Belt Filter Press Research Articles

Influence of water treatment residuals on dewaterability of wastewater biosolids

Co-dewatering of water treatment residuals (WTR) and wastewater biosolids can potentially benefit municipalities by reducing processing equipment and costs. This study investigated dewaterability (using capillary suction time, CST) of combined alum residuals (Al-WTR) and anaerobically digested biosolids at various blending ratios (BR), defined as the mass ratio of WTR to biosolids on a dry solids basis. Without polymer addition, the CST was 160 s for a BR of 0.75 compared with 355 s for the biosolids alone. The optimum polymer dose (OPD), defined as the polymer dose yielding CST of 20 s, was reduced from 20.6 g kg(-1) dry solids for the biosolids alone to 16.3 and 12.6 g kg(-1) when BR was 0.75 and 1.5, respectively. Precipitated Al hydrous oxides in the WTR likely caused flocculation of the biosolids particles through heterocoagulation or charge neutralization. The solids contents of the blended materials and biosolids at their respective OPDs were not statistically different (α = 0.05) following dewatering by a belt-filter press. We conclude addition of Al-WTR improved biosolids dewaterability and reduced polymer dosage. In practice, the extent of these benefits may be limited by the quantity of WTR produced relative to the amount of wastewater solids generated by a municipality.

An economic, sustainability, and energetic model of biodiesel production from microalgae

A new process evaluation methodology of microalgae biodiesel has been developed. Based on four evaluation criteria, i.e. the net energy ratio (NER), biodiesel production costs, greenhouse gases (GHG) emission rate and water footprint, the model compares various technologies for each step of the process, from cultivation to oil upgrading. An innovative pathway (hybrid raceway/PBR cultivation system, belt filter press for dewatering, wet lipid extraction, oil hydrotreating and anaerobic digestion of residues) shows good results in comparison to a reference pathway (doubled NER, lower GHG emission rate and water footprint). The production costs are still unfavourable (between 1.94 and 3.35€/L of biodiesel). The most influential parameters have been targeted through a global sensitivity analysis and classified: (i) lipid productivity, (ii) the cultivation step, and (iii) the downstream processes. The use of low-carbon energy sources is required to achieve significant reductions of the biodiesel GHG emission rate compared to petroleum diesel.

Testing, Selection, and Design of Open Belt Filter Press Facilities with External Frame Mounted Enclosures for Dewatering Unique Thermal Hydrolysis Digested Biosolids for DC Water's Biosolids Program

Testing, Selection, and Design of Open Belt Filter Press Facilities with External Frame Mounted Enclosures for Dewatering Unique Thermal Hydrolysis Digested Biosolids for DC Water's Biosolids Program

Relationship between the Characteristics of Cationic Polyacrylamide and Sewage Sludge Dewatering Performance in a Full-Scale Plant

To identify the key characteristics of cationic polyacrylamide (c-PAM) for evaluating sewage sludge dewatering performance, we examined the properties of 13 types of c-PAMs that come from different manufacturers via a laboratory assay. The sludge dewatering performance was determined through a full-scale test at a large wastewater treatment plant in Beijing. We checked the cationic degree, solution viscosity, dissolution time, and 1 mm sieve residue of c-PAM. The 1 mm sieve residue was found to affect the dissolution time, solution viscosity, and conductivity. The full-scale test indicated that the cationic degree is the most important factor that affects the dosage and treatment capacity of the belt filter press when the cationic degree ranges from 25% to 45%. However, the moisture content of sludge cake is mainly relevant to raw sludge organic content. The sludge dewatering performance of the 13 types of c-PAMs showed that the c-PAM should be selected based on cationic degree, solution viscosity, and 1 mm sieve residue. The dosage should then be adjusted at the appropriate time according to the status of the equipment and facilities during sludge dewatering.

Belt Filter Press Dewatering Trials with Cambi Thermally Hydrolyzed Biosolids – Evaluation of Critical Performance Criteria.

Belt Filter Press Dewatering Trials with Cambi Thermally Hydrolyzed Biosolids – Evaluation of Critical Performance Criteria.

The Effect of Digestion and Dewatering on Sudden Increases and Regrowth of Indicator Bacteria after Dewatering

Several investigators have reported higher densities of indicator bacteria after dewatering of anaerobically digested biosolids. The increases appear to occur at two points in the biosolids process: the first, referred to as "sudden increase", occurs immediately after dewatering; the second, "regrowth", occurs during storage over longer periods. The objectives of this study were to examine the effect of digestion and dewatering processes on sudden increase and regrowth of fecal coliform and E. coli. Samples were collected from five thermophilic and five mesophilic digestion processes, with either centrifuge or belt filter press dewatering. Sudden increase typically was observed in the thermophilic processes with centrifuge dewatering and was not observed in the mesophilic processes with either centrifuge or belt filter press dewatering. Regrowth was observed in both thermophilic and mesophilic processes with centrifuge dewatering but not belt filter press dewatering.

