Human enteric viruses in a wastewater treatment plant: evaluation of activated sludge combined with UV disinfection process reveals different removal performances for viruses with different features

2018 ◽  
Vol 66 (3) ◽  
pp. 215-221 ◽  
Author(s):  
A. Lizasoain ◽  
L.F.L. Tort ◽  
M. García ◽  
L. Gillman ◽  
A. Alberti ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Enteric Viruses ◽  
Uv Disinfection ◽  
Disinfection Process ◽  
Human Enteric Viruses ◽  
Plant Evaluation

A Wastewater Treatment Plant Composed of UASB Reactors, Activated Sludge with DAF and UV Disinfection, in Series

2009 ◽  
Vol 4 (1) ◽  
Author(s):  
J. R. Campos ◽  
M.A.P. Reali ◽  
R. Rossetto ◽  
J. Sampaio
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Treated Wastewater ◽  
Second Step ◽  
Uv Disinfection ◽  
Treatment Level ◽  
Preliminary Treatment ◽  
Uasb Reactors

This paper focuses the Piçarrão wastewater treatment plant (WWTP) located in Brazil; including its project, construction and operation, related to its first step, with working capacity until 2010 (208.785 inhabitants). The conception of the second step is also presented. This WWTP, based on the water quality of the receiving river, was designed to reach a secondary treatment level in the first step, and a tertiary treatment level in the second step. In the first step, preliminary treatment, UASB reactors, activated sludge with dissolved air flotation (DAF) and post-aeration were implanted. For the second step, denitrification, coagulation applying ferric chloride and UV disinfection should be included. In the second step, one of the UASB modules will be adapted to operate as an anoxic reactor for denitrification. The process/operation flow diagram resulted in a low complexity and relatively low cost treatment plant: USD$ 120.9 per inhabitant for implantation, and USD$ 219.05 per 1000m3 of treated wastewater. Average results for this first period of operation are: BOD5.20°C removal in the UASB reactors: 72.0%, global BOD5.20°C removal in the system: 91.4%; effluent turbidity: (11±5)NTU; total suspended solids in the effluent: (16±8)mg.L-1; fecal coliform removal ≥4 log and dewatered sludge production: 12.3 ton.d-1.

Fate of Human Enteric Viruses (Rotaviruses and Entero Viruses) in Sewage after Primary Sedimentation

1986 ◽  
Vol 18 (10) ◽  
pp. 47-52 ◽  
Author(s):  
A. Bosch ◽  
F. Lucena ◽  
J. Jofre
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Enteric Viruses ◽  
Single Step ◽  
Lime Treatment ◽  
Viral Pathogens ◽  
Chemical Coagulation ◽  
Human Enteric Viruses ◽  
Very High

A wastewater treatment plant, which treats sewage by either mechanical primary sedimentation or lime coagulation, was used for modelling the fate of human enteric viruses after these treatments. The occurrence of human rotaviruses and enteroviruses was monitored in sewage influent, effluent and sludge samples. The level of indigenous enteric viruses in raw sewage was very high (up to 10 000 I.U./l); the values for rotavxrus and enterovxrus were of the same magnitude, although no correlation was found between the levels of both kinds of human enteric viruses. Both rotaviruses and enteroviruses were removed from sewage and transferred to sludge at similar rates after mechanical sedimentation, although rotaviruses were more efficiently recovered from sludge samples than enteroviruses. After chemical coagulation by lime treatment, most human enteric viruses in sludge were inactivated. Lime coagulation should be regarded as a most effective single-step treatment for the removal of viral pathogens such as rotaviruses and enteroviruses from sewage.

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.

