scholarly journals Effect of filter media thickness on the performance of sand drying beds used for faecal sludge management

2016 ◽  
Vol 74 (12) ◽  
pp. 2795-2806
Author(s):  
M. Manga ◽  
B. E. Evans ◽  
M. A. Camargo-Valero ◽  
N. J. Horan
Keyword(s):  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Oxygen Demand ◽  
Nutrient Content ◽  
Pilot Scale ◽  
Filter Media ◽  
Media Thickness ◽  
Helminth Eggs ◽  
Significant Difference ◽  
Faecal Sludge

The effect of sand filter media thickness on the performance of faecal sludge (FS) drying beds was determined in terms of: dewatering time, contaminant load removal efficiency, solids generation rate, nutrient content and helminth eggs viability in the dried sludge. A mixture of ventilated improved pit latrine sludge and septage in the ratio 1:2 was dewatered using three pilot-scale sludge drying beds with sand media thicknesses of 150, 250 and 350 mm. Five dewatering cycles were conducted and monitored for each drying bed. Although the 150 mm filter had the shortest average dewatering time of 3.65 days followed by 250 mm and 350 mm filters with 3.83 and 4.02 days, respectively, there was no significant difference (p > 0.05) attributable to filter media thickness configurations. However, there was a significant difference for the percolate contaminant loads in the removal and recovery efficiency of suspended solids, total solids, total volatile solids, nitrogen species, total phosphorus, chemical oxygen demand, dissolved chemical oxygen demand and biochemical oxygen demand, with the highest removal efficiency for each parameter achieved by the 350 mm filter. There were also significant differences in the nutrient content (NPK) and helminth eggs viability of the solids generated by the tested filters. Filtering media configurations similar to 350 mm have the greatest potential for optimising nutrient recovery from FS.

scholarly journals Innovative Effluent Capture and Evacuation Device that Increases COD Removal Efficiency in Subsurface Flow Wetlands

Processes ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 418 ◽  
Author(s):  
Pedro Cisterna-Osorio ◽  
Verónica Lazcano-Castro ◽  
Gisela Silva-Vasquez ◽  
Mauricio Llanos-Baeza ◽  
Ignacio Fuentes-Ortega
Keyword(s):  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Cod Removal ◽  
Discharge Device ◽  
The Impact ◽  
Real Scale ◽  
Conventional Device

The objective of this work is to evaluate the impact of innovative modifications made to conventional effluent capture and discharge devices used in subsurface flow wetlands (SSFW). The main modifications that have been developed extend the influence of the capture and discharge device in such a way that the SSFW width and height are fully covered. This improved innovative device was applied and evaluated in two subsurface flow wetlands, one on a pilot scale and one on a real scale. To evaluate the impact of the innovative device with respect to the conventional one in the operational functioning of subsurface flow wetlands, the elimination of chemical oxygen demand (COD) was measured and compared. The results show that for the innovative device, the COD removal was 10% higher than for the conventional device, confirming the validity and effectiveness of the modifications implemented in the effluent capture and discharge devices used in SSFW.

scholarly journals Effect of Ornamental Plants, Seasonality, and Filter Media Material in Fill-and-Drain Constructed Wetlands Treating Rural Community Wastewater

2019 ◽  
Vol 11 (8) ◽  
pp. 2350 ◽  
Author(s):  
Sergio A. Zamora-Castro ◽  
José Luis Marín-Muñiz ◽  
Luis Sandoval ◽  
Monserrat Vidal-Álvarez ◽  
Juan Manuel Carrión-Delgado
Keyword(s):  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Constructed Wetlands ◽  
Ornamental Plants ◽  
Oxygen Demand ◽  
Biomass Productivity ◽  
Pollutant Removal ◽  
Filter Media ◽  
Control Units ◽  
Phosphorous Compounds

