Stabilized green rusts for aqueous Cr(VI) removal: Fast kinetics, high iron utilization rate and anti-acidification

Chemosphere ◽  
2021 ◽  
Vol 262 ◽  
pp. 127853 ◽  
Author(s):  
Jinxin Zhao ◽  
Shuting Xiong ◽  
Jing Ai ◽  
Jinhua Wu ◽  
Li-Zhi Huang ◽  
...  
Keyword(s):  
Utilization Rate ◽  
Fast Kinetics ◽  
High Iron ◽  
Green Rusts ◽  
Iron Utilization

RESEARCH AND EVALUATE TREATMENT EFFICIENCY ON TAPIOCA PROCESSING INDUSTRIAL WASTEWATER BY AEROBIC BIOFILTER TECHNOLOGY WITH VARIOUS MATERIALS

2010 ◽  
Vol 13 (3) ◽  
pp. 54-66
Author(s):  
Phuong Thi Thanh Nguyen ◽  
Phuoc Van Nguyen ◽  
Anh Cam Thieu
Keyword(s):  
Wastewater Treatment ◽  
Industrial Wastewater ◽  
Utilization Rate ◽  
Organic Loading ◽  
Treatment Efficiency ◽  
Research Results ◽  
Loading Rates

This study was performed to evaluate the efficiency of tapioca processing wastewater treatment using aerobic biofilter with variety of biofilter media: coir, coal, PVC plastic and Bio - Ball BB15 plastic. Research results in the lab demonstrated all four aerobic biofilter models processed can treated completely N and COD which COD reached 90-98% and N reached 61-92%, respectively, at the organic loading rates in range of 0.5, 1, 1.5 and 2 kgCOD/m3.day. The results identified coir filter was the best in four researched materials with removal COD and specific substract utilization rate can reach 98%, and 0.6 kg COD/kgVSS.day. Research results open the new prospects for the application of the cheap materials, available for wastewater treatment.

ON THE PROCESSING OF HEMATITE RAW MATERIALS AT THE KRYVOROZHSK MINING AND PROCESSING PLANT OF OXIDIZED ORE ON TECHNOLOGY OF DIRECT RECOVERY ITmk3

2018 ◽  
pp. 32-37
Author(s):  
P.I. Loboda ◽  
Younes Razaz ◽  
S. Grishchenko
Keyword(s):  
Magnetic Properties ◽  
Cast Iron ◽  
Iron Content ◽  
Raw Materials ◽  
Direct Reduction ◽  
Processing Plant ◽  
High Iron Content ◽  
High Iron ◽  
Direct Restoration ◽  
First Time

Purpose. To substantiate the efficiency of processing hematite raw materials at the Krivoy Rog Mining and Processing Plant of Oxidized Ores using the direct reduction technology itmk3®. Metodology. Analysis of the results of the itmk3® direct restoration technology developed by Kobe Steel Ltd., Japan and Hares Engineering GmbX, Austria, with a view to using it to process Krivbass hematite ores into granulated iron (so-called “nuggets”). Findings. The involvement in the production of hematite ores (oxidized quartzite) of Krivbass with high iron content, but with low magnetic properties for their processing into granular cast iron is grounded. Originality. The use of itmk3® direct reduction technology from Kobe Steel Ltd., Japan and Hares Engineering GmbH, Austria for the processing of Krivbass hematite ores into granular cast iron is justified for the first time. Practical value. The efficiency of the use of hematite ores (oxidized quartzite) has been substantiated, which can significantly reduce the costs in the mining cycle for the economical production of metallurgical products.

