Monitoring cations to predict and improve activated sludge settling and dewatering properties of industrial wastewaters

1998 ◽  
Vol 38 (3) ◽  
pp. 119-126 ◽  
Author(s):  
Sudhir N. Murthy ◽  
John T. Novak ◽  
Robert D. De Haas
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Divalent Cations ◽  
Treatment Plant ◽  
Field Tests ◽  
Ammonium Ion ◽  
Ammonium Ions ◽  
High Concentration ◽  
The Impact

Laboratory and field tests were conducted on activated sludge from an industrial wastewater treatment plant in order to monitor the settling and dewatering properties and to assess the impact cations may have on these properties. The influent to the wastewater treatment plant contained a high concentration of sodium ions and a low concentration of divalent cations. The sludge exhibited poor settling and dewatering properties. Initial laboratory results indicated an improvement in settling and dewatering properties through the addition of calcium and magnesium. After addition of magnesium during field trials, floc density and settling properties improved considerably. In addition, residual ammonium ions in the mixed liquor appeared to interact with the activated sludge flocs to influence their dewatering properties. It was observed that an increase in ammonium ion in the soluble sludge fraction was related to deterioration in the dewatering properties. During these trials, the ammonium ions demonstrated a greater influence on dewatering properties than did the magnesium ions. The tests conducted at the treatment plant revealed that complex interactions between cations and sludge influenced the settling and dewatering properties in a manner that depended on ratios and concentrations of monovalent and divalent cations in the activated sludge feed and solution.

scholarly journals Differential Impact of the Prior Mix by Stirring in the Biodegradation of Sunflower Oil

2021 ◽  
Author(s):  
Pedro Eulogio Cisterna Osorio ◽  
Barbara Faundez-Miño
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Sunflower Oil ◽  
Treatment Plant ◽  
Fats And Oils ◽  
Mass Loading ◽  
Mechanical Agitation ◽  
High Incidence ◽  
The Impact

Fats and oils present in wastewater are usually eliminated by physical and biological processes. In this experience, the fatty wastewaters are treated biologically, and it assesses the impact of the mix in the fats and oils biodegradation and carried out the experiments in a laboratory scale unit. The biodegradation of fats and oils was analysed in two sceneries, with mix previous by mechanical agitation and without mix. Key parameters were monitored, such as the concentration of fats and oils in the influents and effluents, mass loading, and the efficiency of biodegradation. The mass loading range was similar in both sceneries. In the experimental activated sludge plant without mix, the biodegradation of fats and oils reached levels in the range of 28 to 42.5%. For the wastewater treatment plant with a previous mix by mechanical agitation, the levels of biodegradation of fats and oils ranged from 64 to 75%. Therefore, considering the efficiency of the biodegradation of fats and oils in both sceneries, the results indicated that the level mix is a high incidence.

scholarly journals An Investigation of Impact of Iron and Aluminium Addition on the Anaerobic Digestion Process

2017 ◽  
pp. 558-563
Author(s):  
Svetlana Ofverstrom ◽  
Ieva Sapkaite ◽  
Regimantas Dauknys
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Anaerobic Digester ◽  
Anaerobic Digestion Process ◽  
Digestion Process ◽  
Aluminium Addition ◽  
The Impact

In this study, the impact of iron and aluminium salts addition on anaerobic digestion process was investigated. Mixture of primary and activated sludge collected at Vilnius wastewater treatment plant in Lithuania was digested under laboratory conditions by using anaerobic digester (W8, Amfield, UK). To compare the relative digestibility of iron-dosed (Fe-dosed)and aliuminium-iron-dosed (Al-Fe-dosed) sludge with un-dosed sludge three continuous experiments were made. Results showed that iron and aliuminium negatively impacted anaerobic digestion process by reducing the volume of biogas produced. Fe-dosed sludge produced 20-50% less biogas and Al-Fe-dosed sludge produced 30-40% less biogas in comparison to the same un-dosed sludge. VS destruction decreased during dosing of Fe or/and Al salt. Biogas composition was not measured during the experiments.

scholarly journals Activated Sludge Respiration Activity Inhibition Caused by Mobile Toilet Chemicals

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 598 ◽  
Author(s):  
Tomáš Vítěz ◽  
Monika Vítězová ◽  
Markéta Nováčková ◽  
Ivan Kushkevych
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Respiratory Activity ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Respiration Activity ◽  
Wastewater Treatment Process ◽  
The Impact ◽  
Active Substances