The effects of Canna indica (P1), Pontederia sagittata (P2), and Spathiphyllum wallisii (P3) growing in different filter media materials (12 using porous river rock and 12 using tepezyl) on the seasonal removal of pollutants of wastewater using fill-and-drain constructed wetlands (FD-CWs) were investigated during 12 months. Three units of every media were planted with one plant of P1, P2, and P3, and three were kept unplanted. C. indica was the plant with higher growth than the other species, in both filter media. The species with more flower production were: C. indica > P. sagittate > S. wallisii. Reflecting similarly in the biomass of the plants, C. indica and P. sagittata showed more quantity of aerial and below ground biomass productivity than S. wallisii. With respect to the removal efficiency, both porous media were efficient in terms of pollutant removal performance (p > 0.05). However, removal efficiency showed a dependence on ornamental plants. The higher removal of chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total kjeldahl nitrogen (TKN), nitrates (NO3−-N), ammonium (NH4+-N), and phosphates (PO4−3-P) oscillated between 81% to 83%, 80% to 84%, 61% to 69%, 61% to 68%, 65% to 71%, 62% to 68%, and 66% to 69%, respectively, in P1 and P2, removals 15% to 30% higher than P3. The removal in planted microcosms was significantly higher than the unplanted control units (p = 0.023). Nitrogen and phosphorous compounds were highly removed (60%–80%) because in typical CWs, such pollutant removals are usually smaller, indicating the importance of FD-CWs on wastewater treatments using porous river rock and tepezyl as porous filter media. (BOD5), chemical oxygen demand (COD), (NO3−-N), (NH4+-N), (TKN), and (PO4−3-P).

scholarly journals A comparative analysis of selected wastewater pretreatment processes in food industry

2018 ◽  
Vol 30 ◽  
pp. 02003 ◽  
Author(s):  
Katarzyna Jaszczyszyn ◽  
Wojciech Góra ◽  
Zbysław Dymaczewski ◽  
Robert Borowiak
Keyword(s):  
Comparative Analysis ◽  
Chemical Oxygen Demand ◽  
Removal Efficiency ◽  
Phosphorus Removal ◽  
Food Industry ◽  
Oxygen Demand ◽  
Organic Fraction ◽  
Significant Difference ◽  
Adsorption Processes ◽  
Iron Sulphate

The article presents a comparative analysis of the classical coagulation with the iron sulphate and adsorption on bentonite for the pretreatment of wastewater in the food industry. As a result of the studies, chemical oxygen demand (COD) and total nitrogen (TN) reduction were found to be comparable in both technologies, and a 29% higher total phosphorus removal efficiency by the coagulation was observed. After the coagulation and adsorption processes, a significant difference between mineral and organic fraction in the sludge was found (49% and 51% for bentonite and 28% and 72% for iron sulphate, respectively).

Enhancing nitrogen removal efficiency in a dyestuff wastewater treatment plant with the IFFAS process: the pilot-scale and full-scale studies

2017 ◽  
Vol 77 (1) ◽  
pp. 70-78 ◽  
Author(s):  
Yanjun Mao ◽  
Xie Quan ◽  
Huimin Zhao ◽  
Yaobin Zhang ◽  
Shuo Chen ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Nitrogen Removal ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Full Scale ◽  
Nitrification And Denitrification ◽  
Dyestuff Wastewater

Abstract The activated sludge (AS) process is widely applied in dyestuff wastewater treatment plants (WWTPs); however, the nitrogen removal efficiency is relatively low and the effluent does not meet the indirect discharge standards before being discharged into the industrial park's WWTP. Hence it is necessary to upgrade the WWTP with more advanced technologies. Moving bed biofilm processes with suspended carriers in an aerobic tank are promising methods due to enhanced nitrification and denitrification. Herein, a pilot-scale integrated free-floating biofilm and activated sludge (IFFAS) process was employed to investigate the feasibility of enhancing nitrogen removal efficiency at different hydraulic retention times (HRTs). The results showed that the effluent chemical oxygen demand (COD), ammonium nitrate (NH4+-N) and total nitrogen (TN) concentrations of the IFFAS process were significantly lower than those of the AS process, and could meet the indirect discharge standards. PCR-DGGE and FISH results indicated that more nitrifiers and denitrifiers co-existed in the IFFAS system, promoting simultaneous nitrification and denitrification. Based on the pilot results, the IFFAS process was used to upgrade the full-scale AS process, and the effluent COD, NH4+-N and TN of the IFFAS process were 91–291 mg/L, 10.6–28.7 mg/L and 18.9–48.6 mg/L, stably meeting the indirect discharge standards and demonstrating the advantages of IFFAS in dyestuff wastewater treatment.

scholarly journals Post-treatment of tannery wastewater using pilot scale horizontal subsurface flow constructed wetlands (polishing)

