Average maximum plasma nicotine concentration (Cmax ) was 8.4 (5.4-11.5) ng/ml and time of maximal concentration (Tmax ) was 2-5 minutes. One participant had Tmax of 30 minutes. 84.4% and 91.7% of VG and PG, respectively, was systemically retained. Heart rate increased by an average of 8.0 beats per minute after 5 minutes. Withdrawal and urge to smoke decreased and the e-cigarettes were described as satisfying. E-cigarettes can deliver levels of nicotine that are comparable to or higher than typical tobacco cigarettes, with similar systemic retention. Although the average maximum plasma nicotine concentration in experienced e-cigarette users appears to be generally lower than what has been reported from tobacco cigarette use, the shape of the pharmacokinetic curve is similar, suggesting addictive potential.

Green tea protects human osteoblasts from cigarette smoke-induced injury: possible clinical implication

Recent reports discuss the altered bone homeostasis in cigarette smokers, being a risk factor for osteoporosis and negatively influencing fracture healing. Cigarette smoke is known to induce oxidative stress in the body via an increased production of reactive oxygen species (ROS). These increases in ROS are thought to damage the bone-forming osteoblasts. Naturally occurring polyphenols contained in green tea extract (GTE), e.g., catechins, are known to have anti-oxidative properties. Therefore, the aim of this study was to investigate whether GTE and especially catechins protect primary human osteoblasts from cigarette smoke-induced damage and to identify the underlying mechanisms. Primary human osteoblasts were isolated from patients' femur heads. Cigarette smoke medium (CSM) was obtained using a gas-washing bottle and standardized by its optical density (OD(320)) at λ = 320 nm. ROS formation was measured using 2'7'dichlorofluorescein diacetate, and osteoblasts' viability was detected by resazurin conversion. Co-, pre-, and post-incubation with GTE and catechins significantly reduced ROS formation and thus improved the viability of CSM-treated osteoblasts. Besides GTE's direct radical scavenging properties, pre-incubation with both GTE and catechins protected osteoblasts from CSM-induced damage. Inhibition of the anti-oxidative enzyme HO-1 significantly reduced the protective effect of GTE and catechins emphasizing the key role of this enzyme in GTE anti-oxidative effect. Our data suggest possible beneficial effects on bone homeostasis, fracture healing, and bone mineral density following a GTE-rich diet or supplementation.

A tritium diagnostic and trap for JUDITH—First results in disruption simulation experiments with neutron irradiated beryllium during cyclic electron beam testing

In the present study, the effect of disruptions on beryllium has been studied. Disruptions are simulated in the electron beam facility JUDITH by high energetic pulses of up to 250 MJ/m 2. Under these loads, the beryllium surface may roughen combined with the forming of cracks. During the experiments, a special problem arises from the fact that during the neutron irradiation beryllium transmutes to tritium. This tritium is bound in the beryllium matrix, but during the heating of the samples, the tritium may be set free and through the vacuum pump it may be released to the environment. In order to avoid and to quantify this release of tritium, a special tritium trap has been constructed. In this tritium trap the gas is pumped by means of a metal bellows pump through a catalyst tube filled with copper oxide. At a temperature of 300 °C, the tritium is oxidized to HTO. This HTO is lead through gas washing bottles filled with water. Here approximately 98% of the released tritium is caught. The temperatures in the process are controlled by thermocouples, and the tritium content is controlled by a tritium gas monitor and in addition with a liquid scintillation counter (LSC).

A water activity control system for enzymatic reactions in organic media

A water activity control system for enzymatic synthesis in organic media, for litre-scale reactors has been constructed. Water activity, a(w), is a key factor when using enzymes in non-conventional media and the optimum value varies for different enzymes. The control system consists of a water activity sensor in the headspace of a jacketed glass reactor (equipped with narrow steel tubes to introduce air), gas-washing bottles containing blue silica gel (a(w)=0) and water (a(w)=1), a PC to monitor water activity and a programmable logic controller (PLC) to control the water activity. The system was evaluated by adjusting water activity in the medium, with a deviation from the set point of less than +/-0.05. Synthesis of cetyl palmitate, under controlled water activity and catalysed by two different lipase preparations, namely, Novozym 435 (immobilised Candida antarctica lipase B) and immobilised Candida rugosa lipase, were also performed. Novozym 435 catalyses reactions very well at extremely low water activity while C. rugosa lipase shows low activity for a(w)<0.5.

