The Role of Protozoa in High Rate Wastewater Treatment Systems

1980 ◽  
Vol 15 (2) ◽  
pp. 187-201
Author(s):  
R. Booth ◽  
J.G. Henry ◽  
D. Prasad
Keyword(s):  
Wastewater Treatment ◽  
Hydraulic Retention Time ◽  
Mixed Population ◽  
High Rate ◽  
Ciliated Protozoa ◽  
Effluent Quality ◽  
The Poor ◽  
In Series ◽  
Wastewater Treatment Systems ◽  
Sludge Settleability

Abstract Three continuous, laboratory scale, high rate biological wastewater treatment systems operating in a similar mode were evaluated. The feed was a synthetic sewage with a COD and BOD of approximately 300 mg/l and 200 mg/l, respectively. The total hydraulic retention time in each system was 2-1/4 hours - 40 minutes aeration, 95 minutes sedimentation. The applied food to microorganism ratios (F/M) were equal to or greater than one. Systems I and II employed a single aerobic reactor whereas System III employed two aerobic reactors in series each with a hydraulic retention time of 20 minutes. Sludge was returned to the second reactor only, thus establishing dispersed growth in the first reactor and a mixed microbial population in the second. System I was strictly a bacterial system isolated from atmospheric contamination. System II employed a mixed population of ciliated protozoa and bacteria. Tests performed included soluble COD reduction, effluent, mixed liquor and return sludge suspended solids, SVI, pH, polysacharides, bacteria count, and protozoan count. Comparison of System I (bacterial) and System II (mixed population) revealed an improvement in effluent quality (SS, Total COD) as a result of the presence of ciliated protozoa. The higher effluent SS in System I was a result of the poor settleability of dispersed growth. Based on the knowledge of the effects of protozoa on dispersed growth, System III (bacterial reactor and mixed population reactor in series) was established to determine if such a series arrangement would further improve treatment efficiency. Several different two stage reactor system configurations were investigated including sedimentation after the first reactor with the effluent passing to the second reactor. Such an arrangement proved impractical due to the poor settleability of the dispersed growth associated with a predominantly bacterial system. System III resulted in a vast improvement in sludge settleability while maintaining an effluent quality equal to that of System II. This improvement in sludge settleability indicates improved system stability and reduced handling costs.

Waste stabilisation ponds upgrading at Blenheim and Seddon, New Zealand - case studies

2003 ◽  
Vol 48 (2) ◽  
pp. 17-23
Author(s):  
H.E. Archer ◽  
S.A. Donaldson
Keyword(s):  
Wastewater Treatment ◽  
New Zealand ◽  
Lower Cost ◽  
Small Communities ◽  
Large Cities ◽  
Effluent Quality ◽  
Waste Stabilisation Ponds ◽  
Bank Protection ◽  
In Series ◽  
Final Effluent

Waste stabilisation ponds (WSP) have been a popular form of wastewater treatment in New Zealand both for large cities and small communities. Most WSP were constructed from 1960 to 1985 and were single ponds or a primary and secondary pond in series of similar size. Since 1995, improvements comprising primary and maturation ponds, with four to six cells in series have been constructed or retrofitted to original two cell ponds. The Seddon and Blenheim ponds include in-bank rock filters between maturation cells as a lower cost way of providing this feature for reduction of solids. Operating results show reduced variability in final effluent quality for BOD and SS. In addition, very good reductions of faecal coliform and enterococci have been achieved along with good reductions of ammonia and total nitrogen for most of the year except the middle of winter. Extensive use of rock as rip-rap bank protection and in the rock filters, appears to have provided sufficient extra surface area for a nitrifying biofilm to develop.

Design of facultative ponds based on uncertainty analysis

1996 ◽  
Vol 33 (7) ◽  
pp. 41-47 ◽  
Author(s):  
Marcos von Sperling
Keyword(s):  
Sensitivity Analysis ◽  
Monte Carlo ◽  
Wastewater Treatment ◽  
Uncertainty Analysis ◽  
Accurate Determination ◽  
Effluent Quality ◽  
Uniform Distributions ◽  
Wastewater Treatment Systems ◽  
Selection Of

The paper presents a methodology for the utilisation of the Uncertainty analysis based on Monte Carlo simulations for the design of wastewater treatment systems. The special and important case of facultative-ponds design is exemplified. The design is carried out a large number of times, each run with different values of the inputs, randomly selected from uniform distributions within ranges which define the designer's uncertainty with the data. The results are interpreted statistically, giving elements for the selection of more or less conservative designs, according to the resulting effluent quality. The procedure for undertaking a Sensitivity Analysis is also described and exemplified, allowing the designer to concentrate more efforts on a more accurate determination of those inputs found to be significantly important.

scholarly journals Mathematical Analysis for the Optimization of Wastewater Treatment Systems in Facultative Pond Indicator Organic Matter

2018 ◽  
Vol 31 ◽  
pp. 05008 ◽  
Author(s):  
Sunarsih ◽  
Widowati ◽  
Kartono ◽  
Sutrisno
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Wastewater Treatment ◽  
Mathematical Analysis ◽  
Hydraulic Retention Time ◽  
Land Area ◽  
Quality Requirements ◽  
Non Linear Programming ◽  
Main Disadvantage ◽  
Wastewater Treatment Systems

