Nitrogen removal during leachate treatment: comparison of simple and sophisticated systems

2004 ◽  
Vol 50 (6) ◽  
pp. 45-52 ◽  
Author(s):  
J.-L. Vasel ◽  
H. Jupsin ◽  
A.P. Annachhatre

Membrane bioreactors (MBR) have become common in treating municipal wastewaters. Applied to leachates treatment MBR were also successful with pilot scale experiments and full-scale facilities as well. We succeeded previously in designing an efficient nitrificationÐdenitrification process with an ethylene glycol byproduct as carbon source for denitrification. Moreover, an unexpectedly high inert COD removal efficiency was also observed in the full-scale MBR facility thereby making it possible to increase the operating time of the final GAC (Granulated Activated Carbon) adsorber. Since MBR are very sophisticated systems. Simpler and “lower” cost systems can also be considered. For example it is possible to nitrify leachates from sanitary landfill using a simple infiltrationÐpercolation technique with a low energy cost. To validate previously published laboratory experiments, a semi industrial-scale pilot installation was installed at the Montzen landfill site (Belgium). The process is based on infiltrationÐpercolation through a granular bed. This well known process was modified to increase the load, notably by changing the support medium, adding an electric fan that is run intermittently and maintaining temperatures greater than 15°C. The new material is a type of granular calcium carbonate with a large specific surface area. These technical improvements enabled the system to nitrify up to 0.4 kg NH4+-N/m3 of reactor bed per day at a hydraulic load of 0.35 m.d-1, with an ammonia removal rate in the range of 80 to 95%. Despite the high ammonia nitrogen inlet concentrations, this system exhibits remarkable nitrification efficiency. Moreover, these performances are achieved in a batch mode system without recirculation or dilution processes. If complete nitrification is needed, it can be obtained in a second in series of bioreactors. The system can be classified as a low cost process. An international patent is pending. Possible performances of those systems were compared with the usual methods for leachates treatment.

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3000
Author(s):  
Wujie Xu ◽  
Yu Xu ◽  
Haochang Su ◽  
Xiaojuan Hu ◽  
Keng Yang ◽  
...  

Ammonia is the main pollution factor of the aquatic environment in marine shrimp culture systems. In order to demonstrate the feasibility of the combination of biofloc technology and nitrifying biofilter for the ammonia removal, a 70-day production trial was conducted in a simplified pilot-scale hybrid biofloc-based recirculating aquaculture system (biofloc-RAS) with the intensive culture of Litopenaeus vannamei. Nitrogen dynamics and nitrifying microbial communities were investigated in three replicated systems simultaneously under the conditions of high feed loading and zero water exchange. Along with biofloc development in the culture tank and biofilm formation in the nitrifying biofilter during the trial, nitrification could be fastly and effectively established in the system, which was indicated by the dynamics of total ammonia nitrogen (TAN), NO2–-N, NO3–-N, and total nitrogen (TN) concentrations. Meanwhile, similar nitrifying microorganisms could be found between biofloc and biofilm, despite some differences in abundance, diversity, and composition of ammonia-oxidizing archaea and bacteria and nitrite-oxidizing bacteria. High TAN removal rate could be achieved and was significantly and positively correlated with abundances of these nitrifying microbial communities in both biofloc and biofilm, further indicating that both biofloc and biofilm could contribute highly to nitrification performance of the biofloc-RAS. The results of this study indicate a potential application of the biofloc-RAS in coastal intensive aquaculture.


2011 ◽  
Vol 55-57 ◽  
pp. 789-795
Author(s):  
Xiu Ju Duan ◽  
Qiang He ◽  
Ya Li Liu

This thesis put forward the treatment concept of “without Biomass Retention Sequential Batch Intensified Pretreatment (WSIP)” in leachate treatment, for sake of improving performance of nitrogen removal, optimizing excess water’s nutritional ratio and benefitting the follow-up aerobic biological treatment. Based on orthogonal experiment of WSIP Reactor’s leachate treatment performance, Conclusions can be drew: the removal performance of ammonia nitrogen and TN is higher of WSIP, in which short-cut nitrification and denitrification can be realized; HRT, DO and sequential period are remarkable factors of ammonia removal performance, TN removal performance and realization of short-cut nitrification and denitrification; In normal temperature, the most perfect functional parameter of WSIP Reactor is: HRT=4d, DO=0.75mg/L and sequential period is 6h.


