Characterization of raw sludge, chemically modified sludge and anaerobically digested sludge in Hong Kong

1998 ◽  
Vol 38 (2) ◽  
pp. 25-32 ◽  
Author(s):  
C. W. Chu ◽  
C. S. Poon ◽  
R. Y. H. Cheung
Keyword(s):  
Hong Kong ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Properties ◽  
Primary Treatment ◽  
Digested Sludge ◽  
Total N ◽  
Chemically Modified ◽  
Anaerobically Digested Sludge

Chemically Enhanced Primary Treatment (CEPT) or Chemically Assisted Primary Sedimentation (CAPS) is being employed at the new sewage work on Stonecutters Island as part of the Strategic Sewage Disposal Scheme (SSDS) in Hong Kong. CAPS involves the use of chemical coagulants (such as lime or ferric chloride) to induce coagulation or flocculation and let these finely-divided particles form large aggregates (floc) so that they can settle out within a reasonable period of time. In this study, five sludge samples collected from different sewage treatment plants in Hong Kong were physically and chemically characterized. They were chemically modified sludge from Stonecutters Island (CAPS) raw sludge from Tai Po and Yuen Long Sewage Treatment Plant (STP) (rTP & rYL) and anaerobically digested sludge from Tai Po and Yuen Long STP (dTP & dYL). It was found that CAPS sludge was better than other 4 sludge samples in terms of settleability and dewaterability. CAPS sludge contained significant higher amounts (p<0.01) of extractable compounds than other sludges (except NO3− for dTP, NH4+ and PO43− for dYL). The concentration of total N and P in CAPS sludge were significantly higher (p<0.01) than other sludges (except dYL). The concentrations of total Cu, Pb, Ni, Cd, Cr and K in the CAPS sludge were also significantly higher (p<0.01) than other sludge samples. Most of the metals (Cr, Pb, Cr and Zn) in CAPS sludge were associated with the organically-bounded phase. It is concluded that there are significant differences in both physical and chemical properties between the chemically modified sludge and biological treated sludges.

scholarly journals Bacteriological, Physical And Chemical Properties Of The Pagla Sewage Treatment Plant’s Water

1970 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Mihir Lal Saha ◽  
Ashraful Alam ◽  
Mahbubar Rahman Khan ◽  
Sirajul Hoque
Keyword(s):  
Heterotrophic Bacteria ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Properties ◽  
Bacillus Sphaericus ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Treated Water

Samples from Pagla sewage treatment plant at different treatment stages showed more or less similar temperature (26.9 - 27.5°C). The pH ranged from 7.2 - 7.9. Influent water and primary sedimentation tank water were brownish in colour while sludge water was light black. The lagoon water and treated water were greenish. The ammonium?nitrogen (NH+4-N) and nitrate?nitrogen (NO-3?N) ranged from 5.24 - 61.94 mg/l and 2.55 - 11.02 mg/l, respectively. Phosphorus of the water was 1.34 - 4.50 mg/l. The suspended solids (SS) ranged from 25.48 ? 374.69 mg/l. In the present study the amount of SS in the treated water were found to be quite satisfactory. The total bacterial population in Pagla sewage treatments plant was in between 2.9 × 104 and 2.5 × 106 cfu/ml. The qualitative bacterial spectrum showed a potential consortium of bacteria associated with the treatment plant. Both Gram positive and Gram negative bacteria were present. Gram positive bacteria were represented by the different species of the genus Bacillus, Aureobacterium and Kurthia. Among them Bacillus was the dominant genus. The different species of Bacillus were Bacillus sphaericus, B. fastidiosus, B. circulans and B. pasteurii. Gram negative bacteria were Zoogloea, Yersinia, Citrobacter and Pseudomonas. A good number of microorganisms were found to be associated with the bio-oxidation of the organic compounds of the influent. The Zoogloea along with other free flowing aerobic heterotrophic bacteria like Bacillus, Pseudomonas could play the major role in the sewage treatment.DOI: http://dx.doi.org/10.3329/dujbs.v21i1.9739 DUJBS 2012 21(1): 1-7

scholarly journals Bacterial Load Reduction in Guheswori Sewage Treatment Plant, Kathmandu, Nepal

