pH-controlled reject-water-treatment

1998 ◽  
Vol 37 (12) ◽  
pp. 165-172 ◽  
Author(s):  
B. Wett ◽  
R. Rostek ◽  
W. Rauch ◽  
K. Ingerle
Keyword(s):  
Ph Value ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Nitrogen Loading ◽  
High Concentration ◽  
Loop Control ◽  
Reject Water ◽  
Line Measurement ◽  
Initial Ph ◽  
On Line

Dewatering of digested sludge causes significant internal nitrogen loading to a wastewater treatment plant. Due to the high concentration of nitrogen it is more effective to treat the reject-water not directly in the main purification process but to apply a separate biological treatment procedure. The intermittent operation of sludge-press facilities, the high initial pH-value of reject-water and the quick loss of alkalinity during nitrification makes a reliable control of the process necessary. A sequencing batch reactor (SBR) with an operational control based on on-line measurement of the pH-value is well suited to meet this requirement. Such a control system for discontinuous treatment of reject-water has been extensively tested and optimised in full-scale experiments since 1995. The closed loop control of the pH-value was developed to keep the bicarbonate concentration within an optimum range. At the WWTP Strass in western Austria stable nitrification rates of 50 to 60 mg NH4-N/l/h have been achieved (elimination of 200 kg nitrogen per day).

Control Strategies for a Highly Loaded Biological Ammonia Elimination Process

1993 ◽  
Vol 28 (11-12) ◽  
pp. 531-538 ◽  
Author(s):  
B. Teichgräber
Keyword(s):  
Closed Loop ◽  
Control Strategies ◽  
Level Control ◽  
Sludge Dewatering ◽  
Loop Control ◽  
Reject Water ◽  
Line Measurement ◽  
Control Pattern ◽  
On Line ◽  
Treatment Facilities

A nitrification/denitrification process was applied to reject water treatment from sludge dewatering at Bottrop central sludge treatment facilities of the Emschergenossenschaft. On-line monitoring of influent and effluent turbidity, closed loop control of DO and pH, and on-line monitoring of nitrogen compounds were combined to a three level control pattern. Though on-line measurement of substrate and product showed substantial response time it could be used to operate nitrification/denitrification within process boundaries.

scholarly journals Pre-fermentative treatment of a model wine with aim to serve as a functional food with decreased alcohol content

2017 ◽  
Vol 63 (01) ◽  
pp. 47-53
Author(s):  
Irina Mladenoska ◽  
Verica Petkova ◽  
Tatjana Kadifkova Panovska
Keyword(s):  
Enzyme Activity ◽  
Gluconic Acid ◽  
Functional Food ◽  
Ph Value ◽  
Enzymatic Reaction ◽  
Alginate Beads ◽  
High Concentration ◽  
Ph Optimum ◽  
Enzyme Preparations ◽  
Initial Ph

The effect of substrate concentration on the enzyme activity in the reaction of glucose conversion into gluconic acid was investigated by using three different enzyme preparations in media with two different glucose concentrations. The media were simulating the conditions in the must, thus named as minimal model must, and were composed form combination of several organic acids and glucose. Those media were having initial pH of 3.5 that is a very unfavorable for glucose oxidase activity having a pH optimum at the pH value of 5.5. Among the three preparations used, the bakery additive, Alphamalt Gloxy 5080, was the most active in the medium with glucose concentration of 10 g/L, showing conversion of more than 70% for the period of 24 h, while the same enzyme preparation in the medium with 100 g/L glucose converted only about 7% of glucose. The pH value of the medium at the beginning and at the end of the enzymatic reaction was a good indicator of the enzyme activity. It seems that for the conversion of glucose in higher concentration, enzymatic preparation in high concentration should also be used. The preliminary attempt of immobilization of two preparations of glucose oxidases in alginate beads was also performed and a successful immobilization procedure for utilization in food industry was preliminarily developed. Keywords: glucose oxidases, enzymatic pretreatment, glucose, gluconic acid, model wine, functional food

scholarly journals Effect of Intermittent Aeration in a Hybrid Vertical Anaerobic Biofilm Reactor (HyVAB) for Reject Water Treatment

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1151
Author(s):  
Vasan Sivalingam ◽  
Carlos Dinamarca ◽  
Eshetu Janka ◽  
Sergey Kukankov ◽  
Shuai Wang ◽  
...  
Keyword(s):  
Water Treatment ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Biofilm Reactor ◽  
Anaerobic Sludge ◽  
Main Process ◽  
Intermittent Aeration ◽  
High Concentration ◽  
Ammonium Removal ◽  
Reject Water

