scholarly journals Transport effects on hydraulic loading rate and microbial removal performance in biosand filters

2014 ◽  
Vol 12 (4) ◽  
pp. 686-691 ◽  
Author(s):  
Julie Napotnik ◽  
Kristen Jellison
Keyword(s):  
Loading Rate ◽  
E Coli ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Filter Performance ◽  
Implementation Costs ◽  
Transport Effects ◽  
Biosand Filters ◽  
Microbial Removal ◽  
Potential Negative Consequence

Biosand filters (BSFs) are increasingly designed using smaller and/or lighter casing material in an effort to reduce logistical requirements and implementation costs. The increased portability of a smaller, lighter design presents a potential negative consequence: the ability to move the installed/operational filter by the homeowner and potentially disturb the system. This study investigated the effects of moving and agitation on filter performance, using mature BSFs which had been in use for over nine months prior to the move. Data were analyzed for four replicate filters of three different filter types: the traditional concrete BSF and two plastic bucket (5-gal and 2-gal, respectively; 5-gal bucket = 18.9-L bucket, 2-gal bucket = 7.6-L bucket) BSFs. Filters were moved approximately 1 km and monitored for hydraulic loading rates (HLRs) and Escherichia coli removal for 8 weeks following the move. Moving the filters resulted in reduced HLRs, likely due to sand compaction, but E. coli removal remained high (log10 removal ≥2.8 for all sizes) and increased significantly as compared to data collected prior to the move. The resulting operational implications of moving BSFs are discussed.

Coarse filters for pond effluent polishing: comparison of loading rates and grain sizes

2007 ◽  
Vol 55 (11) ◽  
pp. 121-126 ◽  
Author(s):  
M. von Sperling ◽  
J.G.B. de Andrada ◽  
W.R. de Melo Júnior
Keyword(s):  
Loading Rate ◽  
Uasb Reactor ◽  
E Coli ◽  
Effluent Quality ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Grain Sizes ◽  
Belo Horizonte ◽  
The City ◽  
Rock Size

A system comprising a UASB reactor, shallow polishing ponds and shallow coarse filters, treating actual wastewater from the city of Belo Horizonte, Brazil, has been evaluated. The main focus of the research was to compare grain sizes and hydraulic loading rates in the coarse filters. Two filters operating in parallel were investigated, with the following grain sizes: Filter 1: 3 to 10 cm; Filter 2: 8 to 20 cm. Two hydraulic loading rates were tested: 0.5 and 1.0 m3/m3.d. The filter with the lower rock size had a better performance than the filter with the larger rock size in the removal of SS and, as a consequence, BOD and COD. A better performance was obtained with the hydraulic loading rate of 0.5 m3/m3.d, as compared to the rate of 1.0 m3/m3.d. The effluent quality during the period with the lower loading rate was very good for discharge into water bodies or for agricultural reuse (median effluent concentrations from Filter 1: BOD: 20 mg/L; COD: 106 mg/L; SS: 28 mg/L; E. coli: 528 MPN/100 mL).

Field Evaluation of Long-Term Performance and Use of Biosand Filters in Posoltega, Nicaragua

2009 ◽  
Vol 44 (2) ◽  
pp. 111-121 ◽  
Author(s):  
Jason C. Vanderzwaag ◽  
James W. Atwater ◽  
Karen H. Bartlett ◽  
Derek Baker
Keyword(s):  
Loading Rate ◽  
Field Evaluation ◽  
Hydraulic Loading Rate ◽  
Hydraulic Loading ◽  
User Training ◽  
Filter Performance ◽  
Biosand Filter ◽  
Biosand Filters ◽  
And Performance

