Denitrification of industrial wastewater with sulfur and limestone packed column

2002 ◽  
Vol 46 (11-12) ◽  
pp. 99-104 ◽  
Author(s):  
R. Nugroho ◽  
H. Takanashi ◽  
M. Hirata ◽  
T. Hano
Keyword(s):  
Industrial Wastewater ◽  
Dominant Species ◽  
Elemental Sulfur ◽  
Packed Column ◽  
Steel Production ◽  
Thiobacillus Denitrificans ◽  
Autotrophic Denitrification ◽  
Treatment Performance ◽  
Biofilm Process ◽  
Kinetics Of

An autotrophic denitrification system was developed for nitrate contaminated industrial wastewater whose C/N ratio was very low. The microbes containing Thiobacillus denitrificans as a dominant species were attached on the surface of granular elemental sulfur packed in a column. Elemental sulfur was used as an electron donor for autotrophic denitrification. The granules of limestone were mixed with the granular sulfur to moderate the decrease of alkalinity during autotrophic denitrification. The stoichiometry and basic kinetics of denitrification were studied in column runs. The effects of minerals such as phosphorus on treatment performance were clarified. The wastewater from steel production plants was treated by the present biofilm process. Low extent of nitrogen removal was caused by the lack of minerals.

scholarly journals DEVELOPMENT OF AUTOTROPHIC DENITRIFICATION FOR NITRATE-CONTAMINATED INDUSTRIAL WASTEWATER

2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Rudi Nugroho
Keyword(s):  
Rate Constant ◽  
Industrial Wastewater ◽  
Packed Column ◽  
Order Reaction ◽  
Synthetic Wastewater ◽  
Nitrate Content ◽  
Thiobacillus Denitrificans ◽  
Autotrophic Denitrification ◽  
Biofilm Thickness ◽  
Denitrification Kinetics

An autotrophic denitrification system was developed for treatment wastewater from steel industry. The aim was to evaluate the kinetics and capability of the system in reducing nitrate content in such industrial wastewater. The experiments were conducted in batch suspension and continuous runs. The denitrification kinetics in suspension runs obeys first order reaction with the rate constant k1 and k2 were determined to be 0.014 and 0.004 g-N/m3.d, respectively. The continuous runs used a column packed with mixture of granular sulfur and limestone. The microbes of Thiobacillus denitrificans were attached on the surface of granular sulfur in the form of biofilm. The biofilm thickness was investigated to be approximately 40 μm. The denitrification kinetics in the packed column obeys half-order reaction with the rate constant k of 0.172 g-N1/2.m1/2/(kg-S.d). The lower denitrification extent of industrial wastewater compared with the synthetic wastewater might be due to the lack of alkalinity. Keywords: Autotrophic denitrification, sulfur, packed column, thiobacillus denitrificans.

A Kinetic Model for Autotrophic Denitrification using Sulphur:Limestone Reactors

2003 ◽  
Vol 38 (1) ◽  
pp. 183-192 ◽  
Author(s):  
Ashref Darbi ◽  
Thiruvenkatachari Viraraghavan
Keyword(s):  
Particle Size ◽  
Kinetic Model ◽  
Reaction Rate ◽  
Average Particle Size ◽  
Order Reaction ◽  
Average Particle ◽  
Thiobacillus Denitrificans ◽  
Autotrophic Denitrification ◽  
Reaction Rate Constants ◽  
Kinetics Of

Abstract The kinetics of autotrophic denitrification of groundwater by Thiobacillus denitrificans in a sulfur:limestone upflow reactor was examined in order to predict effluent concentrations. Experiments were performed using water containing 60 and 90 mg NO3—N/L and sulfur and limestone with average particle size of 3.5 mm. Results clearly showed that nitrate was completely removed from 60 and 90 mg NO3—N/L influent concentrations. The results showed that the autotrophic denitrification rates in sulfur:limestone reactors can be described by half-order kinetics. The half-order reaction rate constants for the entire media were estimated at 1.34 and 1.54 mg1/2/L1/2 h for influent concentrations of 60 and 90 mg NO3—N/L, respectively.

