Improved alkaline stabilization of municipal wastewater sludge

2002 ◽  
Vol 46 (10) ◽  
pp. 139-146 ◽  
Author(s):  
J.M. Mendez ◽  
B.E. Jiménez ◽  
J.A. Barrios
Keyword(s):  
Municipal Wastewater ◽  
Treatment Plant ◽  
Physicochemical Process ◽  
Wastewater Sludge ◽  
The Other ◽  
Stabilization System ◽  
Municipal Wastewater Treatment ◽  
Faecal Coliforms ◽  
Salmonella Spp ◽  
Closed Systems

In Mexico, physicochemical sludge contains high levels of pathogens; and alkaline stabilization is an alternative for their control. However, the odours caused mainly by ammonia generation represent a disadvantage. On the other hand, the ammonia is known as an effective disinfectant. The aim of this study was to evaluate the disinfectant properties of ammonia in sludge, and use it in a closed alkaline stabilization system, which, not only copes with odours but also increases the efficiency of the process. Raw sludge from a municipal wastewater treatment plant using a physicochemical process was used. Ammonia was applied in doses from 10 to 50% w/w; also, doses from 5 to 40% of CaO were applied in open and closed systems and raw and treated sludge quality was evaluated. Results showed that ammonia removed 6 and 5 logs of faecal coliforms and Salmonella spp., respectively and up to 94% of viable helminth ova. The closed system was more efficient than the open system when applying doses from 5 to 20% of CaO. Finally, the results indicate that the ammonia represents an alternative to disinfecting wastewater sludge and it can be used to enhance alkaline stabilization processes.

Disinfection kinetics of pathogens in physicochemical sludge treated with ammonia

2004 ◽  
Vol 50 (9) ◽  
pp. 67-74 ◽  
Author(s):  
J.M. Mendez ◽  
B. Jimenez ◽  
C. Maya
Keyword(s):  
Contact Time ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Primary Treatment ◽  
Wastewater Sludge ◽  
Municipal Wastewater Treatment ◽  
Faecal Coliforms ◽  
Salmonella Spp ◽  
Kinetics Of ◽  
High Pathogenic

Ammonia is a disinfectant which can diffuse through the membrane of highly resistant structures like helminth ova. Thus, it can be considered an alternative disinfectant of wastewater sludge with high pathogenic content. In this study, the kinetic parameters of the Hom model were used to describe the inactivation with ammonia of faecal coliforms, Salmonella spp. and viable helminth ova. These were obtained in processes considering the addition of ammonia alone as well as for ammonia combined with an increase in temperature. The sludge was sampled from a municipal wastewater treatment plant using an APT (Advanced Primary Treatment) or CEP (Chemical Enhanced Primary) process. With 20% w/w of ammonia, 7 logs of faecal coliforms, 6 logs of Salmonella spp., and 83% of viable helminth ova were reduced in 2 hours contact time. To eliminate 100% of the helminth ova from samples having 88-132 ova/g TS it was needed to combine 20% of ammonia with 50°C. The analysis of parameters k, n and m indicate higher resistancE to inactivation of helminth ova compared to bacteria and a better performance of the ammonia process than lime stabilization to inactivate microorganisms. In addition, ammonia increased the agricultural value of the biosolids produced.

Effects of the incorporation of drinking water sludge on the anaerobic digestion of domestic wastewater sludge for methane production

2015 ◽  
Vol 72 (6) ◽  
pp. 1016-1021 ◽  
Author(s):  
Patricia Torres-Lozada ◽  
José Sánchez Díaz-Granados ◽  
Brayan Alexis Parra-Orobio
Keyword(s):  
Drinking Water ◽  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Methane Production ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Wastewater Sludge ◽  
Municipal Wastewater Treatment ◽  
Methanogenic Activity

Water purification and wastewater treatment generate sludge, which must be adequately handled to prevent detrimental effects to the environment and public health. In this study, we examined the influence of the application of settled sludge from a drinking water treatment plant (SDWTP) on the anaerobic digestion (AD) of the thickened primary sludge from a municipal wastewater treatment plant (SWWTP) which uses chemically assisted primary treatment (CAPT). On both plants the primary coagulant is ferric chloride. The study was performed at laboratory scale using specific methanogenic activity (SMA) tests, in which mixtures of SWWTP–SDWTP with the ratios 100:00, 80:20, 75:25, 70:30 and 00:100 were evaluated. Methane detection was also performed by gas chromatography for a period of 30 days. Our results show that all evaluated ratios that incorporate SDWTP, produce an inhibitory effect on the production of methane. The reduction in methane production ranged from 26% for the smallest concentration of SDWTP (20%) to more than 70% for concentrations higher than 25%. The results indicated that the hydrolytic stage was significantly affected, with the hydrolysis constant Kh also reduced by approximately 70% (0.24–0.26 day−1 for the different ratios compared with 0.34 day−1 for the SWWTP alone). This finding demonstrates that the best mixtures to be considered for anaerobic co-digestion must contain a fraction of SDWTP below 20%.

