scholarly journals Pathogenic micro-organisms in waste waters from daiies

2000 ◽  
Vol 18 (No. 5) ◽  
pp. 170-174
Author(s):  
P. Navrátilová
Keyword(s):  
Waste Water ◽  
Listeria Monocytogenes ◽  
Activated Sludge ◽  
Cleaning Process ◽  
Waste Waters ◽  
Excess Sludge ◽  
Salmonella Spp ◽  
Potential Health ◽  
Treated Water ◽  
Micro Organisms

Waste waters from dairies were tested for the presence of bacterial pathogens – Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. The prevalence of bacteria was investigated in each stage of the cleaning process (activated sludges systems) too. Two hunder samples of raw waste water, activated sludge, returned activated sludge, excess sludge and treated water from 14 dairies were tested. The samples were all negative for Salmonella spp. From a total of 102 (51%) strains Listeria spp., Listeria inoccua 95 (47.5%) and Listeria monocytogenes 7 (3.5%) were identified. 47 samples were positive for S. aureus. L. monocytogenes were detected in raw waste water 1 (1.6%), in activated sludge 3 (5.5%), in excess sludge 1 and in treated water 2 (3.1%). S. aureus were detected in raw waste water 14 (22.6%), in activated sludge 23 (41.8%), in excess sludge 1 and in treated water 8 (12.3%). These results demonstrate a prevalence of L. monocytogenes and S. aureus in waste waters from dairies. During the cleaning process pathogenic bacteria were not devitalized. The excess sludge and treated water including pathogenic micro-organisms represent a potential health hazard.

scholarly journals Study of Within-year Changes of Hydrocoles Composition in Aeration Tanks in the Process of Waste Water Treatment

2012 ◽  
pp. 90-95
Author(s):  
Keyword(s):  
Waste Water ◽  
Heavy Metals ◽  
Water Treatment ◽  
Activated Sludge ◽  
Waste Water Treatment ◽  
Micro Organisms

Activated sludge micro/organisms classes’ composition has been studied in the annual regime of biological facilities operation. Dependence of heavy metals concentration influence on the hydrocoles’ composition has been shown.

Operational aspects on foaming in digesters caused by microthrix parvicella

1998 ◽  
Vol 38 (8-9) ◽  
pp. 29-34 ◽  
Author(s):  
Åsa Dillner Westlund ◽  
Eva Hagland ◽  
Maria Rothman
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Activated Sludge ◽  
Gas Phase ◽  
Waste Water Treatment ◽  
Gas Bubbles ◽  
Excess Sludge ◽  
Water Treatment Plants ◽  
Microthrix Parvicella ◽  
Operational Aspects

Foaming in the digesters has been observed several times at three large waste water treatment plants in Stockholm, Sweden. The foam is caused by the filamentous organism Microthrix parvicella, a hydrophobic filament which traps the gas bubbles and creates a foam. The foam in the digesters causes economical loss and a security hazard. Different solutions to prevent problems with foaming has been tried and applied. By increasing the sludge load in the biological stage the growth of Microthrix parvicella can be reduced. Decreasing the sludge level in the digesters or installing mixers in the gas phase can prevent the foam from blocking the gas pipe. Heating (70°C, 5 min) the excess sludge has in lab scale been shown to change the foam potential of activated sludge with a high content of Microthrix parvicella and could be used as a solution to prevent foaming.

Experimental Study on the Control of Nutrients in Activated Sludge Treatment

1994 ◽  
Vol 29 (5-6) ◽  
pp. 329-342 ◽  
Author(s):  
Reijo Saunamäki
Keyword(s):  
Waste Water ◽  
Activated Sludge ◽  
Phosphorus Content ◽  
Treatment Plant ◽  
Pulp Mill ◽  
Paper Mill ◽  
Waste Waters ◽  
Phosphorus Addition ◽  
Total N ◽  
Mill Waste

