scholarly journals The effect of ensiling and alkaline pretreatment on anaerobic acidification of Napier grass in the leached bed process

2019 ◽  
Vol 25 (5) ◽  
pp. 668-676
Author(s):  
Pratin Kullavanijaya ◽  
Orathai Chavalpalit
Keyword(s):  
Chemical Properties ◽  
Oxygen Demand ◽  
Thermal Conditions ◽  
Solid Content ◽  
Alkaline Pretreatment ◽  
Napier Grass ◽  
Soaking Time ◽  
Treatment Conditions ◽  
Anaerobic Acidification ◽  
Soluble Chemical Oxygen Demand

The characteristics of feedstock are important to the biocatalyst-based processes. Herein the effect of ensiling and alkaline pretreatment on acidification of Napier grass in anaerobic leached bed reactors was investigated. The results depicted clearly that grass preparation affected its chemical properties and leaching ability differently. After pretreatment in 3.0% of NaOH, lignin was reduced significantly by 50.1% to 68.0%, while less deterioration was found for ensiling. About 18.9% to 54.1% of the produced soluble chemical oxygen demand (SCOD) of these biomasses was increased subsequently compared to 0.102 kg SCOD or 0.56 kg SCOD/kg VS<sub>added</sub> of raw grass digestion. However, about 3.3% of SCOD was reduced after the ensiling. An extension of biomass soaking time and heat supplementation under alkali-thermal conditions of raw grass promoted more production of SCOD for 18.9% to 29.9% and 54.1%, respectively. While about 45.5% to 54.4% of SCOD was increased for alkali-thermal pretreated residue. The solid content and lignocelluloses were changed differently and accordingly with treatment conditions. Similar profiles of leachates contained mainly acetic acid were obtained. These results confirm the beneficial application of alkaline soaking and ensiling as a pretreatment method to enhance the solubilization of grass biomass under the leached bed acidification process.

Effect of ultrasonic and alkaline pretreatment on sludge degradation and electricity generation by microbial fuel cell

2010 ◽  
Vol 61 (11) ◽  
pp. 2915-2921 ◽  
Author(s):  
J. Q. Jiang ◽  
Q. L. Zhao ◽  
K. Wang ◽  
L. L. Wei ◽  
G. D. Zhang ◽  
...  
Keyword(s):  
Fuel Cell ◽  
Chemical Oxygen Demand ◽  
Microbial Fuel Cell ◽  
Power Output ◽  
Electricity Generation ◽  
Oxygen Demand ◽  
Alkaline Pretreatment ◽  
Ultrasonic Pretreatment ◽  
Volatile Solids ◽  
Soluble Chemical Oxygen Demand

Both ultrasonic and alkaline pretreatment of excess sewage sludge were investigated to enhance organic degradation and electricity generation from sludge by the subsequent microbial fuel cell (MFC). The ultrasonic pretreatment showed that the degree of sludge disintegration was directly related to the energy input, ultrasonic density and duration. Alkaline pretreatment demonstrated that more soluble organic matters were released from the sludge with more NaOH dose and longer reaction time, and the degree of sludge disintegration within 30 min accounted for 45–76% of that for 24 h. When ultrasonic and alkaline pretreatment were combined, the released chemical oxygen demand (COD) was higher than those with ultrasonic or alkaline pretreatment alone. Ultrasonic and alkaline (pH=11) pretreatment could enhance electricity generation from sludge by the subsequent MFC, resulting in more degradation of total COD (TCOD) and volatile solids (VS). Slight change in power output from the MFC was observed due to the higher soluble chemical oxygen demand (SCOD) in the pretreated sludge. By using the combined ultrasonic and alkaline pretreatment of sludge, the removal efficiencies of TCOD and VS were increased from 27.1% to 61.0% and 35.2% to 62.9% in comparison with raw sludge, respectively, and the power output in MFC was slightly increased from 10.3 W/m3 to 12.5 W/m3.