scholarly journals Escherichia coli and Salmonella spp. early diagnosis and seasonal monitoring in the sewage treatment process by EMA-qPCR method

2015 ◽  
Vol 64 (2) ◽  
pp. 143-148 ◽  
Author(s):  
MAŁGORZATA KACPRZAK ◽  
KRZYSZTOF FIJAŁKOWSKI ◽  
ANNA GROBELAK ◽  
KAROLINA ROSIKOŃ ◽  
AGNIESZKA RORAT
Keyword(s):  
Escherichia Coli ◽  
Early Diagnosis ◽  
Municipal Wastewater ◽  
Sewage Treatment ◽  
Treatment Plant ◽  
Municipal Wastewater Treatment ◽  
Salmonella Spp ◽  
E Coli ◽  
Four Seasons ◽  
Seasonal Monitoring

Numerous studies have recently shown that molecular biology tools can allow for early diagnosis of pathogens and can substitute existing cost and time-taking traditional methods. One of them, the qPCR, is successfully used in microbiology and its utility has been assessed for many different biological materials. The aim of this study was to: 1) determine, optimize and apply qPCR as a method to detect Escherichia coli and Salmonella spp. in primary influents and final effluents from municipal wastewater treatment plant 2) define if addition of ethidium bromide monoazide (EMA) before DNA extraction can allow to distinguish between alive and dead bacteria, 3) quantify E. coli and Salmonella spp. in wastewater during four seasons by qPCR and traditional spread plate method and determine the correlation between the indicator and pathogenic microorganisms. The obtained results has shown that qPCR can be used as a quantitative method in the diagnosis of investigated bacteria in wastewater with EMA pretreatment as a crucial step for a proper quantitative analysis of the presence of these bacteria in wastewater. Both E. coli and Salmonella spp. bacteria species were present in all samples of primary influents and final effluents. Our study shown that the quantity of investigated bacteria is strictly correlated with the season that they were obtained in.

WASTEWATER DISINFECTION BY UV AT TRANI MUNICIPAL PLANT

1994 ◽  
Vol 30 (4) ◽  
pp. 125-132 ◽  
Author(s):  
D. Carnimeo ◽  
E. Contini ◽  
R. Di Marino ◽  
F. Donadio ◽  
L. Liberti ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Continuous Operation ◽  
Secondary Effluent ◽  
Municipal Wastewater Treatment ◽  
South Italy ◽  
Wastewater Disinfection ◽  
Pilot Investigation ◽  
Effluent Characteristics

The pilot investigation on the use of UV as an alternative disinfectant to NaOCI was started in 1992 at Trani (South Italy) municipal wastewater treatment plant (335 m3/h). The results collected after six months continuous operation enabled us to compare UV and NaOCl disinfection effectiveness on the basis of secondary effluent characteristics, quantify photoreactivation effects, evidence possible DBP formation and assess costs.

Performance of hybrid small wastewater treatment system consisting of jet mixed separator and rotating biological contactor

1997 ◽  
Vol 35 (6) ◽  
pp. 63-70 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Yoshihiko Iwasaki
Keyword(s):  
Wastewater Treatment ◽  
Electric Power ◽  
Hybrid System ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Treatment System ◽  
Municipal Wastewater Treatment ◽  
Wastewater Treatment System ◽  
Pre Treatment ◽  
Organic Particles

This paper describes a pilot plant study on the performance of a hybrid small municipal wastewater treatment system consisting of a jet mixed separator(JMS) and upgraded RBC. The JMS was used as a pre-treatment of the RBC instead of the primary clarifier. The treatment capacity of the system was fixed at 100 m3/d, corresponding to the hydraulic loading to the RBC of 117 L/m2/d. The effluent from the grid chamber at a municipal wastewater treatment plant was fed into the hybrid system. The RBC was operated using the electric power produced by a solar electric generation panel with a surface area of 8 m2 under enough sunlight. In order to reduce the organic loading to the RBC, polyaluminium chloride(PAC) was added to the JMS influent to remove the colloidal and suspended organic particles. At the operational condition where the A1 dosage and hydraulic retention time of the JMS were fixed at 5 g/m3 and 45 min., respectively, the average effluent water quality of hybrid system was as follows: TOC=8 g/m3, Total BOD=8 g/m3, SS=8 g/m3, Turbidity=6 TU, NH4-N=7 g/m3, T-P=0.5 g/m3. In this operating condition, electric power consumption of the RBC for treating unit volume of wastewater is only 0.07 KWH/m3.