Belt Filter Press Dewatering Trials with Cambi Thermally Hydrolyzed Biosolids – Evaluation of Critical Performance Criteria

Belt Filter Press Dewatering Trials with Cambi Thermally Hydrolyzed Biosolids – Evaluation of Critical Performance Criteria

Shopping for a Belt Filter Press? Perspectives from Operators and Designers

Shopping for a Belt Filter Press? Perspectives from Operators and Designers

Evaluation of the enterococci indicator in biosolids using culture-based and quantitative PCR assays

The utility of the enterococci indicator for measuring biosolids quality was evaluated in biosolids from 22 U.S. wastewater treatment facilities. Enterococci were enumerated using 23S rRNA quantitative PCR (qPCR) and membrane filtration with mEI-agar culture analyses in biosolids collected after mesophilic anaerobic digestion (MAD, class B, 13 treatment plants), composting (class A, 10 treatment plants), and temperature-phased anaerobic digestion (TPAD, class A, six treatment plants). Enterococci qPCR and culture values were not significantly different for a given treatment ( P > 0.05, paired t-test) and both assays showed differences in biosolid treatment effectiveness—anaerobic digestion treatments averaged 5–5.5 log genomic units (GU) and colony forming units (CFU)/dry g while composting decreased enterococci on average to 3.7 log GU and 3.8 log CFU/dry g. Only in class A TPAD biosolids dewatered with a belt-filter press were culture values significantly lower than qPCR values (1.7 log CFU/dry g vs. 5 GU/dry g). Further investigation of compost inactivation was compared for enterococci and other fecal indicators ( n = 5 treatment plants)—the enterococci indicator was more resistant to compost treatment than fecal coliforms, with reductions averaging only 1–2.5 logs for enterococci, male-specific coliphages, and sulfite-reducing Clostridia while 5-log reductions were observed for fecal coliforms. Lastly, biosolid isolates from culture-based methods were identified using DNA sequencing—these results revealed that non-enterococci, including Bacillus spp. and Vagococcus spp., were commonly isolated from compost and TPAD biosolids using mEI agar. Given the equivalency of culture- and qPCR-based enterococci concentrations in biosolids and the more conservative inactivation noted for both assays during class A composting, the use of enterococci qPCR monitoring could bypass non-specificity issues with culture-based methods while providing an improved description of pathogen fate in biosolids.

Belt Filter Press Dewatering: Operator-Centered Optimization to Extend Useful Life of Installed Equipment

Belt Filter Press Dewatering: Operator-Centered Optimization to Extend Useful Life of Installed Equipment

SEPARATE SIDESTREAM TREATMENT PROVIDES MULTIPLE BENEFITS AT THE SOUTHSIDE WWTP

SEPARATE SIDESTREAM TREATMENT PROVIDES MULTIPLE BENEFITS AT THE SOUTHSIDE WWTPDallas Water Utilities (DWU) currently owns and operates two wastewater treatment plants (WWTP) that service the Dallas area: the Southside WWTP and the Central WWTP. The biosolids processing system at the Southside WWTP is currently being upgraded to process all residuals produced at the Southside and Central WWTPs. The plant uses belt filter presses (BFP) for dewatering prior to disposal. The...Author(s)Ewa GorgiSamir MathurJyh-Wei(Al) SunSourceProceedings of the Water Environment FederationSubjectSession 83: Sidestream and High Strength Treatment (Joint Session with Leading Edge Research, Municipal Wastewater Treatment and Facility Operations)Document typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2008ISSN1938-6478SICI1938-6478(20080101)2008:9L.6316;1-DOI10.2175/193864708788809716Volume / Issue2008 / 9Content sourceWEFTECFirst / last page(s)6316 - 6332Copyright2008Word count182

Belt Filter Press Produces Similar Performance to Centrifugation: Side-By-Side Dewatering Results from three Anaerobic Digested Biosolids

