Determination of chlorine demand in water and wastewater chlorination by oxidation-reduction potential

2003 ◽  
Vol 3 (1-2) ◽  
pp. 313-320 ◽  
Author(s):  
R.F. Yu ◽  
W.P. Cheng
Keyword(s):  
Control Strategy ◽  
Reduction Potential ◽  
Wastewater Treatment Plants ◽  
Water And Wastewater Treatment ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
On Line ◽  
Water And Wastewater ◽  
Chlorine Demand

Chlorination is the most practical way for the destruction of pathogenic and other harmful organisms in water and wastewater treatment plants. However, highly erratic concentrations of ammonia is contained in most water and wastewater treatment plants, which will react to chlorine and seriously alter the required chlorine dosages in the control of chlorination. The conventional control of chlorine dosage is widely practical throughout the batch breakpoint chlorination test in the laboratory, which is not feasible for the requirement of real-time regulation of the chlorine demands. In this study, a simple automatic oxidation-reduction potential (ORP) titration system was developed for on-line determination of the chlorine demand. The experimental results showed that different decrease tendencies on ORP slope profiles were found to correlate to the ammonia concentrations in samples. In addition, the required chlorine demands were found to correlate to ammonia concentrations with a linear relationship. The ORP control strategy was, therefore, developed for on-line determination of the chlorine demands. Applying this ORP control strategy, the required chlorine demands were precisely predicted, and good disinfection efficiency was obtained in the wastewater chlorination experiments.

Effect of co-substrate, biomass and sulfate concentration on the performance of a control strategy used to determine the anaerobic stage length of an anaerobic/aerobic SBR degrading p-nitrophenol

2005 ◽  
Vol 52 (1-2) ◽  
pp. 441-447 ◽  
Author(s):  
G. Buitrón ◽  
G. Moreno ◽  
M.E. García ◽  
J. Moreno
Keyword(s):  
Significant Influence ◽  
Control Strategy ◽  
Reduction Potential ◽  
Biomass Concentration ◽  
Sulfate Concentration ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Acid Ratio ◽  
Line Measurement ◽  
On Line

The effect of the p-nitrophenol to propionic acid ratio, the biomass concentration, and the presence of sulfates on the performance of a control strategy of an anaerobic/aerobic SBR degrading p-nitrophenol was studied. The duration of the anaerobic stage was controlled by an algorithm based on the on-line measurement of the oxidation-reduction potential, which indicates the end of the reduction of p-nitrophenol to p-aminophenol. It was observed that no significant influence on the performance of the algorithm was found when the co-substrate, the biomass concentration and the presence of sulfates were varied, indicating the robustness of the control strategy. Only for the case when a low concentration of co-substrate was used, was there no transformation of p-nitrophenol.

Development of a new system for control and optimization of small wastewater treatment plants using oxidation-reduction potential (ORP)

1998 ◽  
Vol 38 (3) ◽  
pp. 307-314 ◽  
Author(s):  
T. Zipper ◽  
N. Fleischmann ◽  
R. Haberl
Keyword(s):  
Pilot Plant ◽  
Reduction Potential ◽  
Wastewater Treatment Plants ◽  
Control Strategies ◽  
Aeration Tank ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Suitable Parameter ◽  
On Line ◽  
Time Cycle

For the development of new control strategies for small activated sludge systems (<500 P.E.) the oxidation-reduction potential (ORP) has been tested as a suitable parameter. Batch and continuous experiments in a pilot plant with alternating nitrification and denitrification phases proved the relation between the actual load and the behaviour of ORP in the aeration tank. Using a two-point controller, increasing load correlated with an extension of aerated phases in relation to unaerated phases. Decreasing load equalled to a decrease of the ratio of nitrification time-cycle time. On the basis of these results an ORP controller has been developed allowing both automatic setup and on-line adaption. Operational results from a pilot plant are presented, including effluent quality and energy efficiency.

scholarly journals Do Wet-Dry Ratio and Fe-Mn System Affect Oxidation-Reduction Potential Nonlinearly in the Subsurface Wastewater Infiltration Systems?

2018 ◽  
Vol 15 (12) ◽  
pp. 2790
Author(s):  
Xiaorong Zhang ◽  
Haibo Li ◽  
Yinghua Li ◽  
Fei Guo ◽  
Zhongxin Yang ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Water Content ◽  
Reduction Potential ◽  
Initial Period ◽  
Dry Period ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Hypoxic Environment ◽  
Hydraulic Load ◽  
On Line

To understand characteristics of on-line oxidation-reduction potential (ORP) in a subsurface wastewater infiltration system (SWIS) under different intermittent influent conditions, ORP among five matrix depths at wet-dry ratios (Rwds) of 2:1, 1:1 and 1:2 with a hydraulic load of 0.10 m3·(m2·d)−1 were monitored. Results showed that the optimal Rwd for the SWIS was 1:1. In that case, ORP at 40 and 65 cm depths changed significantly, by 529 mV and 261 mV, respectively, from the inflow period to the dry period, which was conducive to the recovery of the oxidation environment. It was concluded that ORP varied nonlinearly in strongly aerobic and hypoxic environment. Wastewater was fed into the SWIS at 80 cm and dissolved oxygen diffused at the initial period of one cycle. As a consequence, ORP at 65 cm increased with water content increasing. However, ORP at 40 and 95 cm displayed inverse trends. Moreover, results showed that ORP decreased with Fe2+ and Mn2+ increasing under aerobic conditions (p < 0.05) because Fe2+ and Mn2+ moved with wastewater flow. Effluent met reuse requirements and no clogging was found in the SWIS during the operation.

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