Optimization of Nitrogen Removal in Small Activated Sludge Plants

1990 ◽  
Vol 22 (3-4) ◽  
pp. 123-130 ◽  
Author(s):  
A. Heduit ◽  
Ph Duchene ◽  
L. Sintes
Keyword(s):  
Activated Sludge ◽  
Field Experiments ◽  
Sewage Treatment ◽  
Operating Time ◽  
Oxygen Demand ◽  
Organic Load ◽  
Residual Concentration ◽  
Aeration Time ◽  
Rag 1 ◽  
Sludge Concentration

In France, many small sewage treatment plants are of the activated sludge/extended aeration type and, generally, only receive a part of their nominal organic load. They are mostly equipped with surface aerators whose Standard wire Aeration Efficiency is in the range 1.3-1.9 kg 02 kwh−1. Consequently the sludge age and the supply of oxygen are sufficient to obtain a large elimination of nitrogen from domestic waste water even when the sludge temperature is low. However the concern is with the optimizing of the nitrogen treatment by the nitrification of ammonia in the aeration basin whilst avoiding any parasitic denitrification in the clarifier. Amongst other investigations, 4 small domestic wastewater treatment plants were studied over several months. A number of adjustment modifications were imposed on them in order to optimize the elimination of nitrogen : The final concentrations to be reached were : N-NH4− lower than 5 mg.l−1 and N-NO3− lower than 3 mg.l−1. The daily operating time of the aerators depends on the received load, the sludge concentration and the oxygenation capacity. When the works are under-loaded, the non-operational periods of the aerators should be as long as 1 1/2 and 2 hours in order to achieve the nitrates reduction. When the load is higher, the time required to attain anoxia after the shutdown of the aerators is shorter and the length of the non-operational periods can be reduced. These field experiments have allowed an evaluation of the tolerances around an optimum adjustment of the aeration operation : a reduction of 5 to 10 % of the daily aeration time may bring about an increase in the residual concentration of Kjeldahl nitrogen which reaches 10 rag.1−1. Conversely, sludge losses may take place in the clarifiers if the daily aeration time is increased by 5 to 10 % in the case of completely mixed basins equipped with slow vertical shaft aerators, and more than 15 % in the case of oxidation ditches (better denitrification probably due to the continuation of the current after stopping the rotors). The sludge concentration should be kept within fairly tight limits (± 0.5 g.1−1). It is however essential to rectify the aeration adjustments during the seasons : a rise in the sludge temperature of 10°C generates an increase in the total oxygen demand by 3 to 5 %. The particular case of plants with anoxic zone ahead is finally discussed.

scholarly journals Shifts in the Microbial Community of Activated Sludge with Different COD/N Ratios or Dissolved Oxygen Levels in Tibet, China

2019 ◽  
Vol 11 (8) ◽  
pp. 2284 ◽  
Author(s):  
Jin Xu ◽  
Peifang Wang ◽  
Yi Li ◽  
Lihua Niu ◽  
Zhen Xing
Keyword(s):  
Dissolved Oxygen ◽  
Activated Sludge ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Operational Taxonomic Unit ◽  
Carbon To Nitrogen Ratio ◽  
Urban Sewage ◽  
Treatment Performance ◽  
Nitrogen Ratio

In this study, we examined the influence of the organic carbon-to-nitrogen ratio (chemical oxygen demand (COD/N)) and dissolved oxygen (DO) levels on the removal efficiency of pollutants and on the change in total microflora in the cyclic activated sludge system (CASS) in the Nyingchi prefecture in Tibet. The results demonstrated that the treatment performance was the best when the COD/N ratio was 7:1 or the DO levels were 2–2.5 mg/L in comparison with four different tested COD/N ratios (4:1, 5:1, 7:1, and 10:1) and DO concentrations (0.5–1, 1–2, 2–2.5, and 2.5–3.5 mg/L). The treatment performance can be explained by the relative operational taxonomic unit richness and evenness of the microbial communities in activated sludge. Evident microbial variance was observed, especially different COD/N ratios and DO concentrations, which were conducive to the disposal of urban sewage in plateaus. The results help to understand sewage treatment under different COD/N ratios or DO concentrations on plateaus. This work provides practical guidance for the operation of any wastewater treatment plant on a plateau.