Belt Filter Press Produces Similar Performance to Centrifugation: Side-By-Side Dewatering Results from three Anaerobic Digested BiosolidsThe recent Biosolids Management Plant conducted by the Ocean County Utilities Authority (OCUA) recommended side-by-side pilot testing of belt filter press and centrifuge technology to select the best technology to dewater their anaerobically digested biosolids from the authority three plants. Initially, screening of available vendors for providing dewatering technologies and conducting the...Author(s)Mohammad Abu-OrfPeter NeseWilliam SuchodolskiSourceProceedings of the Water Environment FederationSubjectSession 9: Innovative Dewatering IDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2008ISSN1938-6478SICI1938-6478(20080101)2008:3L.527;1-DOI10.2175/193864708788806647Volume / Issue2008 / 3Content sourceResiduals and Biosolids ConferenceFirst / last page(s)527 - 541Copyright2008Word count265

Massachusetts' First Rotary Press Installation Improves Operations, Cuts Costs

Massachusetts' First Rotary Press Installation Improves Operations, Cuts CostsWhen replacing equipment that has reached the end of its life cycle, breaking with tradition and exploring the marketplace for industry trends and cutting edge technologies can often yield substantial results. For example, when the Town of Billerica, Massachusetts, needed to replace its aging belt filter press; rather than replacing the equipment in kind the Town installed a rotary sludge press...Author(s)Thomas F. HazlettSourceProceedings of the Water Environment FederationSubjectSession 14: Innovative Dewatering IIDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2008ISSN1938-6478SICI1938-6478(20080101)2008:3L.757;1-DOI10.2175/193864708788806719Volume / Issue2008 / 3Content sourceResiduals and Biosolids ConferenceFirst / last page(s)757 - 764Copyright2008Word count185

Unique Side-By-Side Pilot Testing of Belt Filter Press and Centrifuge Requires Careful Planning, Organization and Control by Authority Personnel

Unique Side-By-Side Pilot Testing of Belt Filter Press and Centrifuge Requires Careful Planning, Organization and Control by Authority Personnel

ADDRESSING DIGESTER FOAMING BY FIXING ACTIVATED SLUDGE SYSTEM AND GAINING CAPACITY IN BOTH

ADDRESSING DIGESTER FOAMING BY FIXING ACTIVATED SLUDGE SYSTEM AND GAINING CAPACITY IN BOTHThe City of Richland Wastewater Treatment Facility digesters have experienced Nocardia induced digester foaming problems from the time they went into operation in 1985. Because of the persistent foam, most or all of the thickened waste activated sludge (TWAS) was often notsent to the digesters but directly to the belt filter press to be dewatered separately from the digested sludge. It was...Author(s)Patricia TamHenryk MelcerL. Emil VogesBill McCarthyWilliam D. HarlanSourceProceedings of the Water Environment FederationSubjectSession 56: Creative Solutions for Solids ManagementDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2007ISSN1938-6478SICI1938-6478(20070101)2007:14L.4288;1-DOI10.2175/193864707787974003Volume / Issue2007 / 14Content sourceWEFTECFirst / last page(s)4288 - 4301Copyright2007Word count226

