scholarly journals Stabilized sewage sludge: Sanitary aspects and potential for conversion to biosolids

2021 ◽  
Vol 26 (52) ◽  
pp. 117-122
Author(s):  
Jelena Jovičić-Petrović ◽  
Anđelka Mijačić ◽  
Blažo Lalević ◽  
Igor Kljujev ◽  
Vera Karličić ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Microbial Diversity ◽  
Fecal Coliforms ◽  
Inorganic Pollutants ◽  
Salmonella Spp ◽  
Effluent Quality ◽  
Waste Sludge ◽  
Treatment Techniques ◽  
Potential Source ◽  
Spore Forming Bacteria

The improvement of wastewater treatment techniques is of crucial importance for effluent quality, but it also results in an increased amount of waste sludge. Dehydrated sludge contains organic matter and nutrients, and therefore it can be used in agriculture and bioremediation, but it is considered a potential source of environmental pollution. As the sludge analyzed in the research does not contain impermissible levels of organic and inorganic pollutants, the aim of the research was to examine microbiological, particularly sanitary, aspects and potential for its further use. Microbial diversity was determined by the standard serial dilution technique and selective media, and sanitary quality indicators (total coliforms, fecal coliforms, Escherichia coli and Salmonella spp.) were determined by the MPN method. The abundance of fungi, actinomycetes, and bacteria (ammonifiers, spore-forming bacteria and Pseudomonas spp.) indicate possibilities for further use of the sludge. The chemical analysis included the following parameters: total nitrogen (N), phosphorus in the form of P2O5 (available P), organic carbon (C), C/N ratio, pH, and water content. The chemical composition indicates the potential of sewage sludge to be used as a soil fertilizer, but its C/N ratio is not adequate to enable successful conversion to biosolids by the composting process. The obtained results indicate a significant level of microbiological contamination, which was most pronounced in the centre of the stabilized sludge pile. The research showed the necessity to conduct further studies on the microbial diversity and sanitary aspects of sewage sludge for proper waste sludge management.

Upgrading effluent quality for lagoon-based systems

1995 ◽  
Vol 31 (12) ◽  
pp. 379-387 ◽  
Author(s):  
Henryk Melcer ◽  
Brian Evans ◽  
Stephen G. Nutt ◽  
Anthony Ho
Keyword(s):  
Urban Communities ◽  
Ammonia Concentration ◽  
Sand Filters ◽  
Plant Operation ◽  
Capital Costs ◽  
Effluent Quality ◽  
Waste Sludge ◽  
Best Available Technology ◽  
Available Technology ◽  
Aeration Plant

To establish Best Available Technology Economically Achievable (BATEA) in non-urban communities which presently use conventional lagoon technology, an investigation was undertaken to evaluate alternatives which can be used to improve lagoon effluent and establish costs. Evaluated were the “Sutton” and the intermittent sand filtration or “New Hamburg” processes. The Sutton concept consists of a nitrifying extended-aeration plant followed by polishing lagoons, with waste sludge discharged into the lagoons. The New Hamburg concept consists of aerated or facultative lagoons, with the lagoon effluent sprayed intermittently over sand filters. The Sutton plants produce an improved effluent quality relative to conventional facultative lagoons in terms of BOD5 and TSS concentrations. Increases in ammonia concentration across the polishing pond occur after 5-7 years of plant operation, suggesting a need to implement a regular program of sludge removal from the lagoon. The New Hamburg process results in a significant improvement in effluent quality in terms of BOD5, TSS, TP, TKN, NH3-N and H2S concentrations. Approximate capital costs for upgrading the existing conventional lagoons in Ontario to Sutton and New Hamburg process facilities are estimated at US $221 million and US $93 million, respectively.

