scholarly journals Assessing local materials for the treatment of wastewater in open drains

2019 ◽  
Vol 79 (5) ◽  
pp. 895-904 ◽  
Author(s):  
Priyanka Jamwal ◽  
Daniel Phillips ◽  
Kim Karlsrud

Abstract In the present study, three low-cost filter aggregate materials were tested and compared for organic matter and fecal coliform (FC) removal at the laboratory scale. Setups were subjected to synthetic wastewater at two hydraulic loading rates (HLR), i.e. 4 cm/day and 40 cm/day. The hydraulic retention time (HRT) at the two HLRs varied from 4 days to 12 h, respectively. The result obtained shows that the biochemical oxygen demand (BOD5) removal efficiency of aggregate materials decreased with the increase in HLR. Both at high and low HLR, the terracotta aggregate material exhibited maximum BOD5 loading removal and without significant difference for the case of FC removal efficiency for all the three aggregate materials. At higher HLR, cell debris and biofilm loss from the aggregate material contributed to the chemical oxygen demand (COD) levels in the treated water. The terracotta aggregate material provided best organic matter removal at both HLRs. The study demonstrates the potential of incorporating inexpensive and readily available local materials into decentralized, frugal green infrastructure interventions capable of lowering the quantum of harmful biological contaminants in open storm water channels in rapidly urbanizing cities of developing countries, and that the terracotta aggregate material provided best organic removal at both HLRs.

2019 ◽  
Vol 9 (13) ◽  
pp. 2680 ◽  
Author(s):  
Nguyen ◽  
Chao ◽  
Chen

In this study, the ability of a bench-scale simulated constructed wetland (CW) to remove organic matter (OM) and tetracycline (TC) from water was examined. The performance of CW was evaluated by varying the initial concentrations of the target compounds and the hydraulic retention times (HRTs). Findings showed that OM removal efficiencies were 55.2–80.8%, 28.1–71.9% and 72.1–79.7% for ultraviolet absorbance at 254 nm (UV-254), dissolved organic carbon (DOC) and soluble chemical oxygen demand (sCOD) respectively, under 1 day-HRT, whereas higher initial DOC concentration achieved better removal efficiencies. Changing from 1 day-HRT to 2 day-HRT, the removal efficiency of OMs remained practically unchanged, while that of NH3-N increased considerably, from 61.7% to 73.0%, implying that the removal of ammonia in CW needs a longer time for complete treatment. CW also showed an excellent performance in removing TC, especially in the first two hours of operation through the absorption process. In addition, the findings from this research revealed an improvement in effluent water quality when photocatalysis (TiO2/α-Al2O3, with ultraviolet A (UVA) irradiation) was used as the post-treatment following CW, presented by the increase in removal efficiency of OMs of the combined system compared to that of CW alone. This study points to the possible and promising application of the low-cost water treatment system for dealing with OMs and TC in water.


2019 ◽  
Vol 6 (1) ◽  
pp. 45-54 ◽  
Author(s):  
Veymar G. Tacias-Pascacio ◽  
Abumalé Cruz-Salomón ◽  
José H. Castañón-González ◽  
Beatriz Torrestiana-Sanchez

Background: Wet coffee processing consists of the removal of the pulp and mucilage of the coffee cherry. This process generates a large amount of acidic wastewater which is very aggressive to the environment because of its high content of recalcitrant organic matter. Therefore, treatment is necessary before discharge to water bodies. Because of this reason, this study aimed to evaluate the organic matter removal efficiency in an Anaerobic Baffled Bioreactor (ABR) coupled to a Microfiltration Membrane (MF) system as a new eco-friendly option in the treatment of wet Coffee Processing Wastewater (CPWW). Methods: Two systems (S1 and S2) were evaluated at Hydraulic Retention Times (HRT) of 59 h and 83 h, respectively. Both systems were operated at mesophilic conditions, at a Transmembrane Pressure (TMP) of 50 kPa during 1800 h. Results: The S2 generated higher organic matter removal efficiency, reaching removal values of turbidity of 98.7%, Chemical Oxygen Demand (COD) of 81%, Total Solids (TS) of 72.6%, Total Suspended Solids (TSS) of 100%, and Total Dissolved Solids (TDS) of 61%, compared with the S1. Conclusion: The S2 represents a new eco-friendly alternative to treat CPWW and reduce its pollutant effect.


