Class B biosolids production from wastewater sludge with high pathogenic content generated in an advanced primary treatment

2000 ◽  
Vol 42 (9) ◽  
pp. 103-110 ◽  
Author(s):  
B. Jimenez ◽  
J. A. Barrios ◽  
C. Maya
Keyword(s):  
The United States ◽  
Primary Treatment ◽  
Land Application ◽  
Wastewater Sludge ◽  
Fecal Coliforms ◽  
Treatment Processes ◽  
Helminth Eggs ◽  
Class B ◽  
Us Epa ◽  
High Pathogenic

Alkaline post-stabilization of wastewater sludge with high pathogenic content (up to 1010 NMP/g TS of Salmonella sp. and up to 89.8 helminth eggs/g TS) was studied to evaluate the feasibility of producing Class B biosolids. The sludge was produced in pilot systems using different advanced primary treatment processes treating wastewater generated in Mexico City. Samples were dewatered to different dryness ranging from 11.5 to 29.0% TS and stabilized using quicklime in doses ranging from 15 to 40% (w/w). The levels of pathogens found in dewatered sludge were up to 8 log and 1.95 log higher than those found in primary sludge generated in the United States for Salmonella sp. and helminth eggs respectively. Distribution of genera of helminths indicated that more than 90% of the eggs found were Ascaris, while the rest were Hymenolepis, Trichuris, Toxocara and Taenia. Minimum and maximum removals ranged between 3.6 to 9.5 log for fecal coliforms; 3.7 to 7.9 log for Salmonella sp.; and 0.1 to 1.3 log for helminths. The recommended quicklime dose was determined for different solids contents in order to achieve the pH-time criteria and the levels of microorganisms required by the US EPA. Metal concentrations were below the maximum levels established for land application of biosolids.

A risk assessment of emerging pathogens of concern in the land application of biosolids

2002 ◽  
Vol 46 (10) ◽  
pp. 225-230 ◽  
Author(s):  
C.P. Gerba ◽  
I.L. Pepper ◽  
L.F. Whitehead
Keyword(s):  
Risk Model ◽  
Hepatitis A Virus ◽  
The United States ◽  
Land Application ◽  
Pathogen Transmission ◽  
Emerging Pathogens ◽  
Response Models ◽  
Treatment Processes ◽  
Class B ◽  
Moisture Conditions

Since the development of the United States Environmental Protection Agency's 503 biosolids Rule, which includes treatment requirements to reduce the threat of pathogen transmission, many new pathogens have been recognized which could be transmitted by biosolids. A risk analysis was performed to assess which emerging pathogens would be most likely to survive treatments required for Class B biosolids before land application. The literature was reviewed on the resistance of emerging pathogens to temperature and other environmental factors to assess their probability of surviving various biosolids treatment processes. In addition existing information on occurrence in biosolids and dose response models for each pathogen was reviewed. It was concluded that adenoviruses and hepatitis A virus are the most thermally resistant viruses and can survive for prolonged periods in the environment. The protozoan parasites microsporidia and Cyclospora were unlikely to survive the temperatures achieved in anaerobic digestion and do not survive well under low moisture conditions. A risk model was used to assess the risk of infection and illness from enteric viruses after application of class B biosolids.

scholarly journals Survey of Wastewater Indicators and Human Pathogen Genomes in Biosolids Produced by Class A and Class B Stabilization Treatments

2008 ◽  
Vol 75 (1) ◽  
pp. 164-174 ◽  
Author(s):  
Emily Viau ◽  
Jordan Peccia
Keyword(s):  
Anaerobic Digestion ◽  
Legionella Pneumophila ◽  
Human Adenovirus ◽  
Land Application ◽  
Fecal Coliforms ◽  
Class A ◽  
Stabilization Methods ◽  
Class B ◽  
Male Specific ◽  
Pathogen Genome