2017 ◽  
Vol 77 (4) ◽  
pp. 988-998 ◽  
Author(s):  
Tadesse Alemu ◽  
Andualem Mekonnen ◽  
Seyoum Leta
Keyword(s):  
Removal Efficiency ◽  
Batch Reactor ◽  
Subsurface Flow ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Surface Flow ◽  
Tannery Wastewater ◽  
Treated Effluent ◽  
Horizontal Subsurface Flow ◽  
Pollutants Removal

Abstract In the present study, a pilot scale horizontal subsurface flow constructed wetland (CW) system planted with Phragmites karka; longitudinal profile was studied. The wetland was fed with tannery wastewater, pretreated in a two-stage anaerobic digester followed by a sequence batch reactor. Samples from each CW were taken and analyzed using standard methods. The removal efficiency of the CW system in terms of biological oxygen demand (BOD), chemical oxygen demand (COD), Cr and total coliforms were 91.3%, 90%, 97.3% and 99%, respectively. The removal efficiency for TN, NO3− and NH4+-N were 77.7%, 66.3% and 67.7%, respectively. Similarly, the removal efficiency of SO42−, S2− and total suspended solids (TSS) were 71.8%, 88.7% and 81.2%, respectively. The concentration of COD, BOD, TN, NO3−N, NH4+-N, SO42 and S2− in the final treated effluent were 113.2 ± 52, 56 ± 18, 49.3 ± 13, 22.75 ± 20, 17.1 ± 6.75, 88 ± 120 and 0.4 ± 0.44 mg/L, respectively. Pollutants removal was decreased in the first 12 m and increased along the CW cells. P. karka development in the first cell of CW was poor, small in size and experiencing chlorosis, but clogging was higher in this area due to high organic matter settling, causing a partial surface flow. The performance of the pilot CW as a tertiary treatment showed that the effluent meets the permissible discharge standards.

scholarly journals Rotating belt sieves for primary treatment, chemically enhanced primary treatment and secondary solids separation

2017 ◽  
Vol 75 (11) ◽  
pp. 2598-2606 ◽  
Author(s):  
B. Rusten ◽  
S. S. Rathnaweera ◽  
E. Rismyhr ◽  
A. K. Sahu ◽  
J. Ntiako
Keyword(s):  
Removal Efficiency ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Primary Treatment ◽  
Biofilm Reactors ◽  
Fine Mesh ◽  
Coagulation And Flocculation ◽  
Successful Removal ◽  
Solids Separation ◽  
Chemically Enhanced Primary Treatment

Fine mesh rotating belt sieves (RBS) offer a very compact solution for removal of particles from wastewater. This paper shows examples from pilot-scale testing of primary treatment, chemically enhanced primary treatment (CEPT) and secondary solids separation of biofilm solids from moving bed biofilm reactors (MBBRs). Primary treatment using a 350 microns belt showed more than 40% removal of total suspended solids (TSS) and 30% removal of chemical oxygen demand (COD) at sieve rates as high as 160 m³/m²-h. Maximum sieve rate tested was 288 m³/m²-h and maximum particle load was 80 kg TSS/m²-h. When the filter mat on the belt increased from 10 to 55 g TSS/m², the removal efficiency for TSS increased from about 35 to 60%. CEPT is a simple and effective way of increasing the removal efficiency of RBS. Adding about 1 mg/L of cationic polymer and about 2 min of flocculation time, the removal of TSS typically increased from 40–50% without polymer to 60–70% with polymer. Using coagulation and flocculation ahead of the RBS, separation of biofilm solids was successful. Removal efficiencies of 90% TSS, 83% total P and 84% total COD were achieved with a 90 microns belt at a sieve rate of 41 m³/m²-h.

Stormwater runoff treatment filtration system and backwashing system

2019 ◽  
Vol 79 (4) ◽  
pp. 771-778 ◽  
Author(s):  
Junho Lee ◽  
Myungjin Lee
Keyword(s):  
Particle Size ◽  
Removal Efficiency ◽  
Recovery Rate ◽  
Stormwater Runoff ◽  
Pilot Scale ◽  
Solid Loading ◽  
Filter Media ◽  
Turbidity Removal ◽  
Filtration System ◽  
Combined Sewer

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.

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