Ensuring high quality drinking water sources is important task nowadays. To reach this task, knowledge about the impact of different chemicals on aerobic wastewater treatment is mandatory. A mixture of different chemicals reaches wastewater treatment plant every day. With the growing discharge volume of mobile toilet chemicals, active substances in these products in the past years have been recorded. The respiratory activity of activated sludge was determined to show how mobile toilet chemicals and their active substances may affect the biological wastewater treatment process. The results show negative effect of formaldehyde and bronopol on respiratory activity of activated sludge. The wastewater treatment plants influent composition and size also play important roles. Results shows that activated sludge microorganisms at a wastewater treatment plant in industrial urban area may be adapted to the higher pollutants concentration. When mobile toilet tanks are directly discharged at smaller wastewater treatment plant, an activated sludge process can be affected. For treating mobile toilet wastewater, bacterial degraders can be used. During our respiratory activity experiments, potential degraders were searched. Ralstonia sp. prevails in all samples and it is therefore a potential mobile toilet chemicals degrader.

scholarly journals Nitrogen Removal in a Full-Scale Domestic Wastewater Treatment Plant with Activated Sludge and Trickling Filter

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Davood Nourmohammadi ◽  
Mir-Bager Esmaeeli ◽  
Hossein Akbarian ◽  
Mohammad Ghasemian
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Treated Wastewater ◽  
Trickling Filter ◽  
High Concentration ◽  
Nitrogen Gas

During the last decade, more stringent effluent requirements concerning the nutrients effluent values have been imposed by legislation and social concern. In this study, efficiency of total nitrogen removal in activated sludge and trickling filter processes (AS/TF) was investigated in Tehran North wastewater treatment plant. Biological system in this site was included, anoxic selector tank, aeration tank, final sedimentation, and trickling filter. A part of treated wastewater before chlorination was mixed with supernatant of dewatered sludge and fed to the trickling filter. Supernatant of dewatered sludge with high concentration of NH4-N was diluted by treated wastewater to provide complete nitrification in trickling filter Produced nitrate in trickling filter was arrived to the anoxic tank and converted to nitrogen gas by denitrification. According to the study result, low concentration of organic carbone and high concentration of NH4-N led to nitrification in TF, then nitrate denitrification to nitrogen gas occurred in selector area. NH4-N concentration decreased from 26.8 mg/L to 0.29 mg/L in TF, and NO3-N concentration increased from 8.8 mg/L to 27 mg/L in TF. Consequently, the total nitrogen decreased approximately to 50% in biological process. This efficiency has been observed in returned flow around 24% from final sedimentation into TF. It was concluded that, in comparison with biological nutrient removal processes, this process is very efficient and simple.

Rehabilitation and Upgrading of the Beni Suef City Wastewater Treatment Plant

1990 ◽  
Vol 22 (7-8) ◽  
pp. 131-138
Author(s):  
Ahmed Fadel
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Primary Treatment ◽  
High Rate ◽  
Shock Load ◽  
Economic Evaluations ◽  
Activated Sludge Process ◽  
Trickling Filter

Many of Egypt's cities have existing treatment plants under operation that have been constructed before 1970. Almost all of these treatment plants now need rehabilitation and upgrading to extend their services for a longer period. One of these plants is the Beni Suef City Wastewater Treatment Plant. The Beni Suef WWTP was constructed in 1956. It has primary treatment followed by secondary treatment employing intermediate rate trickling filters. The BOD, COD, and SS concentration levels are relatively high. They are approximately 800, 1100, and 600 mg/litre, respectively. The Beni Suef city required the determination of the level of work needed for the rehabilitation and upgrading of the existing 200 l/s plant and to extend its capacity to 440 l/s at year 2000 A description of the existing units, their deficiencies and operation problems, and the required rehabilitation are presented and discussed in this paper. Major problems facing the upgrading were the lack of space for expansion and the shortage of funds. It was, therefore, necessary to study several alternative solutions and methods of treatment. The choice of alternatives was from one of the following schemes: a) changing the filter medium, its mode of operation and increasing the number of units, b) changing the trickling filter to high rate and combining it with the activated sludge process, for operation by one of several possible combinations such as: trickling filter-solids contact, roughing filter-activated sludge, and trickling filter-activated sludge process, c) dividing the flow into two parts, the first part to be treated using the existing system and the second part to be treated by activated sludge process, and d) expanding the existing system by increasing the numbers of the different process units. The selection of the alternative was based on technical, operational and economic evaluations. The different alternatives were compared on the basis of system costs, shock load handling, treatment plant operation and predicted effluent quality. The flow schemes for the alternatives are presented. The methodology of selecting the best alternative is discussed. From the study it was concluded that the first alternative is the most reliable from the point of view of costs, handling shock load, and operation.