APLIKASI PROSES DIGESTASI ANAEROBIK LUMPUR BIOLOGI INSTALASI PENGOLAHAN AIR LIMBAH INDUSTRI KERTAS

2014 ◽  
Vol 4 (02) ◽  
Author(s):  
Rina S. Soetopo ◽  
Sri Purwati ◽  
Henggar Hardiani ◽  
Mukharomah Nur Aini ◽  
Krisna Adhitya Wardhana
Keyword(s):  
Oxygen Demand ◽  
Total Solid ◽  
Pilot Scale ◽  
Organic Content ◽  
Solid Content ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Total Solid Content ◽  
Average Value

A continuous pilot scale study has been conducted to investigate the effectiveness of anaerobic digestion of biological sludge. The sludge has a total solid content of 0.53% - 1.1%, pH of 7.20 to 7.32. Its organic content is about 97 %, The research were conducted in two stages, which are acidification (performed in 3 m3 the Continously Stirred Tank Reactor/CSTR at pH of 5.5 to 6.0) and methanation (performed in 5 m3 the Up Flow Anaerobic Sludge Blanket/UASB reactor at pH 6.5 to 7.0). The retention time (RT) was gradually shortened from 6 days to 1 day for acidification and from 8 days to 2 days for methanation. The results showed that operating the CSTR at the RT of 1 day and the organic loading of 8.23 g Volatile Solid (VS)/m3.day could produce Volatile Fatty Acid (VFA) at an average value of 17.3 g/kg VS.day. Operating the UASB reactor at the RT of 2 days and the organic loading (Chemical Oxygen Demand/COD) of 2.4 kg COD/m3.day could produce biogas at an average value of 66.3 L/day, with an average methane content of 69.9%, methane rate of 0.17 L CH4/g COD reduction or 19.06 L CH4/kg VS. Furthermore, methanation could reduce COD at an average value of 51.2 %, resulting in the effluent average value of COD filtrate and COD total of 210.1 mg/L and 375.2 mg /L, respectively.Keywords: acidification, methanation, CSTR, UASB, biogas ABSTRAKPercobaan digestasi anaerobik lumpur IPAL biologi industri kertas secara kontinyu skala pilot telah dilakukan di industri kertas dengan tujuan mengkaji efektivitas proses digestasi anaerobik dalam mengolah lumpur tersebut. Lumpur yang digunakan memiliki total solids sekitar 0,53% – 1,1%, pH netral (7,20 – 7,32) dengan komponen utama senyawa organik sekitar 97%. Percobaan dilakukan dalam dua tahap yaitu asidifikasi dalam reaktor CSTR berkapasitas 3 m3 pada pH 5,5 – 6,0 dan metanasi dalam reaktor UASB berkapasitas 5 m3 pada pH 6,5 – 7,0. Percobaan dilakukan dengan waktu retensi yang dipersingkat secara bertahap dari 6 hari ke 1 hari untuk proses asidifikasi dan dari 8 hari ke 2 hari untuk proses metanasi. Hasil percobaan menunjukkan bahwa pengoperasian reaktor CSTR dengan waktu retensi 1 hari dan beban organik 8,3 g VS/m3.hari dapat menghasilkan VFA rata-rata 17,3 g/kg VS.hari dengan kisaran 8,36 – 30,59 g/kg VS.hari, sedangkan pengoperasian reaktor UASB pada waktu retensi 2 hari dan beban organik 2,4 kg COD/m3.hari dapat menghasilkan biogas rata-rata 66,3 L/hari dengan kadar metana rata-rata 69,9% atau 0,17 L CH4/g COD reduksi atau 19,06 L CH4/kg VS. Selain itu proses metanasi dapat menurunkan COD terlarut rata-rata 51,2%, dengan konsentrasi efluen COD terlarut  rata-rata 210,1 mg/L dan COD total rata-rata 375,2 mg/L.Kata kunci: asidifikasi, metanasi, CSTR, UASB, biogas

Impact of Ogun River pollution on antioxidants and proximate composition of African catfish (Clarias gariepinus)

2019 ◽  
Vol 46 (3) ◽  
pp. 163-184
Author(s):  
B. O. Onunkwor ◽  
T. O. Akinpelu ◽  
O. J. Oladipupo ◽  
R. N. Ugbaja ◽  
O. J. Olaoye ◽  
...  
Keyword(s):  
Proximate Composition ◽  
Clarias Gariepinus ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Control Fish ◽  
Average Weight ◽  
African Catfish ◽  
Fish Samples ◽  
The Impact ◽  
Ogun River