2019 ◽  
Vol 15 (1) ◽  
pp. 40-44 ◽  
Author(s):  
Bikram Gautam ◽  
Anjita Rajbhanshi ◽  
Rameshwar Adhikari
Keyword(s):  
Bacterial Load ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Primary Treatment ◽  
Plate Count ◽  
Coagulase Negative Staphylococcus ◽  
Load Reduction ◽  
Grab Sampling ◽  
Treated Effluent

Background: Water sources such as lakes, ponds, river etc. have been continuously contaminated by the   micro organisms and chemicals. The former can pose a significant threat to human health. This work aims at detecting the bacterial load before and after the sewage treatment and hence isolating pathogens from the sewage before primary treatment and secondary treated effluent. Methods: Grab sampling (50mL sewage before primary treatment and secondary treated effluent) was performed for 20 days in the Guheswori  sewage treatment plant. The reduction in microbial load was determined through heterotrophic plate count. Pathogens were screened from the effluent obtained from the secondary treatment plant. Results: Bacterial load reduction was found to be about 48.02% on average. The observed bacterial load reduction might have been caused by bacteriophage flocculation and sedimentation. Pathogens isolated from the treated effluent were Escherichia coli, Salmonella Typhi, Enterococcus faecalis, Staphylococcus aureus, Coagulase negative Staphylococcus (CONS), Citrobacter fruendii, Enterobacter aerogenes, Proteus mirabilis, P. vulgaris, Pseudomonas  aeruginosa. Conclusions: It has been found that the sewage treatment plant helps to reduce the bacterial load which is, however, not capable of effluent polishing where all pathogens are killed. 

scholarly journals Microbial air contamination on the premises of the sewage treatment plant in Bydgoszcz (Poland) and antibiotic resistance of Staphylococcus spp.

2017 ◽  
Vol 43 (4) ◽  
pp. 58-65 ◽  
Author(s):  
Marta Małecka-Adamowicz ◽  
Łukasz Kubera ◽  
Wojciech Donderski ◽  
Katarzyna Kolet
Keyword(s):  
Heterotrophic Bacteria ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Antibiotic Sensitivity ◽  
Primary Treatment ◽  
Average Concentration ◽  
Diffusion Method ◽  
Air Contamination ◽  
Staphylococcus Spp

AbstractThe study was aimed at evaluating microbial contamination on the premises of the sewage treatment plant by determining the concentrations of selected groups of airborne microorganisms. Another objective was to determine the antibiotic sensitivity patterns of isolated strains of staphylococci. The research was conducted in a seasonal cycle, by the impaction method using Merck MAS-100 air sampler. Samples were collected at six sites, each representing a different stage of sewage treatment. The susceptibility of isolated staphylococci was assessed with the disc-diffusion method, following the recommendations of the EUCAST. The results indicate that the microbial population in the air of the investigated area was dominated by mold fungi, whose highest average concentration was recorded at site IV located near the final clarifier (7672 CFU•m-3). Heterotrophic bacteria and mannitol-positive staphylococci were the most numerous at locations where sewage undergoes primary treatment. In each subseuqent stage the number of microorganisms emitted into the air from the sewage was lower. Antibiograms show that more than 50% of Staphylococcus spp. exhibited resistance to penicillin and 20% to rifampicin. In addition, 90% of the analyzed strains were sensitive to other antibiotics. The fungal community included the following genera: Cladosporium, Fusarium, Alternaria, Penicillium, Aspergillus, Aureobasidium, and Acremonium.The highest air contamination with all studied groups of microorganisms was recorded at the locations where mechanical sewage treatment was performed. During the subsequent stages lower numbers of heterotrophic bacteria were emitted into the air. The air in the investigated sewage treatment plant did not contain multidrug-resistant staphylococci.

scholarly journals Obtaining filamentous fungi and lipases from sewage treatment plant residue for fat degradation in anaerobic reactors

