scholarly journals Addition of Corn Cob in the Free Drainage Zone of Partially Saturated Vertical Wetlands Planted with I. sibirica for Total Nitrogen Removal—A Pilot-Scale Study

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2151
Author(s):  
Aarón Del Toro ◽  
Allan Tejeda ◽  
Florentina Zurita

The aim of this 15-month study was to evaluate and compare two partially saturated (PS) vertical flow (VF) wetlands for total nitrogen (TN) removal. The PS VF wetlands, evaluated in duplicate, were added with corncob (CC) in two different heights of the free-drainage zone (FDZ). The FDZ had a height of 40 cm and the saturated zone (SZ) had a height of 30 cm. The configuration of the system I (SI) was a 20 cm-corncob bed above the SZ followed by a 20 cm-tezontle bed; in system II (SII) the order of the beds were inverted. The SZ was added with tezontle with a size of 1−2 cm. Weekly measurements of water quality parameters including oxygen demand (BOD5), chemical oxygen demand (COD), color, total suspended solids (TSS), organic nitrogen (Org-N), ammonium (NH4+), nitrate (NO3−) and nitrite (NO2−), were taken in the influent and effluents, and interfaces (nitrate and nitrite). Measurements of pH, dissolved oxygen (DO) and oxidation-reduction potential (ORP) were taken in the SZ. The addition of CC in the FDZ did not interfere with the capacity of the PS VF wetlands for BOD5, COD, TSS and true color removal, reaching mass removal efficiencies of 91.9% and 92.2%, 66.6% and 75%, 89.8% and 92%, 63.3% and 66.0%, for SI and SII, respectively; without significant difference between the systems (p > 0.05). The CC in the FDZ neither interfered with the PS VF wetlands nitrification capacity. The removal of TN was similar in SI and SII (p > 0.05), attaining average mass removal efficiencies of 68.2% and 66.0%, respectively. These efficiencies were not sufficiently high due to the limited denitrification process in the SZ as a result of the absence of biodegradable carbon, generated and consumed in the FDZ.

2019 ◽  
Vol 80 (4) ◽  
pp. 707-716 ◽  
Author(s):  
Min Sang ◽  
Miansong Huang ◽  
Wei Zhang ◽  
Wu Che ◽  
Huichao Sun

Abstract Bioretention is an effective technology for urban stormwater management, but the nutrient removal in conventional bioretention systems is highly variable. Thus, a pilot bioretention column experiment was performed to evaluate the nutrient control of systems with commercial activated carbon and river sediment-derived biochar. Significant chemical oxygen demand (COD) and total phosphorus (TP) leaching were found with the addition of activated carbon and biochar, but total nitrogen (TN) leaching was significantly improved when activated carbon was used as the medium. During a semi-synthetic runoff experiment, the bioretention systems containing two types of fluvial biochar showed relatively better COD and TN control (average mass removal efficiencies and cumulative removal efficiencies) than commercial activated carbon. However, the average TP mass removal efficiency with commercial activated carbon (95% ± 3%) was significantly higher than biochar (48% ± 20% and 56 ± 14%). The addition of biochar in the media increased the nitrogen removal efficiency, and the addition of activated carbon significantly increased the phosphorous removal efficiency. Therefore, both biochar and activated carbon are effective materials for bioretention, and fluvial biochar provides an alternative approach to comprehensively utilize river sediment.


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.


2002 ◽  
Vol 45 (1) ◽  
pp. 49-53 ◽  
Author(s):  
C.T. Zanotelli ◽  
W. Medri ◽  
P. Belli Filho ◽  
C.C. Perdomo ◽  
M.R. Mulinari ◽  
...  

This paper shows the performance of a baffled facultative pond for the treatment of piggery wastes. The full-scale system is composed of an equalizer, one decanter (DP), two anaerobic ponds (LA1 and LA2), one facultative pond (LF), with five baffles, and one maturation pond with water hyacinths (LAG). The studies were conducted over a 12 month period in the west region of Santa Catarina, Brazil. The system was supplied daily with a volume of 3 m3/day of farm wastes. A good performance of the treatment system was obtained with average removal efficiencies of 98% for chemical oxygen demand, 93% for total solids, 98% for total phosphorus, 92% for total nitrogen, 7 log units of faecal coliforms and 5 log units of total coliforms. The facultative pond performed well, removing 43% of the chemical oxygen demand, 47% of total nitrogen and 54% of total phosphorus. It was found that the first baffle in the facultative pond was mainly responsible for the efficiency of this pond, and compared with another study the introduction of the baffles improved the removal efficiency by 20% for total phosphorus.


