Combining artificial aeration and biological zeolite mulch for nitrogen removal from eutrophic water bodies

2020 ◽  
Vol 15 (1) ◽  
pp. 151-159
Author(s):  
Cheng Lu ◽  
Wen Cheng ◽  
Min Wang ◽  
Zhiwei Zhou

Abstract Endogenous nitrogen pollution can be a major cause of eutrophication. Nitrogen species release from sediments can be reduced by biologically-enforced zeolite mulch or water column aeration. This study was about their combined effects. Water and surface sediment samples from the Yangzhou ancient canal were aerated and biozeolite mulching was applied separately and in combination for 81 days, while the nitrogen species removal rate was recorded. The combination of aeration and biozeolite mulching removed >95% of the ammoniacal-nitrogen in 15 days. This was better than either the blank control or biozeolite mulch without aeration. The ammoniacal-nitrogen concentration was lowered faster by combined treatment than by aeration alone. Nitrate nitrogen was only detected during aeration between days 10 and18, and reached lower concentration in the presence of biozeolite. Nitrate was formed during aeration but its concentrations were higher and more variable in the absence of biozeolite; that is, mulching stabilized nitrate formation. The total nitrogen concentration reached its lowest levels after 81 days with biozeolite treatment alone, with 78% total nitrogen removal, whereas combined aeration with biozeolite achieved 41%. This shows that biozeolite mulching can remove nitrogen in eutrophic waters, even without aeration.

2012 ◽  
Vol 518-523 ◽  
pp. 214-217
Author(s):  
Tao Hong Liao ◽  
Kang Huai Liu ◽  
Jia Chun Yang ◽  
Kenji Furukawa

This experiment aimed to explore the effect of high- concentration nitrogen removal by Anaerobic ammonium oxidation process. The mixed liquor suspended solid(MLSS)was 510 mg/L. In the beginning of the experiment, the inflow concentration rate of ammonia nitrogen and nitrite nitrogen was about 1:1.3 and the total nitrogen concentration was low. When the reactor reached the ideal treatment effect then gradually increased the total nitrogen concentration, until reaching the maximum nitrogen load rate(NLR) of the reactor. In the temperature of 34.4 °C, PH was 7.23, the inflow concentration of ammonia nitrogen was 223.3 mg. N/L, the inflow concentration nitrite nitrogen was 289.7 mg. N/L, the dissolved oxygen (DO) was 2.3 mg. N/L, the nitrogen load rate (NLR) was 6.08 kg. N / (m3. d), the nitrogen removal rate (NRR) was 5.60 kg. N / (m3. d), the total nitrogen (TN) removal rate was 92.2%, under this conditions, the reactor achieved the best effect.


2003 ◽  
Vol 47 (11) ◽  
pp. 109-114 ◽  
Author(s):  
D. Cecil

At the Ejby Mølle WWTP (300,000 PE) operated by the Odense Water Ltd. a system of aeration control which combines ammonium concentration and redox potential has proven itself as a method of reducing nitrogen levels in the effluent. The nitrogen removal process at this plant proceeds in parallel aeration tanks that alternate between periods of aeration and denitrification. At the same time influent is redirected from one tank to the other such that influent and effluent is primarily to and from the tank where denitrification is going on. The aeration stops and the tanks open and close when the ammonium concentration reaches its set point. Aeration is restarted again when redox potential drops to its low set point or when ammonium reaches its upper set point. The average total nitrogen concentration in the effluent from the Ejby Mølle WWTP went from 4.7 down to 2.1 mgN/l after this control system was implemented. Not all of this reduction can be explained by better control. However we believe that at least 1 mgN/L of the reduction and probably more was the result of the control system based on the combination of ammonium and redox sensors.


1976 ◽  
Vol 87 (2) ◽  
pp. 293-296 ◽  
Author(s):  
A. Gupta ◽  
M. C. Saxena

SummaryLeaf samples were collected, at weekly intervals, throughout the growing season, from potato (Solanum tuberosumL.) plants supplied with varying amounts of nitrogen (0, 60, 120, 180 and 240 kg N/ha) and analysed for total N. Application of nitrogen increased the N concentration in the green leaves at all stages of growth. There was a significant curvilinear relationship between the final tuber yield and the total N concentration in the leaves at 48–90 days after planting in 1968–9 and at 79–107 days after planting in 1969–70. The N concentration at 70–90 days after planting was consistently related to the final tuber yield in both years. Thus this period was ideal for assessing the nitrogen status of potato plants. The critical concentration of total nitrogen generally decreased with advance in age. It ranged from 4·65% at 76 days to 3·30% at 90 days during 1968–9, whereas in 1969–70 it ranged from 4·20% at 79 days to 3·80% at 93 days. During the period from 83 to 86 days the critical percentage was around 3·6% in both the years.