Wastewater sludge processing

Chapter 1. Introduction. 1.1 Introduction. 1.2 40 CFR Part 503 Regulation. 1.2.1 General Provisions. 1.2.2 Land Application. 1.2.3 Surface Disposal. 1.2.4 Pathogen and Vector Attraction Reduction. 1.2.5 Incineration. Chapter 2. Sludge Quantities and Characteristics. 2.1 Types of Sludge. 2.1.1 Primary Sludge. 2.1.2 Secondary Sludge. 2.1.3 Chemical Sludge. 2.1.4 Other Wastewater Residuals. 2.2 Sludge Quantity. 2.2.1 Primary Sludge. 2.2.2 Secondary Sludge. 2.2.3 Activated Sludge. 2.2.4 Attached Growth System Sludge. 2.2.5 Chemical sludge. 2.3 Sludge Characteristics. 2.3.1 Primary Sludge. 2.3.2 Activated Sludge. 2.3.3 Physical and Biological Properties. 2.4 Mass Balance. Chapter 3. Thickening and Dewatering. 3.1 Introduction. 3.2 Conditioning. 3.2.1 Factors Affecting Conditioning. 3.2.2 Chemical Conditioning. 3.2.3 Other Conditioning Methods. 3.3 Thickening. 3.3.1 Gravity Thickening. 3.3.2 Dissolved Air Flotation Thickening. 3.3.3 Centrifugal Thickening. 3.3.4 Gravity Belt Thickening. 3.3.5 Rotary Drum Thickening. 3.3.6 Miscellaneous Thickening Methods. 3.4 Dewatering. 3.4.1 Centrifugal Dewatering. 3.4.2 Belt Filter Press. 3.4.3 Pressure Filter Press. 3.4.4 Drying Beds. 3.4.5 Other Dewatering Methods. Chapter 4. Aerobic Digestion. 4.1 Introduction. 4.1.1 Process Theory. 4.2 Conventional Aerobic Digestion. 4.2.1 Process Design Considerations. 4.2.2 System Design Considerations. 4.2.3 Operational Considerations. 4.3 Process Variations. 4.3.1 High-Purity Oxygen Digestion. 4.3.2 Low Temperature Aerobic Digestion. 4.3.3 Dual Digestion. 4.3.4 Mesophilic Aerobic Digestion. 4.3.5 Autothermal Thermophilic Aerobic Digestion. 4.3.6 Technological Improvements. Chapter 5. Anaerobic Digestion. 5.1 Introduction. 5.1.1 Advantages and Disadvantages. 5.1.2 Theory of Anaerobic Digestion. 5.2 Environmental Factors. 5.2.1 Solids and Hydraulic Retention Times. 5.2.2 Temperature. 5.2.3 pH and Alkalinity. 5.2.4 Toxic Materials. 5.3 Process Variations. 5.3.1 Low-Rate Digestion. 5.3.2 High-Rate Digestion. 5.3.3 Thermophilic Digestion. 5.3.4 Two-Stage Digestion. 5.3.5 Two-Phase Digestion. 5.4 Process Design. 5.4.1 Per Capita Basis. 5.4.2 Solids Loading. 5.4.3 Solids Retention Time. 5.4.4 Volatile Solids Reduction. 5.4.5 Gas Production. 5.5 System Component Design. 5.5.1 Tank Design. 5.5.2 Digester Covers. 5.5.3 . 5.5.4 Heating. 5.5.5 Gas Usage. 5.5.6 Design Example 5-1. 5.6 Operational Considerations. 5.6.1 Reactor Performance. 5.6.2 Odor Control. 5.6.3 Supernatant. 5.6.4 Struvite. 5.6.5 Digester Cleaning. Chapter 6. Alkaline Stabilization. 6.1 Introduction. 6.1.1 Advantages and Disadvantages. 6.1.2 Process Theory. 6.2 Process Application. 6.2.1 Liquid Lime Stabilization. 6.2.2 Dry Lime Stabilization. 6.2.3 Advanced Alkaline Stabilization Technologies. 6.3 Process Design. 6.3.1 Sludge Characteristics. 6.3.2 Contact Time and pH. 6.3.3 Lime Dosage. 6.3.4 Alkaline Material Storage. 6.3.5 Lime Feeding. 6.3.6 Liquid Lime Mixing. 6.3.7 Dry Lime Mixing. 6.3.8 Design Example 6-1. 6.4 Process Performance. 6.4.1 Odor Reduction. 6.4.2 Pathogen reduction. 6.4.3 Dewatering Characteristics. Chapter 7. Composting. 7.1 Introduction. 7.1.1 Composting Process. 7.1.2 Composting Methods. 7.1.3 Advantages and Disadvantages of Composting. 7.1.4 Zoological Characteristics of Compost. 7.2 Process Description. 7.2.1 Factors Influencing Composting. 7.2.2 Windrow Process. 7.2.3 Aerated Static Pile process. 7.2.4 In-Vessel Process. 7.2.5 Design Considerations. 7.3 Theoretical Aspects of Composting. 7.3.1Design Example 7-1. 7.4 New Technology in Composting. 7.4.1 Organic Content. 7.4.2 Odor. 7.4.3 Temperature and Moisture. 7.4.4 Composting Mixture. 7.4.5 Composting Process Control. 7.4.6 Design Example 7-2. 7.4.7 pH. 7.5 Examples of Composting in Europe. 7.6 Examples of Composting in the United States. Chapter 8. Thermal Drying and Incineration. 8.1 Introduction. 8.2 Thermal Drying. 8.2.1 Methods of Thermal Drying. 8.2.2 Design Considerations. 8.3 Incineration. 8.3.1Methods of Incineration. 8.3.2 Design Considerations. Chapter 9. Comparison of Energy Consumption. 9.1 Introduction. 9.1.1 Anaerobic Digestion. 9.1.2 Incineration. 9.1.3 Composting. 9.1.4 Comparison of Thermal Drying and Composting. 9.1.5 Conclusion. Chapter 10. Beneficial Use of Biosolids. 10.1 Introduction. 10.2 Requirements for Beneficial Use. 10.2.1 Pollutant Limits. 10.2.2 Pathogen Reduction. 10.2.3 Vector Attraction Reduction. 10.2.4 Management Practices. 10.2.5 Surface Disposal. 10.3 Land Application. 10.3.1 Site Evaluation and Selection. 10.3.2 Design Application Rates. 10.3.3 Application Methods. 10.3.4 Application to Dedicated Lands. 10.3.5 Conveyance and Storage of Biosolids. 10.4 Beneficial Use of Biosolids in Russia. 10.4.1 Pathogens. 10.4.2 Heavy Metals. A-1 Abbreviations for SI Units. A-2 Abbreviations for U.S. Customary Units. A-3 Conversion from SI Units to U.S. Customary Units. A-4 Conversion from U.S. Customary Units to SI Units.

