Comparison of two types of inocula during acclimation and stable operation for nitrophenol biodegradation in an anaerobic-aerobic SBR

2006 ◽  
Vol 54 (10) ◽  
pp. 39-45
Author(s):  
A. Vargas ◽  
D. González ◽  
A. Estival ◽  
G. Buitrón
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
The Other ◽  
Stable Operation ◽  
Reaction Phase ◽  
Toxic Compound ◽  
Anaerobic Wastewater Treatment ◽  
Significant Difference ◽  
Different Types ◽  
Batch Bioreactors

This work presents a comparison of two inocula used for the acclimation of two anaerobic-aerobic sequencing batch bioreactors used for toxic wastewater treatment. The bioreactors were acclimated with different types of sludge: one coming from an anaerobic wastewater treatment plant and the other one from a conventional aerobic activated sludge plant. The model toxic compound was p-nitrophenol, which is reduced to p-aminophenol during the initial anaerobic phase of the reaction, and later mineralized during a posterior aerated reaction phase. Biodegradation of the compounds was monitored using UV/Vis spectrophotometry. After acclimation stabilization of the sludge and of the process was also monitored. Results show that there is no significant difference in acclimation times and stability of the process between the two employed inocula, and thus an originally anaerobic inoculum presents no apparent advantage over a more easily accessible aerobic one.

scholarly journals Effectiveness of vertical subsurface wetlands for iron and manganese removal from wastewater in drinking water treatment plants

2019 ◽  
Vol 24 (1) ◽  
pp. 135-163
Author(s):  
Jader Martínez Girón ◽  
Jenny Vanessa Marín-Rivera ◽  
Mauricio Quintero-Angel
Keyword(s):  
Drinking Water ◽  
Wastewater Treatment ◽  
Water Treatment ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Pilot Scale ◽  
Treatment System ◽  
Water Treatment Plants ◽  
Significant Difference

Population growth and urbanization pose a greater pressure for the treatment of drinking water. Additionally, different treatment units, such as decanters and filters, accumulate high concentrations of iron (Fe) and manganese (Mn), which in many cases can be discharged into the environment without any treatment when maintenance is performed. Therefore, this paper evaluates the effectiveness of vertical subsurface wetlands for Fe and Mn removal from wastewater in drinking water treatment plants, taking a pilot scale wetland with an ascending gravel bed with two types of plants: C. esculenta and P. australis in El Hormiguero (Cali, Colombia), as an example. The pilot system had three upstream vertical wetlands, two of them planted and the third one without a plant used as a control. The wetlands were arranged in parallel and each formed by three gravel beds of different diameter. The results showed no significant difference for the percentage of removal in the three wetlands for turbidity (98 %), Fe (90 %), dissolved Fe (97 %) and Mn (98 %). The dissolved oxygen presented a significant difference between the planted wetlands and the control. C. esculenta had the highest concentration of Fe in the root with (103.5 ± 20.8) µg/g ; while P. australis had the highest average of Fe concentrations in leaves and stem with (45.7 ± 24) µg/g and (41.4 ± 9.1) µg/g, respectively. It is concluded that subsurface wetlands can be an interesting alternative for wastewater treatment in the maintenance of drinking water treatment plants. However, more research is needed for the use of vegetation or some technologies for the removal or reduction of the pollutant load in wetlands, since each drinking water treatment plant will require a treatment system for wastewater, which in turn requires a wastewater treatment system as well.

scholarly journals Investigation of Job Satisfaction and Occupational Safety Perceptions of Employees in Wastewater Treatment Plants: Study of Istanbul

2020 ◽  
Vol 10 (1) ◽  
pp. 3-10
Author(s):  
Rüştü Uçan ◽  
Hakan Şanlıer ◽  
Müge Ensari Özay
Keyword(s):  
Job Satisfaction ◽  
Wastewater Treatment ◽  
Occupational Safety ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Simple Random Sampling ◽  
Occupational Accidents ◽  
Satisfaction Scale ◽  
Safety Perceptions ◽  
Significant Difference

