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).

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.

scholarly journals The Concept of Wastes to Energy Using Sugary Wastes

2012 ◽  
Vol 9 ◽  
pp. 57-62
Author(s):  
Fiza Sarwar ◽  
Wajeeha Malik ◽  
Muhammad Salman Ahmed ◽  
Harja Shahid
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Sugar Mills ◽  
Anaerobic Sludge Blanket

Abstract: This study was designed using actual effluent from the sugary mills in an Up-flow Anaerobic Sludge Blanket (UASB) Reactor to evaluate treatability performance. The reactor was started-up in step-wise loading rates beginning from 0.05kg carbon oxygen demand (COD)/m3-day to 3.50kg-COD/m3-day. The hydraulic retention time (HRT) was slowly decreased from 96 hrs to eight hrs. It was observed that the removal efficiency of COD of more than 73% can be easily achieved at an HRT of more than 16 hours corresponding to an average organic loading rate (OLR) of 3.0kg-COD/m3-day, at neutral pH and constant temperature of 29°C. The average VFAs (volatile fatty acids) and biogas production was observed as 560mg/L and 1.6L/g-CODrem-d, respectively. The average methane composition was estimated as 62%. The results of this study suggest that the treatment of sugar mills effluent with the anaerobic technology seems to be more reliable, effective and economical.DOI: http://dx.doi.org/10.3126/hn.v9i0.7075 Hydro Nepal Vol.9 July 2011 57-62

Influence of Hydraulic Loading Rate on Horizontal Zeolite Wetland Effluent Quality

2012 ◽  
Vol 573-574 ◽  
pp. 659-662
Author(s):  
Hao Wang
Keyword(s):  
Wastewater Treatment ◽  
Loading Rate ◽  
Wastewater Treatment Plants ◽  
Treatment Plant ◽  
Secondary Effluent ◽  
Nitrogen And Phosphorus ◽  
Nitrogen And Phosphorus Removal ◽  
Hydraulic Loading Rate ◽  
Effluent Quality ◽  
Hydraulic Loading

In Tangshan area, the secondary effluent of wastewater treatment plants was used for this study. Horizontal zeolite wetland was carried out treating it. Hydraulic loading rate was the parameters for analyzing the nitrogen and phosphorus removal efficiency of pollutants from the secondary effluent of wastewater treatment plant. Zeolite constructed wetlands showed different behaviors for nitrogen and phosphorus removals.Under the optimum hydraulic loading rate, the primary pollutions were removed to a large extent.

Anaerobic treatment for C and S removal in “zero-discharge” paper mills: effects of process design on S removal efficiencies

2001 ◽  
Vol 44 (4) ◽  
pp. 189-195 ◽  
Author(s):  
J. B. van Lier ◽  
P. N.L. Lens ◽  
L. W. Hulshoff Pol
Keyword(s):  
Loading Rate ◽  
Anaerobic Treatment ◽  
Process Water ◽  
Uasb Reactor ◽  
Organic Loading ◽  
Production Rates ◽  
Paper Mills ◽  
Loading Rates ◽  
Zero Discharge ◽  
Uasb Reactors

Stringent environmental laws in Europe and Northern America lead to the development towards closure of the process water streams in pulp and paper mills. Application of a "zero-discharge" process is already a feasible option for the board and packaging paper industry, provided in-line treatment is applied. Concomitant energy conservation inside the mill results in process water temperatures of 50-60°C. Thermophilic anaerobic treatment complemented with appropriate post-treatment is considered as the most cost-effective solution to meet re-use criteria of the process water and to keep its temperature. In the proposed closed-cycle, the anaerobic treatment step removes the largest fraction of the biodegradable COD and eliminates “S” as H2S from the process stream, without the use of additional chemicals. The anaerobic step is regarded as the only possible location to bleed "S" from the process water cycle. In laboratory experiments, the effect of upward liquid velocity (Vupw) and the specific gas loading rate (Vgas) on the S removal capacity of thermophilic anaerobic bio-reactors was investigated. Acidifying, sulphate reducing sludge bed reactors were fed with partly acidified synthetic paper mill wastewater and were operated at 55°C and pH 6. The reactors were operated at organic loading rates up to 50 g COD.l−1.day−1 at COD/SO42- ratios of 10. The effect of Vupw was researched by comparing the performance of a UASB reactor operated at 1.0 m.h−1 and an EGSB reactor, operated at 6.8 m.h−1. The Vupw had a strong effect on the fermentation patterns. In the UASB reactor, acidification yielded H2, acetate and propionate, leading to an accumulation of reducing equivalents. These were partly disposed of by the production of n-butyrate and n-valerate from propionate. In the EGSB reactor net acetate consumption was observed as well as high volumetric gas (CO2 and CH4) production rates. The higher gas production rates in the EGSB reactor resulted in higher S-stripping efficiencies. The effect of Vgas was further researched by comparing 2 UASB reactors which were sparged with N2 gas at a specific gas loading rate of 30 m3.m−2.day−1. In contrast to the regular UASB reactors, the gas-supplied UASB showed a more stable performance when the organic loading rates were increased. Also, the H2S stripping efficiency was 3-4 times higher in the gas-supplied UASB, reaching values of 67%. Higher values were not obtained owing to the relatively poor sulphate reduction efficiencies.