Water from anaerobic sludge dewatering (reject water that is recycled to the inlet main process treatment) from the Knarrdalstrand municipal wastewater treatment plant in Porsgrunn, Norway, contains 2.4 g/L of total chemical oxygen demand (TCOD) and 550 mg/L NH4-N (annual average). The high concentration of ammonium causes disturbances in the mainstream physical and chemical processes, while only a small fraction of the organics is biodegradable. A pilot-scale hybrid vertical anaerobic biofilm (HyVAB) reactor combining anaerobic and aerobic treatment was tested for reject water treatment to reduce process disturbances. The pilot HyVAB was prepared for the study with continuous aeration of the aerobic part of the reactor for 200 days, while two intermittent aeration schemes were applied during the three-month test period. Ammonium removal efficiency increased from 8% during the continuous aeration period to 50% at the end of the test when a short (7 min) aeration cycle was applied. COD removal was close to 20%, which was mainly obtained in the anaerobic stage and not significantly influenced by the aerations schemes. Simultaneous partial nitrification and denitrification were established in the biofilm that alternated between aerobic and anoxic conditions. The observed high ammonium removal is explained by two alternative shortcut processes via nitrite. The lack of biodegradable organics in the aerated stage suggests that most of the nitrogen removal was via the anammox pathway (autotrophic denitrification). The HyVAB, combining an anaerobic sludge bed and an intermittently aerated biofilm, appears to be an efficient process to treat high ammonium containing reject water.

Anaerobic bio-hydrogen production using pre-heated river sediments as seed sludge

2005 ◽  
Vol 52 (10-11) ◽  
pp. 31-39 ◽  
Author(s):  
J. Zuo ◽  
Y. Zuo ◽  
W. Zhang ◽  
J. Chen
Keyword(s):  
Hydrogen Production ◽  
Hydrogen Content ◽  
Ph Value ◽  
Batch Reactor ◽  
River Sediments ◽  
Organic Loading Rate ◽  
Seed Sludge ◽  
Initial Ph ◽  
Gas Separator ◽  
Different Levels

Anaerobic bio-hydrogen production is the focus in the field of bio-energy resources. In this paper, a series of batch experiments were conducted to investigate the effects of several factors on anaerobic bio-hydrogen producing process carried out by pre-heated river sediments. The results showed that several factors such as substrate and its concentration, temperature and the initial pH value could affect the anaerobic bio-hydrogen production in different levels. At 35°C and the initial pH of 6.5, using glucose of 20,000mg COD/L as substrate, the highest hydrogen production of 323.8ml-H2/g TVS in a 100ml batch reactor was reached, the specific hydrogen production rate was 37.7ml-H2/g TVSh, and the hydrogen content was 51.2%. Thereafter using the same pre-heated river sediments as seed sludge, continuous anaerobic bio-hydrogen production was achieved successfully in a lab-scale CSTR with gas-separator. At the organic loading rate of 36kg COD/m3d, the highest hydrogen production was 6.3–6.7l-H2/l-reactord, the specific hydrogen production was 1.3–1.4mol-H2/mol-glucose, and the hydrogen content in the gas was 52.3%. The effluent of the bio-reactor contained some small molecular organics, mainly including ethanol, acetate, butyrate and their molar proportion is 1 : 1 : 0.6.

Improving the start-up of an EBPR system using OUR to control the aerobic phase length: a simulation study

2006 ◽  
Vol 53 (4-5) ◽  
pp. 253-262 ◽  
Author(s):  
A. Guisasola ◽  
M. Pijuan ◽  
J.A. Baeza ◽  
J. Carrera ◽  
J. Lafuente
Keyword(s):  
Simulation Study ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Biological Phosphorus Removal ◽  
Measured Variable ◽  
Technical Limitation ◽  
Start Up ◽  
On Line ◽  
Polyphosphate Accumulating Organisms ◽  
Phase Length

The enhanced biological phosphorus removal (EBPR) process is based on enriching the sludge with polyphosphate accumulating organisms (PAO) which are scarce in conventional non-EBPR wastewater treatment plant sludge. Hence, the start-up of EBPR systems (i.e. enriching the sludge with PAO) can be very slow and complex. A simulation study of a possible improvement of the start-up of an EBPR system in a sequencing batch reactor is presented in this work. The improvement is based on reducing the length of the aerobic phase so that it coincides with the depletion of orthophosphate from the medium. This improvement, though verified by simulation to be very successful, requires a good on-line orthophosphate sensor. To avoid this technical limitation, a link between oxygen uptake rate (OUR) measurements and orthophosphate presence is proposed. This link allows the control of the aerobic phase length with OUR as a measured variable and, consequently, a considerable improvement with respect to the conventional fixed aerobic phase length operation. An improvement of 95% in the ratio of PAO to heterotrophs and an increase of 30% in the final amount of PAO in sludge is achieved with this control strategy. The kinetic mod for simulations was a modification of the Activated Sludge Model 2d.

