scholarly journals Simulation of Lab-scale Leachate Treatment Bioreactor with Application of Logistic Growth Equation for Determining Design and Operational Parameters

2017 ◽  
Vol 8 (1) ◽  
pp. 1061-1070
Author(s):  
B.F.A Basnayake

A laboratory scale Leachate Treatment Bioreactor (LTB) was needed to determine the optimum design and operational parameters because of poor performance of a full scale unit. In order to increase the lifespan of LTB, coconut comb and rubber tyres were included in the partially decomposed Municipal Solid Waste (MSW) as biofilter material inside the reactor. A composite liner of clay and waste polythene was used to mineralize excess inorganic compounds. The parameter reductions were from 26,000 mg/L to 6,832 mg/L of Total Solids (TS), 6,230 mg/L to 2,930 mg/L of Total Disolved Solids (TDS), 12,000 mg/L to 1182.6 mg/L of Volatile Solids (VS), 14,000 mg/L to 4,410 mg/L of Total Fixed Solids (TFS) and 29,700 mg/L to 3,000 mg/L of Biochemical Oxygen Demand (BOD). The kinetic analysis using the logistic growth equation showed cyclic events and the application of separating the growth and decay of microbes based on the Total Fixed Solids (TFS) gave a mineralization rate of 1.83 x 102 kg /m3 of leachate/m height of LTB /day for up scaling.

2021 ◽  
Author(s):  
Sushma lavudya ◽  
maneesha vodnala ◽  
Bhagawan Dheeravath ◽  
kiran kumar Panga ◽  
Vijaya krishna saranga ◽  
...  

Abstract Landfill leachate contains organic, inorganic compounds, heavy metals, ammonia, and xenobiotic compounds which are considered unsafe for discharging into surface water which requires to be treated before its discharge into the water. In this paper, preliminary studies are reported on the application of Fenton, Struvite, and Electrooxidation processes for the removal of Chemical Oxygen Demand (COD) and ammonia from landfill leachate. Various operational parameters like pH, dosage, reaction time, and applied voltage were optimized in laboratory batch experiments and evaluated for removal of COD and ammonia. Results demonstrated that the Fenton process could effectively remove COD and ammonia by 75% and 23% respectively at 210 min for Fe+2:H2O2: 1:5 at a fixed pH 3. The Struvite process has been effective in the removal of ammonia by 74% at pH 9 with the dosage of Mg+2:PO43-:NH4+ at 1:1:1 ratio. Results from Electrooxidation for COD and ammonia were observed as 58.25% and 44% respectively at the applied voltage 8 V for a reaction time of 60 min. The efficiency of treatment processes was also evaluated in Sequential processes for COD and ammonia i.e., Sequence-I (Fenton-Electrooxidation-Struvite) and Sequence-II (Fenton-Struvite) at pre-optimized conditions. The sequential processes have been depicted, the removal efficiencies of COD and ammonia of 89% and 82% by Sequence-I; 76.77%, and 77% by Sequence-II respectively. The present study demonstrates that Fenton followed by Electrooxidation and Struvite is an effective treatment process that can enhance the treatment of landfill leachate.


2013 ◽  
Vol 3 (4) ◽  
pp. 572-581 ◽  
Author(s):  
T. Garoma ◽  
C. Williams

The potential for using an enhanced anaerobic digestion (AD) process as a sanitation and energy recovery technology for communities that lack access to basic sanitation was evaluated. For the enhanced AD system to generate a reliable supply of biogas, so that it can be adopted and self-sustained by the community, the use of algal biomass as a supplementary feedstock was evaluated. In addition, the effects of operational parameters on waste mineralization and biogas production were investigated. The results show that the system has the potential to be developed into an effective waste treatment technology, and it has produced high biogas yields and digested waste low in fecal bacteria and high in nutrients. Reductions of 42 to 51% in volatile solids and 29 to 45% in chemical oxygen demand were achieved at 35 °C. On average, total coliform and fecal coliform concentrations of 7.6 × 105 and 1.4 × 104 CFU per gram of total solids, respectively, were measured in the digested waste. The total nitrogen and phosphorus content of the residual was determined to be in the range of 9–17% as N and 3–7% as P (7–16% as P2O5). The biogas yields varied in the range of 0.47–0.57 mL per mg of volatile solids digested.


Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 648
Author(s):  
Erik Samuel Rosas-Mendoza ◽  
Andrea Alvarado-Vallejo ◽  
Norma Alejandra Vallejo-Cantú ◽  
Raúl Snell-Castro ◽  
Sergio Martínez-Hernández ◽  
...  

The aim of this paper is to describe a study of the anaerobic digestion of industrial citrus solid waste (ISCW) in both batch and semi-continuous modes for the production of bioenergy without the elimination of D-limonene. The study was conducted at the pilot plant level in an anaerobic reactor with a working volume of 220 L under mesophilic conditions of 35 ± 2 °C. Cattle manure (CM) was used as the inoculum. Three batches were studied. The first batch had a CM/ISCW ratio of 90/10, and Batches 2 and 3 had CM/ISCW ratios of 80/20 and 70/30, respectively. In the semi-continuous mode an OLR of approximately 8 g total chemical oxygen demand (COD)/Ld (4.43 gVS/Ld) was used. The results showed that 49%, 44%, and 60% of volatile solids were removed in the batch mode, and 35% was removed in the semi-continuous mode. In the batch mode, 0.322, 0.382, and 0.316 LCH4 were obtained at STP/gVSremoved. A total of 24.4 L/d (34% methane) was measured in the semi-continuous mode. Bioenergy potentials of 3.97, 5.66, and 8.79 kWh were obtained for the respective batches, and 0.09 kWh was calculated in the semi-continuous mode. The citrus industry could produce 37 GWh per season. A ton of processed oranges has a bioenergy potential of 162 kWh, which is equivalent to 49 kWh of available electricity ($3.90).


2021 ◽  
Vol 9 (3) ◽  
pp. 611
Author(s):  
Zhendong Yang ◽  
Zhenghua Liu ◽  
Aleksandra Sklodowska ◽  
Marcin Musialowski ◽  
Tomasz Bajda ◽  
...  

Management of excessive aqueous sulfide is one of the most significant challenges of treating effluent after biological sulfate reduction for metal recovery from hydrometallurgical leachate. The main objective of this study was to characterize and verify the effectiveness of a sulfide-oxidizing bacterial (SOB) consortium isolated from post-mining wastes for sulfide removal from industrial leachate through elemental sulfur production. The isolated SOB has a complete sulfur-oxidizing metabolic system encoded by sox genes and is dominated by the Arcobacter genus. XRD analysis confirmed the presence of elemental sulfur in the collected sediment during cultivation of the SOB in synthetic medium under controlled physicochemical conditions. The growth yield after three days of cultivation reached ~2.34 gprotein/molsulfid, while approximately 84% of sulfide was transformed into elemental sulfur after 5 days of incubation. Verification of isolated SOB on the industrial effluent confirmed that it can be used for effective sulfide concentration reduction (~100% reduced from the initial 75.3 mg/L), but for complete leachate treatment (acceptable for discharged limits), bioaugmentation with other bacteria is required to ensure adequate reduction of chemical oxygen demand (COD).


2017 ◽  
Vol 77 (2) ◽  
pp. 279-285 ◽  
Author(s):  
Boram Kim ◽  
Thomas Bel ◽  
Pascal Bourdoncle ◽  
Jocelyne Dimare ◽  
Stéphane Troesch ◽  
...  

Abstract Sustainable treatment and management of fecal sludge in rural areas require adapted solutions. Rustic and simple operating processes such as sludge treatment reed beds (STRB) have been increasingly considered for this purpose. The biggest full scale (2,600 m2 of STRB) septage treatment unit in France had been built in Nègrepelisse with the final objectives of reusing treated sludge and leachates for agriculture spreading and tree irrigation, respectively. The aim of this investigation was to validate the treatment chain of this installation. The obtained field data showed firstly that the overall removal efficiencies of STRB were satisfactory and stable. Removal rates higher than 98% for chemical oxygen demand and suspended solids and a 95% for Kjeldahl nitrogen represented so far a beneficial septage treatment by STRB. The highlighted necessity of a suitable complementary leachate treatment (before tree irrigation) justified the presence of the second stage of vertical flow constructed wetland. The sludge deposit drying and mineralization efficiencies were on the right track. According to hydrotextural diagram analysis, surface deposit was however found to have high deformability probably due to the youth of the installation. An in-depth understanding of STRB system needs continuous long-term studies.