Physical properties of dewatered wastewater sludge for landfilling

1996 ◽  
Vol 34 (3-4) ◽  
pp. 533-540 ◽  
Author(s):  
A. Koenig ◽  
J. N. Kay ◽  
I. M. Wan
Keyword(s):  
Shear Strength ◽  
Hong Kong ◽  
Municipal Wastewater ◽  
Compressibility Factor ◽  
Wastewater Sludge ◽  
Municipal Wastewater Treatment ◽  
Intrinsic Resistance ◽  
Coefficient Of Consolidation ◽  
Minimum Requirement ◽  
Geotechnical Stability

In the context of landfilling dewatered wastewater sludge in Hong Kong, with landfills up to 140 m high, one of the most significant properties of sludge is its physical nature with regard to moisture characteristics and associated geotechnical stability. Commonly, lower limits are set on total solids content, but no geotechnical stability criteria are applied with the exception of Germany where a minimum requirement for vane shear strength is set at 25 kN/m2. The purpose of this study was to determine and evaluate dewatered wastewater sludge from three Hong Kong municipal wastewater treatment plants with regard to the following physical and geotechnical properties: (i) vane shear strength; (ii) consolidation characteristics such as compression index, compressibility factor, coefficient of consolidation and compressibility coefficient; and (iii) hydraulic characteristics such as permeability and intrinsic resistance. Although dewatered sludge exhibits quite different characteristics as compared to soils, predictive logarithmic relationships may be established between various properties which are consistent with the critical state model for soils, conventional filtration and consolidation theory. Such representation provides a valuable basis for understanding the sludge characteristics and behaviour to landfill design.

Treatment of Rural Domestic Sewage by Solar Ozonic Ecological Sewage Treatment Plant

2014 ◽  
Vol 955-959 ◽  
pp. 3393-3399 ◽  
Author(s):  
Wei Zheng ◽  
Yan Ming Yang ◽  
Yun Long Li ◽  
Jian Qiu Zheng
Keyword(s):  
Municipal Wastewater ◽  
Operating Cost ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Domestic Sewage ◽  
Design Parameters ◽  
Small Scale ◽  
Municipal Wastewater Treatment ◽  
Average Percentage

The process technique and design parameters of project of Solar Ozonic Ecological Sewage Treatment Plant (short for SOESTP) which consists of anaerobic reactor, horizontal subsurface flow (HSSF) constructed wetlands(CWs) and the combination of solar power and ozone disinfection are described, the paper further examines the removal efficiency for treating rural domestic sewage, running expense and recycling ability of product water. The results show that the average percentage removal values of CODcr，BOD5，SS，TN，NH3-N，TP range from 95.6% to 98.0%, 96.0% to 98.7%, 93.1% to 96.1%, 97.0% to 98.9%, 96.9% to 99.5%, 98.2% to 99.6%, respectively, the reduction of fecal coliform (FC) reaches 99.9%, the effluent quality meets the first level A criteria specified in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant（GB18918-2002）. The running cost of SOESTP is 0.063yuan/ m3, saves much more than traditional sewage treatment, and the ozone water obtained from the reservoir will be an ideal choice for disinfection .The system has characteristics of easy manipulation, low operating cost, achieving advanced water, energy conservation and environment protection, is thought to be very suitable for use as the promotion of rural small - scale sewage treatment.

scholarly journals Assessment of Microplastics in a Municipal Wastewater Treatment Plant with Tertiary Treatment: Removal Efficiencies and Loading per Day into the Environment

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1339
Author(s):  
Javier Bayo ◽  
Sonia Olmos ◽  
Joaquín López-Castellanos
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Source Control ◽  
Municipal Wastewater Treatment ◽  
Tertiary Treatment ◽  
Stable Performance ◽  
Wastewater Samples

This study investigates the removal of microplastics from wastewater in an urban wastewater treatment plant located in Southeast Spain, including an oxidation ditch, rapid sand filtration, and ultraviolet disinfection. A total of 146.73 L of wastewater samples from influent and effluent were processed, following a density separation methodology, visual classification under a stereomicroscope, and FTIR analysis for polymer identification. Microplastics proved to be 72.41% of total microparticles collected, with a global removal rate of 64.26% after the tertiary treatment and within the average retention for European WWTPs. Three different shapes were identified: i.e., microfiber (79.65%), film (11.26%), and fragment (9.09%), without the identification of microbeads despite the proximity to a plastic compounding factory. Fibers were less efficiently removed (56.16%) than particulate microplastics (90.03%), suggesting that tertiary treatments clearly discriminate between forms, and reporting a daily emission of 1.6 × 107 microplastics to the environment. Year variability in microplastic burden was cushioned at the effluent, reporting a stable performance of the sewage plant. Eight different polymer families were identified, LDPE film being the most abundant form, with 10 different colors and sizes mainly between 1–2 mm. Future efforts should be dedicated to source control, plastic waste management, improvement of legislation, and specific microplastic-targeted treatment units, especially for microfiber removal.

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