Laboratory experiments were conducted to determine the need for addition of phosphorus during the treatment of pulp and paper mill waste waters by the activated sludge method. The study also included the testing of different modifications of the activated sludge method (a completely mixed, three completely mixed reactors in series, anaerobic/aerobic) to see how different forms of phosphorus and nitrogen (total-N, NH+4 - N, NO-2 - N, NO-3 - N) are present in the influent and effluent. The tests were conducted using waste water from two newsprint/magazine paper mills and from a bleached sulphate pulp mill. Different loadings and levels of phosphorus addition were applied. When paper mill waste water was treated at normal loading (sludge load was c. 0.3 kgBOD/(kgMLVSS*d)), a small phosphorus addition was needed to secure efficient operation. The optimum BOD:P ratio was about 100:0.4, in which case the treated effluent had a total phosphorus content of c. 0.5 mg/l (about 70% reduction), a soluble phosphorus content of c. 0.3 mg/l and a phosphate phosphorus content of well below 0.1 mg/l. Larger phosphorus additions produced no further improvement in treatment results (BOD reduction c. 90% and COD c. 75%). Doubling the loading gave poorer results and the situation could not be rectified by adding phosphorus. Addition of phosphorus was not needed when treating pulp mill waste water, as has also been found when running activated sludge treatment plants at several mills. The BOD reduction (c. 95%) was excellent under all conditions. The COD reduction was 30-55%, AOX 30-35% and chlorophenols 90-95%. The total phosphorus content of the treated effluent was 0.3-0.7 mg/l when no phosphorus was added. This treatment also resulted in extremely low phosphate phosphorus levels. The biosludge contained 0.5-1.9% phosphorus, 0.5-0.8% when pulp mill waste waters were treated and occasionally around 2% for the paper mill. The experiments showed that it might be possible to operate the pulp mill treatment plant with even less phosphorus in relation to BOD compared with the BOD level of waste waters to which no phosphorus has been added. The mill could consider removing the excess phosphorus originating from lime mud neutralization before the waste water arrives at the treatment plant. In treating both these waste waters there is the risk of really high phosphorus discharges if care is not taken with the phosphorus addition. A typical situation of this type arises if the plant is run on the old "textbook rule" of BOD:P=100:1. The nitrogen was added as urea resulting in the BOD:N ratio of 100:(2.5-4.5). Total-N in the paper mill untreated waste water was in the range of 8.5-13 mg/l and in the effluent 2.5 - 5.0 mg/l, i.e. the removal was 55-75%. NH+4 - N in the influent was in the range of 1.5-3.0 mg/l and was totally removed in most of the runs. The concentration of (NO-2 - N + NO-3 - N) was only 40-50 µg/l, the removal was 0-85 % depending on the conditions. The activated sludge modification "three completely mixed reactors in series" yielded the best results when all parameters were taken into account.

Lab-scale testing of a low-loaded activated sludge process with membrane filtration

2009 ◽  
Vol 63 (2) ◽  
Author(s):  
Zuzana Jakubčová ◽  
Petr Hlavínek ◽  
Miloslav Drtil ◽  
Igor Bodík
Keyword(s):  
Activated Sludge ◽  
Retention Time ◽  
Membrane Filtration ◽  
Pilot Scale ◽  
Membrane Bioreactors ◽  
Activated Sludge Process ◽  
Excess Sludge ◽  
Treated Water ◽  
Different Types

AbstractTwo membrane bioreactors (MBRs; volume = 300 L) equipped with different types of immersed membrane modules were operated simultaneously under the same laboratory conditions as a low-loaded activated sludge process without any membrane regeneration and excess sludge uptake (sludge retention time SRT up to 170 d; activated sludge concentration MLSS up to 11 g L−1). The aim was to verify the quality of treated water and to study the properties of "very old" activated sludge. Another aim was to compare different selected membrane types and choose the best one for further pilot-scale testing.

scholarly journals MICROBIOLOGICAL AND PHYSICOCHEMICAL QUALITY OF CURD CHESSE SOLD IN THE STATE OF ALAGOAS (BRAZIL)

2013 ◽  
Vol 31 (1) ◽  
Author(s):  
KARLA DANIELLE ALMEIDA SOARES ◽  
AYODHYA CARDOSO RAMALHO ◽  
SILVANA MAGALHÃES SALGADO ◽  
ALDA VERÔNICA SOUZA LIVERA ◽  
RINALDO APARECIDO MOTA ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Physicochemical Characteristics ◽  
Fat Content ◽  
Salmonella Spp ◽  
Potential Health ◽  
Physicochemical Quality ◽  
The Poor ◽  
Brazilian Legislation ◽  
Coagulase Positive Staphylococcus

The present study aimed to evaluate the microbiological and physicochemical quality of curd cheese commercialized in Alagoas (BRAZIL). Thirty samples were collect during a five months period in six points of sale. It was estimated the number of coagulase-positive Staphylococcus and coliforms, as well as the presence of Salmonella spp. and Listeria monocytogenes. Regarding physicochemical characteristics, pH, fat content and humidity were evaluated. Among the thirty analyzed samples, 20 (66.6%) were in accordance with Brazilian legislation parameters for coliforms, while 10 (33.3%) surpassed those limits. For coagulase-positive Staphylococcus 15 samples (50%) showed values above the allowed by legislation. None of the samples analyzed harbored Salmonella spp. or Listeria monocytogenes. Regarding physicochemical parameters, the average values observed were of 5.89 for pH, 23.6% for fat content and 46.96 g/100 g for humidity. Overall, the results obtained reflect the poor hygienic conditions observed from manufacture to commercialization, pointing towards a potential health risk for curd cheese consumers. Furthermore is necessary to regulate physicochemical standards for curd cheese fabication. 