1996 ◽  
Vol 76 (2) ◽  
pp. 367-377 ◽  
Author(s):  
Liangxue Liu ◽  
Barry J. Shelp

In the present study, we tested the hypothesis that continuous chloride treatment decreases nitrate absorption and accumulation by broccoli (Brassica oleracea var. italica) plants. In a field experiment, both fresh and dry weights of shoot and inflorescence increased linearly with increasing nitrogen applied (70–130 kg ha−1). Chloride application (0–450 kg ha−1) did not significantly affect the final yield. In a greenhouse experiment in which the plants were grown in soilless culture and supplied with 10–18 mmol L−1 nitrate, only the fresh weights of shoot and inflorescence decreased linearly with increasing chloride application (0–45 mmol L−1). In both experiments, increasing chloride application slightly decreased the concentrations of nitrate nitrogen and total nitrogen in xylem sap, and increased the chloride concentrations of both xylem sap and phloem exudate and the total-nitrogen concentration of phloem exudate. The shoot-nitrate contents increased with increasing nitrogen application and decreased with increasing chloride application, whereas the shoot-chloride contents increased with increasing chloride application and decreased with increasing nitrate application. The total-nitrogen contents of the shoot were not affected by chloride application. These data are interpreted to suggest that nitrate absorption was not inhibited by the presence of chloride in the growing medium and that the decrease in nitrate accumulation of the shoot resulted from the stimulation of organic-nitrogen formation from absorbed nitrate. Key words: Antagonism, broccoli, chloride, interaction, nitrate


2011 ◽  
Vol 374-377 ◽  
pp. 498-503
Author(s):  
Jin Lan Xu ◽  
Lei Wang ◽  
Jun Chen Kang ◽  
Ting Lin Huang ◽  
Yu Hua Dong

Abstract: Active barrier system (ABS) capping zeolite with large surface area and strong adsorption ability is an effective way to control eutrophication of lake since it can remove ammonia in the lake released by sediment. Influence of the initial nitrogen concentration on eliminating nitrogen load of europhia sediment capping with active barrier system (ABS) were studied through an investigation of the repairment results of serious pollution period (total nitrogen concentration up to 25.33 mg/L), moderate pollution period (14.39 mg/L) and the slight pollution period (3.47 mg/L) of the ancient Canal of Yangzhou. The results showed that: (1) zeolite F1 inhibition effect is stronger than zeolite F2. More TN were removed as the initial TN concentration increased and longer rapid inhibit period were presented with the increased initial TN concentration. (2) The ammonia nitrogen in sediment could be rapidly released into the overlying water, and with lower initial TN concentration in source water, more ammonia would be released from the sediment. Long time treatment was necessary to inhibit the release of ammonia completely if the water showed a high initial TN concentration. (3) After covering zeolite, the total nitrogen in the overlying water were removed mainly through nitrification and denitrification. At the initial TN concentration of 3.47 mg/L, 14.39 mg/L, 25.88 mg/L, 61%, 45% and 52% of TN were removed by the conversion of ammonia to nitrogen gas, however, others left in water as nitrate nitrogen and nitrite residues, and 90% was nitrate nitrogen.


2007 ◽  
Vol 55 (8-9) ◽  
pp. 59-65 ◽  
Author(s):  
A. Onnis-Hayden ◽  
P.B. Pedros ◽  
J. Reade

An experimental study investigating the nitrogen removal efficiency from the recycle stream generated in the dewatering facility of the anaerobically digested sludge at the Deer Island wastewater treatment plant (WWTP) in Boston was conducted using a single submerged attached growth bioreactor (SAGB), designed for simultaneous nitrification and denitrification. The applied nitrogen loading to the reactor ranged from 0.7 to 2.27 kg-N/m3·d, and the corresponding total nitrogen (TN) removal rate ranged from 0.38 to 1.8 kg-N/m3·d. The observed nitrification rates varied from 0.42 kg-N/m3·d to 1.45 kg-N/m3·d with an ammonia load of 0.5 kg-N/m3·d and 1.8 kg-N/m3·d, respectively. An average nitrification efficiency of 91% was achieved throughout the experiment. Denitrification efficiency varied from 55%, obtained without any addition of carbon source, to 95% when methanol was added in order to obtain a methanol/nitrate ratio of about 3 kg methanol/kg NO3−-N.


2015 ◽  
Vol 39 (4) ◽  
pp. 1127-1140 ◽  
Author(s):  
Eric Victor de Oliveira Ferreira ◽  
Roberto Ferreira Novais ◽  
Bruna Maximiano Médice ◽  
Nairam Félix de Barros ◽  
Ivo Ribeiro Silva

The use of leaf total nitrogen concentration as an indicator for nutritional diagnosis has some limitations. The objective of this study was to determine the reliability of total N concentration as an indicator of N status for eucalyptus clones, and to compare it with alternative indicators. A greenhouse experiment was carried out in a randomized complete block design in a 2 × 6 factorial arrangement with plantlets of two eucalyptus clones (140 days old) and six levels of N in the nutrient solution. In addition, a field experiment was carried out in a completely randomized design in a 2 × 2 × 2 × 3 factorial arrangement, consisting of two seasons, two regions, two young clones (approximately two years old), and three positions of crown leaf sampling. The field areas (regions) had contrasting soil physical and chemical properties, and their soil contents for total N, NH+4-N, and NO−3-N were determined in five soil layers, up to a depth of 1.0 m. We evaluated the following indicators of plant N status in roots and leaves: contents of total N, NH+4-N, NO−3-N, and chlorophyll; N/P ratio; and chlorophyll meter readings on the leaves. Ammonium (root) and NO−3-N (root and leaf) efficiently predicted N requirements for eucalyptus plantlets in the greenhouse. Similarly, leaf N/P, chlorophyll values, and chlorophyll meter readings provided good results in the greenhouse. However, leaf N/P did not reflect the soil N status, and the use of the chlorophyll meter could not be generalized for different genotypes. Leaf total N concentration is not an ideal indicator, but it and the chlorophyll levels best represent the soil N status for young eucalyptus clones under field conditions.


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