2015 ◽  
Vol 26 (3) ◽  
pp. 49-53 ◽  
Author(s):  
Anna Kwarciak-Kozłowska ◽  
Aleksandra Krzywicka

Abstract The goal of this article was to compare the efficiency of Fenton and photo-Fenton reaction used for stabilised landfill leachate treatment. The mass ratio of COD:H2O2 was fixed to 1:2 for every stages. The dose of reagents (ferrous sulphate/hydrogen peroxide) was different and ranged from 0.1 to 0.5. To determine the efficiency of treatment, the BOD (biochemical oxygen demand COD (chemical oxygen demand), TOC (total organic carbon) , ammonia nitrogen and BOD/COD ratio was measured. The experiment was carried out under the following conditions: temperature was 25ºC, the initial pH was adjusted to 3.0. Every processes were lasting 60 minutes. The most appropriate dose of reagents was 0.25 (Fe2+/H2O2). It was found that the application of UV contributed to increase of COD, TOC and ammonia removal efficiencies by an average of 14%.


2013 ◽  
Vol 664 ◽  
pp. 454-457
Author(s):  
Xiu Juan Yu ◽  
Li Hong Ning

The removal of ammonia nitrogen in simulated wastewater with 90mg/L NH4Cl was researched by ammonia stripping, electrochemical oxidation and the combination of the ammonia stripping and electrochemical oxidation. It is shown that the reduction of ammonia is enlarged with increasing of wastewater’s alkalinity during stripping. And the removal rates of ammonia nitrogen are 2.1% at pH2 and 43.1% at pH7 which is not related to the stripping time. The ammonia removal is higher efficiency in pH12 which is in the range of 45.1% and 61.4% when the stripping time is changed from 40 to 100 min. The removal rate of ammonia nitrogen is increased with the extension of electrolysis time by the way of the electrochemical oxidation. For 100min electrolysis, the ammonia removal in the cathodic and anodic compartments are 55.8% and 86.9%, respectively. Moreover, by using the ammonia stripping and electrochemical oxidation simultaneously, the ammonia removal in the cathodic and anodic compartments are up to 91.8% and 99.8% for 100min, respectively. The combining of the ammonia stripping with electrochemical oxidation technology has obviously synergistic effect in purifying ammonia nitrogen wastewater.


Author(s):  
Izabela Anna Tałałaj

Abstract Purpose In this paper the performance and effectiveness of the reverse osmosis (RO) process for the biologically pretreated leachate was investigated. The RO process was carried out separately for two different pH: 8.0 and 9.3. Methods A general pollution parameters as well as organic and inorganic indicators were determined in raw, biologically pretreated and RO treated leachate. The performance characteristics of the reverse osmosis system were made on the basis of permeate flux, electroconductivity removal rate, concentration factor and efficiency in removal of analyzed parameters. Results The use of SBR pretreatment had very good efficiency in BOD (97.3%) and ammonia nitrogen (95.4%) removal. The lowest effectivity was observed for chloride (11.6%), boron (3.9%) and TDS (1.2%). Pretreated leachate was subjected to RO system. The normalized average flux was 0.53 (42.3 L/m2·h) for pH = 8.0 and 0.68 (33.5 L/m2·h) for pH = 9.3. The lower membrane fouling at higher pH can be explained by electrostatic repulsion between the negatively charged membrane surface and organic substances. Independently of the process pH, a two-step membrane fouling was observed. The greatest differences in removal rates were observed for boron, which had a higher retention rate at higher pH, and ammonia nitrogen, whose removal rate decreased at higher pH. The obtained permeate pH after RO process was lower than the feed pH in two analyzed value of pH. Conclusions The higher flux value at pH = 9.3 is result of high content of organic matter in leachate, which is better rejected at higher pH because of higher electrostatic repulsion between organic matter and membrane surface. This indicates that the organic matter content should be taken into account when determining the operating parameters (pH values) of the RO system.


Author(s):  
Hiba Tlili ◽  
Mahmoud Bali ◽  
Rachid Boukchina

Abstract Intermittent planted filters are extensive biological purification techniques aimed at oxidizing and decontaminating urban wastewater at a low cost and with minimum environmental impacts. The main purpose of this study was to evaluate the performances of intermittent planted filters in treating urban wastewater under arid conditions of southern Tunisia. The experimental study was carried out on a pilot scale plant comprising five constructed gravel-sand basins. Screened urban wastewater effluent was intermittently applied with a daily hydraulic load of 400 L/m2. Several water quality parameters were monitored at the inlet and outlet of this treatment plant. The average removal rate were 94.8%, 92.3%, 99.3%, 89.9% and 93.3% for chemical and biological oxygen demand, total suspended solids, ammonium nitrogen and orthophosphate, respectively. Additionally, results demonstrated that this treatment system is capable to remove 3.67, 3.22 and 2.44 log units of total and faecal coliforms, and faecal streptococci, respectively. Results showed that Phragmites australis allowed the development of biofilm in the sand filter beds, improving their purification efficiency. Furthermore, no bio-sludge production, no mechanical aeration, low energy requirement (0.02 kW/m2) and green aesthetic ambience are the additional particular strengths of the proposed pilot-plant.