scholarly journals PENCIRIAN TEMPORAL SKALA KECIL AIR SISA DOMESTIK PERBANDARAN

2021 ◽  
Vol 83 (5) ◽  
pp. 35-44
Author(s):  
Z. M. Hanafiah ◽  
W. H. M. W. Mohtar ◽  
N. A. Bachi' ◽  
N. A. Abdullah ◽  
M. Z. Abdullah ◽  
...  
Keyword(s):  
Sewage Treatment ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Ammonia Removal ◽  
Organic Load ◽  
Chemical Characteristics ◽  
Temperature Conductivity ◽  
Physico Chemical ◽  
Health Association ◽  
Kjeldahl Nitrogen

Sewage treatment plants (STP) in Malaysia are designed to treat a load of contaminants according to the level of concentration for chemical oxygen demand (COD) and nitrogen ammonia (NH3-N) of 250 mg/L and 30 mg/L, respectively. However, studies show that the organic load of Malaysian wastewater is low and even temporarily fluctuates resulting in the low effectiveness of treatment especially in ammonia removal and consequently cause effluents that do not undergo proper treatment to be released into the environment. Therefore, this study aims to identify concentrations of COD and NH3-N in the influent of urban domestic wastewater along with other physico-chemical characteristics. Two locations of the STP were chosen based on the urban area with different catchment sizes for a population equivalent (PE) 60,000 for the first STP (LRK#1), and 150,000 for the second STP (LRK#2). These parameters include pH, temperature, conductivity, turbidity, total suspended solids (TSS), nitrogen nitrate (NO3-N), total Kjeldahl nitrogen (TKN) as well as heavy metals such as Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni), Lead (Pb), and Zinc (Zn). The sampling and analysis methods used the guidelines recommended in the American Public Health Association (APHA). The results give the highest average COD concentrations for the LRK#1 and LRK#2 are 180.5 mg/L and 380.9 mg/L, respectively. The highest NH3-N concentrations were 33.53 mg/L for LRK#1 and 31.63 mg/L for LRK#2. Overall, the wastewater physico-chemical characteristics of both treatment plants show wastewater in the medium and low concentration categories.

Is sonication effective to improve biogas production and solids reduction in excess sludge digestion?

2008 ◽  
Vol 57 (4) ◽  
pp. 479-483 ◽  
Author(s):  
C. M. Braguglia ◽  
G. Mininni ◽  
A. Gianico
Keyword(s):  
Activated Sludge ◽  
Residence Time ◽  
Energy Input ◽  
Biogas Production ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
High Energy ◽  
Organic Load ◽  
Ultra Sound

Results of three semi-continuous anaerobic tests were reported and discussed. Each test was carried out by two parallel anaerobic reactors fed with waste activated sludge, either as it was sampled from the sewage treatment plant of Rome North or previously disintegrated by ultra-sound treatment. Activated sludge was sonicated at the energy input of 5,000 or 2,500 kJ kg−1 dry solids corresponding to a disintegration degree of approximately 8 or 4%, respectively. Sonication proved to be effective both in increasing VS destruction and cumulative biogas production. The best increase of VS destruction (from 30 to 35%) was achieved in test #3 carried out at high organic load (10 d residence time) and low energy input (2,500 kJ kg−1 dry solids). The best increase in cumulative biogas production (from 472 to 640 NL after 67 d of tests i.e.) was obtained in test #1 at low organic load (20 d residence time) and high energy input (5,000 kJ kg−1 dry solids). Specific biogas production varied in the tests carried out with untreated sludge (0.55 – 0.67 Nm3 kg−1 VS destroyed) but was practically unchanged for all the tests with sonicated sludge (0.7 Nm3 kg−1 VS destroyed).

scholarly journals Effects of rainwater intrusion on an activated sludge sewer treatment system

2020 ◽  
Vol 15 (3) ◽  
pp. 1
Author(s):  
Diogo Botelho Correa de Oliveira ◽  
Willames De Albuquerque Soares ◽  
Marco Aurélio Calixto Ribeiro de Holanda
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Design Flow ◽  
Organic Load ◽  
Effluent Quality ◽  
Pumping Stations ◽  
Load Removal ◽  
Rainy Days ◽  
Full Operation

