Distribution of Giardia Cysts in Wastewater

1991 ◽  
Vol 24 (2) ◽  
pp. 187-192 ◽  
Author(s):  
Jan L. Sykora ◽  
Charles A. Sorber ◽  
Walter Jakubowski ◽  
Leonard W. Casson ◽  
Patrick D. Gavaghan ◽  
...  

This study was designed to determine geographic and seasonal distribution of Giardia cysts in wastewater and sludge and their removal by sewage treatment processes. Eleven wastewater treatment plants located in cities across the United States were included in the study. Flow weighted, composite samples of raw and treated wasteWaters and sludges were collected at monthly intervals for a period of one year. The cysts were concentrated by sucrose flotation or by simple centrifugation (“direct count”) and assayed microscopically. Sucrose flotation counts of cysts in the raw sewage were extremely variable producing results ranging from 0.4% to 77.8% of the direct counts. Based on 12 consecutive months of sampling, and using the direct counts, the highest geometric mean Giardia cyst concentrations occurred at the California site (3375 cysts/L), the Florida site (3087 cysts/L) and the Vermont site (2040 cysts/L). The lowest geometric mean Giardia cyst levels were in samples from the Pennsylvania site (642 cysts/L), the Tennessee site (762 cysts/L) and the Maryland site (957 cysts/L). Cyst concentrations in raw sewage were highest in late summer, fall and early winter. Although all raw sewage samples contained cysts, only about one half of the wastewater treatment plant effluents were positive with cyst concentrations ranging up to 44 cysts/L. Based on sucrose flotation counts, the concentrations of cysts detected in the sludges ranged from 70 to 30,000 cysts/L.

1991 ◽  
Vol 24 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Walter Jakubowski ◽  
Jan L. Sykora ◽  
Charles A. Sorber ◽  
Leonard W. Casson ◽  
Patrick D. Gavaghan

Raw sewage samples were collected monthly for one year from 11 wastewater treatment plants located across the United States. Giardia cyst concentrations in the raw sewage were determined by direct count using criteria of size, shape and the presence of two or more internal morphological characteristics for identification. The data were adjusted based on percentage of industrial wastewater reported processed by each plant. Although differences in the adjusted annual geometric mean cyst concentrations were noted among the sites (the highest was 3750 cysts/L and the lowest was 683 cysts/L), there was no correlation of cyst concentration with geographical location as determined by either latitude or longitude. However, when the three southernmost sites were grouped and compared against the group of all remaining sites, there was a significant difference in the annual geometric mean cyst concentration with the southernmost sites being higher. There was no significant association of geometric mean cyst concentration with size of the wastewater treatment plant as represented by mean daily flow. Attempts were made to obtain and correlate giardiasis cases with the monthly cyst levels at each of the sites. Due to reporting problems, low number of cases or unavailability of data, case information was deemed usable for only four of the 11 sites. A significant positive correlation with cases in the community was found at one site. Lack of correlation at other sites was believed to be due to deficiencies in case reporting. The results suggest that sewage examination may be useful for surveillance of Giardia infections in the community.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


1993 ◽  
Vol 28 (10) ◽  
pp. 1-8 ◽  
Author(s):  
A. Gaber ◽  
M. Antill ◽  
W. Kimball ◽  
R. Abdel Wahab

The implementation of urban village wastewater treatment plants in developing countries has historically been primarily a function of appropriate technology choice and deciding which of the many needy communities should receive the available funding and priority attention. Usually this process is driven by an outside funding agency who views the planning, design, and construction steps as relatively insignificant milestones in the overall effort required to quickly better a community's sanitary drainage problems. With the exception of very small scale type sanitation projects which have relatively simple replication steps, the development emphasis tends to be on the final treatment plant product with little or no attention specifically focused on community participation and institutionalizing national and local policies and procedures needed for future locally sponsored facilities replication. In contrast to this, the Government of Egypt (GOE) enacted a fresh approach through a Local Development Program with the United States AID program. An overview is presented of the guiding principals of the program which produced the first 24 working wastewater systems including gravity sewers, sewage pumping stations and wastewater treatment plants which were designed and constructed by local entities in Egypt. The wastewater projects cover five different treatment technologies implemented in both delta and desert regions.