ABSTRACT Accurate modeling of the infectious aerosol risk associated with the land application of biosolids requires an in-depth knowledge of the magnitudes and changes in pathogen concentrations for a variety of class A and class B stabilization methods. The following survey used quantitative PCR (qPCR) and culture assays to detect environmentally resistant bacterial and viral pathogens and biosolid indicator organisms for 36 biosolid grab samples. Biosolids were collected from 14 U.S. states and included 16 class B mesophilic anaerobic digestion (MAD) samples and 20 class A biosolid samples from temperature-phased anaerobic digestion (TPAD), MAD plus composting (COM), and MAD plus heat pelletization processes. The indicator concentrations of fecal coliforms and male-specific coliphages as well as pathogen genome concentrations for human adenovirus species, Legionella pneumophila, Staphylococcus aureus, and Clostridium difficile were significantly lower in the class A samples, and a multivariate analysis of variance ranked the stabilization processes from the lowest pathogen/indicator load to the highest as (i) class A COM, (ii) class A TPAD, and (iii) class B MAD. Human adenovirus genomes were found in 88% of the class B samples and 70 to 100% of the class A samples. L. pneumophila, S. aureus, and C. difficile genomes were detected at the qPCR assay detection limits in 19 to 50% of the class B and class A anaerobic digestion samples, while L. pneumophila was detected in 50% of the class A compost samples. When considering all the stabilization methods, both the fecal coliform and the male-specific coliphage concentrations show a significant linear correlation with the pathogen genome concentrations. This survey provides the necessary pathogen concentrations to add to biosolid aerosol risk and pathogen exposure analyses and clarifies the effectiveness of class A stabilization methods with the pathogen and indicator loads in biosolids.

Effectiveness of Wastewater Sludge Treatment Processes to Inactivate Parasites

1986 ◽  
Vol 18 (7-8) ◽  
pp. 397-404 ◽  
Author(s):  
R. S. Reimers ◽  
D. B. McDonell ◽  
M. D. Little ◽  
D. D. Bowman ◽  
A. J. Englande ◽  
...  
Keyword(s):  
Heat Treatment ◽  
The United States ◽  
Wastewater Sludge ◽  
Sludge Treatment ◽  
Treatment Processes ◽  
Sludge Digestion ◽  
Thermophilic Digestion ◽  
Sludge Drying ◽  
Aerobic And Anaerobic ◽  
Trichuris Vulpis

In the United States, Ascaris spp., Trichuris trichiura, Trichuris vulpis and Toxocara spp. are the most commonly found viable parasites in both treated and untreated municipal sludges. As expected, heat treatment, thermophilic digestion (aerobic and anaerobic) and thermophilic composting were effective in parasite inactivation, and with good sludge digestion (both aerobic and anaerobic), the effectiveness of sludge lagoon storage and sludge drying beds to inactivate parasites and pathogens is greatly enhanced. At present two commercial sludge processes, Chemfixation and Ozonics treatment have shown potential to inactivate parasites.

Removal of helminth eggs and fecal coliforms by anaerobic thermophilic sludge digestion

2002 ◽  
Vol 45 (10) ◽  
pp. 269-274 ◽  
Author(s):  
N. Cabirol ◽  
M. Rojas Oropeza ◽  
A. Noyola
Keyword(s):  
Primary Treatment ◽  
Fecal Coliforms ◽  
Volatile Fraction ◽  
Waste Sludge ◽  
Biological Sludge ◽  
Sludge Stabilization ◽  
Sludge Digestion ◽  
Helminth Eggs ◽  
Thermophilic Conditions ◽  
Thermophilic Digestion

Anaerobic digestion of two types of waste sludge was applied in order to assess the suitability of thermophilic conditions for the stabilization of organic matter and removal of fecal coliforms and helminth eggs. Feeding sludge was taken from an activated sludge municipal facility (BS) and from an enhanced primary treatment municipal plant (EPT). As an accompanying experiment, mesophilic digesters were also operated. The four digesters (M1, M2, T1, T2) had a 5 litre volume and an egg shape. A highly stabilized material was obtained at both temperatures with BS type of sludge, taking the reduction of volatile fraction of suspended solids (%RVSS) as indicator (84% for M1 and 74% for T1). In general, EPT sludge was a more difficult substrate, if compared with BS sludge; thermophilic condition was better adapted than mesophilic for this kind of sludge. Satisfactory reductions on counts of fecal coliforms and helminth eggs were achieved under thermophilic digestion for both types of feeding sludge. T1 digester, fed with biological sludge, removed fecal coliforms below 1000 MPN/gTS and helminth eggs down to 0.28 HELarval/gTS, at an HRT of 20 days. As a general conclusion, anaerobic thermophilic digestion may be an appropriate option for sludge stabilization, in order to meet EPA Class A biosolids final disposal regulations. However, further research is needed in order to consistently remove helminth eggs and fecal coliforms from waste sludge at shorter hydraulic retention times.

