Enhanced pathogen removal in on-site biofiltration systems over organic filtration materials

2008 ◽  
Vol 3 (2) ◽  
Author(s):  
Marco A. Garzón-Zúñiga ◽  
Ana C. Tomasini-Ortíz ◽  
Gabriela Moeller-Chavez ◽  
Yolanda Hornelas-Uribe ◽  
Gerardo Buelna ◽  
...  

Municipal wastewater was treated in 4 biofilters packed with a mix of endemic tropical woodchips and natural fibers to evaluate the removal efficiency of organic matter and pathogen microorganisms under tropical conditions. Biofilters were operated during 400 days, with a hydraulic rate of 0.3 m3/m2.d and an aeration rate of 0.68 m3air/m2 h-1. Raw municipal wastewater presented higher concentrations, of organic matter and pathogens, than those reported for municipal wastewaters in temperate countries. However, pollutants were successfully removed: <98.5% of the organic matter as BOD5 < 99.99% of Faecal Coliforms (FC) and Total Colony Forming Units (TCFU), and < 96.93% Helminth eggs (HE) were removed remaining only very low concentrations in the treated effluent (≤2.5 mg DBO5/L; ≤ 240 FC/100 mL; ≤ 240 TCFU /100 mL and < 1.0 HE/5L). According with Mexican regulations (Nom 001-SEMARNAT, 1996) and with the EPA suggested guidelines for water reuse (U.S. EPA, 1992a) treated effluents with this quality can be safely reused for three main activities: Nonfood crop irrigation, landscape impoundments and for construction activities. The high removal efficiency of TCFU and FC may be related with a predatory activity of testate amoebas which were detected growing into the biofilters and, the most plausible hypothesis concerning HE removal is that they are retained by filtration over the organic materials.

1994 ◽  
Vol 30 (11) ◽  
pp. 25-33 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Satoshi Okabe ◽  
Tomochika Arata ◽  
Yuji Haruta

A comprehensive wastewater treatment system that accomplishes oxidation of organic matter, nitrification, and denitrification was developed, and its characteristics and performance were investigated. A municipal wastewater was treated by an up-flow aerated biofilter (UAB), in which biofilms were developed on stainless meshes installed horizontally. This UAB exhibited a great potential ability of oxidation of organic matter, SS stabilization, and nitrification due to a unique aeration mechanism giving high DO concentrations with relatively low aeration rates. Another unique feature of the UAB was that attached biofilms on stainless meshes physically filtered out and/or adsorbed suspended solids in the wastewater in addition to the biological oxidation of organic matter. A stable nitrification could be achieved at HRT=10 hours corresponding to a hydraulic loading of 86 L m−2 d−1 and at a ratio of aeration rate to wastewater flow rate (A/W) of 2, which is considerably low as compared to aeration rates of typical activated sludge systems. This UAB system also could handle relatively high hydraulic loading rates. The UAB used in this study still have enough space to install more stainless meshes so as to reduce hydraulic loading rates resulting in the reduction of HRT and aeration rate, which leads to improvement of the system performance as well as reduction of the running cost.


2020 ◽  
Vol 167 ◽  
pp. 01010 ◽  
Author(s):  
Boonchai Wichitsathian ◽  
Jareeya Yimratanabovorn ◽  
Watcharapol Wonglertarak

The excess sludge problem from a wastewater treatment plant is a great concerned due to the high cost of sludge management accounting for about 20% to 50% of the total operating cost. Therefore, sludge reduction is critical. Currently, aerobic and/or anaerobic sludge digestions are widely used in the industries for treating the excess sludge. The objective of this research was to study the effects of aeration rate and temperature on the excess sludge reduction by using the aerobic-anaerobic digestion system in the laboratory. The aeration rates of 1.0, 0.5, and 0.1 volume air per volume slurry per minute (vvm) at the room temperature and the thermophilic temperature (55 ± 2°C) were investigated. The results showed that the highest removal efficiency of aerobic sludge digestion was obtained at the thermophilic temperature and aeration rate of 1.0 vvm. The removal efficiency of organic matter in terms of COD, total solids (TS) and volatile solids (VS) were 34.76%, 33.01% and 43.45%, respectively. Consequently, the highest specific growth rate of microorganisms was 0.39 per hour and the substrate removal rate was 0.55 milligram CODremoved per milligram VSS per hour. Furthermore, slowly biodegradable organic matter was hydrolyzed to readily biodegradable organic matter and inert soluble organic matter. When the sludge effluent from aerobic sludge digestion was feed to the anaerobic sludge digestion, the removal efficiency of organic matter in terms of COD, TS and VS were increased by 25%, 17% and 28%, respectively. Moreover, the obtained methane production rate in the anaerobic sludge digestion was approximate 0.234 m3/kg COD removed.