Most rivers in Nigeria are polluted without conscious efforts to abate ensuant consequences. Thus, Clarias gariepinus, an aquatic commercial food from Ogun River, Nigeria, was studied to investigate the impact of pollution on antioxidants and proximate composition. During the rainy season, 50 C. gariepinus (average weight 426.53 ± 24.40g and length 37.73 ± 0.95cm) were site sampled, 10 from each of Ago-Odo, Ago-Ika, Oke-Sokori, and Quarry along Ogun River course. Ajegunle-Adao cultured pond, served as control. The parameters assayed for included: some heavy metals and physico-chemical properties of sampled water, antioxidants and proximate composition of the fish samples. Physicochemical parameters of river studied showed that temperature of all sites ranged from 26 to 29°C, pH: 6.9 to 7.8, dissolved oxygen: 9.5 to 21.6, biochemical oxygen demand: 3.60 to 14.10, and chemical oxygen demand: 60 to 650. Lead (Pb) concentration ranged from 4.0 to 17.0 μg/L and cadmium (Cd): 0.0 to 6.0 μg/L. Blood Pb, Cd, activities of: superoxide dismutase, catalase, glutathione-S-transferase, plasma xanthine oxidase, and lipid peroxidation level of fish samples from Ago-Ika were most significantly (p < 0.05) high, with significant (p < 0.05) lowest reduced glutathione concentration amongst the samples from polluted sites when compared to control fish. Proximate analysis showed that the fish samples from Ogun River had significantly (p < 0.05) lower protein, fat contents, and higher nitrogen-free extract while Ago-Ika, Oke-Sokori and Quarry sites had significantly (p < 0.05) lower moisture, ash and fibre contents when compared with control. It can be concluded that the impact of pollution induced oxidative stress and significantly diminished the nutritional value of C. gariepinus from Ogun River.

Anaerobic co-digestion of winery waste and waste activated sludge: assessment of process feasibility

2013 ◽  
Vol 69 (2) ◽  
pp. 269-277 ◽  
Author(s):  
C. Da Ros ◽  
C. Cavinato ◽  
F. Cecchi ◽  
D. Bolzonella
Keyword(s):  
Activated Sludge ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Waste Activated Sludge ◽  
Organic Loading ◽  
Operational Conditions ◽  
Loading Rates ◽  
Thermophilic Conditions ◽  
Soluble Chemical Oxygen Demand

In this study the anaerobic co-digestion of wine lees together with waste activated sludge in mesophilic and thermophilic conditions was tested at pilot scale. Three organic loading rates (OLRs 2.8, 3.3 and 4.5 kgCOD/m3d) and hydraulic retention times (HRTs 21, 19 and 16 days) were applied to the reactors, in order to evaluate the best operational conditions for the maximization of the biogas yields. The addition of lee to sludge determined a higher biogas production: the best yield obtained was 0.40 Nm3biogas/kgCODfed. Because of the high presence of soluble chemical oxygen demand (COD) and polyphenols in wine lees, the best results in terms of yields and process stability were obtained when applying the lowest of the three organic loading rates tested together with mesophilic conditions.

Two-stage entrapped mixed microbial cell process for simultaneous removal of organics and nitrogen for rural domestic sewage application

2004 ◽  
Vol 49 (5-6) ◽  
pp. 281-288 ◽  
Author(s):  
S.J. Kim ◽  
P.Y. Yang
Keyword(s):  
Removal Efficiency ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Domestic Wastewater ◽  
Microbial Cell ◽  
Two Stage ◽  
Rate Limiting Step ◽  
Soluble Chemical Oxygen Demand ◽  
Removal Efficiencies ◽  
Entrapped Mixed Microbial Cell

A two-stage entrapped mixed microbial cell (2SEMMC) process which separates nitrification and denitrification phases by the installation of the anoxic and oxic EMMC reactors packed with EMMC carriers was operated with 6, 4, 3, and 2 hours of hydraulic retention time (HRT) using simulated domestic wastewater. The activated sludge was immobilized using cellulose acetate for the EMMC carriers. Similar soluble chemical oxygen demand (SCOD) removal efficiencies of 90-97% were observed for all HRTs (SCOD loading rate of 0.84-2.30 g/L/d) applied. In order to achieve more than 80 % of TN removal efficiency, the HRT should be maintained higher than 4 hours (less than 0.24 g/L/d of TN loading rate). Denitrification was a rate-limiting step which controlled overall TN removal efficiency at TN loading rate of 0.15-0.31 g/L/d although nitrification efficiencies achieved 97-99 %. The effluent TSS of less than 25 mg/L in the 2SEMMC process was maintained at the SCOD loading rate of less than 1.23 g/L/d with back-washing intervals of 5 and 10 days in the anoxic and oxic EMMC reactors, respectively. The minimum HRT of 4 hours is required for high removal efficiencies of organics (average 95.6 %) and nitrogen (average 80.5 %) in the 2SEMMC process with 3 times of recirculation ratio.

