scholarly journals The influence of hydraulic loading on biofilm properties in a subsurface wastewater infiltration system

2016 ◽  
Vol 42 (4) ◽  
pp. 70-79 ◽  
Author(s):  
Liangbo Zhang ◽  
Jian Yang
Keyword(s):  
Spatial Distribution ◽  
Water Treatment ◽  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Pollutant Removal ◽  
Unit Weight ◽  
Hydraulic Loading ◽  
Protein Levels ◽  
Landscape Water

AbstractIn this study, a pilot-scale subsurface wastewater infiltration system (SWIS) was deployed to study landscape water treatment. The goal of the study was to investigate the effects of hydraulic loading on pollutant removal and the spatial distribution of biofilm properties in SWIS. Results showed that the efficiencies of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) removal degraded as hydraulic loading increased. Furthermore, quantities of the biofilm properties parameter s increased with the hydraulic loading. Polysaccharide and protein levels ranged from 560 to 1110 μg/g filler and 60 to 190 μg/g filler, respectively, at a hydraulic loading of 0.2 m/d. At a hydraulic loading of 0.4 m/d, the quantities of polysaccharide and protein ranged from 1200 to 3300 μg/g filler and 80 to 290 μg/g filler, respectively. Biofilm intensity and biofilm activity per unit weight decreased with the increase in hydraulic loading.

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 Pollutant removal and growth dynamics of macrophyte species for faecal sludge treatment with constructed wetland technology

2019 ◽  
Vol 80 (6) ◽  
pp. 1145-1154
Author(s):  
Agyemang Richard Osei ◽  
Yacouba Konate ◽  
Felix Kofi Abagale
Keyword(s):  
Constructed Wetland ◽  
Growth Parameters ◽  
Oxygen Demand ◽  
Growth Dynamics ◽  
Pilot Scale ◽  
Pollutant Removal ◽  
Local Context ◽  
Organic Chemical ◽  
Bambusa Vulgaris ◽  
Faecal Sludge

Abstract Constructed wetland technology is an innovative engineering technique for faecal sludge (FS) management. The presence of emergent macrophytes enhances the important processes of evapotranspiration, sludge mineralisation, and contaminant reduction. Consequently, selecting a species that can withstand the difficult sludge contaminated conditions within a local context is vital. This study monitored the pollutant removal potentials and growth dynamics of Bambusa vulgaris and Cymbopogon nardus as promising macrophytes for the constructed wetland technology in the Sudano-Sahelian context. The experiment, at pilot scale, consisted of plastic reactors (27 litre) filled with filter media of sand and fine gravels at the base, and planted with the selected species. Pollutant removal efficiencies were evaluated based on differences between influent and effluent concentrations, and physiological growth parameters of plant height, number of leaves and number of plants were monitored monthly. Total annual sludge loading rate of 31.4 and 103.4 kg TS/(m2·yr) (TS: total solids) were determined for FS + wastewater (acclimatisation phase) and FS load respectively. Both species recorded appreciable pollutant removal efficiency >80% for the organic (chemical oxygen demand), nutrients (PO43_P and NH4-N) and solid (total suspended solids and total volatile solids) contents. The species thus demonstrated satisfactory performance of resistance for faecal polluted wetland conditions.

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.

Performance of denitrifying microbial fuel cell subjected to variation in pH, COD concentration and external resistance

2013 ◽  
Vol 68 (1) ◽  
pp. 250-256 ◽  
Author(s):  
Jin-Tao Li ◽  
Shao-Hui Zhang ◽  
Yu-Mei Hua
Keyword(s):  
Fuel Cell ◽  
Chemical Oxygen Demand ◽  
Microbial Fuel Cell ◽  
Electricity Generation ◽  
Oxygen Demand ◽  
Pollutant Removal ◽  
Acidic Ph ◽  
External Resistance ◽  
Weakly Alkaline ◽  
Effects Of Ph

The effects of pH, chemical oxygen demand (COD) concentration and external resistance on denitrifying microbial fuel cell were evaluated in terms of electricity generation characteristics and pollutant removal performance. The results showed that anodic influent with weakly alkaline or neutral pH and cathodic influent with weakly acidic pH favored pollutant removal and electricity generation. The suitable influent pH of the anode and cathode were found to be 7.5–8.0 and 6.0–6.5, respectively. In the presence of sufficient nitrate in the cathode, higher influent COD concentration led to more electricity generation and greater pollutant removal rates. With an anodic influent pH of 8.0 and a cathodic influent pH of 6.0, an influent COD concentration of 400 mg/L was deemed to be appropriate. Low external resistance favored nitrate and COD removal. The results suggest that operation of denitrifying microbial fuel cell at a lower external resistance would be desirable for pollutant removal but not electricity generation.