Automatic control for DO and pH in the activated sludge process in a coke wastewater treatment plant

1998 ◽  
Vol 37 (12) ◽  
pp. 141-148 ◽  
Author(s):  
B. K. Lee ◽  
S. W. Sung ◽  
H. D. Chun ◽  
J. K. Koo
Keyword(s):  
Wastewater Treatment ◽  
Control System ◽  
Activated Sludge ◽  
Automatic Control ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Pi Controller ◽  
Activated Sludge Process ◽  
Set Point ◽  
Coke Wastewater

The objective of this study is to develop an automatic control system for dissolved oxygen (DO) and pH of the activated sludge process in a coke wastewater treatment plant. A discrete type autotuned proportional-integral (PI) controller using an auto-regressive exogenous (ARX) model as a process model was developed to maintain the DO concentration in aerators by controlling the speed of surface aerators. Also a nonlinear pH controller using the titration curve was used to control the pH of influent wastewater. This control system was tested in a pilot scale plant. During this pilot plant experiment, there was small deviation of pH and the electric power consumption of surface aerators was reduced up to 70% with respect to the full operation when the DO set point was 2 mg/l. For real plant operation with this system, the discrete PI controller showed good tracking for set point change. The electricity saving was more than 40% of the electricity consumption when considering surface aerators. As a result of maintaining the DO constantly at the set point by the automatic control system, the fluctuation of effluent quality was decreased and overall improvement of the effluent water quality was achieved.

Savings with upgraded performance through improved activated sludge denitrification in the combined activated sludge–biofilter system of the Southpest Wastewater Treatment Plant

2008 ◽  
Vol 57 (8) ◽  
pp. 1287-1293 ◽  
Author(s):  
A. Jobbágy ◽  
G. M. Tardy ◽  
Gy. Palkó ◽  
A. Benáková ◽  
O. Krhutková ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Biological Treatment ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Process Efficiency ◽  
Initial Value ◽  
Initial Profile ◽  
Biological Treatment System

The purpose of the experiments was to increase the rate of activated sludge denitrification in the combined biological treatment system of the Southpest Wastewater Treatment Plant in order to gain savings in cost and energy and improve process efficiency. Initial profile measurements revealed excess denitrification capacity of the preclarified wastewater. As a consequence, flow of nitrification filter effluent recirculated to the anoxic activated sludge basins was increased from 23,000 m3 d−1 to 42,288 m3 d−1 at an average preclarified influent flow of 64,843 m3 d−1, Both simulation studies and microbiological investigations suggested that activated sludge nitrification, achieved despite the low SRT (2–3 days), was initiated by the backseeding from the nitrification filters and facilitated by the decreased oxygen demand of the influent organics used for denitrification. With the improved activated sludge denitrification, methanol demand could be decreased to about half of the initial value. With the increased efficiency of the activated sludge pre-denitrification, plant effluent COD levels decreased from 40–70 mg l−1 to < 30–45 mg l−1 due to the decreased likelihood of methanol overdosing in the denitrification filter

Evaluating the treatment performance of a full scale Activated Sludge Plant in Islamabad, Pakistan

2012 ◽  
Vol 7 (1) ◽  
Author(s):  
S. S. Fatima ◽  
S. Jamal Khan
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Wastewater Treatment Plant ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Full Scale ◽  
Operational Parameter ◽  
Mixed Liquor ◽  
Treatment Performance

In this study, the performance of wastewater treatment plant located at sector I-9 Islamabad, Pakistan, was evaluated. This full scale domestic wastewater treatment plant is based on conventional activated sludge process. The parameters which were monitored regularly included total suspended solids (TSS), mixed liquor suspended solids (MLSS), mixed liquor volatile suspended solids (MLVSS), biological oxygen demand (BOD), and chemical oxygen demand (COD). It was found that the biological degradation efficiency of the plant was below the desired levels in terms of COD and BOD. Also the plant operators were not maintaining consistent sludge retention time (SRT). Abrupt discharge of MLSS through the Surplus Activated sludge (SAS) pump was the main reason for the low MLSS in the aeration tank and consequently low treatment performance. In this study the SRT was optimized based on desired MLSS concentration between 3,000–3,500 mg/L and required performance in terms of BOD, COD and TSS. This study revealed that SRT is a very important operational parameter and its knowledge and correct implementation by the plant operators should be mandatory.

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