Biolixiviation des métaux lourds et stabilisation des boues d'épuration : essai en bioréacteur opéré en mode cuvée

1993 ◽  
Vol 20 (1) ◽  
pp. 57-64 ◽  
Author(s):  
R. D. Tyagi ◽  
J. F. Blais ◽  
N. Meunier ◽  
D. Kluepfel
Keyword(s):  
Heavy Metals ◽  
Sewage Sludge ◽  
Suspended Solids ◽  
Elemental Sulfur ◽  
Batch Reactor ◽  
Fecal Coliforms ◽  
Sludge Stabilization ◽  
Sludge Digestion ◽  
Batch Time ◽  
Phosphorus And Potassium

A biological process of heavy metals solubilization and sewage sludge stabilization was studied in a batch reactor of 30-L capacity. The acclimatized leaching microflora was composed of two major groups of thiobacilli: less acidophilic and acidophilic. A batch time of 10 days allows a substantial metal solubilization: cadmium (100%), copper (80%), manganese (80%), nickel (46%), and zinc (100%). The bioleaching process also causes a significative decrease in sludge total suspended solids (25%) and volatile suspended solids (32%), and a considerable reduction (under the detection limit of 10 cfu∙mL−1) of indicator bacteria (total coliforms, fecal coliforms, fecal streptococci). After filtration or centrifugation of the leached sludge, the solubilized metals were precipitated by lime neutralization. The phosphorus and potassium sludge contents were not affected by bioleaching process. These results indicate that the process of sludge digestion and metal leaching can be conducted in parallel in the same reactor. Key words: sewage sludge, heavy metals, bioleaching, stabilization, thiobacilli, elemental sulfur.

scholarly journals Development and bacteriological, chemical and sensory characterization of fishburgers made of Tilapia minced meat and surimi

2012 ◽  
Vol 64 (5) ◽  
pp. 1389-1397 ◽  
Author(s):  
S.C.R.P. Mello ◽  
M.Q. Freitas ◽  
S.C. São Clemente ◽  
R.M. Franco ◽  
E.B. Nogueira ◽  
...  
Keyword(s):  
Considerable Increase ◽  
Fecal Coliforms ◽  
Salmonella Spp ◽  
Isolation And Identification ◽  
Psychrotrophic Bacteria ◽  
Smoked Fish ◽  
Process Waste ◽  
Minced Meat ◽  
Sensory Tests

In this study fishburger samples obtained from tilapia minced meat and surimi retrieved from fillet frames - filleting process waste - have been assessed. Four different preparations of fishburger were made. Chemical analyses was performed for protein, lipids, moisture and ash assessments, as well as bacteriological analyses through mesophilic aerobic heterotrophic and psychrotrophic bacteria counts, isolation and identification of Salmonella spp., coagulase-positive Staphylococcus and fecal coliforms. Instrumental measurements were also carried out for texture and tested sensory acceptance. The costs of the ingredients used in the preparation of formulas were also assessed. Microbiological standards, established by current regulations, were met by all samples. No significant gap (P>0.05) was detected among the percentage of protein, moisture and ashes, while a significant gap (P<0.05) was verified for lipids. A significant gap (P<0.05) for the instrumental measurements of texture was also observed. Both surimi and minced meat fishburger presented good acceptance on sensory tests for taste, texture and overall impression. The use of smoked fish flavoring and surimi caused a considerable increase in costs due to ingredient acquisition. This study shows a positive result for the industrialization and consumption potential of fishburgers made of minced fish retrieved from fillet frames.