Abstract An evaluation was conducted in 2007 on biosand filters that were installed in Posoltega, Nicaragua in 1999 and 2004.The objectives were to characterize the condition and use of filters eight and three years after installation, determine filter performance of those filters still in use, and identify determinants of successful long-term use and performance. Methods consisted of household identification, user questionnaires, and water quality testing. Of the 234 filters installed, only 24 were found to still be in use. Average log reductions were 1.73 (98%) for total coliforms, 1.36 (96%) for Escherichia Coli, and 0.91 (88%) for turbidity. Statistically significant effects were detected for the magnitude of the contamination of source water, the peak hydraulic loading rate, and the standing depth of water over the filter media. Questionnaire results indicated user training on filter maintenance could improve the peak hydraulic loading rate and hence filter performance. The low rate of sustained use (10%) is an indication of failed implementation, and is attributable to structural failure, particularly cracking of the concrete filters from 2004. Nonetheless, this evaluation demonstrated the biosand filter technology to be robust since those filters still in use were performing as expected three and eight years postimplementation.

scholarly journals Effects of hydraulic loading rate and aeration mode on nitrogen removal and nitrogen functional gene abundances in subsurface wastewater infiltration systems

2017 ◽  
Vol 76 (1) ◽  
pp. 210-218 ◽  
Author(s):  
Yafei Sun ◽  
Jing Pan ◽  
Shiyue Qi ◽  
Hexin Fei
Keyword(s):  
Nitrogen Removal ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Functional Gene ◽  
Intermittent Aeration ◽  
Anaerobic Conditions ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Artificial Aeration ◽  
Operation Cost

Matrix dissolved oxygen, nitrogen removal and nitrogen functional gene abundances in two artificial aeration modes, continuous aeration (CA) and intermittent aeration (IA), in subsurface wastewater infiltration systems (SWISs) under different hydraulic loading rates (HLRs) were investigated. Aeration not only successfully created aerobic conditions at 50 cm depth, but also did not change anoxic or anaerobic conditions at 80 and 110 cm depths. Meanwhile, aeration significantly enhanced chemical oxygen demand, NH4+-N, and total nitrogen (TN) removal and the enrichment of nitrogen removal functional genes (amoA, nxrA, napA, narG, nirK and qnorB) compared to the non-aerated SWIS, especially for high HLRs. IA SWIS (79.7%–85.8%) had a better performance on TN removal compared with CA SWIS (73.8%–82.2%) when the HLRs ranged from 0.06 to 0.3 m3/(m2 d). Intermittent aeration is a sensible strategy to achieve high HLR, good nitrogen removal performance and comparatively low operation cost for SWISs.

scholarly journals Estimating the Importance of Hydrologic Conditions on Nutrient Retention and Plant Richness in a Wetlaculture Mesocosm Experiment in a Former Lake Erie Basin Swamp

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2509
Author(s):  
Bingbing Jiang ◽  
William J. Mitsch ◽  
Chris Lenhart
Keyword(s):  
Lake Erie ◽  
Agricultural Land ◽  
Loading Rate ◽  
Nutrient Retention ◽  
Mesocosm Experiment ◽  
Loading Rates ◽  
Standing Water ◽  
Hydraulic Loading ◽  
Wetland Mesocosms ◽  
Hydrologic Conditions

The western basin of Lake Erie, the shallowest of the Laurentian Great Lakes in North America, is now plagued by harmful algal blooms annually due to nutrient discharges primarily from its basin. Water quality was impacted so significantly by toxic cyanobacteria in 2014 that the city of Toledo’s water supply was shut off, affecting hundreds of thousands of residents. A new agricultural land management approach, ‘wetlaculture (=wetland + agriculture)’, has a goal of reducing the need for fertilizer applications while preventing fluxes of nutrients to downstream aquatic ecosystems. A wetlaculture mesocosm experiment was set up on agricultural land near Defiance, Ohio, on the northwestern edge of the former ‘Great Black Swamp’. The mesocosms were randomly assigned to four hydrologic treatments involving two water depths (no standing water and ~10-cm of standing water) and two hydraulic loading rates (10 and 30 cm week−1). Nearby agricultural ditch water was pumped to provide weekly hydraulic loading rates to the mesocosms. During the two-year period, the net mass retention of phosphorus from the water was estimated to have averaged 1.0 g P m−2 in the wetland mesocosms with a higher hydraulic loading rate, while the highest estimated net nitrogen mass retention (average 22 g N m−2) was shown in the wetland mesocosms with 10 cm of standing water and higher hydraulic loading rate. Our finding suggests that hydrologic conditions, especially water level, contribute directly and indirectly to nutrient retention, partially through the quick response of the wetland vegetation community. This study provides valuable information for scaling up to restore significant areas of wetlaculture/wetlands in the former Great Black Swamp, strategically focused on reducing the nutrient loading to western Lake Erie from the Maumee River Basin.

