Modeling of volatile organic contaminants in trickling filter systems

1995 ◽  
Vol 31 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Henryk Melcer ◽  
Wayne J. Parker ◽  
Bruce E. Rittmann

Despite the widespread use of trickling filters, there has been minimal investigation of the fate of volatile organic contaminants (VOCs) in such systems. A model describing the fate of VOCs in trickling filters is described. The removal of VOCs was investigated in a pilot-scale trickling filter receiving a feed of sewage dosed with a constant concentration of selected VOCs. Increasing hydraulic loading tended to increase the proportion of influent VOCs found in the effluent. Imposing effluent recycle also increased the fraction of VOCs found in the effluent but also decreased the fraction stripped and increased the fraction that was biodegraded. The values of the biodegradation coefficient, Kb, were found to be reproducible and affected by a combination of high hydraulic loading rate and effluent recycle.

2013 ◽  
Vol 67 (12) ◽  
pp. 2746-2752 ◽  
Author(s):  
P. C. Vieira ◽  
M. von Sperling ◽  
L. C. M. Nogueira ◽  
B. F. S. Assis

The objective of the work is to evaluate the performance of an innovative design of a trickling filter for small population sizes, which has been implemented for the post-treatment of sanitary effluent from a UASB (upflow anaerobic sludge blanket) reactor. The unit, named open trickling filter (OTF), operates with no side walls, no perforated bottom slab and no secondary settler. The OTF packing was 3.5 m high, composed of crushed stone, with a fixed distribution system made of channels with V-notch weirs. The OTF was operated with mean surface hydraulic loading rates of 4.1 and 9.3 m3 m−2 d−1, corresponding to population equivalents of approximately 250 and 550 inhabitants, respectively. For the surface hydraulic loading rate of 4.1 m3 m−2 d−1, the median removal efficiencies obtained by the OTF and overall system (UASB + OTF) were, respectively, 24 and 83% for total suspended solids (TSS), 44 and 79% for chemical oxygen demand (COD), 42 and 82% for biochemical oxygen demand (BOD), 40 and 40% for N-ammonia. For the surface hydraulic loading rate of 9.3 m3 m−2 d−1, the median removal efficiencies obtained by the OTF and global system (UASB + OTF) were 14 and 76% for TSS, 28 and 76% for COD, 25 and 86% for BOD, 15 and 15% for N-ammonia. Considering the great simplicity, no mechanization and small footprint of the system, these results can be considered satisfactory, suggesting that the OTF is suitable for small communities, especially in developing countries.


1987 ◽  
Vol 22 (1) ◽  
pp. 49-64 ◽  
Author(s):  
J.F. Devlin ◽  
W.A. Gorman

Abstract The Gloucester Landfill is located near Ottawa, Ontario, on a northeast trending ridge of Quaternary age. The ridge comprises outwash sediments which make up two aquifer systems. A confined system exists next to bedrock, and is overlain by a silty-clayey stratum (the confining layer) which is, in turn, overlain by an unconfined aquifer system. Two independent volatile organic plumes have previously been identified at the landfill: the southeast plume, which has penetrated the confined aquifer system, and the northeast plume which is migrating in the unconfined aquifer. The distribution of volatile organic contaminants at the northeast plume site appears to be a function of two factors: (1) heterogeneities in the aquifer sediments are causing the channeling of contaminants through a narrow path; (2) the low fraction of organic carbon in the unconfined aquifer sediments at the northeast site is resulting in little retardation of the contaminants there, relative to those at the southeast site. Acetate was the only volatile fatty acid detected in the leachate. It was measurable only in areas where the volatile organic contamination was significant. Although methane was detected in the contaminated sediments, suggesting that microbial activity was present, the high concentration of acetate (>1000 ppm) which was detected down-gradient from the source area indicates that any biodegradation which is occurring is proceeding at a very slow rate.


2000 ◽  
Vol 41 (1) ◽  
pp. 163-166 ◽  
Author(s):  
W. Gebert ◽  
P.A. Wilderer

The investigated effects of heating the filling material in trickling filters were carried out at the Ingolstadt wastewater treatment plant, Germany. Two pilot scale trickling filters were set up. Heat exchanger pipings were embedded in the filter media of one of these trickling filters, and the temperature in the trickling filter was raised. The other trickling filter was operated under normal temperature conditions, and was used as a control. The results clearly demonstrate that the performance of trickling filters cannot be constantly improved by heating the biofilm support media. A sustained increase of the metabolic rates did not occur. The decrease of the solubility of oxgen in water and mass transfer limitations caused by an increase of the biofilm thickness are the main reasons for that. Thus, the heating of trickling filters (e.g. by waste heat utilization) in order to increase the capacity of trickling filters under cold weather conditions cannot be recommended.