The Impact of a Chemostat Discharge Containing Oil Degrading Bacteria on the Biological Kinetics of a Refinery Activated Sludge Process

1988 ◽  
Vol 20 (11-12) ◽  
pp. 131-136 ◽  
Author(s):  
A. D. Wong ◽  
C. D. Goldsmith
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Waste Treatment ◽  
Treatment Plant ◽  
Utilization Rate ◽  
Activated Sludge Process ◽  
Kinetic Evaluation ◽  
Degrading Bacteria ◽  
Waste Treatment Plant ◽  
The Impact

The effect of discharging specific oil degrading bacteria from a chemostat to a refinery activated sludge process was determined biokinetically. Plant data for the kinetic evaluation of the waste treatment plant was collected before and during treatment. During treatment, the 500 gallon chemostatic growth chamber was operated on an eight hour hydraulic retention time, at a neutral pH, and was fed a mixture of refinery wastewater and simple sugars. The biokinetic constants k (days−1), Ks (mg/L), and K (L/mg-day) were determined before and after treatment by Monod and Lineweaver-Burk plots. Solids discharged and effluent organic concentrations were also evaluated against the mean cell retention time (MCRT). The maximum utilization rate, k, was found to increase from 0.47 to 0.95 days−1 during the operation of the chemostat. Subsequently, Ks increased from 141 to 556 mg/L. Effluent solids were shown to increase slightly with treatment. However, this was acceptable due to the polishing pond and the benefit of increased ability to accept shock loads of oily wastewater. The reason for the increased suspended solids in the effluent was most likely due to the continual addition of bacteria in exponential growth that were capable of responding to excess substrate. The effect of the chemostatic addition of specific microbial inocula to the refinery waste treatment plant has been to improve the overall organic removal capacity along with subsequent gains in plant stability.

A Technique to Determine Unsteady-State Inhibition Kinetics in the Activated Sludge Process

1989 ◽  
Vol 21 (6-7) ◽  
pp. 593-602 ◽  
Author(s):  
Andrew T. Watkin ◽  
W. Wesley Eckenfelder
Keyword(s):  
Activated Sludge ◽  
Kinetic Parameters ◽  
Curve Fitting ◽  
Glucose Utilization ◽  
Batch Reactor ◽  
Synthetic Data ◽  
Utilization Rate ◽  
Fitting Algorithm ◽  
Test Reactor ◽  
Two Parameter

A technique for rapidly determining Monod and inhibition kinetic parameters in activated sludge is evaluated. The method studied is known as the fed-batch reactor technique and requires approximately three hours to complete. The technique allows for a gradual build-up of substrate in the test reactor by introducing the substrate at a feed rate greater than the maximum substrate utilization rate. Both inhibitory and non-inhibitory substrate responses are modeled using a nonlinear numerical curve-fitting technique. The responses of both glucose and 2,4-dichlorophenol (DCP) are studied using activated sludges with various acclimation histories. Statistically different inhibition constants, KI, for DCP inhibition of glucose utilization were found for the various sludges studied. The curve-fitting algorithm was verified in its ability to accurately retrieve two kinetic parameters from synthetic data generated by superimposing normally distributed random error onto the two parameter numerical solution generated by the algorithm.

Inhibition kinetics for propionate degradation using propionate-enriched mixed cultures

1998 ◽  
Vol 38 (8-9) ◽  
pp. 443-451 ◽  
Author(s):  
S. H. Hyun ◽  
J. C. Young ◽  
I. S. Kim
Keyword(s):  
Phase I ◽  
Competitive Inhibition ◽  
Gas Production ◽  
Phase Iii ◽  
Utilization Rate ◽  
Inhibition Kinetics ◽  
Wide Range ◽  
Propionate Degradation ◽  
Acetate Utilization ◽  
Velocity Coefficient

