Automation in sludge dewatering by novel on-line characterisation of flocculation

Sievers, Michael; Schroeder, Christian; Bormann, H.; Onyeche, T.; Schlaefer, Ottmar; Schaefer, Sabine

doi:10.2166/wst.2003.0110

Cited by 8 publications

(4 citation statements)

References 15 publications

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“…Narayanan et al (2003) recommended the use of dispersed instead of total Nocardiaform counts for process control purposes since they found that that dispersed Nocardiaform filaments, generated in large quantities by the release of floc-bound Nocardiaform filaments during deflocculation caused by non-ionic surfactants, were directly related to the amount of foaming observed in ASP plants. To correlate floc distribution to degree of dewatering from a pilot filter press, Sievers et al (2003) used a sensor based on image processing of a conventional line scan camera's output in order to derive the particle size distribution of sludge particles above 50 microns. They developed a correlation (n = 24, R 2 = 0.92) between a dimensionless factor summarizing the size distribution and output-to-input solids concentrations ratio.…”

Section: Instrumentation and Measurementsmentioning

confidence: 99%

Modeling, Instrumentation, Automation, and Optimization of Wastewater Treatment Facilities

Sweeney¹,

Kabouris²

2001

Water Environment Research

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MODELING Mechanistic ModelsA review by Hu et al. (2003) of available activated sludge models led them to conclude that the most complete model was the Barker and Dold model and that the highly interactive nature of its processes, particularly with respect to the chemical oxygen demand (COD) loss mechanism, resulted in a non-unique identification of certain model parameters using the Wentzel et al. pilot scale data sets. Muller et al. (2003) validated the theoretical reduction of the anoxic yield to 79% of the aerobic yield value of 0.67 mgCOD/mgCOD, and noted that in updating the Activated Sludge Model 1 (ASM1) model parameters to reflect this change, the value of the hydrolysis reduction coefficient _ g should be adjusted to reflect the higher denitrification potential associated with the lower anoxic yield. The applicability to the ASM3 parameters was unclear. Jimenez et al. (2003) fitted pilot test data with a first order particulate COD removal rate, and concluded that flocculation of colloidal COD is slow and comparable to the removal rate of soluble COD and that flocculation of suspended solids is rapid but not instantaneous. Manga et al. (2003) used a modified version of ASM2, including the modeling of phosphate/glycogen accumulating organism (PAO/GAO) competition to model the data obtained at the anaerobic, anoxic, and aerobic compartments of a pilot scale modified University of Cape Town (UCT) process operated at solids residence times (SRTs) of 12, 14, and 16 days. Good agreement of effluent soluble P and nitrate-1437a N was obtained at the SRTs of 16 and 14 days, as opposed to the 12 day SRT. Copp et al. (2003) presented a state variable mapping between ASM1 and anaerobic digestion model 1 (ADM1) based on mass balance for COD and total Kjeldahl nitrogen (TKN) to facilitate the coupling of the two models. Fonseca et al. (2003) described a customized MS Excel interface to a plant's GPS-X TM simulator software that facilitated ease-of-use of the simulator by the plant operators by including a familiar description of the plant's processes, measurements and nomenclature and restricting access for modifying process model parameters. Using computational fluid dynamics (CFD) simulation, Vermande et al. (2003) obtained good agreement of the horizontal velocity profile along the length of an oxidation ditch bioreactor, in particular for velocity measurements near the ditch's bottom and near the water surface. Littleton et al. (2003) summarized the results of an investigation of simultaneous biological nutrient removal in Orbal TM processes and concluded that both the bioreactor macroenvironment and floc microenvironment are important factors in establishing a balance among the required nutrient removal microorganism populations. A full-scale extended aeration multi-loop bioreactor was modeled by Insel et al. (2003b) using ASM2d and 20 days of 15-minute measurements of flow rate and nutrient concentrations. They calibrated the inert particulate COD fraction of influent wastewater and 8 of the ASM2d parameters and...