Background: There exist many fatal occupational accidents in the works carried out in wastewater treatment plants. Objective: This research was carried out to determine the relationship between job satisfaction levels and occupational safety perceptions of employees working in wastewater treatment plants. Methods: In this study, a questionnaire including Minnesota Job Satisfaction Scale and Occupational Safety Scale is applied to a total of 161 people aged 16-65 years working in two different Advanced Biological Wastewater Treatment Plants in Istanbul by simple random sampling. Statistical Package for Social Science version-22 was used. Seventeen hypotheses were analyzed to show the relation between the occupational safety perceptions and socio-demographic parameters of employees. Results: The results show that there is no significant relationship between job satisfaction and occupational safety perception of the personnel working in wastewater treatment plants (F=0.096 and p=0.227 >0.05). On the other hand, it is found that there is a statistically significant difference between the level of job satisfaction perception and age of the employees (F=2.358 and p=0.002 <0.05), as well as monthly income ranges (F=4.126 and p=0.008 <0.05). Conclusion: Consequently, the hazards associated with the work should be explained to employees of the wastewater treatment plant in detail. Furthermore, it is suggested to maintain an increase in wages to increase job satisfaction.

scholarly journals Quality of bio-solids produced in a Spanish Wastewater Treatment Plant (Córdoba-Spain) and its use in agronomy along 2000-2019

2020 ◽  
Vol 1 (4) ◽  
pp. 9-15
Author(s):  
Rafael Marín Galvín
Keyword(s):  
Escherichia Coli ◽  
Organic Matter ◽  
Wastewater Treatment ◽  
Treatment Plant ◽  
The Other ◽  
Treated Wastewater ◽  
Urban Wastewater ◽  
Main Metal ◽  
Colony Forming Units

Bio-solids are the final fate of pollution present in urban wastewater, reaching the production of these ones in Spanish WWTPs 701,751 T/year (dates of 2018). Considering that 85% of Spanish bio-solids are used in agronomy, it is important to know characteristics of biosolids there produced, and in this way, we have investigated bio-solids generated in La Golondrina´s WWTP (Córdoba, Spain) along 2000-2019. This WWTP is a conventional facility operated by activated sludges (26.55x106 m3/year treated) which has produced 1.43 kg of bio-solids per m3 of treated wastewater (38.000 T/year). Our results indicated that bio-solids had a dryness over initial mass of 22.3%, and 74.9% of organic matter over dried matter (o.d.m.). At the same time, major components detected in bio-solids were N, P and Ca which levels were 5.0%, 3.5% and 3.7%, respectively. On the other hand, concentration of total metals in bio-solids ranged 13,024 mg/kg o.d.m., being the main metal Fe (11.749 mg/kg o.d.m.) followed by Zn, Cu and Mn, with levels as mg/kg o.d.m. of 463.1, 392.8 and 265.7, respectively. Evolution per year of all the investigated parameters are shown in the paper. Taking into account the use of bio-solids in agronomy, we have evaluated levels of metals limited by the Spanish normative to this respect: thus, the seven metals restricted (Cd, Cu, Ni, Pb, Zn, Hg and Cr) exhibited concentration in bio-solids very lower than parametric values established. Moreover, we have estimated the ratios of accumulation of organics and metals from wastewater to bio-solids: thus, organic matter, N and P, were accumulated in bio-solids respectively, 342, 356 and 643 times, and total metals, 2,632 times. Finally, levels of Escherichia coli slightly varied from wastewater to bio-solids: 1.5x108 colony-forming units/L in the first one, and 0.9x108/g (o.d.m.) in the second ones.

scholarly journals The importance of pollutional loads during wet weather

2019 ◽  
pp. 271-282
Author(s):  
Oddvar Georg Lindholm ◽  
Lars Aaby
Keyword(s):  
Time Series ◽  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
The Other ◽  
Combined Sewer Overflows ◽  
Combined Sewer ◽  
Receiving Waters ◽  
Wet Weather ◽  
Annual Discharge