Oxidation of Aged Raw Landfill Leachate with O3 Only and O3/H2O2: Treatment Efficiency and Molecular Size Distribution Analysis

ABSTRACT An aged raw landfill leachate was taken from the equalization storage tank at Clover Bar Landfill Leachate Treatment Plant, Edmonton, Alberta, Canada. The average quality parameters of this leachate were: COD=1,090mg/L, BOD5=39mg/L, color=1,130 TCU, NH3-N=455mgN/L, alkalinity=4,030mg/L as CaCO3and pH=8.30. The major fraction of this leachate was large refractory organic compounds. Ozone (O3) only and O3 combined with hydrogen peroxide (O3/H2O2) were applied to treat this leachate, aiming at enhancing COD and color reduction and increasing its biodegradability (i.e., the ratio of BOD5/COD). All of the O3 only and O3/H2O2 oxidation experiments were performed in a gas washing bottle equipped with a fine bubble diffuser. The used ozone dose ranged from 1.2 to 12.5g O3/L leachate for O3 only treatment, and 1.8 to 13.8g O3/L leachate for O3/H2O2 treatment. H2O2 dose for O3/H2O2 treatment was 0.63g H2O2/L leachate. COD, BOD5, color, NH3-N, nitrite+nitrate, and alkalinity were measured before and after treatment. Meanwhile the molecular size distribution of the leachate, before and after treatment, was analyzed by using a high-performance liquid chromatograph (HPLC) with gel filtration column and UV detector at 254nm. The addition of H2O2 had an insignificant effect (at 5% significance level) on enhancing COD and color reduction. After oxidation, the maximum BOD5 increase was about 110% for O3/H2O2 treatment and about 141% for O3 only treatment at a used ozone dose of 3.6g O3/L leachate and 2.6g O3/L leachate for O3/H2O2 and O3 only, respectively. As the used ozone dose increased, NH3-N and alkalinity decreased considerably, and nitrite+nitrate increased accordingly. Treatment efficiency models, which describe the changes in COD, BOD5/COD, NH3-N, nitrite+nitrate, and alkalinity as functions of the used ozone dose, were developed. Statistically (at 5% significance level), the treatment efficiency models for both treatments are not different. According to the results of molecular size distribution analysis, no correlation was observed between the BOD5 increase and oxidation by-products’ formation.

Determination of triacetonetriperoxide in ambient air

A method for the analysis of the explosive triacetonetriperoxide (TATP) in ambient air is introduced. The high volatility of the peroxide leads to significant concentrations in the air surrounding even minute quantities of TATP, thus enabling the analyst to avoid direct contact with the sensitive explosive. Air sampling is performed using gas-washing bottles filled with acetonitrile and air sampling pumps at a flow-rate of 0.6 l min −1. A sampling and a back-up gas-washing bottle are connected in series to allow monitoring of possible breakthroughs in the sampling gas-washing bottle. After sampling, two different analytical methods were used: first, reversed-phase high-performance liquid chromatography (HPLC) with subsequent post-column UV irradiation and electrochemical detection; and second, photochemical degradation of TATP with enzyme-catalyzed photometric detection. The limits of detection for 20 min of sampling time (12 l sample volume) were 190 ng l −1 air for the photometric method and 550 ng l −1 air for LC with electrochemical detection. The recovery was at least 75%.

ISE Analysis of Hydrogen Sulfide in Cigarette Smoke

Many advanced undergraduate analytical laboratory courses focus on exposing students to various modern instruments. However, students rarely have the opportunity to construct their own analytical tools for solving practical problems. We designed an experiment in which students are required to build their own analytical module, a potentiometric device composed of a Ag/AgCl reference electrode, a Ag/Ag2S ion selective electrode (ISE), and a pH meter used as voltmeter, to determine the amount of hydrogen sulfide in cigarette smoke. Very simple techniques were developed for constructing these electrodes. Cigarette smoke is collected by a gas washing bottle into a 0.1 M NaOH solution. The amount of sulfide in the cigarette smoke solution is analyzed by standard addition of sulfide solution while monitoring the response of the Ag/Ag2S ISE. The collected data are further evaluated using the Gran plot technique to determine the concentration of sulfide in the cigarette smoke solution. The experiment has been successfully incorporated into the lab course Instrumental Analysis at Georgia Institute of Technology. Students enjoy the idea of constructing an analytical tool themselves and applying their classroom knowledge to solve real-life problems. And while learning electrochemistry they also get a chance to visualize the health hazard imposed by cigarette smoking.