Nitrogen removal during secondary treatment by aquatic systems

2004 ◽  
Vol 48 (11-12) ◽  
pp. 355-361 ◽  
Author(s):  
B. Erol Nalbur ◽  
L. Akça ◽  
H. Bayhan
Keyword(s):  
Nitrogen Removal ◽  
Aquatic Plant ◽  
Loading Rate ◽  
Lemna Minor ◽  
Domestic Wastewater ◽  
Secondary Treatment ◽  
Mass Loading ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Nitrogen Conversion

Within the context of this study, two lab-scale aquatic plant reactors consisting of duckweed (Lemna minor) ponds, were investigated for the removal of nitrogen forms during the secondary treatment of domestic wastewater. TKN, NH3-N and NO3-N parameters have been measured in both reactors for hydraulic retention times ranging from 3.3 days to 23 days and at various distances from the inlet of reactors. The results were evaluated for hydraulic retention times, hydraulic loading rates and mass loading rates. It was concluded that hydraulic and mass loading parameters were more meaningful than hydraulic retention time. Optimum nitrogen removal values of hydraulic loading rate and mass loading rate were found to be 1.2 cm/day and 90-160 mg TKN/m2-day, respectively. At the higher and lower loading rates, nitrogen removal efficiency was lower than those at optimum conditions. Effluent TKN concentration was around 2.5 to 3.0 mg/l while NH3-N concentration was almost zero at these loading conditions. On the other hand, effluent NO3-N concentrations changed between 7 mg/l to 11 mg/l. When investigating the longitudinal profile, values were reduced rapidly along the reactors. It was concluded that most of the nitrogen conversion occurred at the beginning of the reactor.

scholarly journals Improvement of organic matter and nutrient removal from domestic wastewater by using intermittent hydraulic rates on earthworm–microorganism biofilters

2020 ◽  
Author(s):  
C. Chicaiza ◽  
L. Huaraca ◽  
C. E. Almeida-Naranjo ◽  
V. H. Guerrero ◽  
C. A. Villamar
Keyword(s):  
Organic Matter ◽  
Redox Potential ◽  
Nutrient Removal ◽  
Loading Rate ◽  
Domestic Wastewater ◽  
Nitrogen And Phosphorus ◽  
Hydraulic Loading Rate ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Global Performance

Abstract Biofilters based on earthworms–microorganisms represent, particularly in developing countries, an interesting alternative for domestic wastewater treatment due to their easy operation and low cost. However, there are several operational aspects that should be better understood in order to improve their performance. This paper studies the effect of using intermittent hydraulic loading rates to improve organic matter and nutrient removal from domestic wastewater using these biofilters. Three laboratory-scale columns, operating at a 2.5 m3 m−2day−1 hydraulic loading rate, were used. The B1–24 h, B2–8 h, B3–4 h column loading rates indicate that the columns were operated continuously for 24, 8 and 4 h, respectively. Each column (biomass biofilm/earthworms, redox potential, and head loss) and its corresponding operational performance parameters (TCOD, NH4+, NO3−, NO2−, TP) were monitored. The results showed that the B2–8 h intermittent hydraulic loading rate results in the best global performance, with 74%, 57%, and 20% average removal efficiencies for TCOD, nitrogen, and phosphorus, respectively. Moreover, it showed the best biomass growth (biofilm and earthworms), activity (as redox potential changes) and the lowest clogging effects (up to −1.0 cm). The intermittent operation influences the behavior of the earthworm–microorganism biofilters and offers the possibility of optimizing its global performance and achieving a resilient technology.

