Application of nano-silver coated granular activated carbon for inactivation of septic tank effluent

2015 ◽  
Vol 5 (4) ◽  
pp. 632-637
Author(s):  
Thammarat Koottatep ◽  
Saroj Kumar Chapagain ◽  
Jaruwat Watanatanachart ◽  
Chongrak Polprasert
Keyword(s):  
Activated Carbon ◽  
Granular Activated Carbon ◽  
Post Treatment ◽  
Septic Tank ◽  
Pathogen Inactivation ◽  
Treatment Unit ◽  
Nano Silver ◽  
Septic Tanks ◽  
Study Results ◽  
Septic Tank Effluent

On-site sanitation systems such as cesspools and septic tanks are widely used in most developing countries. These systems primarily aim to collect and treat toilet wastewater or blackwater. Although septic tanks are commonly used in non-sewered areas, their effluents are still rich in pathogens and other pollutants. The practice of direct discharge of septic tank effluents into the surrounding environment in the absence of proper treatment has increased health risks. In order to reduce this problem, a post-treatment unit consisting of nano-silver coated granular activated carbon (NS-GAC) has been developed. The study results revealed that the inactivation efficiency of the NS-GAC unit increased with increasing hydraulic retention times (HRT) from 10, 20 and 30 minutes; however, for economy of scale, the NS-GAC unit could be operated at the 10 minutes HRT to achieve complete removal of Escherichia coli bacteria. The study showed a high feasibility of utilizing the NS-GAC media as a post-treatment unit for pathogen inactivation of septic tank effluent.

Modeling of pathogen inactivation in thermal septic tanks

2013 ◽  
Vol 4 (1) ◽  
pp. 81-88 ◽  
Author(s):  
T. Koottatep ◽  
S. Phuphisith ◽  
T. Pussayanavin ◽  
A. Panuvatvanich ◽  
C. Polprasert
Keyword(s):  
Oxygen Demand ◽  
Weibull Model ◽  
Septic Tank ◽  
Most Probable Number ◽  
Pathogen Inactivation ◽  
Probable Number ◽  
E Coli ◽  
Septic Tanks ◽  
Log Reduction ◽  
Safe Level

Thermal application has been widely used for pathogen inactivation in various fields. The purpose of this research was to develop a model of pathogen inactivation in septic tanks operating at various temperatures. Four laboratory-scale septic tanks fed with septage were operated at temperatures of 30, 40, 50 and 60 °C and Escherichia coli (E. coli) was selected as the pathogenic indicator. The efficiencies of E. coli inactivation were found to increase with increasing temperatures, while the opposites were observed for chemical oxygen demand (COD) reduction. At 60 °C, the E. coli concentrations were reduced from 9.6 × 106 to about 10 most probable number (MPN)/100 mL or 6 log reduction. The kinetics of E. coli reduction followed a modified Weibull model which could be applied to septic tank design and operation. The percentage COD removal was found to be 93, 94, 89 and 84 at temperatures of 32, 40, 50 and 60 °C, respectively. The results of this study suggested that pathogenic microorganisms in septic tanks could be inactivated to be at a safe level with thermal application.

Use of ozone and hydrogen peroxide in the post-treatment of UASB treated alkaline fruit cannery effluent

2001 ◽  
Vol 44 (5) ◽  
pp. 69-74 ◽  
Author(s):  
G.O. Sigge ◽  
T.J. Britz ◽  
P.C. Fourie ◽  
C.A. Barnardt ◽  
R. Strydom
Keyword(s):  
Hydrogen Peroxide ◽  
Activated Carbon ◽  
Treatment Options ◽  
Water System ◽  
Granular Activated Carbon ◽  
Post Treatment ◽  
Legal Limit ◽  
Treated Effluent ◽  
Direct Discharge

UASB treatment of cannery effluents was shown to be feasible. However, the treated effluent still does not allow direct discharge to a water system and a further form of post-treatment is necessary to reduce the COD to lower than the legal limit of 75 mg/l. The use of ozone, hydrogen peroxide and granular activated carbon were used singly or in combination to assess the effectiveness as post-treatment options for the UASB treated alkaline fruit cannery effluent. Colour reduction in the effluent ranged from 15% to 92% and COD reductions of 26-91% were achieved. Combinations of ozone and hydrogen peroxide gave better results than either oxidant singly. The best results were achieved by combining ozone, hydrogen peroxide and granular activated carbon, and COD levels were reduced to levels sufficiently below the 75 mg/l limit.

scholarly journals Eliminace mikropolutantů z vod kombinací oxidačních a sorpčních procesů v laboratorním měřítku

Entecho ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 15-20
Author(s):  
Tamara Pacholská ◽  
Ivan Karpíšek ◽  
Jana Zuzáková ◽  
Vojtěch Kužel ◽  
Stanislav Gajdoš ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Wastewater Treatment Plants ◽  
Granular Activated Carbon ◽  
Pilot Scale ◽  
Post Treatment ◽  
Operational Parameters ◽  
Activated Carbon Adsorption ◽  
Boron Doped Diamond ◽  
Carbon Adsorption ◽  
Wwtp Effluent