Evaluation of the determination of mercury at the trace and ultra-trace levels in the presence of high concentrations of NaCl by flow injection–cold vapour atomic absorption spectrometry using SnCl2 and NaBH4 as reductands

The influence of different concentrations of NaCl (0–20%m/v) on the analytical figures of merit for the determination of mercury by flow injection–CVAAS was studied. The determination was performed with and without preconcentration by gold amalgamation and by employing different reducing agents, NaBH4 and SnCl2. When using the reductand SnCl2, stable operation both with and without preconcentration was obtained, resulting in RSDs below 5% (n 30), even in the presence of high concentrations of NaCl. Without preconcentration the sensitivity was a function of the concentration of NaCl (between 0.033 and 0.013 ml ng–1). With preconcentration the sensitivity could be improved by a factor of 2.5 (i.e., from 0.084 to 0.037 ml ng–1, depending on the concentration of NaCl). With the reducing agent NaBH4, sufficient stability for routine analysis was observed only without preconcentration (RSD ⩽ 2%, n = 45) and a sensitivity of 0.022 ml ng–1 was obtained for matrix-free solutions. In the presence of high concentrations of NaCl the sensitivity increased up to 0.030 ml–1 ng, but owing to the unsystematically unstable blank values it was not a monotonic function of the concentration of NaCl. The use of preconcentration in the case of NaBH4 was hampered by the gold trap being covered with gaseous reaction products or entrained droplets as a result of the generation of foam in the gas–liquid separator. This could be improved by the use of two gas-washing bottles (NaOH, H2O). With the different methods, for which the detection limits finally were between 15 and 230 pg ml–1 (without) and 2 and 11 pg ml–1 (with preconcentration), mercury was determined in five standard reference samples of soil and sedimented sludge at the ng g–1 to µg g–1 level subsequent to their dissolution with aqua regia.

A simple passive sampler for measuring ammonia emission in the field

A new type of passive sampler for the determination of NH3 emission from land surfaces and manure storages was tested in a micrometereological mass balance method. The sampler consists of 2 glass tubes, each with a length of 10 cm and an internal diameter of 0.7 cm. The two glass tubes are connected in series, with one end fitted with a thin stainless steel disc having a 1 mm hole in the center. The inner surface of each glass tube is coated with oxalic acid. The results show that the passive flux sampler can be used to give accurate determinations of NH3 emission. The passive flux sampler makes gas washing bottles, pumps, flow meters, anemometers, and electricity unnecessary and ammonia loss can be determined easily and cheaply without the requirement of a large labor force.

Inorganic carbonate elimination from water samples for dissolved organic carbon analysis.

Inorganic carbonate is eliminated by passing CO2 and organic free air through acidified samples for DOG analysis. The air is supplied from a manual rubber air pump by way of two gas washing bottles containing concentrated sulfuric acid and 1N-NaOH and a sodalime tube. The precision of the present method is the same as that of the standard method, which removes inorganic carbonate by high quality nitrogen gas supplied from a high pressure nitrogen gas tank. The present method is especially useful in remote areas such as alpine lakes.

Determination of Carbonate in Detergent by the Acid-decomposition/Neutralization Titration Method

A simple and rapid method for the determination of carbonate was developed. A carbonate sample was decomposed in a hydrochloric acid solution and the evolved carbon dioxide was absorbed in a barium hydroxide solution. The absorption was carried out with apparatus consisting of two gas washing bottles with a circulating air pump (Fig.-1). The air pump was operated for 5min to fix carbon dioxide completely in the barium hydroxide solution to form BaCO3. Finally, the excess barium hydroxide was titrated with a standard solution of 1N hydrochloric acid using phenolphthalein as an indicator. Removal of precipitated barium carbonate during titration was unnecessary. The determination required about 10min per sample with a recovery of more than 99% and a coefficient of variation within 0.5%.The proposed method was applied to the determination of sodium carbonate in various commercial granulate detergents. The results were compared with those from an autoanalyzer method. Good agreement was obtained with both methods, thus concluding the content of sodium carbonate in a granulated detergent can be determined more conveniently by the proposed method.