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Section: Instrumentation and Measurementsmentioning

confidence: 99%

Modeling, Instrumentation, Automation, and Optimization of Wastewater Treatment Facilities

Sweeney¹,

Kabouris²

2001

Water Environment Research

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“…Coagulation/flocculation can effectively agglomerate sludge colloids to form large flocs through charge neutralization and bridging flocculation effects, is beneficial to sludge sedimentation, filtration and permeability, and is thus one of the most commonly used sludge conditionings in practical operation 15 – 17 . The employed coagulants/flocculants are of great significance in coagulation/flocculation 18 , 19 .…”

Section: Introductionmentioning

confidence: 99%

Evaluation of hydrophobically associating cationic starch-based flocculants in sludge dewatering

Shen

Yang

2021

Sci Rep

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Two series of binary graft cationic starch-based flocculants (CS-DMCs and CS-DMLs) with different hydrophilicity and charge density (CD) were prepared by graft copolymerization of acrylamide with 2-(Methacryloyloxy)-N,N,N-trimethylethanaminium chloride and methacrylic acid 2-(benzyldimethylaminio) ethyl chloride, respectively, on the starch (St) backbone. The sludge dewatering performance of CS-DMCs and CS-DMLs were evaluated and compared based on the changes in filter cake moisture content (FCMC), specific resistance of filtration (SRF), fractions and components of extracellular polymeric substances, and various physiochemical characteristics of sludge flocs and cakes. Increase in CD of the St-based flocculants caused improved sludge dewaterability. Under the similar CD, CS-DML with relatively high hydrophobicity exhibited lower FCMC and SRF, larger and denser sludge flocs, and better permeability of sludge cakes than CS-DMCs due to the synergistic effects of charge neutralization, bridging flocculation and hydrophobic association. Furthermore, a second-order polynomial model on the basis of phenomenological theory was successfully applied to quantitatively evaluate the influences of the two important structural factors of these St-based flocculants, i.e., hydrophobicity and CD, on the sludge dewaterability. The structure–activity relationship of the St-based flocculants in sludge dewatering was obtained according to the theoretic simulation. The dewatering mechanisms was discussed in depth on the basis of the experimental and simulated results; besides, the FCMC and optimal dose can be predicted by the established structure–activity relationship. This current work offered a novel and valuable way to exploit and design of low-cost and high-performance graft natural polymeric flocculants applied in efficient conditioning of sludge.

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“…However, pelleted aggregates are difficult to control due to the fluctuations of sludge and wastewater both in flow rate and quality. A better understanding of hydrodynamic effects on development of layered pellet structure of aggregates is needed.METHODSBased on previous prototypes(Schroeder 2001;Sievers et al 2003), a bench scale replica of the FlocFormer system has been constructed(Stoll 2007) and installed in the municipal wastewater treatment plant "Zweckverband Klä rwerk Steinhä ule" (ZVK) located in Neu-Ulm, Germany. For the Model of pelleting flocculation(Ay 2004).…”

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confidence: 99%

“…The main principle of the Floc-analyser is described in more detail bySievers et al (2003). By means of this optical measuring system, the sludge is automatically scanned and evaluated on-line.…”

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confidence: 99%

Aggregate characterisation by using the FlocFormer system to improve sludge dewatering

Stoll

Sievers

Schroeder

et al. 2009

Water Science and Technology

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In this paper, the influence of the polymer-induced flocculation on undigested sludge dewatering is investigated by image analysis. The mixing of flocculants in a so-called rapid-mixer and the subsequent forming of aggregates is carried out by the FlocFormer system, a new sludge conditioning system. For the mechanical dewatering a decanter device is used. To evaluate the efficiency of the dewatering process, the total solid content (TS) of the dewatered sludge is analysed. The results of this study show that this type of flocculation represents an alternative to improve sludge dewatering of undigested sludge. Compared with the standard conditioning (T-mixer), the FlocFormer leads to a better improvement (1.37 to 3.46%-points) in terms of TS while the rapid-mixer improves the dewatering efficiency only by 0.50 to 1.73%-points. Additionally, by using the FlocFormer conditioning, an optimal polymer dose of 5 g/kg TS has been detected. By increasing the polymer consumption (4-20% above the optimal dose) the dewatering efficiency remains practically constant (TS approximately 26.5%).

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Automation in sludge dewatering by novel on-line characterisation of flocculation

Cited by 8 publications

References 15 publications

Modeling, Instrumentation, Automation, and Optimization of Wastewater Treatment Facilities

Modeling, Instrumentation, Automation, and Optimization of Wastewater Treatment Facilities

Evaluation of hydrophobically associating cationic starch-based flocculants in sludge dewatering

Aggregate characterisation by using the FlocFormer system to improve sludge dewatering

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