 Effluent collection and stormwater management make use of different drainage systems, which should remain unconnected with one another. If stormwater drains into sewage collection systems, it often causes changes in effluent quality indicators at sewage treatment plants. This study sought to quantify the changes caused by rain in a Wastewater Treatment Plant (WWTP) located in Paulista, PE, which uses the activated sludge system. Accordingly, changes in pH, temperature, BOD, and treatment efficiency at the inlet and outlet, as well as inlet flow were analyzed on dry and rainy days at the plant, which has a sewage capacity of 400 L s-1. The input volume was found to be greater than the design flow of the station, about 25%. With this, some relevant operational controls were identified, such as temporarily shutting down sewage pumping stations in order to maintain full operation of the system and avoid overload. The pH increases slightly in alkalinity, about 0.3, but this does not interfere with the treatment process. The temperature of the influent on rainy days is about 3 to 5 degrees cooler, depending on the intensity of the event. Using the T and Z tests, it was possible to identify that BOD concentrations in the influent and the effluent were not significantly different (uneq. var. t: 1.18 > 0.26 and uneq var. z: 0.71 > 0.48, respectively), and the organic load removal efficiency was maintained, contrary to what is expected with other, more simple types of treatment.

scholarly journals Evaluation and Performance of Activated Sludge Hi-Kleen Treatment Plant (ASHTP): A Case Study

2021 ◽  
Vol 11 (2) ◽  
pp. 15-24
Author(s):  
Nur Diana Wakimin ◽  
Juferi Idris ◽  
Lydia Dundun Francis ◽  
Maureen Neging ◽  
Siti Rafiqah Muskil ◽  
...  
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Treated Effluent ◽  
Overall Performance ◽  
Removal Efficiencies ◽  
And Performance

Pollutants from sewage wastewater are major concerns due to their environmental effects. Thus, an effective sewage wastewater treatment plant is important to ensure discharged effluent is well treated before it can be released to rivers or water streams. This study aims to evaluate the performance of the Activated Sludge Hi-Kleen Treatment Plant (ASHTP) located at H Block (ASHTP at H Block) and L Block (ASHTP at L Block) in UiTM Sarawak Branch, Samarahan Campus, Sarawak, Malaysia. The evaluation was based on physicochemical and removal efficiency namely pH, temperature, turbidity, chemical oxygen demand (COD), and total suspended solids (TSS) from raw influent and treated effluent. The findings indicated that the overall performance of both ASHTP at H Block and L Block were satisfactory where treated effluent meets the standard discharge limits of Environmental Quality (Sewage) Regulations 2009 (Standard B). For ASHTP at H Block, the removal efficiencies of turbidity, COD, and TSS were found to be 86.00, 13.76, and 88.02% respectively, in which the pH, temperature, turbidity, COD, and TSS of the treated effluent were 7.30, 28.10°C, 10.40 NTU, 14.10 mg/L and 8.90 mg/L respectively. Meanwhile, for ASHTP at L Block, the removal efficiencies of turbidity, COD, and TSS were found to be 43.20, 41.90, and 51.61% respectively, in which the pH, temperature, turbidity, COD, and TSS in the treated effluent were 7.30, 27.90°C, 21.10 NTU, 58.10 mg/L and 18.00 mg/L respectively. Proper maintenance of sewage treatment plant is important to ensure its effectiveness as well as to prolong its lifespan.

scholarly journals Performance evaluation of a large sewage treatment plant in Brazil, consisting of an upflow anaerobic sludge blanket reactor followed by activated sludge

2017 ◽  
Vol 76 (8) ◽  
pp. 2003-2014 ◽  
Author(s):  
Pollyane Diniz Saliba ◽  
Marcos von Sperling
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Domestic Sewage ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Removal Efficiencies ◽  
Anaerobic Sludge Blanket