Wet weather discharges consist mainly of washed out surface pollution in separate sewered areas, but in combined sewered areas; resuspended pipe deposits, surface washoff and sewage, discharging via combined sewer overflows (CSOs). Of the three mentioned sources, resuspended pipe solids is dominating over the other two and may contribute as much as 50 to 90 % of the total amount of the CSO. The CSO in a normal catchment may also on an annual bases be of the same amount, or even twice as much as the effluent from the wastewater treatment plant (WWTP). If the receiving waters are vulnerable to shock loads on a daily base, it is important to be aware that the amount of CSO might, at its most adverse be up to I 00 times more than the effluent from the WWTP during a day. The annual discharge via CSOs in a catchment may easily vary with a factor of up to 8 from the driest to the wettest year, during time series of 20 to 40 years.

An integrated system to remote monitor and control anaerobic wastewater treatment plants through the internet

2005 ◽  
Vol 52 (1-2) ◽  
pp. 457-464 ◽  
Author(s):  
O. Bernard ◽  
B. Chachuat ◽  
A. Hélias ◽  
B. Le Dantec ◽  
B. Sialve ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Integrated System ◽  
The Internet ◽  
Anaerobic Wastewater Treatment ◽  
Control Centre ◽  
Automatic Controllers ◽  
New Sensors ◽  
And Control

The TELEMAC project brings new methodologies from the Information and Science Technologies field to the world of water treatment. TELEMAC offers an advanced remote management system which adapts to most of the anaerobic wastewater treatment plants that do not benefit from a local expert in wastewater treatment. The TELEMAC system takes advantage of new sensors to better monitor the process dynamics and to run automatic controllers that stabilise the treatment plant, meet the depollution requirements and provide a biogas quality suitable for cogeneration. If the automatic system detects a failure which cannot be solved automatically or locally by a technician, then an expert from the TELEMAC Control Centre is contacted via the internet and manages the problem.

Determining Giardiasis Prevalence by Examination of Sewage

1991 ◽  
Vol 24 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Walter Jakubowski ◽  
Jan L. Sykora ◽  
Charles A. Sorber ◽  
Leonard W. Casson ◽  
Patrick D. Gavaghan
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Geometric Mean ◽  
Treatment Plant ◽  
Geographical Location ◽  
Morphological Characteristics ◽  
The United States ◽  
Giardia Cyst ◽  
Significant Difference ◽  
Cyst Concentration

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.

Stochastic modeling to identify requirements for centralized monitoring of distributed wastewater treatment

2012 ◽  
Vol 65 (6) ◽  
pp. 1067-1075 ◽  
Author(s):  
T. Hug ◽  
M. Maurer
Keyword(s):  
Wastewater Treatment ◽  
Treatment Plant ◽  
Sensor Technology ◽  
Individual Treatment ◽  
Treatment Unit ◽  
Significant Difference ◽  
Site Staff ◽  
Treatment Technologies ◽  
On Line ◽  
The Individual

Distributed (decentralized) wastewater treatment can, in many situations, be a valuable alternative to a centralized sewer network and wastewater treatment plant. However, it is critical for its acceptance whether the same overall treatment performance can be achieved without on-site staff, and whether its performance can be measured. In this paper we argue and illustrate that the system performance depends not only on the design performance and reliability of the individual treatment units, but also significantly on the monitoring scheme, i.e. on the reliability of the process information. For this purpose, we present a simple model of a fleet of identical treatment units. Thereby, their performance depends on four stochastic variables: the reliability of the treatment unit, the respond time for the repair of failed units, the reliability of on-line sensors, and the frequency of routine inspections. The simulated scenarios show a significant difference between the true performance and the observations by the sensors and inspections. The results also illustrate the trade-off between investing in reactor and sensor technology and in human interventions in order to achieve a certain target performance. Modeling can quantify such effects and thereby support the identification of requirements for the centralized monitoring of distributed treatment units. The model approach is generic and can be extended and applied to various distributed wastewater treatment technologies and contexts.

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