scholarly journals A Bioreactor Designed for Restricting Oversize of Aerobic Granular Sludge

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 374
Author(s):  
Hongbo Feng ◽  
Honggang Yang ◽  
Jianlong Sheng ◽  
Zengrui Pan ◽  
Jun Li
Keyword(s):  
Particle Size ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
Pollutant Removal ◽  
Volume Index ◽  
Aerobic Granular Sludge ◽  
Air Bubbles

Aerobic granular sludge (AGS) with oversized diameter commonly affects its stability and pollutant removal. In order to effectively restrict the particle size of AGS, a sequencing batch reactor (SBR) with a spiny aeration device was put forward. A conventional SBR (R1) and an SBR (R2) with the spiny aeration device treating tannery wastewater were compared in the laboratory. The result indicates that the size of the granular sludge from R2 was smaller than that from R1 with sludge granulation. The spines and air bubbles could effectively restrict the particle size of AGS by collision and abrasion. Nevertheless, there was no significant change in mixed liquor suspended solids (MLSS) and the sludge volume index (SVI) in either bioreactors. The removal (%) of chemical oxygen demand (COD) and ammonia nitrogen (NH4+-N) in these two bioreactors did not differ from each other greatly. The analysis of biological composition displays that the proportion of Proteobacteria decreased slightly in R2. The X-ray fluorescence (XRF) analysis revealed less accumulation of Fe and Ca in smaller granules. Furthermore, a pilot-scale SBR with a spiny aeration device was successfully utilized to restrict the diameter of granules at about 300 μm.

Application of an Innovative Effluent Capture and Evacuation Device that Increases the Efficiency of Subsurface Flow Wetlands

2018 ◽  
Author(s):  
Pedro Cisterna-Osorio ◽  
Gisela Silva-Vasquez ◽  
Mauricio Llanos-Baeza ◽  
Veronica Lazcano-Castro ◽  
Felipe Fuentes-Ortega
Keyword(s):  
Chemical Oxygen Demand ◽  
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 the innovative modifications made to the conventional effluent capture and discharge devices used in subsurface flow wetlands (SSFW). The main modifications developed consist on extending 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 conventional one in the operational functioning of subsurface flow wetlands, the elimination of chemical oxygen demand 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 Comparison between the coagulants surfactant modified bentonite, combination chitosan-natural bentonite and combination chitosan-modified bentonite for peat water treatment

2014 ◽  
Vol 4 (3) ◽  
pp. 194-208 ◽  
Author(s):  
Nor Farhana Zakaria Siti ◽  
S. Syafalni ◽  
Qamaruz Zaman Nastaein
Keyword(s):  
Water Treatment ◽  
Water Supply ◽  
Chemical Oxygen Demand ◽  
Rural Areas ◽  
Contact Time ◽  
Oxygen Demand ◽  
Modified Bentonite ◽  
Water Characteristics ◽  
Surface Method ◽  
Optimal Reaction

Peat water is an abundant water resource in Asia, especially in rural areas. However, it is unsuitable to be used as a commercial water supply. Monitoring peat water characteristics at Beriah swamp, Perak, recorded colour (238 PtCo), turbidity (12.86 NTU), iron (0.89 mg/L), pH (4.8) and chemical oxygen demand (COD) (27 mg/L) over the national limitation standards. In this study, surfactant modified bentonite (SMB) shows high removal of colour (95%), turbidity (97%) and iron (100%) from peat water, but not COD (almost non-removal). From the results obtained, treatment of peat water using a combination of chitosan-natural bentonite was more efficient by the resulting optimal removal for all parameters such as colour (78%), turbidity (89%), iron (90%) and COD (67%). Meanwhile, a combination of chitosan-SMB gave similar results as SMB alone; however, reducing the amount of pollutants used in combination was advantageous in this combination. The response surface method was applied and the optimal reaction between coagulant and sample due to pH, dosage and contact time was determined.

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