2013 ◽  
Vol 67 (3) ◽  
pp. 587-593 ◽  
Author(s):  
L. Yerushalmi ◽  
M. Alimahmoodi ◽  
C. N. Mulligan

Simultaneous removal of carbon, nitrogen and phosphorus was examined along with reduced generation of biological sludge during the treatment of synthetic wastewater and hog waste by the BioCAST technology. This new multi-environment wastewater treatment technology contains both suspended and immobilized microorganisms, and benefits from the presence of aerobic, microaerophilic, anoxic and anaerobic conditions for the biological treatment of wastewater. The influent concentrations during the treatment of synthetic wastewater were 1,300–4,000 mg chemical oxygen demand (COD)/L, 42–115 mg total nitrogen (TN)/L, and 19–40 mg total phosphorus (TP)/L. The removal efficiencies reached 98.9, 98.3 and 94.1%, respectively, for carbon, TN and TP during 225 days of operation. The removal efficiencies of carbon and nitrogen showed a minimal dependence on the nitrogen-to-phosphorus (N/P) ratio, while the phosphorus removal efficiency showed a remarkable dependence on this parameter, increasing from 45 to 94.1% upon the increase of N/P ratio from 3 to 4.5. The increase of TN loading rate had a minimal impact on COD removal rate which remained around 1.7 kg/m3 d, while it contributed to increased TP removal efficiency. The treatment of hog waste with influent COD, TN and TP concentrations of 960–2,400, 143–235 and 25–57 mg/L, respectively, produced removal efficiencies up to 89.2, 69.2 and 47.6% for the three contaminants, despite the inhibitory effects of this waste towards biological activity. The treatment system produced low biomass yields with average values of 3.7 and 8.2% during the treatment of synthetic wastewater and hog waste, respectively.


2016 ◽  
Vol 74 (12) ◽  
pp. 2795-2806
Author(s):  
M. Manga ◽  
B. E. Evans ◽  
M. A. Camargo-Valero ◽  
N. J. Horan

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.


Author(s):  
Tasrina R. Choudhury ◽  
U. H. Bodrun Naher ◽  
Sarifa Akter ◽  
Bilkis A. Begum ◽  
M. Safiur Rahman

In recent years, the rapid industrialization leads to increase industrial discharges without any appropriate treatment. The present study deals with the removal of Cr (III) ions from aqueous solutions by ZnCl2 treated biochar produced from vegetable tanned leather shaving dust. Effect of various process parameters like solution pH, adsorbent dose, adsorbent type, initial Cr (III) concentration and temperature have been studied in batch system. The thermal resistivity and scanning electron microscopy (SEM) analysis were engaged to perceive the surface morphologies of chemically treated and untreated biochar adsorbent. The experimental data was fitted well to the Langmuir adsorption isotherm model and the adsorption efficiency of chromium (III) was found to be maximum (70%) at low values of pH (around 3) for 0.75 g/50 mL dose of ZnCl2 treated biochar adsorbent. The model matrix of 24 full factorial design approach has been applied at a 95% confidence level to find the impact of different variables on removal Cr(III) ions from waste water. This study revealed that three main factors: Adsorbent type (p < 0.0001; 66.39%), pH (p < 0.001; 16.01%) and adsorbent dose (p = 0.032; 12.15%) have significant impact on Cr (III) ions removal efficiency. For using ZnCl2 biochar, Cr(III) ions removal efficiency was increased 66.39% compared to using untreated biochar. Subsequently, two interaction factors: pH-time and adsorbent type-time (α = 0.05, p < 0.05) have shown statistically significant on Cr(III) ions removal efficiency. The ZnCl2 treated biochar adsorbent prepared from vegetable tanned leather shaving dust is efficient and it is proposed that it can be conveniently employed as a low cost alternative in the treatment of industrial waste water.


2021 ◽  
Vol 11 (6) ◽  
Author(s):  
Khaled Abd el naser I. Ibrahim ◽  
Tarek Ismail M. Sabry ◽  
Ahmed S. El-Gendy ◽  
Sayed I. A. Ahmed

AbstractIn an attempt to improve the quality of the agricultural drain in Egypt for its reuse again in the irrigation, low-cost solution such as sand filter along with/without other filtration media has been used in this research. As a result of that, pilot plant of sand filter mixed with other filtration media was tested for its ability to improve the sand performance in removing the suspended solids and organic matters from agricultural drain water of the Belbeis drain (in Sharkia governorate in Egypt). Sand only, sand mixed with sponge, sand mixed with activated carbon and sand mixed with ceramic cylinders have been tested to find the best media combination and optimum mixing sand/ medium ratio and optimum infiltration rate. The work has been done on four runs. It was found that sand mixed with ceramic cylinders gave the best removal efficiency with respect to total chemical oxygen demand and chemical oxygen demand for solution which were 77, 74%, respectively, whereas sand mixed with sponge had the best removal efficiency with respect to total suspended solids which was 89%. Also, all tested media combination had effluent quality that complied with Egyptian law 48 for the year 1982 regarding the disposal of wastewater into agricultural drains (chemical oxygen demand ≤ 80 mg/l, total suspended solids ≤ 50 mg/l).