2015 ◽  
Vol 19 (2) ◽  
pp. 7
Author(s):  
Andrés Felipe Torres Franco ◽  
Nancy Vásquez Sarria ◽  
Jenny Rodriguez Victoria

A pilot-scale study was conducted to evaluate a traditional contact stabilization activated sludge system (CSASC) and a modified CSAS (CSASM) treating domestic wastewater. The CSASC system was comprised of a contact reactor (CR), a stabilization reactor (SR) and a secondary settler (SS); the CSASM included a second CR, a second SS (CR2 and SS2), and a modified SR (SRM) divided into four zones: an attached-suspended growth zone which allowed the system to reach an average sludge retention time close to 36 d and favored the occurrence of nitrification; an anoxic zone for denitrification occurrence; an aerated suspended growth zone with a high presence of organic carbon; and an additional aerated suspended growth zone with a high ammonia concentrations environment. The CSASC’s removal efficiencies of chemical oxygen demand (COD) and total ammonia nitrogen (TAN) were respectively 94±4 % and 53±12%; whereas CSASM’s efficiencies were 88±7% for COD and 92±7% for TAN. Concentrations of TAN and NO3 --N in the CSASC’s final effluent were 14.3±5.2 and 5.0±2.9 mg×L-1; and 4.8±4.4 and 9.1±5.8 mg×L-1 in the CSASM’s final effluent. Results demonstrated that the proposed configuration obtained higher nitrogen removal efficiencies than traditional CSAS.</p>


2009 ◽  
Vol 36 (4) ◽  
pp. 690-700 ◽  
Author(s):  
J. Mena ◽  
R. Gómez ◽  
J. Villaseñor ◽  
A. de Lucas

Synthetic wastewaters simulating physically pre-treated low-loaded winery effluents were treated for four months with five pilot-scale horizontal subsurface flow constructed wetlands (HSSF-CWs) using different plants. Species under study were Phragmites australis (HSSF-CW2), Lythrum salicaria (HSSF-CW3), Cladium mariscus (HSSF-CW4), and Iris pseudacorus (HSSF-CW5). The designation HSSF-CW1 was not planted, and was used as a control. The mean dissolved oxygen and oxidation–reduction potential values in all HSSF-CWs indicated anaerobic conditions in the bulk liquid. High pollutant-removal efficiencies were obtained. Apparently, the species with higher growth (Phragmites, Lythrum, and particularly Iris) improved total nitrogen (TN) and nitrogen as ammonium (N-NH4+) removals, but adversely affected sulphate (SO42–) anaerobic reduction. Chemical oxygen demand (COD) removal efficiencies were high, although there were no clear indications how the kinds of plants might have influenced this parameter. A statistical analysis of variance indicated that only N-NH4+ removal efficiencies were statistically different owing to the influence of the different plants. In a second 6 month experimental period, polyphenols (13 mg L–1) were added to the synthetic wastewater to study possible inhibition effects. The addition of polyphenols did not seem to cause inhibition effects on COD, TN, and N-NH4+ removals, but clearly negatively affected SO42– removal. A new two-way analysis of variance confirmed that only SO42– removal was negatively affected by polyphenols, while the effects of the different plants were only significant for N-NH4+ removal. Polyphenols were nearly completely removed. First order rate constants obtained for COD, TN, SO42–, and polyphenol removals were similar to those reported by other authors.


Author(s):  
Osayomwanbo Osarenotor ◽  
Helen M. K. Essandoh ◽  
Isoken Tito Aighewic

Abstract Slaughterhouses generate wastewater daily and often discharge it to the environment. Many lack wastewater treatment systems, due to such systems' typically high cost and technological demands. In this study slaughterhouse wastewater was filtered through columns of mycelium – Pleurotus ostreatus – grown on sawdust substrates of different particle sizes. The columns' pollutant removal efficiencies were evaluated for color, turbidity, total suspended solids, total dissolved solids, electrical conductivity, dissolved oxygen, biological oxygen demand (BOD), chemical oxygen demand, total nitrogen and total phosphorus. The best color (75%), BOD (88%) and total nitrogen (86%) removal efficiencies were recorded with 2.36 mm particle size and 9 cm depth. Electrical conductivity removal efficiency was best with 2.36 mm particle size but 3 cm bed depth. The study showed that particle size has a significant effect on physiochemical pollutant removal by mycelium-colonized sawdust systems.