NH4 automatic analysers for wastewater treatment plant: evaluation test at laboratory and field level

1996 ◽  
Vol 33 (1) ◽  
pp. 193-201
Author(s):  
H. Wacheux ◽  
J.-L. Million ◽  
C. Guillo ◽  
E. Alves
Keyword(s):  
Wastewater Treatment ◽  
Response Time ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Field Tests ◽  
Time Range ◽  
Data Link ◽  
Factors Of Influence ◽  
June July ◽  
Plant Evaluation

Nine NH4 automatic analysers or monitors were tested in June-July 1995 (among them 2 prototypes): - 5 based on ion electrode; ABB, Applikon, Contronic, Hydro-Environnement, STIP, - 4 based on colorimetry; Danfoss, Data Link (UV absorption), Meerestechnik, Skalar Laboratory tests are aimed to determine response time, repeatability, response linearity, short-term stability, influence of various factors on the measurement. The field test relates to real conditions: all the sensors were installed in parallel at the discharge point of a Wastewater treatment plant (WWTP). Recorded outputs were compared with conventional laboratory analysis of average hourly samples. Response time range from 2 to 21 minutes. Repeatability varies from 1 to 10%, stability from 1 to 17%. Linearity is always good and detection limits (about 0.2 mg/l) do not seem to be critical for use in a WWTP. Among factors of influence, power voltage has limited effect, sample temperature is affecting some monitors, chemical interferents have nearly no effect excepted for one monitor. Field tests have shown that NH4 monitors are still very sensitive and that installation is crucial. Each monitor suffered several failures, some of them required high maintenance and used costly reagents.

Operational Results of the Wolfsburg Wastewater Treatment Plant

1992 ◽  
Vol 25 (4-5) ◽  
pp. 203-209 ◽  
Author(s):  
R. Kayser ◽  
G. Stobbe ◽  
M. Werner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Content ◽  
Total Nitrogen ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Phosphate Removal ◽  
Total Nitrogen Content ◽  
Activated Sludge Process

At Wolfsburg for a load of 100,000 p.e., the step-feed activated sludge process for nitrogen removal is successfully in operation. Due to the high denitrification potential (BOD:TKN = 5:1) the effluent total nitrogen content can be kept below 10 mg l−1 N; furthermore by some enhanced biological phosphate removal about 80% phosphorus may be removed without any chemicals.

Management of toxicity effects in a large wastewater treatment plant

1997 ◽  
Vol 36 (2-3) ◽  
pp. 1-8 ◽  
Author(s):  
P. Grau ◽  
B. P. Da-Rin
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Severe Case ◽  
Treatment Efficiency ◽  
Filamentous Bulking ◽  
Biological Phenomena ◽  
Inhibition Of Nitrification ◽  
Toxicity Effects

An unusually severe case of toxicity accompanied by activated sludge filamentous bulking was observed at the wastewater treatment plant Sao Paulo-Barueri. Treatment efficiency of the plant, operated without major problems for more than five years before, was significantly hindered for almost six months. Occurrence of toxic shocks was confirmed partly directly but mostly indirectly by inhibition of nitrification and biological phenomena related to toxicity. Several measures adopted, including the recycled activated sludge chlorination, are described in the paper.

Optimisation and control of the inflow to a wastewater treatment plant using integrated modelling tools

1998 ◽  
Vol 37 (1) ◽  
pp. 347-354 ◽  
Author(s):  
Ole Mark ◽  
Claes Hernebring ◽  
Peter Magnusson
Keyword(s):  
Wastewater Treatment ◽  
Real Time ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pilot Project ◽  
Integrated Modelling ◽  
Real Time Control ◽  
Sewer System ◽  
Time Control ◽  
The Impact

The present paper describes the Helsingborg Pilot Project, a part of the Technology Validation Project: “Integrated Wastewater” (TVP) under the EU Innovation Programme. The objective of the Helsingborg Pilot Project is to demonstrate implementation of integrated tools for the simulation of the sewer system and the wastewater treatment plant (WWTP), both in the analyses and the operational phases. The paper deals with the programme for investigating the impact of real time control (RTC) on the performance of the sewer system and wastewater treatment plant. As the project still is in a very early phase, this paper focuses on the modelling of the transport of pollutants and the evaluation of the effect on the sediment deposition pattern from the implementation of real time control in the sewer system.

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