2017 ◽  
Vol 76 (5) ◽  
pp. 1044-1058 ◽  
Author(s):  
Amir Mohammad Mansouri ◽  
Ali Akbar Zinatizadeh

The performance of two bench scale activated sludge reactors with two feeding regimes, continuous fed (an up-flow aerobic/anoxic sludge fixed film (UAASFF) bioreactor) and batch fed (sequencing batch reactor (SBR)) with intermittent aeration, were evaluated for simultaneous nutrients (N, P) removal. Three significant variables (retention/reaction time, chemical oxygen demand (COD): N (nitrogen): P (phosphorus) ratio and aeration time) were selected for modeling, analyzing, and optimizing the process. At high retention time (≥6 h), two bioreactors showed comparable removal efficiencies, but at lower hydraulic retention time, the UAASFF bioreactor showed a better performance with higher nutrient removal efficiency than the SBR. The experimental results indicated that the total Kjeldahl nitrogen removal efficiency in the UAASFF increased from 70.84% to 79.2% when compared to SBR. It was also found that the COD removal efficiencies of both processes were over 87%, and total nitrogen and total phosphorus removal efficiencies were 79.2% and 72.98% in UAASFF, and 71.2% and 68.9% in SBR, respectively.


2007 ◽  
Vol 56 (3) ◽  
pp. 199-205 ◽  
Author(s):  
D. Paredes ◽  
M.E. Vélez ◽  
P. Kuschk ◽  
R.A. Mueller

Constructed wetlands are used for the treatment of wastewater containing metals. In order to clarify the role of plants, flow and the impact of organic matter, an investigation of three factors, each at two different levels, was carried out in small-scale model wetlands. The evaluated factors and levels were: type of flow (subsurface and surface); presence of plants (planted with Typha latifolia and unplanted) and addition of organic matter (with and without). Eight different experimental units were run for a year. The units were fed with synthetic wastewater containing chromium (VI) (1.5 mg L−1), zinc (1.5 mg L−1), macro, micronutrients and organic matter (to those units in which this factor was being investigated). Subsurface flow wetlands showed a significantly higher rate of chromium removal in comparison with surface flow systems (97 and 60 mg m−2 d−1, respectively). Planted systems removed significantly more chromium compared to unplanted systems (85 and 76 mg m−2 d−1, respectively), and the addition of organic matter increased the removal rate in a comparison with the units without it (88 and 69 mg m−2 d−1, respectively). Similar results were found for zinc; however, the addition of organic matter made no significant difference to zinc removal.


2017 ◽  
Vol 75 (10) ◽  
pp. 2434-2442 ◽  
Author(s):  
Kang Liang ◽  
Yanran Dai ◽  
Feihua Wang ◽  
Wei Liang

Effects of seasons and hydraulic loading rates (HLR) on the treatment performance and the response of the microbial community of vertical flow constructed wetland treating tail water were investigated. The seasonal treatment performance was evaluated at four HLR of 125, 250, 375 and 500 mm/d, respectively. The microbial community was detected by MiSeq Illumina platform at HLR 125 and 375 mm/d. The wetland showed significantly higher chemical oxygen demand (COD) and total nitrogen (TN), total phosphorus (TP) at HLR 125 mm/d, compared with other HLR. Overall removal efficiency was 61.47%, 71.40% and 76.31% for COD, TN and TP, respectively, while no significant differences for COD, TN and TP removal were found at HLR of 250, 375 and 500 mm/d. The best removal efficiency for COD and TN was achieved in summer and autumn, while the best TP removal was achieved in winter. Nitrification bacteria (Nitrosomonas and Nitrospira) were significantly higher in HLR 125 mm/d, whereas sequences associated with denitrification had no significant difference at the two HLR. The results can partially explain the significantly higher NH4+-N removal in HLR 125 mm/d and relatively low nitrogen performance in winter.


2017 ◽  
Vol 7 (2) ◽  
pp. 103 ◽  
Author(s):  
Borislav N. Malinović ◽  
Miomir G. Pavlović ◽  
Tijana Djuričić

This study focused on testing the efficacy of iron (Fe) electrode in an electrochemical treatment (electrocoagulation) of wastewater containing a mixture of organic dyes. The mixture consists of the following azo dyes: Acid Black 194, Acid Black 107 and Acid Yellow 116. The present organic dyes are toxic, cause skin and eye irritation and are extremely dangerous to aquatic organisms. The study was conducted on a synthetic wastewater prepared in a laboratory electrochemical reactor. During the research, the impact of the current density, various concentrations of dye and supporting electrolyte, electrolysis duration and <em>pulsed current regime </em><em>were tracked</em>. The results are shown through color removal efficiency, chemical oxygen demand (COD) removal efficiency, current efficiency, and specific energy consumption. At the initial concentration of dye (γ=200 mg/L) and concentration of supporting electrolyte (γ<sub>NaCl</sub>=1 g/L) the color removal efficiency of 80.64% was achieved for 420 seconds of treatment (ј=10 mA/cm<sup>2</sup>). At the initial concentration of dye (γ=50 mg/L) and γ<sub>NaCl</sub>= 8 g/L, the color removal efficiency of 96.01% was attained for 300 seconds of treatment (ј=10 mA/cm<sup>2</sup>)


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