Jurnal BiBieT ◽  
2017 ◽  
Vol 2 (2) ◽  
pp. 49
Author(s):  
Welly Herman ◽  
Darmawan Darmawan ◽  
Gusnidar Gusnidar

<p><em>The research aimed to make Volcanic soil of Multiple Soil Layering (MSL) with different Hydraulic Loading Rate (HLR) on the purification of polluted irrigation water and to determine the appropriate HLR against purification of polluted irrigation water. The research used an MSL system of the same Soil Mixture Block (SMB) size from a study done by </em><em>(Chen et al., 2007)</em><em> arranged in an Acrylic box measuring 50 cm x 10 cm x 60 cm (PxLxT). Making SMB is done by mixing volcanic soil, sawdust, iron, charcoal that has been mashed by 50 mesh sieve, with a combination of 7: 1: 1: 1. The MSL system is supplied with irrigation water taken from the Gunuang Nago irrigation and Pasar Baru area, Cupak Tangah village, Pauh IX sub-district, Padang continuously with different HLR of 250 L/m<sup>2</sup>/day,     500 L/m<sup>2</sup>/ day and 1000 L/m<sup>2</sup>/day. From the result of this research, it is found that MSL system can decrease pollutant content in polluted irrigation water until the concentration below the water quality standard based on PP. 82 of 2001 and MSL system with HLR 250 L/m<sup>2</sup>/day have high ability in purifying BOD and COD and HLR 1000 L/m<sup>2</sup>/day has a high ability in purifying NH<sub>4</sub><sup>+</sup>, NO<sub>2</sub><sup>-</sup> and NO<sub>3</sub><sup>-</sup> on polluted irrigation water.</em></p><p class="jbd-alamat"> </p><p class="jbd-alamat">Tujuan penelitian ini adalah untuk menentukan pengaruh tanah vulkanik dalam sistem <em>Multiple Soil Layering</em> (MSL) dengan <em>Hydraulic Loading Rate</em> (HLR) yang berbeda terhadap pemurnian air irigasi terpolusi. Penelitian  menggunakan sistem MSL dengan ukuran <em>Soil Mixture Block</em> (SMB) yang sama dari penelitian yang telah dilakukan (Chen, Sato, Wakatsuki, &amp; Masunaga, 2007)yang disusun di dalam kotak Acrylic berukuran 50 cm x 10 cm x 60 cm (PxLxT).  <em>Soil Mixture Block</em> terdiri dari tanah vulkanik, serbuk gergaji, besi, arang yang telah dihaluskan oleh ayakan 50 mesh, dengan perbandingan kombinasi 7:1:1:1.  Sistem MSL dialirkan air irigasi yang diambil dari irigasi Gunuang Nago dan Kawasan Pasar Baru, Kelurahan Cupak Tangah, Kecamatan Pauh IX, Padang secara terus menerus dengan HLR yang berbeda yaitu 250 L/m<sup>2</sup>/hari,  500 L/m<sup>2</sup>/hari dan 1000 L/m<sup>2</sup>/hari. Dari hasil penelitian diperoleh bahwa sistem MSL mampu menurunkan kandungan zat pencemar pada air irigasi terpolusi  mencapai kosentrasi di bawah baku mutu air berdasarkan PP No. 82 tahun 2001 dengan HLR 250 L/m<sup>2</sup>/hari mempunyai kemampuan yang tinggi dalam memurnikan kadar pencemar BOD dan COD sedangkan HLR 1000 L/m2/hari mempunyai kemampuan yang tinggi dalam memurnikan kadar pencemar NH<sub>4</sub><sup>+</sup>, NO<sub>2</sub><sup>-</sup> dan NO<sub>3</sub><sup>-</sup> pada air irigasi terpolusi.</p>


2010 ◽  
Vol 61 (2) ◽  
pp. 415-420 ◽  
Author(s):  
Sanjib Moulick ◽  
Naresh V. Tambada ◽  
Basant K. Singh ◽  
B. C. Mal

Aeration experiments, maintaining nappe flow conditions, were carried out on a rectangular stepped cascade of total height 3.0 m to determine the total number of steps, slope of the entire cascade and hydraulic loading rate at which maximum overall aeration efficiency occurs, keeping the surface area of individual steps constant. Based on dimensional analysis, the overall aeration efficiency at standard conditions (E20) was expressed as a function of square of total number of steps (N2) and dimensionless discharge (dc/h), where dc and h represent critical depth in a rectangular prismatic channel and individual step height respectively. An empirical equation with E20 as the response and N2 and dc/h as the independent parameters was developed based on the experimental results subject to 36 ≤ N2 ≤ 196 and 0.009 ≤ dc/h ≤ 0.144. The experimental results showed that the overall aeration efficiency (E20) for a particular step height of stepped cascade increases with increase in dc/h up to a certain value and then decreases. This may be due to at higher dc/h, i.e., at higher hydraulic loading rate, the flow approaches the transition zone and thereby aeration efficiency decreases. E20 was also found to increase with number of steps at any hydraulic loading rate, because of the increased surface area of fall. The optimum number of steps, slope of the entire stepped cascade and hydraulic loading rate were found to be 14, 0.351 and 0.009 m2/s respectively producing the maximum value of overall aeration efficiency of 0.90.


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