VERMICOMPOSTING TECHNOLOGY FOR STABILIZING THE SEWAGE SLUDGE FROM RURAL WASTE WATER TREATMENT PLANTS

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
V. Lina Cardoso ◽  
C. Esperanza Ramírez ◽  
E. Violeta Escalante
Keyword(s):  
Rural Communities ◽  
Sewage Sludge ◽  
Low Cost ◽  
Waste Water Treatment ◽  
Treatment Plant ◽  
Microbiological Quality ◽  
Fecal Coliforms ◽  
Nitrogen And Phosphorus ◽  
Sludge Management

There are problems associated with sludge management in small treatment plants (&lt;10 L/s) located in rural communities, due to costly conventional technology for sludge stabilization. Many of these plants have only sludge drying beds. Mexican Institute of Water Technology has proposed developing suitable low-cost technologies, one of which is vermicomposting a biodegradation system using earthworms of the species Eisenia foetida (earthworm) which stabilize sludge and reduce its pathogenicity. The objective of this work is to present two case studies where vermicomposting technology has been applied in Mexico. The first study corresponds to a plant where 4.8 m3/month of sludge are produced; for these wastes, a vermicomposting system was built and installed. The second study is a treatment plant where 9 m3/month of sludge are produced; experimental tests were conducted with sludge and water hyacinth and a vermicomposting system was designed. The vermicomposts were analyzed using parameters defined by Mexican standards. In regards to stabilization, TVS was reduced by 38% and the microbiological quality of the vermicompost was Class A and B, with a reduction in fecal coliforms and Helminth eggs according to NOM-004-SEMARNAT-2002. A CRETI (Corrosivity, Reactivity, Explosivity, Toxicity and Ignitability) analysis (NOM-052-SEMARNAT-2005) was used to show that the process reduced the concentration of releasable sulfides. The agronomic quality of the vermicompost exhibited a high content of organic matter comparable to many organic manures and high content of nutrients such as nitrogen and phosphorus. It is concluded that it is possible to improve the conditions of sewage sludge management in small plants of rural communities with a minimum investment (less than $10,000.00 USD) and with a requirement of a minimum area of 60 to 70 m2 for a production of less than 9 m3/month of dehydrated sludge (80% humidity).

Innovative biological treatment for sustainable development in the chemical industries

1998 ◽  
Vol 38 (4-5) ◽  
pp. 111-120 ◽  
Author(s):  
W. Wesley Eckenfelder ◽  
A. J. Englande
Keyword(s):  
Sustainable Development ◽  
Biological Treatment ◽  
Ecological Integrity ◽  
Cost Effective ◽  
Wastewater Management ◽  
Effluent Quality ◽  
Treatment Techniques ◽  
Conventional Technology ◽  
Receiving Waters ◽  
Specific Oxygen Uptake Rate

This paper presents a perspective of wastewater management in the chemical industries as related to sustainable development. The scope of wastewater management must therefore further be expanded to include the concept of ecological integrity of receiving waters. Ecological integrity of receiving waters is compromised by contaminants which are not effectively removed by Best Conventional Technology (BCT). Biological treatment typically offers the most cost-effective conversion and/or stabilization of wastewaters; however, modifications must be employed in the design and operation to provide satisfactory effluent quality. Enhanced treatment techniques for wastewaters containing high organic concentrations, VOCs, elevated TDS levels, toxics and priority pollutants are discussed. The importance of design and operational procedures including pretreatment technologies, two stage vs. single stage activated sludge, selector design and maximum specific oxygen uptake rate determinations are also presented.

Evaluation of the Bacteriological Health Risk of 60-Day Aged Raw Milk Cheddar Cheese

1984 ◽  
Vol 47 (7) ◽  
pp. 530-531 ◽  
Author(s):  
MICHAEL H. BRODSKY
Keyword(s):  
Staphylococcus Aureus ◽  
Alkaline Phosphatase ◽  
Health Risk ◽  
Campylobacter Jejuni ◽  
Alkaline Phosphatase Activity ◽  
Geometric Mean ◽  
Cheddar Cheese ◽  
Raw Milk ◽  
Fecal Coliforms ◽  
Salmonella Spp