Mikropolutanty v životním prostředí působí negativně na vodní ekosystémy a též představují potenciální riziko pro lidské zdraví. Zásadním zdrojem vnosu mikropolutantů do životního prostředí jsou městské ČOV, jejichž konvenční mechanicko-biologická technologie není na odstraňování mikropolutantů navržena. V této práci jsme testovali účinnost odstranění mikropolutantů řadou oxidačních (např. ozonizace, UV/H2O2, Fentonova reakce, borem dopovaná diamantová elektroda) a sorpčních (např. granulované aktivní uhlí GAU, zeolity) procesů. Účinnost odstranění vybraných léčiv (např. erythromycin, sulfamethoxazol, ibuprofen atd.) a metabolitů pesticidů (např. acetochlor ESA, metazachlor ESA) jsme testovali v jednorázových vsádkových testech. S přihlédnutím k ekonomickým i provozním parametrům byla pro následné testování v reálných podmínkách (poloprovozní měřítko) zvolena kombinace oxidace UV/H2O2 a sorpce na GAU. Mikropolutanty v modelové vodě byly úspěšně odstraněny z 91% (suma léčiv) a cca 100% (suma metabolitů pesticidů) při použití optimální dávky H2O2 5 mg/l a intenzity UV záření 4 kJ/m2 s následnou sorpcí na GAU. Tyto velmi slibné výsledky v současné době ověřujeme v pilotní jednotce pro dočištění reálného odtoku z městské ČOV. Abstract (EN) Micropollutants cause harm to aquatic ecosystems and can also negatively affect human health. Major sources of micropollutants input to aquatic environments are wastewater treatment plants due to their insufficient removal during the conventional mechanical-biological process. This study aimed to evaluate potential WWTP effluent post-treatment processes for the removal of selected pharmaceuticals and pesticides using oxidation (e.g., ozonization, UV/H2O2, Fenton, boron-doped diamond electrode) and sorption (e.g. granular activated carbon, zeolite) processes and their combinations. The removal of selected pharmaceuticals (e.g. erythromycin, sulphamethoxazole, ibuprofen) and pesticides (e.g. acetochlor ESA, metazachlor ESA) was tested in batch assays. The combination of UV/H2O2 and activated carbon adsorption was the most favorable in terms of removal efficiency and economic and operational parameters. This combination achieved the removal efficiencies of pharmaceuticals and pesticides of 91 and 100%, respectively, using an optimum H2O2 dose of 5 mg/L and UV intensity of 4 kJ/m2 followed by granular activated carbon adsorption. These promising results are currently adopted in a pilot-scale study for the post-treatment of a real WWTP effluent.

scholarly journals Integrating granular activated carbon in the post-treatment of membrane and settler effluents to improve organic micropollutants removal

2018 ◽  
Vol 345 ◽  
pp. 79-86 ◽  
Author(s):  
Lidia Paredes ◽  
Carolina Alfonsin ◽  
Tomás Allegue ◽  
Francisco Omil ◽  
Marta Carballa
Keyword(s):  
Activated Carbon ◽  
Granular Activated Carbon ◽  
Post Treatment ◽  
Organic Micropollutants

Fate of oestrogens during anaerobic blackwater treatment with micro-aerobic post-treatment

2007 ◽  
Vol 56 (5) ◽  
pp. 15-23 ◽  
Author(s):  
T.Z.D. de Mes ◽  
K. Kujawa-Roeleveld ◽  
G. Zeeman ◽  
G. Lettinga
Keyword(s):  
Total Concentration ◽  
Post Treatment ◽  
Treatment System ◽  
Septic Tank ◽  
High Sorption ◽  
Septic Tank Effluent ◽  
Final Effluent ◽  
Sulphate Conjugate

The fate of oestrone (E1), 17β-oestradiol (E2) and 17α-ethynyloestradiol (EE2) was investigated in a concentrated blackwater treatment system consisting of an UASB septic tank, with micro-aerobic post-treatment. In UASB septic tank effluent a (natural) total concentration of 4.02 μg/L E1 and 18.69 μg/L E2, comprising the sum of conjugated (>70% for E1 and >80% for E2) and unconjugated forms, was measured. During post-treatment the unconjugated oestrogens were removed to below 1 μg/L. A percentage of 77% of the measured unconjugated E1 and 82% of E2 was associated with particles >1.2 μm in the final effluent implying high sorption affinity of both compounds. When spiking the UASB septic tank effluent with E1, E2, EE2 and the sulphate conjugate of E2, removal in the micro-aerobic post-treatment was >99% for both E2 and EE2 and 83% for E1. The lower removal value for E1 was a result of (slow) deconjugation during the treatment, and in the final effluent still 40% of E1 and 99% of E2 was present in conjugated form. The latter was the result of incomplete deconjugation of the spiked E2(3S) in the post-treatment system.