2011 ◽  
Vol 27 (5) ◽  
pp. 1407-1414 ◽  
Author(s):  
Meile Liu ◽  
Claudia Udhe-Stone ◽  
Chetan T. Goudar

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Muath Awadalla ◽  
Yves Yannick Yameni Noupoue ◽  
Kinda Abu Asbeh

This article studies modeling of a population growth by logistic equation when the population carrying capacity K tends to infinity. Results are obtained using fractional calculus theories. A fractional derivative known as psi-Caputo plays a substantial role in the study. We proved existence and uniqueness of the solution to the problem using the psi-Caputo fractional derivative. The Chinese population, whose carrying capacity, K, tends to infinity, is used as evidence to prove that the proposed approach is appropriate and performs better than the usual logistic growth equation for a population with a large carrying capacity. A psi-Caputo logistic model with the kernel function x + 1 performed the best as it minimized the error rate to 3.20% with a fractional order of derivative α  = 1.6455.


Author(s):  
Siti Nor Farhana Zakaria

Landfill leachate is a hazardous pollutant generated from a landfill site. Discharge of landfill leachate has caused a major contamination to the environment and detrimental to human health. This chapter introduces an alternative method to treat recalcitrant pollutant in leachate by using ozonation with catalyst. The production of hydroxyl radical in ozonation was not enough to oxidize complex molecular structure in the leachate. Theoretically, the addition of catalyst enhances the capacity of radical and accelerates the chemical reaction. The effectiveness of ozonation with Fenton (O3/Fenton), hydrogen peroxide (O3/H2O2), and zirconium tetrachloride (O3/ZrCl4) in removing pollutant such as chemical oxygen demand (COD), color, and improvement of biodegradability by using this process were also discussed in this chapter. Comparison in term of treatment cost and benefits of the application of chemical as catalyst are briefly elaborated at the end of this chapter.


Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 231 ◽  
Author(s):  
Renata Xavier Alberico Freitas ◽  
Lara Aguiar Borges ◽  
Handray Fernandes de Souza ◽  
Fernando Colen ◽  
Alex Sander Rodrigues Cangussu ◽  
...  

The generation of large volumes of waste by industrial processes has become an object of study because of the necessity to characterize the composition of residues in order to suggest appropriate treatments and to minimize adverse environmental impacts. We performed analyses of total fixed and volatile solids, moisture, and chemical oxygen demand (COD). We found high organic matter content. We also measured physicochemical characteristics, including corrosivity, reactivity, and toxicity. Sewage sludge showed levels of chloride and sodium above the maximum allowed limits. These data suggest the potential for anaerobic digestion as a treatment option for sewage sludge and for its use as a biofertilizer.


2019 ◽  
Vol 9 (4) ◽  
pp. 385-395 ◽  
Author(s):  
Hongbin Xu ◽  
Jaap de Koning ◽  
Ying Geng

Abstract A reliability study for the reclamation of wastewater treatment plant effluent using continuous sand filtration-multimedia filtration (CSF-MMF) combined with ultrafiltration (UF) and reverse osmosis (RO) has been conducted. The objectives of the research are two-fold: (1) effluent of CSF-MMF can be used for surface water supplementation and (2) permeate of UF-RO can be applied as greenhouse irrigation water. The removal efficiencies for nutrients and electric conductivity (EC) as well as some operational parameters of the pilot plant were investigated. The concentration of T-N, chemical oxygen demand (COD) and turbidity in the filtrate of CSF-MMF with external C-course methanol dosage and FeCl3 dosage could be kept at less than 2.2 mg/L, 35 mg/L and 0.9 NTU respectively. Average EC exceeded the required surface water standard by 10% and it was difficult to meet the low surface water standard for T-P (below 0.15 mg/L). The EC of RO permeate was below 20 μS/cm, which was much lower than the standard for greenhouse irrigation. With frequent back flushes, cleaning in place (CIP) and enhanced cleaning the UF could be operated with a constant permeability of 100 L/(m2·h·bar). An appropriate CIP resulted in a recovery of 47–52% of the RO. The protective cartridge filter prior to the RO should be replaced every 2 weeks.


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