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5368 ◽  
Author(s):  
Anna Cristina P. Lima ◽  
Magali C. Cammarota ◽  
Melissa L.E. Gutarra
Keyword(s):  
Filamentous Fungi ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Basal Medium ◽  
Primary Treatment ◽  
Lipase Production ◽  
Plant Residue ◽  
Anaerobic Reactors

A residue from the primary treatment of a Wastewater Treatment Plant (WWTP) was used to isolate filamentous fungi with lipase production potential. Two of the 27 isolated fungi presented high hydrolysis index and were selected for lipase production by solid-state fermentation (SSF). The fermentations were conducted at 30 °C for 48 h, with moist air circulation, using 20% (w/w) of the residue mixture with a basal medium (agroindustrial residue—babassu cake), obtaining a solid enzymatic preparation (SEP) with lipase activity of 19 U/g with the fungus identified as Aspergillus terreus. Scum, collected in an anaerobic reactor operating in a WWTP, was hydrolyzed with SEP and subjected to anaerobic biodegradability tests at 30 °C. Different dilutions of crude (Control) or hydrolyzed scum in raw sewage were evaluated. The dilution of 5% (v/v) of hydrolyzed scum in raw sewage proved the most adequate, as it resulted in higher methane yield compared to the raw sewage (196 and 133 mL CH4/g CODadded, respectively), without increasing the chemical oxygen demand (COD) of the treated sewage (138 and 134 mg/L). The enzymatic hydrolysis of the scum, followed by dilution in the influent sewage, is technically feasible and increases methane production in anaerobic reactors.

Operational Experiences with the Industrial and Communal Waste Water Treatment System in the District of Linz

1990 ◽  
Vol 22 (5) ◽  
pp. 87-92 ◽  
Author(s):  
Gerd E. Reichel
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Hydroelectric Plant ◽  
Waste Water Treatment ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Treatment System ◽  
Digested Sludge ◽  
Water Treatment System

The waste water treatment system of the central region Linz is described. Because of the construction of the hydroelectric plant in Abwinden-Asten a central sewage treatment plant for 22 communities and the waste waters of the chemical and steel industry was constructed. Purification efficiency in terms of BOD5 is 93 % and 83 % for COD. The anaerobic digested sludge is deposited in lagoons.

SCREENING OF CHEMICAL SPILL RISKS TO MUNICIPAL SEWAGE TREA TMENT PLANTS

1994 ◽  
Vol 30 (4) ◽  
pp. 25-34
Author(s):  
M. Ettala ◽  
E. Rossi
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plants ◽  
Sewage Treatment ◽  
Screening Method ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Properties ◽  
Carbonaceous Material ◽  
Field Studies ◽  
Municipal Sewage

Seven operational mishaps were specified on the basis of a questionnaire on wastewater treatment plants, some of them large. In this study a process was developed for screening the chemical spill risks to municipal biological sewage treatment plant. Data on wastewater treatment processes, potential spill sources and chemical properties were combined to determine the threshold chemical quantities which may inhibit the removal of carbonaceous material, prevent nitrification and methanogenesis, cause sludge contamination or lead to the aeration capacity being exceeded. Two sewage treatment plants and eleven industrial sites were chosen for field studies. The influence of spill duration and maintenance activities on threshold quantities are discussed. A field survey lasting 1-2 hours at each site was long enough for the most relevant data to be obtained when the screening method developed was applied. Several chemical spill risks to the plants studied were specified. In addition, cases were identified in which failure of the pretreatment facilities for industrial wastewaters could cause severe mishaps at a biological wastewater treatment plant.