One hundred twenty-seven 60-d aged Cheddar cheese samples produced by 21 provincially inspected cheese plants were analyzed by 8 regional laboratories of the Ontario Ministry of Health. Coliforms were detected in 37 (31.2%) and fecal coliforms confirmed in 22 (18.3%) samples, with geometric mean counts per g of 92.5 and 79.3, respectively. Staphylococcus aureus was found in only two products at a level of &gt;1000 per g. Salmonella spp. and Campylobacter jejuni were not isolated from any of the samples tested. Yersinia enterocolitica was isolated from one product; however, the isolate was bile esculin-and salicin-positive, and considered a non-pathogenic biotype. The pH of these aged Cheddars ranged between 4.98 and 5.50, with a mean of 5.26. Alkaline phosphatase activity was detected in 94 (79.7%) of the 118 samples tested. These results suggest that 60-d aged raw milk Cheddar cheese produced in Ontario does not pose a significant bacteriological health risk.

Alternative Approaches for Upgrading Effluent Quality for Lagoon Based Systems

1993 ◽  
Vol 28 (10) ◽  
pp. 201-205
Author(s):  
Brian Evans ◽  
Stephen Nutt ◽  
Tony Ho ◽  
Henryk Melcer
Keyword(s):  
Suspended Solids ◽  
Total Population ◽  
Sewage Treatment ◽  
Effluent Quality ◽  
Waste Sludge ◽  
Clean Environment ◽  
Alternative Approaches ◽  
The Cost ◽  
Phosphorus Levels ◽  
Lagoon Systems

The province of Ontario is Canada's most populous province with over 8 million residents out of a total population of 27 million. The province has 512 sewage treatment plants of which 137 or 27% are lagoons. Improved environmental effluent quality standards since the introduction of the lagoons has resulted in many of these being unable to achieve proper effluent quality. Typical effluent quality requirements across the province require a minimum of secondary treatment, that is 15 mg/l of BOD and suspended solids and 1 mg/l of total phosphorus. The movement towards a clean environment has resulted in phosphorus levels as low as 0.3 mg/l TP and in an increasing number of cases, full nitrification year round. Because many of these lagoons serve small populations in the 100 - 3 000 population equivalents category, the cost of upgrading such lagoons to tertiary quality effluent is significant. Two approaches for upgrading conventional lagoon systems were evaluated. They are called the Sutton and New Hamburg processes after the towns in Ontario where they were first installed. The Sutton process consists of extended aeration plant, followed by polishing lagoons with waste sludge sent directly to the lagoons, while the New Hamburg process consists of conventional lagoons followed by intermittent sand filtration.

Identification of Salmonella Serovars Isolated from Live Molluscan Shellfish and Their Significance in the Marine Environment

2003 ◽  
Vol 66 (2) ◽  
pp. 226-232 ◽  
Author(s):  
JAIME MARTINEZ-URTAZA ◽  
MONTSERRAT SACO ◽  
GUSTAVO HERNANDEZ-CORDOVA ◽  
ANTONIO LOZANO ◽  
OSCAR GARCIA-MARTIN ◽  
...  
Keyword(s):  
Marine Environment ◽  
Fecal Coliform ◽  
Seasonal Pattern ◽  
Maximum Level ◽  
Fecal Coliforms ◽  
Salmonella Spp ◽  
Low Levels ◽  
Slight Rise ◽  
Contamination Events ◽  
Salmonella Senftenberg

A study on the presence of Salmonella spp. in live molluscs was performed, which included a description of the different serovars isolated and their relationship to the marine environment. A total of 2,980 samples of shellfish from Galicia (N.W. Spain) were tested for the presence of Salmonella spp. between September 1998 and August 2001. The overall incidence of Salmonella was 1.8% and showed a slight rise during the 3 years of the study. Mussels and oysters presented a higher incidence than clams and cockles, possibly because of their distinct growing habitat. A seasonal pattern was noted for the isolation of Salmonella spp.: 54% of the isolations were detected from September to November. That nearly 67% of the total Salmonella was isolated from shellfish with fecal coliform levels &lt;300/100 g (the maximum level criteria in the European Communities regulations) supported the view that low levels of fecal coliforms do not necessarily indicate the absence of Salmonella. A total of nine serovars were found in the 54 Salmonella isolated. Salmonella Senftenberg was the most frequent (50%), followed by Salmonella Typhimurium (18%) and Salmonella Agona (17%). Salmonella Senftenberg was detected frequently during the year, whereas the remaining serovars were detected only on occasional contamination events.