Final products and kinetics of biochemical and chemical sulfide oxidation under microaerobic conditions

2018 ◽  
Vol 78 (9) ◽  
pp. 1916-1924 ◽  
Author(s):  
Lucie Pokorna-Krayzelova ◽  
Dana Vejmelková ◽  
Lara Selan ◽  
Pavel Jenicek ◽  
Eveline I. P. Volcke ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Oxidation Rate ◽  
Elemental Sulfur ◽  
Sulfide Oxidation ◽  
Cost Effective ◽  
Anaerobic Treatment ◽  
Batch Experiments ◽  
Cost Effective Method ◽  
Microaerobic Conditions ◽  
Kinetics Of

Abstract Hydrogen sulfide is a toxic and usually undesirable by-product of the anaerobic treatment of sulfate-containing wastewater. It can be removed through microaeration, a simple and cost-effective method involving the application of oxygen-limiting conditions (i.e., dissolved oxygen below 0.1 mg L−1). However, the exact transformation pathways of sulfide under microaerobic conditions are still unclear. In this paper, batch experiments were performed to study biochemical and chemical sulfide oxidation under microaerobic conditions. The biochemical experiments were conducted using a strain of Sulfuricurvum kujiense. Under microaerobic conditions, the biochemical sulfide oxidation rate (in mg S L−1 d−1) was approximately 2.5 times faster than the chemical sulfide oxidation rate. Elemental sulfur was the major end-product of both biochemical and chemical sulfide oxidation. During biochemical sulfide oxidation elemental sulfur was in the form of white flakes, while during chemical sulfide oxidation elemental sulfur created a white suspension. Moreover, a mathematical model describing biochemical and chemical sulfide oxidation was developed and calibrated by the experimental results.

New Insights into the Kinetics of the Gas-Phase Oxidation of Hexafluoropropene

2016 ◽  
Vol 41 (4) ◽  
pp. 418-427 ◽  
Author(s):  
David Lokhat ◽  
Maciej Starzak ◽  
Deresh Ramjugernath
Keyword(s):  
Gas Phase ◽  
Oxidation Process ◽  
Flow Reactor ◽  
Packed Column ◽  
Phase Reaction ◽  
Analytical Technique ◽  
Tubular Flow Reactor ◽  
Gas Phase Oxidation ◽  
Tubular Flow ◽  
Kinetics Of

The gas-phase reaction of hexafluoropropene and molecular oxygen was investigated in a tubular flow reactor at 450 kPa and within a temperature range of 463–493 K using HFP/O2 mixtures containing 20–67% HFP on a molar basis. Capillary and packed column chromatography served as the main analytical technique. The reaction yielded HFPO, COF2, CF3COF, C2F4 and c-C3F6 as gas-phase products. High molecular weight oligomers were also formed. The oligomers were found to have a polyoxadifluoromethylene structure according to elemental and 19F NMR analysis. At 493 K HFP is proposed to undergo oxygen-mediated decomposition to difluorocarbene radicals, yielding greater quantities of difluorocarbene recombination products. Kinetic parameters for a revised model of the oxidation process were identified through least squares analysis of the experimental data.

scholarly journals Chlorine and Chlorinated Compounds Removal from Industrial Wastewater Discharges: A Review

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Mohammad Al-Hwaiti ◽  
Hamidi Abdul Aziz ◽  
Mohd Azmier Ahmad ◽  
Reyad Al-Shawabkeh
Keyword(s):  
Industrial Wastewater ◽  
Electrochemical Techniques ◽  
Parent Compound ◽  
Water Soluble ◽  
Human Beings ◽  
Catalytic Method ◽  
Chlorinated Compounds ◽  
Water Treatment Process ◽  
Chlorine Removal ◽  
Kinetics Of