Treatment of dairy wastewaters by electrocoagulation using iron electrodesTraitement des eaux résiduaires d'une laiterie par électrocoagulation avec des électrodes de fer

2014 ◽  
Vol 50 (2) ◽  
pp. 198-209 ◽  
Author(s):  
Malika Aoudjehane ◽  
Mohamed Elghazali Benatallah
Keyword(s):  
Electrical Conductivity ◽  
Removal Efficiency ◽  
Current Density ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Electrolysis Time ◽  
Electrode Consumption ◽  
Treatment Conditions ◽  
Consumption Energy ◽  
Optimal Efficiency

A procedure of electrocoagulation (EC) using iron electrodes has been used for the treatment of the wastewaters produced by the Beni-Tamou dairy in Algeria. The effect of the operating conditions, such as the current intensity, the electrolysis time, the pH of the solution and the electrical conductivity, on the removal efficiency of chemical oxygen demand (COD) and the total suspended solids (TSS) has been studied. An inter-electrode distance of 1 cm has been maintained constant during the tests. It has been found that an increase in electrolysis time and current density improved the treatment significantly, albeit with a greater consumption of energy as well as an increased electrode consumption. The results of the electrocoagulation treatment under various operating conditions show that the optimal efficiency has been obtained under the following conditions: 60 minutes of electrolysis, a current density of 200 A/m2, a pH 8, an electrical conductivity of 4.72 mS/cm and a consumption energy of 13.57 kWh/m3. Under these conditions, the removal efficiency for the COD and TSS parameters is 93.26 and 99.3%, respectively. The optimal treatment conditions of dairy wastewaters have resulted in final COD and TSS concentrations of 41.5 and 27 mg/L, respectively, values that are conform to industrial liquid effluents discharge norms.

scholarly journals Biodegradation of main carbon sources in vinasse stillage by a mixed culture of bacteria: influence of temperature and pH of the medium

2018 ◽  
Vol 78 (4) ◽  
pp. 764-775 ◽  
Author(s):  
Agnieszka Ryznar-Luty ◽  
Edmund Cibis ◽  
Krzysztof Lutosławski
Keyword(s):  
Mixed Culture ◽  
Organic Pollutants ◽  
Carbon Sources ◽  
Oxygen Demand ◽  
Aerobic Biodegradation ◽  
Medium Ph ◽  
Initial Ph ◽  
Fourth Series ◽  
Soluble Chemical Oxygen Demand ◽  
Available Carbon

Abstract The aim of the study was to examine how temperature and the pH influence the progress and efficiency of an aerobic biodegradation process, where major organic pollutants are removed from beet molasses vinasse by a mixed culture of Bacillus bacteria. It was conducted in an aerated bioreactor with a stirring system in four experimental series, each composed of five processes run at temperatures of 27, 36, 45, 54 and 63 °C. In the first and second series, medium pH was not controlled, the initial pH amounted to 6.5 and 8.0, respectively. In the third and fourth series, medium pH was controlled at 6.5 and 8.0, respectively. Under optimal conditions, the pollution load of the vinasse stillage expressed as soluble chemical oxygen demand was removed with an 88.73% efficiency. The bacterial culture assimilated all organic pollutants simultaneously, but the rate of assimilation was different. An exception was the process of betaine assimilation, which intensified only when readily available carbon sources were depleted in the medium. Synthesis and assimilation of organic acids were observed in all experiments. Advantages of the proposed method include: possibility of its use at high temperatures, and no necessity for medium pH adjustment during the process.

scholarly journals Physico-chemical properties and heavy metal contents of a tropical estuarine ecosystem, Nigeria

2018 ◽  
Vol 5 (11) ◽  
pp. 781-797
Author(s):  
Paul Chinedu Echi ◽  
Daberechi Ndudim Okpechi ◽  
Janet Azu Urum ◽  
Izuchukwu Samson Arukwe
Keyword(s):  
Heavy Metal ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
International Standards ◽  
Anthropogenic Pressure ◽  
Estuarine Ecosystem ◽  
Metal Concentrations ◽  
Metal Contents ◽  
Zinc Cadmium ◽  
Lead Zinc