The objective of this study was to evaluate the behaviour of a system comprising an upflow anaerobic sludge blanket reactor followed by activated sludge to treat domestic sewage. The Betim Central sewage treatment plant, Brazil, was designed to treat a mean influent flow of 514 L/s. The study consisted of statistical treatment of monitoring data from the treatment plant covering a period of 4 years. This work presents the concentrations and removal efficiencies of the main constituents in each stage of the treatment process, and a mass balance of chemical oxygen demand (COD) and nitrogen. The results highlight the good overall performance of the system, with high mean removal efficiencies: BOD (biochemical oxygen demand) (94%), COD (91%), ammonia (72%) and total suspended solids (92%). As expected, this system was not effective for the removal of nutrients, since it was not designed for this purpose. The removal of Escherichia coli (99.83%) was higher than expected. There was no apparent influence of operational and design parameters on the effluent quality in terms of organic matter removal, with the exceptions of the BOD load upstream of the aeration tank and the sludge age in the unit. Results suggest that this system is well suited for the treatment of domestic sewage.

scholarly journals Assessment of Surface Water Quality of River Kali-east: A Tributary of River Ganga in Uttar Pradesh, India

2021 ◽  
Author(s):  
Vivek Rana
Keyword(s):  
Sewage Treatment ◽  
Industrial Effluent ◽  
Oxygen Demand ◽  
Uttar Pradesh ◽  
Surface Water Quality ◽  
Industrial Effluents ◽  
Organic Load ◽  
Long Distance ◽  
River Ganga

Abstract River Kali-East, a tributary of river Ganga, is a non-perennial river of India which is highly driven by the discharge of sewage and industrial effluent. Twenty-seven locations on the entire stretch (approx. 550 km) of river Kali-East were monitored which indicated that color varied as 20-200 Hazen, dissolved oxygen (DO) as 0-8.16 mg/l, biochemical oxygen demand (BOD) as 6.6-410 mg/l, chemical oxygen demand (COD) as 22-1409 mg/l, total suspended solids as 38-4386 mg/l, total dissolved solids as 180-2536 mg/l and fecal coliform as 4.9 × 102 - 34 × 107 MPN/100 ml. High BOD and COD in the river revealed untreated/partially treated industrial discharge into the river and the self-purification capacity of the river Kali-East has been inhibited for a long distance by heavy and undiminished influx of domestic sewage into the river. Twenty-six drains discharge a total organic load of 148 tonnes per day into the river. Maximum pollution load was contributed by Odean Nala (42%) in Meerut district. This study recommends strict regulatory norms for discharge of industrial effluents by the industries in the catchment area of the river, reduction in sewage treatment gap by utilizing alternative treatment technologies (such as constructed wetlands) and proper dilution of polluted river water to improve the overall quality of the river.

Sewage Treatment by Waste Stabilization Pond Systems

2018 ◽  
Vol 3 (1) ◽  
pp. 7-14
Author(s):  
J. Kenneth, R. S. Suglo
Keyword(s):  
Management Practices ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Wastewater Management ◽  
Stabilization Pond ◽  
Waste Stabilization Pond ◽  
Quality Guidelines ◽  
Waste Stabilization ◽  
High Reduction ◽  
Wastewater Samples

Sewage generated in Ghana is commonly discharged into the environment without any form of treatment to reduce the degree ofcontamination and mitigate potential public health and environmental issues. Although some attempts have been made in someparts of Ghana to utilize the waste stabilization pond (WSP) system to treat domestic sewage, the ponds often fail to achievetheir purpose due to lack of basic maintenance and supervision. To assess the utility of the WSP system for treating sewage,wastewater samples were collected from the raw sewage, anaerobic, facultative and maturation ponds of WSPs at Obuasi inGhana, and analyzed for physicochemical and microbiological contaminants. The results show that the final pond effluent meetsrecommended microbiological and chemical quality guidelines. The waste stabilization pond system demonstrates high removalefficiencies of wastewater contaminants. The biochemical oxygen demand, total suspended solids, nitrate and faecal coliformsreduction efficiencies of 97.3%, 97.6%, 83.3% and 99.94% respectively are highly significant, and compare well with reportedremoval efficiencies in the literature. Additionally, the ponds have high reduction efficiencies for heavy metals and pathogenicmicroorganisms. The wastewater treatment system complies with standard wastewater management practices, and provides auseful method for treating and disposing wastewater in Ghana.