Characterisation and conditioning of Fenton sludges issued from wastewater treatment

2002 ◽  
Vol 46 (10) ◽  
pp. 43-49 ◽  
Author(s):  
R.M. Ramírez Zamora ◽  
M.T. Orta de Velásquez ◽  
A. Durán Moreno ◽  
J. Malpica de la Torre
Keyword(s):  
Wastewater Treatment ◽  
Specific Resistance ◽  
Land Application ◽  
Cationic Polymer ◽  
Fecal Coliforms ◽  
Fenton Reagent ◽  
Class B ◽  
Microbiological Parameters ◽  
Combined Action ◽  
Alum Sludge

Characterisation tests were conducted to determine the feasibility of land application of the sludges produced in wastewater treatment by means of Fenton's Reagent. Physicochemical and microbiological parameters of Fenton sludges were compared to the values obtained for raw alum sludges. The Fenton sludges presented preferable characteristics such as the specific resistance to filtration (SRF), metals and pathogen content (fecal and total coliforms, helminth ova, and Salmonella sp.). The SRF of the Fenton sludges (1.55 × 1013 m/kg) was 24% less than the alum sludge value (1.92 × 1013 m/kg). The concentrations of fecal coliforms (0 MPN/g TS), Salmonella sp. (0 MPN/g TS), Helminth ova (22 HH/g TS) and metals correspond to the limits for biosolids of Class B for land application of the Mexican legislation. The Fenton reagent efficiently removes most of the pathogens, considered by the norms, by means of the combined action of the different stages that constitute this process. These results exhibit the Fenton reagent as a feasible treatment for generating sludges with characteristics of biosolids of Class B for land application. The preliminary results of conditioning tests show that Fenton sludges present better dewatering characteristics with regard to the alum sludge, for a dose of cationic polymer of 1 mg/g TS.

scholarly journals Quantification of Enteric Viruses, Pathogen Indicators, and Salmonella Bacteria in Class B Anaerobically Digested Biosolids by Culture and Molecular Methods

2010 ◽  
Vol 76 (19) ◽  
pp. 6441-6448 ◽  
Author(s):  
Kelvin Wong ◽  
Brandon M. Onan ◽  
Irene Xagoraraki
Keyword(s):  
Salmonella Enterica ◽  
Hepatitis A Virus ◽  
A549 Cells ◽  
Enteric Viruses ◽  
The United States ◽  
Land Application ◽  
Most Probable Number ◽  
Probable Number ◽  
Pathogen Indicators ◽  
Class B

ABSTRACT The most common class B biosolids in the United States are generated by mesophilic anaerobic digestion (MAD), and MAD biosolids have been used for land application. However, the pathogen levels in MAD biosolids are still unclear, especially with respect to enteric viruses. In this study, we determined the occurrence and the quantitative levels of enteric viruses and indicators in 12 MAD biosolid samples and of Salmonella enterica in 6 MAD biosolid samples. Three dewatered biosolid samples were also included in this study for purposes of comparison. Human adenoviruses (HAdV) had the highest gene levels and were detected more frequently than other enteric viruses. The gene levels of noroviruses (NV) reported were comparable to those of enteroviruses (EV) and human polyomaviruses (HPyV). The occurrence percentages of HAdV, HAdV species F, EV, NV GI, NV GII, and HPyV in MAD samples were 83, 83, 42, 50, 75, and 58%, respectively. No hepatitis A virus was detected. Infectious HAdV was detected more frequently than infectious EV, and all infectious HAdV were detected when samples were propagated in A549 cells. Based on most-probable-number (MPN) analysis, A549 cells were more susceptible to biosolid-associated viruses than BGM cells. All indicator levels in MAD biosolids were approximately 104 MPN or PFU per gram (dry), and the dewatered biosolids had significantly higher indicator levels than the MAD biosolids. Only two MAD samples tested positive for Salmonella enterica, where the concentration was below 1.0 MPN/4 g. This study provides a broad comparison of the prevalence of different enteric viruses in MAD biosolids and reports the first detection of noroviruses in class B biosolids. The observed high quantitative and infectivity levels of adenoviruses in MAD biosolids indicate that adenovirus is a good indicator for the evaluation of sludge treatment efficiency.

