scholarly journals Influence of Leachate and Nitrifying Bacteria on Photosynthetic Biogas Upgrading in a Two-Stage System

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1503
Author(s):  
Luis Fernando Saldarriaga ◽  
Fernando Almenglo ◽  
Domingo Cantero ◽  
Martín Ramírez
Keyword(s):  
Landfill Leachate ◽  
Scale Up ◽  
Economic Feasibility ◽  
Nitrifying Bacteria ◽  
Co2 Uptake ◽  
Co2 Absorption ◽  
Nutrient Source ◽  
Two Stage ◽  
Biogas Upgrading ◽  
G Ratio

Photosynthetic biogas upgrading using two-stage systems allows the absorption of carbon dioxide (CO2) in an absorption unit and its subsequent assimilation by microalgae. The production of microalgae requires large amounts of nutrients, thus making scale-up difficult and reducing economic feasibility. The photosynthetic process produces oxygen (O2) (1 mol per mol of CO2 consumed), which can be desorbed into purified biogas. Two-stage systems reduce its impact but do not eliminate it. In this study, we test the use of landfill leachate as a nutrient source and propose a viable and economical strategy for reducing the O2 concentration. First, the liquid/gas (L/G) ratio and flow mode of the absorber were optimized for 20% and 40% CO2 with COMBO medium, then landfill leachate was used as a nutrient source. Finally, the system was inoculated with nitrifying bacteria. Leachate was found to be suitable as a nutrient source and to result in a significant improvement in CO2 absorption, with outlet concentrations of 0.01% and 0.6% for 20% and 40% CO2, respectively, being obtained. The use of nitrifying bacteria allowed a reduction in dissolved oxygen (DO) concentration, although it also resulted in a lower pH, thus making CO2 uptake slightly more difficult.

scholarly journals Scaling-Up and Long-Term Operation of a Full-Scale Two-Stage Partial Nitritation-Anammox System Treating Landfill Leachate

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 800
Author(s):  
Albert Magrí ◽  
Maël Ruscalleda ◽  
Albert Vilà ◽  
Tiago R. V. Akaboci ◽  
M. Dolors Balaguer ◽  
...  
Keyword(s):  
Landfill Leachate ◽  
Research Group ◽  
Biological Treatment ◽  
Scale Up ◽  
Full Scale ◽  
Landfill Site ◽  
Two Stage ◽  
Partial Nitritation ◽  
N Removal

(1) Background: Biological treatment of leachate in landfill sites using anaerobic ammonium oxidation (anammox) is challenging because of the intrinsic characteristics of this complex wastewater. In this work, the scale-up and subsequent full-scale implementation of the PANAMMOX® technology (LEQUIA Research Group, Girona, Catalonia, Spain) are presented as a case study to achieve long-term nitrogen (N) removal from mature leachate mostly through a completely autotrophic pathway. (2) Methods: The treatment system consists of two sequencing batch reactors (SBRs) running in series to individually operate partial nitritation (PN) and anammox (A). Following biological treatment, physicochemical oxidation (i.e., Fenton-based process) was used to remove the remaining non-biodegradable organic matter. A cost analysis comparative was conducted in relation to the former technology used on-site for treating the leachate. (3) Results: The scale-up of the process from pilot- to full-scale was successfully achieved, finally reaching an average removal of 7.4 kg N/d. The composition of the leachate changed over time, but especially once the landfill site stopped receiving solid waste (this fact involved a marked increase in the strength of the leachate). The adjustment of the alkalinity-to-ammonium ratio before feeding PN-SBR helped to improve the N-removal efficiency. Values of conductivity above 25 mS/cm in A-SBR could negatively affect the performance of the anammox process, making it necessary to consider a dilution strategy according to the on-line monitoring of this parameter. The analysis of the operational costs showed that by implementing the PANAMMOX® technology (LEQUIA Research Group, Girona, Catalonia, Spain) in the landfill site, savings up to 32% were achievable. (4) Conclusions: Treatment of mature landfill leachate in such a two-stage PN-A system was demonstrated as feasible and economically appealing despite the complexity of this industrial wastewater. Accurate expert supervision of the process was a key factor to reaching good performances.