2014 ◽  
Vol 70 (12) ◽  
pp. 2031-2039 ◽  
Author(s):  
Qiuzhuo Zhang ◽  
Chi Ding ◽  
Varenyam Achal ◽  
Dan Shan ◽  
Yang Zhou ◽  
...  

A new integrated water remediation technology, including a floating bed, a buffer zone of floating plants, enclosed ‘water hyacinth’ purification, economic aquatic plants and near-shore aquatic plant purification, was used in Dishui Lake to improve its water quality. A channel of 1,000 m length and 30 m width was selected to implement pilot-scale experiments both in the static period and the continuous water diversion period. The results showed that the new integrated water remediation technology exhibited the highest removal rate for permanganate index in a static period, which achieved 40.6%. The average removal rates of total nitrogen (TN), ammonia nitrogen (NH3-N) and total phosphorus (TP) in a static period were 23.2, 21.6 and 19.1%, respectively. However, it did not exhibit an excellent removal rate for pollutants in the continuous water diversion period. The average removal rates for all pollutants were below 10%. In winter, the new integrated remediation technology showed efficient effects compared to others. The average removal rate for CODMn, TN, NH3-N and TP were 7, 5.3, 7.6 and 6.5%, respectively. Based on our results, the new integrated water remediation technology was highly efficient as a purification system, especially during the static period in winter.


2012 ◽  
Vol 496 ◽  
pp. 42-45 ◽  
Author(s):  
Hao Wang ◽  
Guan Wen Cheng ◽  
Xiao Wei Song ◽  
Zai Han Xu ◽  
Jin Jie Meng ◽  
...  

Ammonia is one of the most important contaminants affecting the quality of water environment. Magnesium ammonium phosphate (MgNH4PO4·6H2O), which is a slow releasing fertilizer, is one possible way to remove high strength ammonia from the wastewater. The wastewater is collected from the effluent of extraction of rare earth elements factory, the study investigate the influence of pH, magnesium and phosphate dosing molar ratio and reaction time for ammonia removal rate. The results show that: when the pH = 9.2, n (Mg): n (N): n (P) = 2.2:1:2, reaction time t = 20min, ammonia concentration of the wastewater from 4420mg / L down to 1440mg / L , ammonia nitrogen removal rate can reach 67%, the remaining TP = 0.9mg / L; higher Ca2 + concentration will affect the MAP precipitation for removing ammonia, but it help to reduce total phosphorus concentrations of effluent; it is not the longer reaction time the better removal rate, because the MAP-formation will destroy with longer reaction time.


2013 ◽  
Vol 448-453 ◽  
pp. 604-607 ◽  
Author(s):  
Hong Jie Sun ◽  
Xin Nan Deng ◽  
Rui Chen

Research was conducted on pilot-scale, two-stage batch-flow constructed wetland systems for domestic wastewater treatment. Synthetic domestic wastewater was treated in a pre-acidification reactor with a hydraulic retention time (HRT) of 3 hours and the average removal rate of chemical oxygen demand (COD) and ammonia-nitrogen (NH4-N) reached 30% and 13.6%, respectively. The first-stage constructed wetland operated with up-flow and batch feed and drain. One cycle was 12h, including 6h feed and 6h drain. With HRT of 3 days, the effluent COD concentrations fluctuated from 32.5 mg/L to 103.4 mg/L, removal rates varied from 60% to 88%; effluent NH4-N concentrations were in the range of 4.8 mg/L to 10.8 mg/L, removal rates varied from 50% to 70%. The second-stage constructed wetland operated with down-flow, which one cycle was 24h, including 12h feed and 12h drain. With HRT of 1 day, effluent COD concentrations varied from 15.7 mg/L to 48.7 mg/L, removal averaged 53.2%; effluent NH4-N concentrations ranged from 0 mg/L to 0.4 mg/L, average removal exceeded 99%. The spatial variation of COD and NH4-N in the first-stage constructed wetland demonstrated that entrainment of air during draining of constructed wetland could strengthen the removal of COD and NH4-N. Temperature had no significant effect on COD degradation while obviously affected the removal of NH4-N.


2011 ◽  
Vol 183-185 ◽  
pp. 720-724 ◽  
Author(s):  
Ping Li ◽  
Li Long Yan ◽  
Fang Ma

Biological Aerated Filter has the drawback of severe plug under low temperature, and frequent back-washing would cause the bad performance of ammonia removal. To solve these shortcomings, partial backwashing experiment was carried out to test its amelioration effect on Biological Aerated Filter. The result showed that performing backwashing at the 40 cm of filter had strong protective effect on nitrifying bacteria, the ammonia removal could be improved gradually with the highest removal rate of 71.71%. Partial backwashing affected less on ammonia removal and the removal efficiency could be restored to the previous level after the backwashing completed for 2.5 h.


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