2017 ◽  
Vol 35 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Michał Marzec

AbstractThe reliability of removal of selected contaminants in three technological solutions of the household sewage treatment plants was analysed in this paper. The reliability of the sewage treatment plant with activated sludge, sprinkled biological deposit and hybrid reactor (activated sludge and immersed trickling filter) was analyzed. The analysis was performed using the Weibull method for basic indicators of impurities, BOD5, COD and total suspended solids. The technological reliability of the active sludge treatment plant was 70% for BOD5, 87% for COD and 66% for total suspended solids. In the sewage treatment plant with a biological deposit, the reliability values determined were: 30% (BOD5), 60% (COD) and 67% (total suspended solids). In a treatment plant with a hybrid reactor, 30% of the BOD5and COD limit values were exceeded, while 30% of the total suspended solids were exceeded. The reliability levels are significantly lower than the acceptable levels proposed in the literature, which means that the wastewater discharged from the analysed wastewater treatment plants often exceeds the limit values of indicators specified in currently valid in Poland Regulation of the Minister of Environment for object to 2000 population equivalent.


1994 ◽  
Vol 30 (4) ◽  
pp. 25-34
Author(s):  
M. Ettala ◽  
E. Rossi

Seven operational mishaps were specified on the basis of a questionnaire on wastewater treatment plants, some of them large. In this study a process was developed for screening the chemical spill risks to municipal biological sewage treatment plant. Data on wastewater treatment processes, potential spill sources and chemical properties were combined to determine the threshold chemical quantities which may inhibit the removal of carbonaceous material, prevent nitrification and methanogenesis, cause sludge contamination or lead to the aeration capacity being exceeded. Two sewage treatment plants and eleven industrial sites were chosen for field studies. The influence of spill duration and maintenance activities on threshold quantities are discussed. A field survey lasting 1-2 hours at each site was long enough for the most relevant data to be obtained when the screening method developed was applied. Several chemical spill risks to the plants studied were specified. In addition, cases were identified in which failure of the pretreatment facilities for industrial wastewaters could cause severe mishaps at a biological wastewater treatment plant.


This Study Was Made To Study The Use Of Circular Aeration Tanks Instead Of Rectangular One In Wastewater Treatment Plants. The Study Covered The Effect Of Tank Geometric Shape On Action Stability, Effective Parameters Homogeneity And Treatment Efficiency Inside The Aeration Tank And Its Reflection On The Final Sedimentation Tank Performance. A Pilot Scale Was Erected In Balaqs Wastewater Treatment Plant Pilot Consists From Two Lines One Circular Aeration Tank Followed By Final Settling Tank And Second Rectangular Aeration Tank Followed By Final Settling Tank For Comparison Purpose Under The Same Conditions. The Samples Were Taken Continuously For 5 Weeks From The Inlet, Outlet For (Bod, & Tss) To Measure The Aeration Removal Efficiency. Also Measurements Inside Both Types Of Aeration Tanks To Determine The Parameters Of Temperature & Do Distribution And Stability In Different Depths And Sides Of Tank. Also The Consumed Power Had Been Measured. The Results Shows That The Circular Aeration Tank Achieved Better Stability Inside The Tank With Minimal Variation In Both Of Do And Temperature That Varied Widely In The Rectangular Tank Between Different Depths And Also Longitudinally And In Cross Section Directions That Affects Mainly On The Tank Efficiency And The Consumed Power Needed For Surface Aerators Operation. The Circular Safe About 50% Of The Consumed Power That Also Safe In The Construction And Operation Costs For Such Treatment.


Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3410 ◽  
Author(s):  
Iwona Skoczko ◽  
Pawel Puzowski ◽  
Ewa Szatyłowicz

Biological membrane reactors or membrane bioreactors (MBRs) based on pressure separation techniques are placed among the latest and most modern methods of wastewater treatment. Currently, this method is becoming more and more popular and is being implemented in smaller and larger wastewater treatment plants (WWTPs). However, technologists, operators, and managers of small WWTPs often do not understand the MBR technology installed in their sites and need extensive professional and technological information. The aim of this study was to analyze the modernized WWTP in a small town of Wydminy, located in northeastern Poland in the Great Masurian Lakes region, where the traditional secondary settling tank was replaced by an MBR. The effectiveness of wastewater treatment before modernization and after installation of the membrane module was compared. On the basis of the conducted research, it was noted that the operation of the plant after modernization is more cost-intensive. There were additional electricity costs due to ensuring adequate pressure on the membrane. Nevertheless, the obtained results of the removal of contaminants place the plant in Wydminy in the group of the most effective Polish sewage treatment plants, as compared to the results obtained in other facilities. The MBR operation also places high demands on the exploiters, prompting them to observe even the smallest changes. The conducted research is a type of a case study, which could give the readers an understanding of the necessity of traditional WWTP modernization with MBR.


Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2850
Author(s):  
Yinan Zhang ◽  
Shihuan Lu ◽  
Yuxin Fang ◽  
Kexin Yang ◽  
Jiafeng Ding ◽  
...  

The efficient removal of carbon (COD) and nitrogen (NH3-N) is vital to improving tailwater from municipal wastewater treatment plants. In this study, denitrification and decarburization bacteria with stable removal efficiencies were introduced into a membrane bioreactor (MBR) for 45 days of field experiments in a QJ Wastewater Treatment Plant (Hangzhou, China) to enhance carbon and nitrogen removal. After adding the decarbonization microorganisms into the denitrification reactor, COD removal increased from 31.2% to 80.2%, while compared to the same MBR with only denitrification microorganisms, the removal efficiency of NH3-N was greatly increased from 76.8% to 98.6%. The results of microbial analysis showed that the cooccurrence of Proteobacteria and Bacillus with high abundance and diverse bacteria, such as Chloroflexi, with autotrophic decarburization functions might account for the synchronous high removal efficiency for NH3-N and COD. This technology could provide a reference for industrial-scale wastewater treatment with the goal of simultaneous nitrogen and carbon removal.


1996 ◽  
Vol 33 (12) ◽  
pp. 189-198 ◽  
Author(s):  
Franz Bischof ◽  
Marcus Höfken ◽  
Franz Durst

The construction and operation of large wastewater treatment plants are very important tasks today. Choosing the optimum process design can help to keep initial costs low. Careful operation and modern equipment reduces the operational costs. Taking into account the huge demand (Anonymous EEC-Report 1990) for new wastewater treatment plants or plants which need to be upgraded after the new EEC legislation concerning sewage treatment came into force in May, 1991 (Anonymous EEC-Guideline 1991) it is quite clear that only cost-effective processes supported by energy-efficient equipment are the answer to economical wastewater treatment. Regarding the operational costs for biological treatment, approximately 70% of the total energy consumption is used for the activated sludge part of the treatment plant, i.e. for the stirring and aeration systems (Höfken et al. 1992). That shows how important the proper design of such systems is and implies that only innovative and energy-efficient equipment should be used. This paper presents theoretical considerations for the design of aeration systems for aerobic processes. These considerations lead to recommendations for the construction and the operation of aeration systems.


Author(s):  
Narendra Pal Gole

The implementation of wastewater treatment plants has been a challenge for most countries. Economic resources, political will, institutional strength, and cultural background are important factors that define the trajectory of pollution control in many countries. Technology is sometimes mentioned as one of the reasons hindering further development. Therefore, a key objective of this research is to evaluate the performance of a plant based on the 345 MLD Upflow Anaerobic Sludge Blanket (UASB) technology by analyzing the physical and chemical parameters of the water treated by UASB to evaluate the performance of the plant located. at Bharwara Tech from Gomti Nagar Lucknow. In this study, the performance of the wastewater treatment plant and the UASB reactor was calculated. Wastewater is mixed with domestic wastewater, so the concentration of BOD and COD is relatively low. The amount of biogas produced by the UASB reactor is also less than its design value. All STP inlet and outlet water concentration results are displayed graphically.


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