Enhanced sludge conditioning by enzyme pre-treatment: comparison of laboratory and pilot scale dewatering results

The effect of enzyme pre-treatment on dewaterability of anaerobically digested sludge was investigated at both laboratory and pilot scale. Our results revealed a significant increase in cake solid content (27% cake solids compared to 18% without enzyme pre-treatment), using an enzyme dose of only 20 mg/L. In order to assess practical application, enzyme pre-treatment was applied at the Wilmington, Delaware (U.S.) wastewater treatment plant, using a pilot-scale centrifuge. However, the efficiency reached in laboratory scale could not be obtained in pilot scale, where the final cake solids content did not exceed 20%. Centrifuge and belt filter press (simulated by Crown Press) dewatering were compared in terms of the process efficiencies in the absence and presence of enzyme pre-treatment. Possible factors that might cause the differences were tested by experimental and statistical comparisons. Results indicated that the higher shear applied in centrifugation is responsible for the lack of improved cake solids. The network strength of sludge determined by rheological measurements revealed that enzymatic treatment weakens the gel structure of the sludge floc through the hydrolysis of extracellular polymeric substances; this allows improved dewatering by filtration processes, but leads to floc deterioration when subjected to high shear during centrifugation.

Characterization and Dewatering Evaluation of Acid Mine Drainage Sludge from Ammonia Neutralization

A major problem in the active treatment of acid mine drainage (AMD) is the generation of large volumes of sludge through pH neutralization and subsequent metal precipitation. The sludge typically contains a low concentration of solids, resulting in associated handling and disposal difficulties. Anhydrous ammonia is one reagent commonly used to neutralize AMD due to its quick reaction rate, easy implementation, and relatively low chemical and operational costs. However, very limited information is available in the literature related to the detailed characterization and dewaterability of ammonia-treated AMD sludge. In this study, sludge was collected from an AMD treatment facility where ammonia neutralization was used. The sludge characteristics included high pH and alkalinity, high total Fe and Al, elevated sulfate, and low solids content (0.72 ± 0.24%). Coagulants and flocculants were not effective in reducing the settled sludge volume. Based on filtration tests, ammonia-treated AMD sludge demonstrated relatively good dewaterability in terms of specific resistance to filtration (SRF). Sludge cake containing 4.5–6.3% solids were obtained using vacuum filtration at a vacuum of 50.8 kPa (15-inch Hg). The appropriate immersion time was 60 s for a vacuum filter, and sludge cakes of 6.2% solids and a yield of 3.04 kg/m2h were achieved. Overall, the belt filter press showed the best performance in improving total solids content in the sludge cakes, where concentrations of ∼10% solids were achieved.

Municipal sludge dewatering by belt filter press: effect of operating parameters

AbstractA belt filter press is commonly used to dewater sewage sludge but few data concerning this process have been published. A laboratory‐scale investigation was carried out to highlight the main process parameters affecting belt filter press efficiency as measured by the dry solid content of the final cake, percentage of solids recovered, and lateral sludge migration on the belt. Belt speed was determined to be the most important parameter: a low belt speed produces drier cakes with lower lateral sludge migration on the belt and also improves filtrate quality. At low belt speed, pressure is gently applied to the initial sludge, enabling a slow structuring of the cake and leading to better water release. Copyright © 2005 Society of Chemical Industry

Enzymatic treatment effects on dewaterability of anaerobically digested biosolids-II: laboratory characterizations of drainability and filterability

This paper provides an analysis of different measurements and derived parameters that may be used to characterize drainability and filterability dynamics. To better simulate the phenomena of gravity drainage and expression dewatering, specific devices and procedures were used in bench-scale conditioning and dewatering experiments. The setup included a plow simulator kit for drainage simulation and a mechanical dewatering unit, namely, the Crown Press™, which simulates full-scale belt filter press dewatering. The effects of enzyme product additions prior to polymer conditioning of biosolids samples were investigated. The results showed that enzyme additions enhanced the drainability of the biosolids samples and this positively affected filterability of the samples in the press unit. According to these results, enzyme product addition for biosolids samples with polymer conditioning seems a promising new method of enhancing the performance of mechanical dewatering units in the future.