Ibaka Estuarine in Mbo, Nigeria, has little or no information on its basic properties, therefore its water samples were studied from March to June 2018 in three different stations and compared with International Standards to evaluate its physic-chemical properties as well as heavy metal contents. The physic-chemical properties studied include pH, salinity (g/L), EC (μs/cm), turbidity (NTU), total suspended solids (mg/L), total dissolved solids (mg/L), dissolved oxygen (mg/L), BOD5 (mg/L), and chemical oxygen demand (mg/L). In addition, some metal concentrations of manganese, iron, copper, lead, zinc, cadmium, chloride and magnesium were determined by atomic absorption spectroscopy (AAS). The range of metal concentrations manganese (0.08-0.12 mg/L), copper (0.05-0.09 mg/L), lead (0.01-0.03 mg/L), iron (1.86-4.66 mg/L), zinc (0.68-1.16 mg/L), cadmium (0.04-0.08 mg/L), chloride (675.0-791.25 mg/L), magnesium (10.66-14.30 mg/L). The study infers that anthropogenic pressure plays damaging role to its properties in addition to general health implication of high values for Fe, Zn, Cd, Cl and Mg which exceeded international standard.

scholarly journals Effect of Slice Weight and Soaking Time on the Physico-Chemical Properties of Cassava Flour (Manihotesculentus) used for Bakery Products

2021 ◽  
pp. 10-24
Author(s):  
C. R. Abah ◽  
C. N. Ishiwu ◽  
J. E. Obiegbuna ◽  
E. F. Okpalanma ◽  
C. S. Anarado
Keyword(s):  
Chemical Properties ◽  
Process Variables ◽  
Soaking Time ◽  
Cassava Flour ◽  
Baked Goods ◽  
Cassava Root ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
And Chemical Properties

Quality cassava(Manihotesculentus, Crantz) flour is often influenced by process variables such as slice weight and soaking time which may affect its nutritional quality. In this study, the effect of process variables (slice weight and soaking time) on quality of cassava flour was carried out. Cassava root was peeled, washed and cut into varied sizes (25.86 - 54.14 g) and soaked at varied time (7.03 - 40.97 h). The proximate composition, physical and chemical properties of the flour were carried out using standard methods. The result in our findings showed that slice weight and soaking time had significant increase (p<0.05) on the proximate and physico-chemical properties of the flour.The amylose and amylopectin content of the flour increased with increasing soaking time while the hydrogen cyanide content decreased with increase in soaking time. Overall, the quality cassava flour displayed desirable properties for its incorporation into baked goods.

scholarly journals Rumen Inoculum Enhances Cathode Performance in Single-Chamber Air-Cathode Microbial Fuel Cells

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 379
Author(s):  
Ignacio T. Vargas ◽  
Natalia Tapia ◽  
John M. Regan
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Rumen Fluid ◽  
Oxygen Demand ◽  
Air Cathode ◽  
Single Chamber ◽  
Higher Power ◽  
Mixed Microbial Community ◽  
Current Production ◽  
Soluble Chemical Oxygen Demand

During the last decade, bioprospecting for electrochemically active bacteria has included the search for new sources of inoculum for microbial fuel cells (MFCs). However, concerning power and current production, a Geobacter-dominated mixed microbial community derived from a wastewater inoculum remains the standard. On the other hand, cathode performance is still one of the main limitations for MFCs, and the enrichment of a beneficial cathodic biofilm emerges as an alternative to increase its performance. Glucose-fed air-cathode reactors inoculated with a rumen-fluid enrichment and wastewater showed higher power densities and soluble chemical oxygen demand (sCOD) removal (Pmax = 824.5 mWm−2; ΔsCOD = 96.1%) than reactors inoculated only with wastewater (Pmax = 634.1 mWm−2; ΔsCOD = 91.7%). Identical anode but different cathode potentials suggest that differences in performance were due to the cathode. Pyrosequencing analysis showed no significant differences between the anodic community structures derived from both inocula but increased relative abundances of Azoarcus and Victivallis species in the cathodic rumen enrichment. Results suggest that this rarely used inoculum for single-chamber MFCs contributed to cathodic biofilm improvements with no anodic biofilm effects.

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