scholarly journals Isolation and quantification of indicator and pathogenic microorganisms along with their drug resistance traits from bottled and jar water samples within Dhaka city, Bangladesh

2020 ◽  
Vol 9 (1) ◽  
pp. 12-14
Author(s):  
Md Aftab Uddin ◽  
Mst Aysha Siddiqua ◽  
Mst Sadia Ahmed
Keyword(s):  
Water Samples ◽  
Bacterial Count ◽  
Fecal Coliforms ◽  
Pathogenic Microorganisms ◽  
Dhaka City ◽  
Bacterial Isolates ◽  
Salmonella Spp ◽  
Potential Threat ◽  
Antibiotic Susceptibility Pattern ◽  
Shigella Spp

Commercial drinking water may serve as potential threat to public health if these items are contaminated with a number of pathogenic microorganisms due to faulty manufacturing process. Present study attempted to isolate and quantify the microorganisms from various jar and bottle water samples collected from various areas of Dhaka city. Antibiotic susceptibility pattern of suspected bacterial isolates were also determined in this study. Out of the eighteen samples studied, ten were jar water samples and eight were bottled water samples. The range of total viable bacterial count (TVBC) in these samples ranged from 102 to 105 cfu/ml. Specific pathogens such as, Salmonella spp., Shigella spp., Vibrio spp. and fecal coliforms could not be found in these samples. However coliforms could be detected in 10 samples. The antibiogram study showed that all Escherichia coli and Klebsiella spp. isolates found from these samples were sensitive against gentamicin (10 μg) and azithromycin (30 μg). Variable antibiotic resistance among these bacterial isolates was detected against cefotaxime (30 μg), streptomycin (10 μg) and erythromycin (15 μg). Stamford Journal of Microbiology, Vol.9(1) 2019: 12-14

Presence of toxigenic Clostridioides (Clostridium) difficile in edible bivalve mollusks in Spain

2019 ◽  
Vol 26 (5) ◽  
pp. 413-419
Author(s):  
Carmen Candel-Pérez ◽  
Elvira Zapata-Galián ◽  
Ruben López-Nicolás ◽  
Gaspar Ros-Berruezo ◽  
Carmen Martínez-Graciá
Keyword(s):  
Microbiological Quality ◽  
Grocery Stores ◽  
Bivalve Mollusks ◽  
Salmonella Spp ◽  
Legal Requirements ◽  
E Coli ◽  
Clostridioides Difficile ◽  
Potential Source ◽  
Cooking Temperature

Clostridioides difficile reservoirs other than humans are becoming increasingly recognized, and the occurrence of the pathogen in shellfish raises concern because spores can survive cooking temperature and edible bivalve mollusks are often consumed raw or poorly cooked. This study was conducted to determine the occurrence of pathogenic C. difficile in retail bivalve mollusks. The microbiological quality of samples was also checked through the isolation of Salmonella spp. and Escherichia coli. We analyzed 129 mollusk samples from different fishmongers and grocery stores in Murcia. C. difficile was isolated from 8.53% (11/129) of the mollusks investigated. Four C. difficile isolates harbored genes for the production of toxin A and B. Salmonella spp . were not isolated from any sample and E. coli was isolated from 1.55% (2/129) of the samples, in both cases in accordance with the current legal requirements for consumption. Our findings indicate that the intake of raw or poorly cooked contaminated bivalve mollusks could be a potential source of C. difficile, leading to a risk for human health.

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