scholarly journals Analysis of Hydraulic Characteristics and Treatment Efficiency by Filter Media Composition During Backwashing of Filtration-Type Non-Point Pollution Facilities

2021 ◽  
Vol 21 (6) ◽  
pp. 385-394
Author(s):  
Ingun Park ◽  
Jungmin Lee ◽  
Hayong Kim

In this study, the hydraulic characteristics and pollutant treatment efficiency during backwashing were analyzed through laboratory-scale hydraulic model experiments for filtration-type non-point pollution reduction facilities. The filter media used in the experiment were analyzed by calculating the change in head loss for single or complex arrangements of wood chips (WC), sand (SA), and bottom ash (BA). These are commonly used to improve the adsorption mechanism in non-point pollution reduction facilities, from which the pollutant treatment efficiency was derived. The SS treatment efficiency experiments for each filter media layer were conducted with SA+WC (WC 0.3 m in the upper layer, SA 0.3 m in the lower layer) and SA+BA (SA 0.3 m in the upper layer, BA 0.3 m in the lower layer), and the removal efficiency was greater than 80%, indicating good efficiency. In the case of SA+BA, analysis showed a high removal efficiency of 87.4% at a linear velocity of 20 m/hr.

2012 ◽  
Vol 66 (9) ◽  
pp. 1950-1957 ◽  
Author(s):  
J. Y. Choi ◽  
M. C. Maniquiz ◽  
F. K. Geronimo ◽  
S. Y. Lee ◽  
B. S. Lee ◽  
...  

Constructed wetlands (CWs) are well recognized as having low construction and maintenance cost and low energy requirement. However, CW design has been mainly based on rule-of-thumb approaches. In this study, the efficiency of a modular horizontal subsurface flow (HSSF) CW using four different design schemes was investigated. Based on the results, the four systems have attained more than 90% removal of total suspended solids and more than 50% removal efficiency for total phosphorus, PO4-P and Zn. The planted system achieved higher pollutant removal rates than the unplanted system. In terms of media, bottom ash was more effective than woodchip in reducing the pollutants. Considering the flow length, optimum removal efficiency was achieved after passing the sedimentation tank and vertical media layer; with respect to depth, more pollutants were removed in the upper sand layer than in the lower gravel layer. This study recommended a surface area of 0.25 to 0.8% of catchment area for planted CW and 0.26 to 0.9% for unplanted CW using the 7.5 to 10 mm design rainfall.


Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 990
Author(s):  
Ki Woong Bang ◽  
Jin Chul Joo ◽  
Jin Ho Kim ◽  
Eunbi Kang ◽  
Jongsoo Choi ◽  
...  

The potential application of bottom ash (BA) for construction site runoff control as an alternative filter media with high removal efficiency of total suspended solids (TSS) and longer operation period were evaluated. Both lab-scale single-layer and pilot-scale multi-layer filtration experiments were performed using BA filter media with different particle sizes and various volumetric flow rates. Due to the mesoporous, irregular, and spherical shape of gravel-size BA filter media used in this study, relatively low surface area, negligible pore volume, and greater pore size were observed. Both TSS removal efficiencies and clogging of BA filter media were a complex function of particle size of BA filter media and loading rate of TSS. Incoming TSS particles did not significantly penetrate beyond 46-cm BA filter media depth, accumulating on the upper layers and gradually forming a clogging layer to critical thickness, and finally the clogging filtration mechanism dominated the overall removal efficiency of TSS. Accumulation of TSS on BA filter media can be explained by the lumped sigmoidal empirical model, and an exponential decline in accumulation of TSS with depth results in minimal accumulation beneath the clogging layer. As practical implications, BA filter media depth of less than 46 cm is recommended with dual- or multi-media filters using mixtures of gravel-size BA and silt-size fine media, and a combination of detention basins can reduce frequent periodic de-clogging operation and management.


Author(s):  
K. Nagarajan ◽  
S. Ramya ◽  
T. Thangamani ◽  
A. Selvaperumal ◽  
T. Arthi

The parameters require for maintaining the crop's health and the integrity of the irrigation system has a relation with quality of irrigation water. In Micro irrigation appropriate filtration is very much important to prevent clogging. Filtration unit is one of the main components in micro irrigation system that too, Primary filter is more important to be installed along with the unit, when the water source is from open reservoir and other water sources. Though it is essential, the primary filter is not being installed by the farmers due to its high cost. Hence this study is an attempt to fabricate low-cost filter and to evaluate its performance with different filter media layer. A low-cost primary filter for drip irrigation system is fabricated. Different filter media layer like silex sand (fine silex, coarse silex), pebbles with different sizes are selected. The results revealed that the removal efficiency of filter using silex sand and pebbles were 71% in terms of turbidity, 78% in terms of total suspended solids removal at flow rate of 12 m3 /hr. This fabricated low-cost filter will be cost effective for small farm applications.


Author(s):  
Youssef-Amine Boussouga ◽  
Marina Valentukeviciene ◽  
Ramune Zurauskiene

In this article, an enhanced recycled filter media for the removal of fluoride compounds from groundwater via filtration process was investigated. Experiments were made to investigate the influence of recycled filter media on removal efficiency of fluoride compounds. The recycled backwash cake based filter media used at Lithuanian water works were inves-tigated in a pilot test-bench constructed for this research in the Water Management Laboratory of Vilnius Gediminas Technical University.


2020 ◽  
Vol 12 (17) ◽  
pp. 7196 ◽  
Author(s):  
Salvatore Falco ◽  
Giuseppe Brunetti ◽  
Giovanna Grossi ◽  
Mario Maiolo ◽  
Michele Turco ◽  
...  