Pyridine Degradation by Suspensions and Biofilms of Achromobacter pulmonis PNOS and Burkholderia dolosa BOS Strains Isolated from Activated Sludge of Sewage Treatment Plants

2020 ◽  
Vol 36 (2) ◽  
pp. 86-98
Author(s):  
A.A. Sergeeva ◽  
G.V. Ovechkina ◽  
A.Yu. Maksimov
Keyword(s):  
Activated Sludge ◽  
Sewage Treatment ◽  
Local Treatment ◽  
Carbon Sources ◽  
Mining Institute ◽  
Bacterial Strains ◽  
Federal Research ◽  
Registration Number ◽  
Treatment Facilities ◽  
Pyridine Degradation

Bacterial strains capable of degradation of 0.8-15.8 g/1 pyridine hydrochloride have been isolated from activated sludge of municipal biological treatment plants in Perm (BOS) and local treatment facilities of the LUKOIL-Permnefteorgsintez enterprise (PNOS). The strains were identified as Achromobacter pulmonis and Burkholderia dolosa. The optimal pyridine concentration for the growth of the isolated strains was 4.0 g/1. The pyridine degradation during the A. pulmonis PNOS and B. dolosa BOS cultivation on a medium with ammonium chloride and glucose and without additional nitrogen or carbon sources was studied. It was shown that the strains are able to accumulate biomass in a medium with pyridine as the sole carbon and nitrogen source; the addition of glucose to the medium (1 g/L) accelerated the pyridine degradation by A. pulmonis PNOS, but inhibited the process carried out by B. dolosa BOS. B. dolosa BOS and A. pulmonis PNOS biofilms efficiently utilized pyridine during growth on basalt and carbon fibers; the highest rate of pyridine utilization (1.8 g /(L day)) was observed in A. pulmonis PNOS biofilms on basalt fibers. pyridine, biodegradation, activated sludge, biofilms, Achromobacter pulmonis, Burkholderia dolosa The authors grateful to Dr. I.I. Tchaikovsky, Head of the Laboratory of Geology of Mineral Deposits of the Mining Institute, a branch of the Perm Federal Research Center, for help with electron microscopy of the samples. This work was carried out as part of a state assignment on the topic « Study of the Functional and Species Diversity of Microorganisms Useful for Ecocenoses and Human Practical Activity», registration number R&D AAAA-A19-119112290008-4.

The Effect of Metallic and Ionic Species on the Performance of a Biological Effluent Treatment System

1977 ◽  
Vol 12 (1) ◽  
pp. 191-212
Author(s):  
B. Volesky ◽  
Q. Samak ◽  
P. Waller
Keyword(s):  
Activated Sludge ◽  
Inorganic Ions ◽  
Industrial Effluents ◽  
Original Data ◽  
Ionic Species ◽  
Threshold Concentration ◽  
Effluent Treatment ◽  
Organic Load ◽  
Metallic Ions ◽  
Activated Sludge Systems

Abstract Review of the available results appearing in the recent literature is presented focusing particularly upon the effects of metallic ions such as Cr, Cu, Zn, Cd, Hg, V, Zn, Ni and Co. Some original data involving the effects of Na are presented and discussed. Development of parameters used in evaluating the influence of toxic or inhibitory species on the mixed microbial population of an activated sludge system is of crucial importance and different techniques employed such as BOD-COD-TOC-removal rates, Oxygen Uptake Rate, and others are discussed, showing relative inadequacy of currently applied assays. From the data available, certain trends can be discerned. There is a definite threshold concentration for each metallic ion, depending on the organic load of the feed. In the order of increasing toxicity to activated sludge systems reflected in lower BOD removals the following metals have been listed as inhibiting factors at concentrations starting from 1 ppm applied on a continuous basis: hexavalent chromium, cobalt, zinc, cadmium, trivalent chromium, copper and nickel. Metals in combination have not been reported to exhibit any significantly different effects as compared to those observed with individually introduced metallic ions. Tolerance of some activated sludge systems to shock loadings by various inorganic ions and metals is reviewed. The conclusions are of particular importance for estimating the performance of biox systems handling industrial effluents which are likely to contain toxic components of inorganic or metallic nature.

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