Comparison of the quantity and quality of the microbiological content of sludge in countries with low and high content of pathogens

2002 ◽  
Vol 46 (10) ◽  
pp. 17-24 ◽  
Author(s):  
B. Jimínez ◽  
C. Maya ◽  
E. Sãnchez ◽  
A. Romero ◽  
L. Lira ◽  
...  
Keyword(s):  
Giardia Lamblia ◽  
Microbiological Quality ◽  
The United States ◽  
Salmonella Typhi ◽  
Fecal Coliforms ◽  
Residual Water ◽  
Industrialized Countries ◽  
Treatment Processes ◽  
Residual Sludge

The parasites present in the residual sludge generated by the diverse treatment processes of residual water vary, depending on the socioeconomic and epidemiological conditions of different communities. And although data exist at the global level regarding the microbiological quality of sludge, these data are practically nonexistent in developing countries. Therefore, this project compares the content of the four principal groups of parasites in residual sludge from the United States and Mexico. The marked differences between the orders of magnitude found in the two countries (coliphages 103-106 and 1.3 × 105 PFU/gTS, fecal coliforms 107-1010 and 107, Salmonella typhi 106-108 and 103 MPN/gTS, Giardia lamblia 102-104 and 102 cysts/gTS and helminth ova from 73-177 and <1 to 10 viable HO/gTS, respectively) will permit proposing real, effective and economical stabilization processes (undoubtedly different from those of industrialized countries), and will thus take advantage of the benefits represented by the reuse and disposal of sludge, in addition to developing regulations in agreement with the conditions of each region.

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.

Alternative Treatment for Wastewater Destined for Agricultural Use

1999 ◽  
Vol 40 (4-5) ◽  
pp. 355-362 ◽  
Author(s):  
B Jinénez ◽  
A. Chávez ◽  
C. Hernández
Keyword(s):  
Water Quality ◽  
Alternative Treatment ◽  
Drainage System ◽  
Primary Treatment ◽  
Fecal Coliforms ◽  
Filter Media ◽  
Helminth Eggs ◽  
Start Up ◽  
Agricultural Use ◽  
Water Quality And Quantity

An Advanced Primary Treatment (APT) system commercially known as ACTIFLO®, coupled with a system of filtration and chlorination are described. The system used microsand grains in the coagulation phase. This allowed an almost immediate start-up as well as an increase in loading in the sedimentation tank to rates far higher than those previously described (up to 180 m/h). The process was shown capable of treating wastewater from a combined drainage system, which typically varies in water quality and quantity. The ACTIFLO® process reduced TSS from 354 to 27 mg/L, helminth eggs from 24.8 to 1.2 HE/L, COD from 460 to 198 mg/L, TKN from 21.7 to 18.3 mg/L, and TP-P from 8.7 to 3.2 mg/L. To comply with WHO, 1989 recommendations regarding HE quality in water destined for irrigation of crops eaten raw it is necessary to add to the APT a system of filtration. In the paper two types of filter media are compared. In both cases the HE were reduced to <1.0 HE/L for filtration rates of up to 40 m/h. In the disinfection phase 10 mg Cl2/L were used to reduce the number of fecal coliforms from 6.5 × 108 to 340 MPN/100 mL.

Wastewater Treatment by Stabilization Ponds with and without Macrophytes under Arid Climate

1993 ◽  
Vol 28 (10) ◽  
pp. 177-181 ◽  
Author(s):  
L. Mandi ◽  
N. Ouazzani ◽  
K. Bouhoum ◽  
A. Boussaid
Keyword(s):  
Bacterial Load ◽  
Fecal Coliforms ◽  
Arid Climate ◽  
Organic Load ◽  
Experimental Systems ◽  
Helminth Eggs ◽  
Stabilization Ponds ◽  
Treated Effluents ◽  
Summer Time ◽  
Influent Flow

This paper presents a comparative study of two experimental systems, stabilization ponds without macrophytes and macrophytic ponds, to purify wastewater under arid climate of Marrakesh. Organic load (COD, TSS), bacterial load (SF, CF) and parasitical load (helminth eggs) are significantly reduced in both systems. Even though water loss was more important at the macrophytic ponds (evapotranspiration reaches 60% of influent flow), this system shows generally the best efficiency in purifying wastewater. In summer time, TSS and COD depletion is better on macrophytic ponds (TSS: 95%, COD: 87%). The stabilization ponds are more efficient to reduce nutrients: NH4+: 72%. PO4: 63% at the same period. Fecal streptococci and fecal coliforms are reduced more in stabilization ponds (CF: 99.4%, SF: 99.7%) than macrophytic ponds (CF: 96.2%, SF: 94.7%). No helminth eggs were found in the effluent from either system. The two systems ensure optimal removal of parasites allowing the eventual reuse of the treated effluents for agricultural purposes.

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