2021 ◽  
Vol 12 (3) ◽  
pp. 85-102
Author(s):  
Marcella Yuri Almeida Sawaguchi ◽  
Emily Giany Assunção ◽  
Isabela Bruna de Tavares Machado Bolonhesi ◽  
Gabriela Fonseca da Costa ◽  
Vilson Gomes da Assunção Júnior

The leachatefrom landfillhas high concentrations of organic matter, humic and nitrogenous compounds, heavy metals and inorganic salts, which requiresproper treatment for its final destinationand does not cause damage to the environment. Studies show that the biologically treated effluent requires an association of physical-chemical techniques.Thisstudy aimed to evaluate the application of complementary techniques to thebiological treatmentsuch as coagulation-flocculation-sedimentation(CFS)andFenton's reaction oxidation(FR), followed by adsorption. The CFS with ferric chloride and FRpost-treatments isolated had100% and 87,9%, organic mattercorrelated with true color removal and 53,6% and 67,0% of CODremoval,which meetwiththe requirements of CONAMA 357/05 e 430/11 for disposal in water bodies. The adsorption after Fenton reaction resulted in 84,5% organic matter correlated with true color removal and 67,0% of CODremoval. Adsorption after coagulation-flocculation-sedimentation was able to reduce 76,9% of COD. CFSshowed higher removal efficiency of organic matter correlated to the true color, while RFobtained higher removal efficiency of NKT, N-ammoniacal and COD parameters. The biologically treated leachate did not show significant toxicityacute to the test organism saline artemia, however, after the post-treatment, acute ecotoxicity in the limits established by CEMA 81/10.


2005 ◽  
Vol 52 (1-2) ◽  
pp. 315-322 ◽  
Author(s):  
F. Tessele ◽  
L.O. Monteggia ◽  
J. Rubio

Post-treatment of an UASB reactor effluent, fed with domestic sewage, was conducted using two-stage flotation and UV disinfection. Results were compared to those obtained in a parallel stabilisation pond. The first flotation stage employed 5–7.5 mg L−1 cationic flocculant to separate off more than 99% of the suspended solids. Then, phosphate ions were completely recovered using carrier flotation with 5–25 mg L−1 of Fe (FeCl3) at pH 6.3–7.0. This staged flotation led to high recoveries of water and allowed us to separate organic matter and phosphate bearing sludge. The water still contained about 1 × 102 NMP/100 mL total coliforms, which were removed using UV radiation to below detection levels. Final water turbidity was <1.0 NTU, COD <20 mg L−1 O2 and 71 mNm−1, the liquid/air interfacial tension. This flotation-UV flowsheet was found to be more efficient than the treatment in the stabilisation pond and appears to have some potential for water reuse. Results were discussed in terms of the biological, chemical and physicochemical mechanisms involved.


2011 ◽  
Vol 1 (3) ◽  
pp. 141-151 ◽  
Author(s):  
Hussein I. Abdel-Shafy ◽  
Inka Hobus ◽  
Werner Hegemann

Upgrading of a pond system for municipal wastewater treatment in a decentralized area is evaluated. The pond was constructed for the treatment of 63 m3/d. Currently it receives 83 m3/d, therefore poor treatment efficiency was recorded. An expansion of 1.6 times the present land area was required. In addition to construction, operation and maintenance were required to meet the permissible limits. The other option was to introduce aeration system to the ponds without any additional requirements. The efficiency of the successive treatment steps on the wastewater quality, including metals in the treated effluent/sludge and bacterial counts, was evaluated for agricultural reuse. The physical, chemical and bacterial parameters as well as the input aeration load (h) during the study period were investigated extensively. The results indicated that remarkable improvement in the treated effluent was achieved after upgrading the pond system via aeration. The removal rate of the pollution parameters ranged from 75 to 85%. The level of heavy metals in the produced sludge was below the permissible concentration and does not represent any risk. Meanwhile, it was possible to avoid any requirements for addition land area or construction of treatment and proved that the treated effluents can be reused for restricted water reuse.


Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1452
Author(s):  
Hodon Ryu ◽  
Yao Addor ◽  
Nichole E. Brinkman ◽  
Michael W. Ware ◽  
Laura Boczek ◽  
...  