Improving the effluent quality of facultative stabilization ponds by means of submerged aerated biofilters

1996 ◽  
Vol 33 (3) ◽  
pp. 145-152 ◽  
Author(s):  
R. F. Gonçalves ◽  
F. F. de Oliveira
Keyword(s):  
Tertiary Treatment ◽  
Nitrogen And Phosphorus ◽  
Effluent Quality ◽  
Loading Rates ◽  
Hydraulic Loading ◽  
Stabilization Ponds ◽  
The Mean

This paper describes the use of a submerged aerated biofilter (BF) in the tertiary treatment of effluent from facultative stabilization ponds (FSP). The results, obtained over four months of tests, confirm the ability of the BF to remove algae and, principally, to achieve tertiary nitrification. For hydraulic loading rates of 2m3/m2.h, the mean efficiency of the process in the removal of algae (SS) and COD was 58% and 63% respectively. Concentrations above 70 mg SS/1 and 195 mg O2/1 (COD) in the effluent from the ponds was reduced to 30 mg SS/1 and 70 mg O2/1 (COD) in the effluent from the BF. In addition to the removal of organic forms of nitrogen and phosphorus, the biofilter also reaches the soluble COD and ammonia. Tertiary nitrification was achieved with a mean efficiency of 86% for volumetric loads of up to 0.7 kg N-NH4+/m3.day (27°C). For concentrations above 20 mg n-NH4+/1 in the feed, the process can produce with safety effluents with less than 1 mg N-NH4+/1. The period of operation between the 2 successive washings of the bed filter was in the order of three days.

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.

Pilot-scale two-stage process: a combination of acidogenic hydrogenesis and methanogenesis

2005 ◽  
Vol 52 (1-2) ◽  
pp. 131-138 ◽  
Author(s):  
S.-K. Han ◽  
S.-H. Kim ◽  
H.-W. Kim ◽  
H.-S. Shin
Keyword(s):  
Food Waste ◽  
Environmental Conditions ◽  
Loading Rate ◽  
Pilot Scale ◽  
Uasb Reactor ◽  
Maximum Efficiency ◽  
Two Stage ◽  
Loading Rates ◽  
High Loading Rate ◽  
Stage Process

This study was performed to optimize both acidogenic hydrogenesis and methanogenesis, and then to develop a pilot-scale two-stage process producing not only CH4 but also H2. Firstly, acidogenic hydrogenesis of food waste was examined in pilot-scale leaching-bed reactors using dilution rate (D) as a tool to improve the environmental conditions. The maximum efficiency of 71.4% was obtained by adjusting D from 4.5 to 2.5 d−1 depending on the state of degradation. Secondly, the wastewater from acidogenic hydrogenesis was converted to CH4 in a pilot-scale UASB reactor. The COD removal efficiency exceeded 95% up to the loading rates of 13.1 g COD/L/d, which corresponded to HRT of 0.25 d (6 h). Lastly, a pilot-scale two-stage process was devised based on a combination of acidogenic hydrogenesis and methanogenesis. Over 120 days, the pilot-scale process resulted in large VS reduction of 70.9% at the high loading rate of 12.5 kg VS/m3/d in a short SRT of 8 days.

Sign in / Sign up

Export Citation Format

Share Document