At the outlet of the Vermicelli catchment—a peri-urban area located in the campus of University of Calabria (Cosenza, Southern Italy)—a sedimentation tank is located, aiming at collecting the basin surface runoff and improve its quality. First, experimental results of the treatment effects are here presented and analyzed. In addition, a monitoring campaign was conducted in order to characterize the particles transported by surface runoff and to determine the treatment efficiency of the tank. The analysis showed the presence of a pollutant load in the surface runoff of the Vermicelli basin and provided information on its particle-size distribution (PSD). Results were considered in terms of the treatment efficiency of the sedimentation tank, showing a good overall removal efficiency value, together with a high variability of the removal sedimentation efficiency. This variability is mainly due to the different grain size of the suspended solids and the characteristics of the rainfall event.


2019 ◽  
Vol 79 (4) ◽  
pp. 771-778 ◽  
Author(s):  
Junho Lee ◽  
Myungjin Lee

Abstract This study has been carried out to evaluate the applicability of the pilot scale hybrid type of stormwater runoff treatment system for treatment of combined sewer overflow. Also, to determine the optimum operation parameter such as coagulation dosage concentration, effectiveness of coagulant usage, surface loading rate and backwashing conditions. The pilot scale stormwater filtration system (SFS) was installed at the municipal wastewater plant serving the city of Cheongju (CWTP), Korea. CWTP has a capacity of 280,000 m3/day. The SFS consists of a hydrocyclone coagulation/flocculation with polyaluminium chloride silicate (PACS) and an upflow filter to treat combined sewer overflows. There are two modes (without PACS use and with PACS use) of operation for the SFS. In case of no coagulant use, the range of suspended solids (SS) and turbidity removal efficiency were 72.0–86.6% (mean 80.0%) and 30.9–71.1% (mean 49.3%), respectively. And, the recovery rate of filter was 79.2–83.6% (mean 81.2%); the rate of remaining solid loading in filter media was 16.4–20.8% (mean 18.8%) after backwashing. The influent turbidity, SS concentrations were 59.0–90.7 NTU (mean 72.0 NTU), 194.0–320.0mg/L (mean 246.7mg/L), respectively. The range of PACS dosage concentration was 6.0–7.1mg/L (mean 6.7mg/L). The range of SS and turbidity removal efficiency was 84.9–98.2 (mean 91.4%) and 70.7–96.3 (mean 84.0%), respectively. It was found that removal efficiency was enhanced with PACS dosage. The recovery rate of filter was 92.0–92.5% (mean 92.3%) the rate of remaining solid loading in filter media was 6.1–8.2% (mean 7.2%) after backwashing. In the case of coagulant use, the particle size of the effluent is bigger than influent particle size. The results showed that SFS with PACS use more effective than without PACS use in SS and turbidity removal efficiency and recovery rate of filter.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4344
Author(s):  
Jakub Matusik ◽  
Youjun Deng

Mycotoxins in feed and food are highly toxic and pose a serious danger even at very low concentrations. The use of bentonites in animal diet can reduce toxin bioavailability. However, some mycotoxins like fumonisin B1 (FB1) form anionic species which excludes the use of negatively charged clays. Layered double hydroxides (LDH) with anion-exchange properties, in theory, can be perfect candidates to adsorb FB1. However, fundamental research on the use of LDH for mycotoxins removal is scarce and incomplete. Thus, the presented study was designed to explore such a possibility. The LDH materials with differing chemistry and layer charge were synthesized by co-precipitation both from metal nitrates and chlorides and were then tested for FB1 removal. XRD, FTIR, XPS, and chemical analysis were used for the LDH characterization and to obtain insight into the removal mechanisms. A higher adsorption capacity was observed for the Mg/Al LDH samples (~0.08–0.15 mol/kg) in comparison to the Mg/Fe LDH samples (~0.05–0.09 mol/kg) with no difference in removal efficiency between Cl and NO3 intercalated LDH. The adsorption capacity increased along with lower layer charge of Mg/Al and was attributed to the lower content of bonded carbonates and the increase of non-polar sites which led to matching between the adsorption domains of LDH with FB1. The FTIR analysis confirmed the negative effect of carbonates which hampered the adsorption at pH 7 and led to the highest adsorption at pH 5 (FB1 content ~15.8 ± 0.75 wt.%). The fast surface adsorption (1–2 min) was dominant and XRD analysis of the basal spacing indicated that no FB1 intercalation occurred in the LDH. The XPS confirmed a strong interaction of FB1 with Mg sites of LDH at pH 5 where the interaction with FB1 carboxylate moieties COO− was confirmed. The research confirmed a high affinity and selectivity of LDH structures towards anionic forms of FB1 mycotoxin.


2010 ◽  
Vol 113-116 ◽  
pp. 87-90
Author(s):  
Qing Jie Xie

The microwave irradiation (MI) was found that it had significantly treatment efficiency for pollutants removal. It was developed to treat the alage in this paper. The granular activated carbon (GAC) was used as catalyst. The effect of the acting time, MI power, GAC amount and the initial concentration on alage removal were studied. The results showed: with the increasing of the acting time, MI power, GAC amount the alage removal rate were increased, but the effect of the initial concentration to alage removal was opposite; the optimum value of acting time, MI power and GAC amount were 5min, 450W and 3g respectively with the alage removal efficiency reached up to 100%. It also showed that with the alage removed under the MI the COD, SS were removed too. It was discovered that the oxidation process was basically in conformity with the first-order dynamic reaction(ln(C/C0)=-0.9371t+0.6744(R2=0.9472)).


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