Facing challenges in water demands and population size, particularly in the water-scarce regions in the United States, the reuse of treated municipal wastewater has become a viable potential to relieve the ever-increasing demands of providing water for (non-)potable use. The objectives of this study were to assess microbial quality of reclaimed water and to investigate treatability of microorganisms during different treatment processes. Raw and final treated effluent samples from three participating utilities were collected monthly for 16 months and analyzed for various microbial pathogens and fecal indicator organisms. Results revealed that the detectable levels of microbial pathogens tested were observed in the treated effluent samples from all participating utilities. Log10 reduction values (LRVs) of Cryptosporidium oocysts and Giardia cysts were at least two orders of magnitude lower than those of human adenovirus and all fecal indicator organisms except for aerobic endospores, which showed the lowest LRVs. The relatively higher LRV of the indicator organisms such as bacteriophages suggested that these microorganisms are not good candidates of viral indicators of human adenovirus during wastewater treatment processes. Overall, this study will assist municipalities considering the use of wastewater effluent as another source of drinking water by providing important data on the prevalence, occurrence, and reduction of waterborne pathogens in wastewater. More importantly, the results from this study will aid in building a richer microbial occurrence database that can be used towards evaluating reuse guidelines and disinfection practices for water reuse practices.


2011 ◽  
Vol 183-185 ◽  
pp. 683-689
Author(s):  
Shi Quan Sun ◽  
Li Jun Bi ◽  
Ping Ping Xu ◽  
Chang Bo Jiang ◽  
Wan Chun Tan ◽  
...  

Cloth media filter was applied in the treatment of the effluent of a municipal wastewater plant through pilot scale test for water reuse. Ferric chloride (FeCl3), PAFC and polyaluminum chloride (PAC) were employed as coagulants respectively to carry out the test. The average removal efficiency of TP and CODCr was 28.76% and 8% after cloth media filter without coagulation, and TP removal was influenced by the influent water quality. However, precoagulation with coagulants of ferric chloride, PAFC, PAC, the average removal efficiency of TP was 63.58%, 60.13%, 66.94% respectively, and no influence of TP removal can be found by the influent water quality. The average removal efficiency of CODCr was increased to 17.7%、26.3% and 27.7%,SS was 70.7%、64.3% and 49.1%. TN and NH3-N were removed unstably after cloth media filter.


2008 ◽  
Vol 57 (6) ◽  
pp. 821-827 ◽  
Author(s):  
C. Kazner ◽  
T. Wintgens ◽  
T. Melin ◽  
S. Baghoth ◽  
S. Sharma ◽  
...  

Direct nanofiltration and nanofiltration combined with powdered activated carbon known as the PAC/NF process were tested regarding the removal of effluent organic matter for reclamation of tertiary effluent from a municipal wastewater treatment plant. They can be regarded as a promising treatment alternative for high quality water reuse applications, especially for direct injection. The total removal for DOC was above 90% with permeate concentrations below 0.5 mg/l. Size exclusion chromatography and fluorescence EEM proved to trace origin of the organic matter even in low concentration ranges. The type and dosage of adsorbent influences the process performance significantly and allows process optimization.


2016 ◽  
Vol 11 (1) ◽  
pp. 104-117 ◽  
Author(s):  
C. Zaffaroni ◽  
G. Daigger ◽  
P. Nicol ◽  
T. W. Lee

Industrial wastewater differs from municipal wastewater. The limits for treated effluent discharge and targets for re-use are typically the same, and derived from the best available technology for municipal wastewater treatment. The main treatment unitary processes are also the same; although proper adaptation to specific, different, industrial wastewater streams is needed. This paper provides some examples of the challenges presented by specific wastewater sources (high total dissolved solids, high temperature, spent caustic, etc.), lack of previous similar experience – e.g., using membrane bioreactors for refinery wastewaters, and/or absorption chillers, and plate and frame heat exchangers) or to legislation protecting sensitive environments (limits on total nitrogen or soluble metals). The methods by which these were faced and overcome to achieve treatment and/or re-use standards are described. General water cycle optimization issues around industrial facilities with appropriate use of existing wastewater treatment units are also discussed, as well as selecting between treated municipal and industrial effluents as sources for water re-use.


2009 ◽  
Vol 36 (7) ◽  
pp. 1272-1283 ◽  
Author(s):  
Joel Citulski ◽  
Khosrow Farahbakhsh ◽  
Fraser Kent

In-line addition of alum and ferric chloride was conducted at a hollow-fibre immersed ultrafiltration (UF) membrane pilot plant, using secondary effluent from a municipal wastewater treatment plant (WWTP) as the feed. The objective of such pretreatment was to remove phosphorus from the feed from an initial concentration of approximately 5 mg/L to below 0.3 mg/L. The simplified in-line coagulant addition process involved hydraulic mixing of the coagulant into the feed and subsequent flocculation, and a greatly reduced (12–14 min) flocculation time relative to conventional coagulation-flocculation-settling treatment. Both alum and ferric chloride effectively removed phosphorus to below the 0.3 mg/L threshold when applied as a pretreatment at optimized doses, both of which were below the WWTP’s current coagulant dose (as ferrous chloride). This simplified pre-treatment scheme provided consistent enhanced removal of phosphorus and organic compounds. These results suggest that simplified in-line coagulant addition in advance of immersed UF membranes enhances the ability to produce treated effluent suitable for water-reuse applications.


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