Study on the performance of an up-flow aerated biofilter (UAB) in municipal wastewater treatments

1994 ◽  
Vol 30 (11) ◽  
pp. 25-33 ◽  
Author(s):  
Yoshimasa Watanabe ◽  
Satoshi Okabe ◽  
Tomochika Arata ◽  
Yuji Haruta
Keyword(s):  
Organic Matter ◽  
Suspended Solids ◽  
Municipal Wastewater ◽  
Unique Feature ◽  
Aeration Rate ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Running Cost ◽  
And Performance ◽  
Activated Sludge Systems

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.

PEMANFAATAN TANAH VULKANIK DALAM SISTEM MULTIPLE SOIL LAYERING (MSL) TERHADAP PEMURNIAN AIR IRIGASI TERPOLUSI

Jurnal BiBieT ◽  
2017 ◽  
Vol 2 (2) ◽  
pp. 49
Author(s):  
Welly Herman ◽  
Darmawan Darmawan ◽  
Gusnidar Gusnidar
Keyword(s):  
Irrigation Water ◽  
Loading Rate ◽  
Quality Standard ◽  
High Ability ◽  
Volcanic Soil ◽  
Soil Mixture ◽  
Hydraulic Loading Rate ◽  
Hydraulic Loading ◽  
Soil Layering ◽  
Mesh Sieve

<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>

Aeration characteristics of a rectangular stepped cascade system

2010 ◽  
Vol 61 (2) ◽  
pp. 415-420 ◽  
Author(s):  
Sanjib Moulick ◽  
Naresh V. Tambada ◽  
Basant K. Singh ◽  
B. C. Mal
Keyword(s):  
Surface Area ◽  
Loading Rate ◽  
Experimental Results ◽  
Step Height ◽  
Optimum Number ◽  
Hydraulic Loading Rate ◽  
Hydraulic Loading ◽  
Aeration Efficiency ◽  
Stepped Cascade ◽  
Independent Parameters

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.

scholarly journals Development of friction-induced triboluminescent sensor for load monitoring

2017 ◽  
Vol 29 (5) ◽  
pp. 883-895 ◽  
Author(s):  
Md Abu S Shohag ◽  
Zhengqian Jiang ◽  
Emily C Hammel ◽  
Lucas Braga Carani ◽  
David O Olawale ◽  
...  
Keyword(s):  
Applied Load ◽  
Loading Rate ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Loading Rates ◽  
Load Monitoring ◽  
The Coefficient Of Friction ◽  
Dynamic Structures ◽  
Sample Configuration

Real-time load monitoring of critical civil and mechanical structures especially dynamic structures such as wind turbine blades is imperative for longer service life. This article proposed a novel sensor system based on the proprietary in situ triboluminescent optical fiber (ITOF) sensor for dynamic load monitoring. The new ITOF sensor patch consists of an ITOF sensor network with micro-exciters integrated within a polymer matrix. The sensor patch was subjected to repeated flexural loading and produced triboluminescent emissions due to the friction between micro-exciters and ITOF sensors corresponding to each loading cycle. The friction-induced triboluminescent intensity directly depends on the loading rate, the coefficient of friction, and the applied load on patch. In general, the triboluminescent intensity increases exponentially with an increase in load. Additionally, the sensor patches comprising the coarser micro-exciters exhibited better results. Similarly, better results were achieved at higher loading rates although a threshold loading rate is required to excite the triboluminescent crystals for this sample configuration. The proposed new sensor has the ability to monitor dynamic continuous applied loads.

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