Wastewater quality relationships with reuse options

2001 ◽  
Vol 43 (10) ◽  
pp. 147-154 ◽  
Author(s):  
R. A. Patterson
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Land Application ◽  
Chemical Additives ◽  
Beneficial Effects ◽  
Wastewater Quality ◽  
Reuse Options

The trend towards reuse of effluent for land application of domestic and industrial wastewater is driven by the need to maximise limited water resources and benefit from the plant nutrients available in the effluent. Of significant impact upon the value of the wastewater for reuse is its chemical properties as well as biochemical oxygen demand and suspended solids. While the sewage treatment plant is expected to treat all wastewater received to a minimum environmental standard, no efforts are given to reducing the chemical load derived from uses of chemicals in the domestic household. That the regulation of industry and commerce far exceeds those of the combined effects of thousands of household is remiss of environmental regulators. This paper examines the results of research into the more common sources of chemical additives to the wastewater stream. Twenty five potable water supplies are examined for their salt load, 20 liquid and 40 powder laundry detergents and five dishwashing products were used to simulate discharges to the sewer, measured for their phosphorus, salt and sodium concentrations. The results of the research indicate that choices in the products available for general use within the house can be made only where product labelling and consumer education is improved. Technical improvements in wastewater treatment are not the answer. The improvement in effluent quality will have significant beneficial effects upon land application areas and expand the range of reuse options available for commercial operations.

Size fractionation of COD in urban wastewater from a combined sewer system

2004 ◽  
Vol 50 (12) ◽  
pp. 79-86 ◽  
Author(s):  
D. Marani ◽  
V. Renzi ◽  
R. Ramadori ◽  
C.M. Braguglia
Keyword(s):  
Large Fraction ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Complete Removal ◽  
Primary Treatment ◽  
Size Fractionation ◽  
Urban Wastewater ◽  
Physical Fractionation ◽  
Coagulation Tests

The objective of this work was to determine the partitioning of the pollutant load in urban wastewater in order to improve the conventional sewage treatment. In addition to settling tests, physical fractionation of COD in the degritted influent of Roma-Nord sewage treatment plant was performed via sequential filtration through sieves and membrane filters of the following pore size: 150-100-50-25-1-0.2 μm, and 100 kD (about 0.02 μm). Biodegradability studies were also performed on the different size fractions. Size fractionation showed that COD in Roma-Nord sewage is predominantly associated with settleable and supracolloidal (> 1 μm) particles, each size range including about 40% of total COD. Biodegradability tests indicated that the large fraction of COD associated with supracolloidal particles, which are not removed in the primary treatment, is characterised by slow degradability. This suggests that removal of these particles prior to biological treatment may greatly improve the overall treatment scheme. Preliminary pilot plant coagulation tests with lime at pH 9 showed that lime-enhanced primary treatment may increase COD removal efficiencies from typical 30-35% up to 65-70%, by inducing almost complete removal of the COD fraction associated with supracolloidal particles.

Behavior and fate of anthropogenic substances at a Swedish sewage treatment plant

2010 ◽  
Vol 62 (12) ◽  
pp. 2880-2888 ◽  
Author(s):  
U. Olofsson ◽  
S. Lundstedt ◽  
P. Haglund
Keyword(s):  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Specific Treatment ◽  
Water Soluble ◽  
Organophosphate Esters ◽  
Anaerobically Digested Sludge ◽  
Pass Through ◽  
Biological Methods ◽  
High Degree

The behavior and fate of anthropogenic substances during sewage treatment were investigated at a sewage treatment plant (STP) in Sweden which uses mechanical, chemical, and biological methods for sewage treatment and anaerobic digestion of sludge. Influent and effluent water, and sludge from two specific treatment sites were sampled. Mass balances were calculated from measured concentrations of various substances and estimates of the mass flows (water, solids) throughout the process. The results show that the metals (As, Cd, Cr, Hg, Pb) and the majority of PCBs, PCDD/Fs, and PBDEs enter and leave the STP bound to particles. Triclosan and di-(2-ethylhexyl)phthalate adsorb to sludge to a high degree, while the metals (Co, Cu, Ni, Zn) and organophosphate esters seem to pass through the STP unaffected by the process. Generally, the STP was better in removing lipophilic than water soluble compounds. Most of the substances end up in anaerobically digested sludge in almost the same concentrations as in primary sludge. A fugacity based STP model was evaluated for its ability to predict the behavior and fate of the substances and was found feasible for lipophilic compounds. It did however produce poor predictions for water soluble compounds such as organophosphate esters (overestimated) and antibacterial agents (underestimated).

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