Treatment of Septic Tank Effluent in a Subsurface Biofilter

1993 ◽  
Vol 28 (10) ◽  
pp. 117-124 ◽  
Author(s):  
Robert Netter ◽  
Eckhard Stübner ◽  
Peter A. Wilderer ◽  
Ivan Sekoulov
Keyword(s):  
Bacterial Count ◽  
Septic Tank ◽  
Residential Areas ◽  
Negative Effects ◽  
Septic Tanks ◽  
Treated Effluent ◽  
Septic Tank Effluent ◽  
Per Capita ◽  
Private Homes ◽  
Complete Nitrification

A horizontal flow biofilter to be buried in the backyard of private homes and residential areas was developed to treat effluents of septic tanks. Pilot and full scale experiments have been conducted to study the efficiency of the biofilter. A tank volume of about 0.6 m3 per capita is needed to achieve advanced COD removal, complete nitrification and up to 60 per cent nitrogen removal. The bacterial count was reduced by 2 to 3 orders of magnitude. The treated effluent may be used for irrigation or toilet flushing. Percolation is possible without negative effects on groundwater quality.

Removal of bromate and assimilable organic carbon from drinking water using granular activated carbon

2004 ◽  
Vol 50 (8) ◽  
pp. 73-80 ◽  
Author(s):  
W.J. Huang ◽  
H.S. Peng ◽  
M.Y. Peng ◽  
L.Y. Chen
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
Organic Carbon ◽  
Removal Rate ◽  
Operation Time ◽  
Granular Activated Carbon ◽  
Small Scale ◽  
Term Operation ◽  
Assimilable Organic Carbon ◽  
Study Results

This study investigated the feasibility of using granular activated carbon (GAC) to remove bromate ion (BrO3-) and assimilable organic carbon (AOC) from drinking water through a rapid small-scale column test (RSSCT) method and a pilot-scale study. Results from RSSCT indicated that the GAC capacity for BrO3- removal was dependent on the GAC type, empty bed contact time (EBCT), and source water quality. The GAC with a high number of basic groups and higher pHpzc values showed an increased BrO3- removal capacity. BrO3- removal was improved by increasing EBCT. The high EBCT provides a greater opportunity for BrO3- to be adsorbed and reduced to Br- on the GAC surface. On the other hand, the presence of dissolved organic carbon (DOC) and anions, such as chloride, bromide, and sulfate, resulted in poor BrO3- reduction. In the GAC pilot plant, a GAC column preloaded for 12 months achieved a BrO3- and AOC removal range from 79-96% and 41-75%, respectively. The BrO3- amount removed was found to be proportional to the influent BrO3- concentration. However, the BrO3- removal rate apparently decreased with increasing operation time. In contrast, the AOC apparently increased during the long-term operation period. This may be a result of the contribution due to new GAC being gradually transformed into biological activated carbon (BAC), and the bacterial biomass adsorbed on GAC surface hindering BrO3- reduction by GAC either by blocking pores or adsorbing at the activated sites for BrO3- reduction.

scholarly journals Human impact of septic tank effluent on groundwater quality in the rural area of Ain Soltane (Ain Defla), Algieria

2019 ◽  
Vol 7 (2) ◽  
pp. 1-9
Author(s):  
Abdelkader Bouderbala
Keyword(s):  
Groundwater Quality ◽  
Rural Area ◽  
Significant Degree ◽  
Septic Tank ◽  
Septic Tanks ◽  
Groundwater Samples ◽  
Septic Tank Effluent ◽  
Pre Treatment ◽  
High Concentrations ◽  
The Impact

Abstract The impact of individual septic tank effluent on groundwater quality was investigated in the rural area of the Ain Soltane municipality in Algeria. This area has an important number of individual septic tanks, and it is devoid of a drinking water supply and sewerage systems. The septic tank is a pre-treatment solution of sewage by bacteria living without oxygen (anaerobic). The alluvial aquifer in this area is covered by a layer of good permeability on the surface, which can pollute groundwater by vertical transport of pollutants through the soil, including microbial contamination. Groundwater samples were collected from 33 wells in the dry period of 2016. The monitoring of groundwater quality has shown a significant degree of organic and inorganic pollution in the majority of wells, with very high concentrations of sulphate and chloride exceeding 450 mg/l and 250 mg/l respectively. The analyzes also show the presence of bacterial germs in the groundwater of which the origin is faecal (faecal coliform densities are above 10 organisms per 100 ml, and the Total Streptococcus is more than 240 colonies per 100 ml). Monitoring confirms the contamination of these wells from septic tanks and that it was moving into groundwater, which makes it unfit for drinking due to the pathogenic germs. This poses a major problem for public health. This study has identified the effects of septic tank effluent on groundwater quality in this area.

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