A new side stream process for easily degradable industrial waste waters to avoid sludge bulking

2004 ◽  
Vol 50 (7) ◽  
pp. 229-236
Author(s):  
G. Wandl ◽  
N. Matsché ◽  
H. Bayer
Keyword(s):  
Waste Water ◽  
Industrial Waste ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Waste Waters ◽  
Excess Sludge ◽  
Treatment Line ◽  
Peak Loads ◽  
Side Stream ◽  
Dairy Waste

A new treatment scheme for the treatment of easily biodegradable industrial waste waters has been developed. The side stream treatment of dairy waste water with the excess sludge from the domestic treatment line of the regional treatment plant Bad Vöslau has been operated successfully for a period of three years during which the industrial load stemming from the dairy increased from 800 kg COD/d to 2,500 kg COD/d with peak loads up to 5,000 kg/d. Despite of the increased load to the treatment plant the total aeration tank volume had not been increased. This treatment is performed in an existing aeration tank of the WWTP (V = 1,800 m3) which is now used as contact tank for the combined aeration of dairy waste water and excess sludge from the domestic treatment line (volume aeration tank = 15,000 m3). In this tank the easily degradable substrate from the industrial waste is mainly adsorbed to the biological sludge and after a mechanical dewatering transferred to the anaerobic digester where it yields in an increased gas production. The filtrate of the dewatering process is completely free from biodegradable material and can without danger of bulking be fed to the aeration tank of the domestic treatment line. The new process has proven to be extremely flexible since already now daily peak loads exceeding the design load by more then 60% could be treated in the plant without any problems. Compared to other alternatives for the dairy waste water treatment that were investigated during this study, the new side stream process is very advantageous. No other pre-treatment process for industrial waste water could have been operated under comparable loading conditions without severe operating problems.

scholarly journals Elimination of Dyes from Waste Water via Adsorption Materials - A Mini Review

2018 ◽  
Vol 15 (2) ◽  
pp. 141-144 ◽  
Author(s):  
Masood Ayoub Kaloo ◽  
Bilal A Bhat ◽  
Gulzar Ahmad Sheergojri ◽  
Tajamul Islam Seh
Keyword(s):  
Waste Water ◽  
Activated Sludge ◽  
Exposure Time ◽  
Organic Dyes ◽  
Aqueous Media ◽  
Cost Effective ◽  
Living Organism ◽  
Waste Waters ◽  
Aquatic Life ◽  
The Cost

The problem with waste waters containing dyes is that these impurities impart acute and/or chronic consequences once exposed to living organism. The results of this exposure depend upon dye concentration, exposure time, besides their ability to absorb/reflect sunlight entering in to the aqueous media. Thus the concentration of these organic dyes leads to severe effects on the growth of aquatic life as well as other living organism that found entrance. Unlike the existing reports which present chemical decomposition by oxidation, photodegradation, microbial decoloration, use of activated sludge, etc., here in this work we have purely highlighted the cost-effective and easy to handle approach (adsorption) for the removal of dyes from the waster waters. Conclusions have been drawn from the compiled literature and few crucial regarding futuristic research for the removal of dyes have been presented.

The new technology of waste water treatment by using bioreactors with bio membranous movable bed – biochips

2020 ◽  
Vol 10 (3) ◽  
pp. 276-292
Author(s):  
Maria Y. Savostyanova ◽  
◽  
Lidia А. Norina ◽  
Arina V. Nikolaeva ◽  
◽  
...  
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Water Resources ◽  
Waste Water Treatment ◽  
Combined Treatment ◽  
Research Work ◽  
Pollution Level ◽  
Waste Waters ◽  
Treatment Facilities ◽  
Movable Bed

Retaining of water resources quality is one of the global ecological problems of the modern time. The most promising direction in solving the problem of water resources protection is the reduction of negative environmental influence of waste water from production facilities by upgrading the existing water treatment technologies. To treat utility water, technical and rain water from site facilities of Transneft system entities, the specialists developed and approved standard technological diagrams, which are used in producing treatment facilities. The standard technological diagrams provide for all necessary stages of waste water treatment ensures the reduction of pollution level to normal values. However, during operation of treatment facilities it was established, that to ensure the required quality of waste water treatment with initially high levels of pollution, the new technological solutions are necessary. The author presents the results of scientific-research work, in the context of which the best affordable technologies were identified in the area of the treatment of waste water with increased content of pollutants and non-uniform ingress pattern. On the basis of the research results the technical solutions were developed for optimization of operation of existing waste water treatment facilities by means of using combined treatment of technical and rain waters and utility waste waters and applying bioreactor with movable bed – biochips. The use of bioreactor with movable bed allows the increase in the area of active surface, which facilitates increase and retention of biomass. Biochips are completely immersed into waste waters, and biofilm is formed on the entire volume of immersion area, facilitating retention of biomass and preventing formation of sediments. Due to mixing the floating device with biofilm constantly moves along the whole area of bioreactor, and, in doing so, speeds up biochemical processes and uniformity of treatment. The advantages of a bioreactor with movable bed – its active sludge durability against increased and changing pollutant concentrations, change of waste water temperature and simplicity of application – ensured the possibility of its use for blending utility waters, technical and rain waters.

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