Stabilization ponds are easy to operate and their maintenance is simple. Treatment is carried out naturally and they are recommended in developing countries. The main disadvantage of these systems is large land area they occupy. The aim of this study was to perform an optimization of the wastewater treatment systems in a facultative pond, considering a mathematical analysis of the methodology to determine the model constrains organic matter. Matlab optimization toolbox was used for non linear programming. A facultative pond with the method was designed and then the optimization system was applied. The analyse meet the treated water quality requirements for the discharge to the water bodies. The results show a reduction of hydraulic retention time by 4.83 days, and the efficiency of of wastewater treatment of 84.16 percent.

scholarly journals Treatment of wastewater from service areas at motorways

2016 ◽  
Vol 42 (4) ◽  
pp. 80-89 ◽  
Author(s):  
Małgorzata Makowska ◽  
Jakub Mazurkiewicz
Keyword(s):  
Wastewater Treatment ◽  
Water Use ◽  
Septic Tank ◽  
Effluent Quality ◽  
Aeration System ◽  
Service Areas ◽  
Design Values ◽  
Reed Bed ◽  
Wastewater Treatment Systems

Abstract This paper deals with wastewater treatment systems placed in motorway service areas (MSAs). In the years 2008-2009 eight of such facilities installed on the stretch of the A2 motorway between Poznań and Nowy Tomyśl were examined and analyzed. The system consists of a septic tank, a submerged aerated biofilter and an outflow filter. The volume of traffic on the highway was analyzed, the amount of water use was measured and peak factors were calculated. On this basis it was concluded that the inflows to the wastewater treatment systems in many cases exceeded the nominal design values. Based on the analysis of effluent quality it was found that the effects of plant operation in large part did not meet the requirements. It was found that the bioreactor aeration system and the design of the suspension separator (outflow filter) should be modified. One of the solutions was to use the soil-reed bed for wastewater treatment. The treatment of wastewater from the MSAs is a task that must take into account the unusual character of these facilities and the atypical quality of the effluent.

High rate aerated biofilters for plant upgrading

1994 ◽  
Vol 29 (12) ◽  
pp. 207-216 ◽  
Author(s):  
F. Rogalla ◽  
A. Lamouche ◽  
W. Specht ◽  
B. Kleiber
Keyword(s):  
Complete Removal ◽  
High Rate ◽  
Nitrogen And Phosphorus ◽  
Effluent Quality ◽  
Inner Cities ◽  
European Directive ◽  
Complete Treatment ◽  
In Series ◽  
One Year ◽  
Site Test

Biocarbone aerated biofilters were developed more than ten years ago. Almost one hundred plants worldwide provide complete treatment in very short hydraulic retention time. This allows to construct compact plants in sensitive areas such as inner cities, sea or mountain resorts. The filters can be adapted to high effluent qualities expected by the European directive on wastewater treatment. Full oxidation of ammonia can be achieved in less than two hours. A plant for complete removal of nitrogen has been operated for more than a year in Denmark to meet Europe's most stringent effluent requirements by using an anoxic biofilter in series with the Biocarbone. A new aerated biofilter, turning the Biocarbone principle upside down, is presented : a synthetic floating material allows enhanced performance, simplified backwash and a combination of anoxic and aerobic zones in one reactor. Effluent quality of less than 10 mg/l for all components (BOD, SS, TN) was demonstrated in a one-year long on-site test in Denmark and the first facility for 60 000 population equivalents is under startup. Full scale results of the upflow floating filter, Biostyr, are presented for nitrogen and phosphorus removal according to the European directive.

Bacterial removal in three pilot-scale wastewater treatment systems for rural areas

1997 ◽  
Vol 35 (11-12) ◽  
pp. 197-200 ◽  
Author(s):  
M. Garcia ◽  
E. Bécares
Keyword(s):  
Wastewater Treatment ◽  
Rural Areas ◽  
Pathogenic Bacteria ◽  
Removal Rate ◽  
Treatment Plant ◽  
Free Water ◽  
Pilot Scale ◽  
High Rate ◽  
Total Coliforms ◽  
Wastewater Treatment Systems

A comparative study on the removal of several pathogenic bacteria and their indicators was carried out at three natural wastewater treatment systems: stabilisation pond, high-rate algal pond and a free-water macrophyte system, retention times being 24, 5 and 3 days respectively. The macrophyte system showed higher removal efficiency for most of the groups, followed by stabilisation pond and high rate algal pond. All systems showed their highest efficiencies in the reduction of total coliforms, ranging from 98.68% for the stabilisation pond to 99.48% for the macrophyte process. Highly significant differences were found between the systems for bifidobacteria, C. perfringens and total coliforms removal. Pathogens and their indicators showed a different behaviour in their daily removal rate depending on the treatment plant.

Impact of separate urine collection on wastewater treatment systems

2003 ◽  
Vol 48 (1) ◽  
pp. 103-110 ◽  
Author(s):  
J. Wilsenach ◽  
M. van Loosdrecht
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Energy Demand ◽  
Biological Nutrient Removal ◽  
Urine Collection ◽  
Sustainable Society ◽  
Effluent Quality ◽  
Save Energy ◽  
Sustainable Wastewater Treatment ◽  
Wastewater Treatment Systems

Wastewater treatment should not only be concerned with urban hygiene and environmental protection, but development of a sustainable society must also be considered. This implies a minimisation of the energy demand and potential recovery of finite minerals. Urine contains 80% of the nitrogen (N) and 45% of the phosphorus (P) in wastewater. Separate collection and treatment would improve effluent quality and save energy in centralised biological nutrient removal (BNR). BNR processes are not optimal to treat water with very low N concentration resulting from separate urine collection. Relying on nutrient removal through sludge production, methanation of the sludge, subsequent nutrient removal from the digestion effluent results in optimised and more sustainable wastewater treatment. This paper quantitatively evaluates this option and discusses the potential.

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