Scale-up and cost analysis of a photo-Fenton system for sanitary landfill leachate treatment

2016 ◽  
Vol 283 ◽  
pp. 76-88 ◽  
Author(s):  
Tânia F.C.V. Silva ◽  
Amélia Fonseca ◽  
Isabel Saraiva ◽  
Rui A.R. Boaventura ◽  
Vítor J.P. Vilar
Keyword(s):  
Cost Analysis ◽  
Landfill Leachate ◽  
Scale Up ◽  
Sanitary Landfill ◽  
Leachate Treatment ◽  
Fenton System ◽  
Sanitary Landfill Leachate

scholarly journals A Review of Landfill Leachate Treatment by Microalgae: Current Status and Future Directions

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 384 ◽  
Author(s):  
Tabish Nawaz ◽  
Ashiqur Rahman ◽  
Shanglei Pan ◽  
Kyleigh Dixon ◽  
Burgandy Petri ◽  
...  
Keyword(s):  
Solid Waste ◽  
Landfill Leachate ◽  
Scale Up ◽  
Resource Recovery ◽  
Current Status ◽  
Future Research ◽  
Potential Candidate ◽  
Leachate Treatment ◽  
Treatment Scenario ◽  
Environmental Footprints

Solid waste generation has been projected to increase worldwide. Presently, the most applied methodology to dispose of solid waste is landfilling. However, these landfill sites, over time release a significant quantity of leachate, which can pose serious environmental issues, including contamination of water resources. There exist many physicochemical and biological landfill leachate treatment schemes with varying degrees of success. With an increasing focus on sustainability, there has been a demand for developing eco-friendly, green treatment schemes for landfill leachates with viable resource recovery and minimum environmental footprints. Microalgae-based techniques can be a potential candidate for such a treatment scenario. In this article, research on microalgae-based landfill leachate treatments reported in the last 15 years have been summarized and critically reviewed. The scale-up aspect of microalgae technology has been discussed, and the related critical factors have been elucidated. The article also analyzes the resource recovery potential for microalgal techniques with respect to leachate treatment and explores possible methodologies to minimize the environmental footprints of the microalgae-based treatment process. The future research potential in the area has been identified and discussed.

Biological Treatment of High Ammonium Content Urban Landfill Leachate Using an Anaerobic-Aerobic Process

2013 ◽  
Vol 781-784 ◽  
pp. 2095-2099
Author(s):  
Hong Wei Sun ◽  
Yong Jun You ◽  
Ying Guo
Keyword(s):  
Landfill Leachate ◽  
Inhibitory Effect ◽  
Nitrifying Bacteria ◽  
Anaerobic Sludge ◽  
Nitrite Accumulation ◽  
Fish Analysis ◽  
Free Nitrous Acid ◽  
Nitrite Oxidizing Bacteria ◽  
Anaerobic Sludge Blanket

Biological system consisting of an up-flow anaerobic sludge blanket (UASB) and anoxic-oxic (A/O) reactor was applied to treat high ammonium content urban landfill leachate. Inhibitory effect of free ammonia (FA) and free nitrous acid (FNA) on nitrifying bacteria activity was used to achieve nitrogen removal via nitrite pathway in the A/O. Results demonstrated that removed efficiencies of COD, total nitrogen (TN) and NH4+-N were 95.3%, 84.6 %and 99.2%, respectively. Stable nitrite pathway with above 90% nitrite accumulation was successfully achieved in the A/O reactor by synergetic inhibition of FA and FNA on the activity of nitrite oxidizing bacteria (NOB). Moreover, Fluorescence in situ hybridization (FISH) analysis showed that AOB was dominant microorganism.

Hybrid Evolutionary Optimization of Two-Stage Stochastic Integer Programming Problems: An Empirical Investigation

2009 ◽  
Vol 17 (4) ◽  
pp. 511-526 ◽  
Author(s):  
Thomas Tometzki ◽  
Sebastian Engell
Keyword(s):  
Evolutionary Algorithm ◽  
Empirical Investigation ◽  
Scale Up ◽  
Exact Algorithm ◽  
Integer Program ◽  
Mixed Integer ◽  
Two Stage ◽  
Integer Programming Problems ◽  
Problem Instances ◽  
Feasible Solutions

In this contribution, we consider decision problems on a moving horizon with significant uncertainties in parameters. The information and decision structure on moving horizons enables recourse actions which correct the here-and-now decisions whenever the horizon is moved a step forward. This situation is reflected by a mixed-integer recourse model with a finite number of uncertainty scenarios in the form of a two-stage stochastic integer program. A stage decomposition-based hybrid evolutionary algorithm for two-stage stochastic integer programs is proposed that employs an evolutionary algorithm to determine the here-and-now decisions and a standard mathematical programming method to optimize the recourse decisions. An empirical investigation of the scale-up behavior of the algorithms with respect to the number of scenarios exhibits that the new hybrid algorithm generates good feasible solutions more quickly than a state of the art exact algorithm for problem instances with a high number of scenarios.

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