To study propionate inhibition kinetics, seed cultures for the experiment were obtained from a propionate-enriched steady-state anaerobic Master Culture Reactor (MCR) operated under a semi-continuous mode for over six months. The MCR received a loading of 1.0 g propionate COD/l-day and was maintained at a temperature of 35±1°C. Tests using serum bottle reactors consisted of four phases. Phase I tests were conducted for measurement of anaerobic gas production as a screening step for a wide range of propionate concentrations. Phase II was a repeat of phase I but with more frequent sampling and detailed analysis of components in the liquid sample using gas chromatography. In phase III, different concentrations of acetate were added along with 1.0 g propionate COD/l to observe acetate inhibition of propionate degradation. Finally in phase IV, different concentrations of propionate were added along with 100 and 200 mg acetate/l to confirm the effect of mutual inhibition. Biokinetic and inhibition coefficients were obtained using models of Monod, Haldane, and Han and Levenspiel through the use of non-linear curve fitting technique. Results showed that the values of kp, maximum propionate utilization rate, and Ksp, half-velocity coefficient for propionate conversion, were 0.257 mg HPr/mg VSS-hr and 200 mg HPr/l, respectively. The values of kA, maximum acetate utilization rate, and KsA, half-velocity coefficient for acetate conversion, were 0.216 mg HAc/mg VSS-hr and 58 mg HAc/l, respectively. The results of phase III and IV tests indicated there was non-competitive inhibition when the acetate concentration in the reactor exceeded 200 mg/l.

Recent Advances in Heterostructured Photocatalysts for Degradation of Organic Pollutants.

2020 ◽  
Vol 17 ◽  
Author(s):  
Chen-Jing Sun ◽  
Li-Ping Zhao ◽  
Rui Wang
Keyword(s):  
Organic Pollutants ◽  
High Efficiency ◽  
Separation Efficiency ◽  
Organic Pollution ◽  
Utilization Rate ◽  
Type I ◽  
Human Beings ◽  
Global Challenge ◽  
Global Environmental ◽  
High Efficient

: With the development of industrialization, the global environmental pollution and energy crisis are becoming increasingly serious. Organic pollutants pose a serious health threat to human beings and other organisms. The removal of organic pollutants in environment has become a global challenge. The photocatalytic technology has been widely used in the degradation of organic pollutants with its characteristics of simple process, high efficiency, thorough degradation and no secondary pollution. However, the single photocatalyst represented by TiO2 has disadvantages of low light utilization rate and high recombination rate of photocarriers. Building heterojunction is considered one of the most effective methods to enhance the photocatalytic performance of single photocatalyst, which can improve the separation efficiency of photocarriers and utilization of visible light. The classical heterojunction can be divided into four different cases: type I, typeⅡ, p–n heterojunctions and Z-scheme junction. In this paper, the recent progress in the treatment of organic pollution by heterostructure photocatalysts is summarized and the mechanism of heterostructure photocatalysts for the treatment of organic pollutants is reviewed. It is expected that this paper can deepen the understanding of heterostructure photocatalysts and provide guidance for high efficient photocatalytic degradation of organic pollutants in the future.

Reduction of the Low Voltage Substation Constraints by Inserting Photovoltaic Systems in Underserved Areas

2019 ◽  
Vol 12 (2) ◽  
pp. 105-112
Author(s):  
Benbouza Naima ◽  
Benfarhi Louiza ◽  
Azoui Boubekeur
Keyword(s):  
Low Voltage ◽  
Voltage Drop ◽  
Electrical Energy ◽  
Utilization Rate ◽  
Photovoltaic Systems ◽  
Voltage Distribution ◽  
Medium Voltage ◽  
Pv Systems ◽  
Transformer Substation ◽  
Load Pattern

Background: The improvement of the voltage in power lines and the respect of the low voltage distribution transformer substations constraints (Transformer utilization rate and Voltage drop) are possible by several means: reinforcement of conductor sections, installation of new MV / LV substations (Medium Voltage (MV), Low Voltage (LV)), etc. Methods: Connection of mini-photovoltaic systems (PV) to the network, or to consumers in underserved areas, is a well-adopted solution to solve the problem of voltage drop and lighten the substation transformer, and at the same time provide clean electrical energy. PV systems can therefore contribute to this solution since they produce energy at the deficit site. Results: This paper presents the improvement of transformer substation constraints, supplying an end of low voltage electrical line, by inserting photovoltaic systems at underserved subscribers. Conclusion: This study is applied to a typical load pattern, specified to the consumers region.

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