Nutrient sensor based real-time on-line process control of a wastewater treatment plant using recirculation

1996 ◽  
Vol 33 (1) ◽  
pp. 183-192 ◽  
Author(s):  
P. Balslev ◽  
A. Lynggaard-Jensen ◽  
C. Nickelsen
Keyword(s):  
Process Control ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Aeration Tank ◽  
Biological Phosphorus Removal ◽  
Line Measurement ◽  
On Line ◽  
Line Process ◽  
New Generation ◽  
Biological Phosphorus

A new generation of sensors for on-line measurement of nitrate, ammonium and phosphorus has been used for process control in a pilot-scale plant. The pilot plant is designed for nitrogen removal using the recirculation principle for pre-denitrification. It has been shown that the supply of oxygen and recirculation of activated sludge to the denitrification tank can be controlled directly by a simple control routine using an on-line measurement of nitrate and ammonium in the aeration tank. There is potential for implementing biological phosphorus removal, when the level of nitrate in the recirculated sludge can be monitored on-line.

An on-line optimisation of a SBR cycle for carbon and nitrogen removal based on on-line pH and OUR: the role of dissolved oxygen control

2006 ◽  
Vol 53 (4-5) ◽  
pp. 171-178 ◽  
Author(s):  
S. Puig ◽  
Ll. Corominas ◽  
A. Traore ◽  
J. Colomer ◽  
M.D. Balaguer ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Nitrogen Removal ◽  
Pilot Plant ◽  
Batch Reactor ◽  
Treatment Plant ◽  
Ammonia Removal ◽  
Ph Profile ◽  
Carbon And Nitrogen ◽  
Dissolved Oxygen Control ◽  
On Line

A pilot plant sequencing batch reactor (SBR) was applied in a wastewater treatment plant treating urban wastewater focused on carbon and nitrogen removal. From an initial predefined step-feed cycle definition, the evolution of the on-line monitored pH and calculated oxygen uptake rate (OUR) were analysed in terms of knowledge extraction. First, the aerobic phases of the SBR cycle were operated using an On/Off dissolved oxygen (DO) control strategy that concluded with a sinusoidal pH profile that made detecting the “ammonia valley” difficult. After changing to fuzzy logic control of the dissolved oxygen and by adding an air flow meter to the pilot plant, the pH evolution and on-line calculated OUR showed a clearer trend during the aerobic phases. Finally, a proposed algorithm for adjusting the aerobic phases of the SBR for carbon and ammonia removal is presented and discussed.

Study of Removing Bacteria and Microcystis aeruginosa by Hydroxyl Radical

2013 ◽  
Vol 864-867 ◽  
pp. 418-421
Author(s):  
Wei Xu ◽  
Rong Jie Yi ◽  
Jing Jing Li ◽  
Jin De Song ◽  
Chen Wu Yi ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Microcystis Aeruginosa ◽  
Large Scale ◽  
Microbial Contamination ◽  
Treatment Process ◽  
Treatment Time ◽  
Ph Value ◽  
High Concentration ◽  
Initial Ph ◽  
Strong Ionization Discharge

The 1.5t/h algae and bacteria wastewater with high concentration was treated by hydroxyl radical (OH) produced by a strong ionization discharge. In this paper, the feasibility of kill bacteria and alga by OH was investigated, and effects of OH concentration, treatment time and pollution initial concentration on degrading microorganisms by OH were investigated in detail. The results indicated that the treatment process was effective in the degradation of the bacteria and alga at the initial pH value of 7.1, OH dosage of 2.33mg/L, the initial microcystis aeruginosa concentration of 106/mL and the initial bacterial dosage of 106cfu/mL, the bacteria and alga degradation rate reached 99.99% at 303K after 15min treatment. The results provided a theoretical basis for the OH treatment of microbial contamination in drinking water in large-scale.

scholarly journals Engineered electrocoagulation reactor for the removal of E. coli from wastewaters

2021 ◽  
Vol 877 (1) ◽  
pp. 012048
Author(s):  
Eman A. Al-Imara ◽  
Rand L. Al-Jaryan ◽  
Sabrean F. Jawad ◽  
Mohanad M. Kareem ◽  
Hayfaa A. Mubarak
Keyword(s):  
Biocontrol Agent ◽  
Ph Value ◽  
Low Cost ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Steel Plates ◽  
E Coli ◽  
Initial Ph ◽  
Treatment And Disposal ◽  
A Current

Abstract As a consequence of natural pollution, water and sewage are polluted in many nations across the globe. Especially in poorer countries, sewage treatment and disposal practices are often substandard. Throughout many limited-income nations, the poor economic condition and absence of resources assistance severely hamper the planning and application of novel water and sewage systems. This has resulted in a rise in the number of bio-contaminants in the environment. The objective of this study is to use electrocoagulation as a low-cost method to remove or lower the amount of bio contaminant in sewage. By transmitting a voltage between the two conductors, disinfectants are generated in place. Sewerage samples were obtained at the Kerbala wastewater treatment plant, which is situated south of Kerbala, Iraq. In this work, steel plates were utilized to create coagulants. Furthermore, the effect of many factors on the performance of the electrolysis device was studied, namely spacing among electrodes and current density. The analysis indicates after 40 min of irradiation employing electrodes spaced 5mm apart and a current intensity of 2 mA/cm2, the E. coli bacteria as a biocontrol agent were killed. Furthermore, the results demonstrated that an initial pH value of 6.0 is appropriate for bio-contaminants removal utilizing electrocoagulation.

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