Adsorption techniques for industrial wastewater treatment rich in heavy metals and aqueous solutions of water-soluble such as Cl−, F−, HCO3−, NO3−, SO2−4, and PO3−, often include technologies for toxicity removals. The recent advancement and technical applicability in the treatment of chlorine and chlorinated compounds from industrial wastewater are reviewed in this article. Chlorine and chlorinated compounds are among the common discharged constituents from numerous industries. They can be carcinogenic or naturally toxic and can pose issues to aquatic ecosystems and human beings. Thus, elimination of chlorides and chlorinated compounds from water or wastewater is inevitable to get rid of the problem. Several techniques are being applied for the reduction of chlorine and chlorinated compounds in water. These include biodegradation, photochemical, adsorption, chemical, electrochemical, photo-electrochemical, membrane, supercritical extraction and catalytic method. Chlorine can react with various organic and inorganic micro-pollutants. However, the potential reactivity of chlorine for specific compounds is small, and only minor variations in the structure of the parent compound are anticipated in the water treatment process under typical conditions. This paper reviews different techniques and aspects related to chlorine removal, the types of chlorine species in solution and their catalyst, chlorine fate and transport into the environment, electrochemical techniques for de-chlorination of water, kinetics, mechanisms of reduction of chlorinated compounds, and kinetics of the electrochemical reaction of chlorine compounds. Keywords: Industrial waste, Kinetics, Wastewater, Water purification

scholarly journals Adsorption Equilibrium, Kinetics, Thermodynamics and Dynamic Separation of Magnesium and CalciumIons from Industrial Wastewater by New Strong Acid Cation Resin of SPVC

2021 ◽  
Vol 22 (1) ◽  
pp. 127-138
Author(s):  
Dilfuza Nuriddinova
Keyword(s):  
Calcium Ions ◽  
Industrial Wastewater ◽  
Adsorption Equilibrium ◽  
Dynamic Condition ◽  
Research Work ◽  
Strong Acid ◽  
Cation Resin ◽  
Acid Cation ◽  
Kinetics Of ◽  
Separation Results

In the research work, the adsorption equilibrium, kinetics, thermodynamics and dynamic separation of magnesium and calcium ions from industrial wastewater by new strong acid cation resin of SPVC (sulphonated polyvinylchloride) were investigated. The sorption capacity of the studied resin was 3.78 mmol/g and 3.74 mmol/g for magnesium and calcium ions, respectively, according to Langmuir isotherm. It was found that the pseudo−first−order model was better fitted for the adsorption kinetics of magnesium and calcium ions on the resin. The dynamic separation results confirmed that the selected resin effectively separated magnesium and calcium ions from industrial wastewater in the dynamic condition. The change of the standard Gibbs free energy (G) and enthalpy (H), and entropy (S) were calculated. The obtained results confirmed that the adsorption of magnesium and calcium ions on the selected resin is endothermic.

The Submerged Biofilm Process as a Pre-Treatment for Polluted Raw Water for Tap Water Supply

1990 ◽  
Vol 22 (1-2) ◽  
pp. 137-148 ◽  
Author(s):  
M. Takasaki ◽  
H. Kim ◽  
A. Sato ◽  
M. Okada ◽  
R. Sudo
Keyword(s):  
Tap Water ◽  
Ammonium Nitrogen ◽  
Raw Water ◽  
Factors Affecting ◽  
Treatment Performance ◽  
N Concentration ◽  
Pilot Plant Scale ◽  
Pre Treatment ◽  
Biofilm Process

The submerged biofilm process is a promising system for polluted raw water pre-treatment systems. General treatment performance and factors affecting treatment efficiency were investigated through pilot plant scale experiments using water from four different lakes. Regarding the quality of the raw waters, BOD was generally below 10 mg/l and the ammonium nitrogen (NH4-N) concentration was below 0.4 mg/l. The efficiency of removal of NH4-N was about 80% under complete mixing conditions and when the raw water quality did not fluctuate rapidly. Under the adverse conditions of the low water temperatures which occurred in winter and spring, the removal of NH4-N was 60 to 80%. The critical NH4-N concentration was observed to be approximately 0.01 to 0.02 mg/l, and a moderate decrease in E260 was also observed in the experiments. Overall treatment performance of the submerged biofilm process was superior in those systems with carriers which were not likely to become clogged.

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