2013 ◽  
Vol 69 (2) ◽  
pp. 350-357 ◽  
Author(s):  
Miriam Ben-shalom ◽  
Semion Shandalov ◽  
Asher Brenner ◽  
Gideon Oron

Three pilot-scale duckweed pond (DP) wastewater treatment systems were designed and operated to examine the effect of aeration and effluent recycling on treatment efficiency. Each system consisted of two DPs in series fed by pre-settled domestic sewage. The first system (duckweed+ conventional treatment) was ‘natural’ and included only duckweed plants. The second system (duckweed aeration) included aeration in the second pond. The third system (duckweed+ aeration+ circulation) included aeration in the second pond and effluent recycling from the second to the first pond. All three systems demonstrated similarly efficient removal of organic matter and nutrients. Supplemental aeration had no effect on either dissolved oxygen levels or on pollutant removal efficiencies. Although recycling had almost no influence on nutrient removal efficiencies, it had a positive impact on chemical oxygen demand and total suspended solids removals due to equalization of load and pH, which suppressed algae growth. Recycling also improved the appearance and growth rate of the duckweed plants, especially during heavy wastewater loads.


2014 ◽  
Vol 955-959 ◽  
pp. 2133-2138
Author(s):  
Ahmed M. Osman Khairalla ◽  
Xi Wu Lu ◽  
John Leju Celestino Ladu

The rural domestic wastewater system has been evaluated by using a pilot scale of a biological – ecological process which was built and monitored under operation for a long time. The system was operated for six months with an ambient temperature ranged of (5 – 22°C). The process used in this study was set up as a modified anaerobic/anoxic/oxic process followed by a constructed wetland. Stability and acclimatization of the anaerobic bacteria was achieved after 35 days by using glucose and trace nutrient. The system was then continuously operated with a real domestic wastewater. Hydraulic retention time and temperature are more important parameters of the biological-ecological process performance. Therefore, the system was operated with different HRT and temperature to evaluate the performance efficiency. The influent and effluent of the chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) were analyzed. The anaerobic reactor showed that the optimal HRT was 4 days and the reactor demonstrated a removal efficiency rate of COD (55.5%). The average biogas production in the summer season was 6.8 l/d and in the winter was 1.24 l/d. The Biological– ecological process revealed good efficiency in the removal of the COD, total nitrogen and total phosphorous, where the maximum average removal was 85.5%, 79.8%, 74.9% respectively.


2018 ◽  
Vol 30 (4) ◽  
pp. 662-671
Author(s):  
Emmanuel A Odey ◽  
Kaijun Wang ◽  
Zifu Li ◽  
Abdulmoseen S Giwa ◽  
Bodjui O Abo

With the growing interest in resource recovery from wastewater, research has been put forward to realize this aim using different approaches. Here, we considered several conditions necessary for the experiment, with the primary goal of recovering concentrates suitable for biogas recovery and water reuse through the pilot-scale membrane reactor (PSMR). The new concept enables the feasibility of recovering permeates and concentrates directly from the PSMR. From the results obtained, permeate chemical oxygen demand was within 20 mg/L to 38 mg/L; the total nitrogen yielded an average value of 22.14 ± 3.53 mg/L; ammonia yielded an average value of 13.34 ± 1.18 mg/L; and the total phosphorus presented a value of 0.46 ± 0.32 mg/L. Permeates recovered from the experiment feature potential use for agriculture, groundwater, and lake recharge, as the chemical oxygen demand, total nitrogen, total phosphorus, and ammonia contents are low and acceptable for these purposes. Concentrates from two days of solid retention time ranged from 6050 mg/L to 10,000 mg/L, which was suitable for anaerobic digestion for biogas recovery. A further experiment is suggested to enable the removal of more ammonia, total phosphorus, and total nitrogen in permeate to enable its use for a domestic purpose.


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