scholarly journals Combination of Dry Milling and Separation Processes with Anaerobic Digestion of Olive Mill Solid Waste: Methane Production and Energy Efficiency

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3295 ◽  
Author(s):  
Doha Elalami ◽  
Hélène Carrère ◽  
Karima Abdelouahdi ◽  
Abdallah Oukarroum ◽  
Driss Dhiba ◽  
...  
Keyword(s):  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Phase System ◽  
Electrostatic Separation ◽  
Dry Fractionation ◽  
Separation Processes ◽  
Three Phase ◽  
Olive Mill Solid Waste ◽  
Methane Potential ◽  
Soluble Chemical Oxygen Demand

This experimental work aims at investigating the effects of milling; sieving; and electrostatic separation on the biochemical methane potential of two olive pomaces from traditional olive oil extraction (M) and from a three-phase system (T). Sieving proved to be efficient for increasing the soluble chemical oxygen demand in the smallest fractions of the sieve of both M (62%) and T (78%) samples. The positive fraction following electrostatic separation also enhanced chemical oxygen demand (COD) solubilisation by 94%, in comparison to sample T milled at 4 mm. Sieve fractions with a size greater than 0.9 mm contained 33% and 47% less lipids for the M and T biomasses; respectively. Dry fractionation modified sample properties as well as lipid and fiber distribution. Concomitantly; milling increased the accessibility and facilitated the release of organic matter. The energy balance was positive after knife milling and sieving; while ball milling and ultrafine milling proved to be inefficient.

scholarly journals Improvement of Waste Dehydrated Sludge for Anaerobic Digestion through High-Temperature and High-Pressure Solubilization

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 88 ◽  
Author(s):  
Eui-Hwan Hong ◽  
Jun-Gyu Park ◽  
Beom Lee ◽  
Wei-Qi Shi ◽  
Hang-Bae Jun
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Stable Operation ◽  
Thermal Hydrolysis ◽  
Methane Generation ◽  
Methane Potential ◽  
Higher Temperature ◽  
Soluble Chemical Oxygen Demand ◽  
Pre Treatment

Biochemical methane potential tests and lab-scale continuous experiments were conducted to improve the yield and energy efficiency of anaerobic digestion through thermal hydrolysis pre-treatment. Methane generation, yield, and solubilization efficiency were evaluated through lab-scale tests. The pre-treated samples presented 50% biodegradability at 140 °C and 61.5% biodegradability at 165 °C. The increase in biodegradability was insignificant at 165 °C or higher temperature, and it was confirmed that the optimum conditions were achieved at 165 °C and 20 min of solubilization. The lab-scale continuous experiments confirmed that polymers were decomposed into low-molecular-weight compounds due to thermal hydrolysis, and pH decreased. NH4HCO3 produced by thermal hydrolysis acted as an alkali to enable a more stable operation compared to that before thermal hydrolysis. Total chemical oxygen demand as chromium (TCODCr) and soluble chemical oxygen demand as chromium (SCODCr) indicated 35.4% and 23.1% removal efficiency in terms of organic matter removal, respectively. Methane yield was approximately 0.35 kg m−3 at 2.0–4.0 kg (m3 d)−1 and 0.26 kg m−3 at 5.0 kg (m3 d)−1. The solubilization rate of 40.9% by thermal hydrolysis was confirmed through the lab-scale tests to determine its full-scale applicability.

Treatment of anaerobically digested dairy manure in a two-stage biofiltration system

2012 ◽  
Vol 65 (11) ◽  
pp. 1975-1981 ◽  
Author(s):  
Mengjing Xia ◽  
Wendong Tao ◽  
Ziyuan Wang ◽  
Yuansheng Pei
Keyword(s):  
Chemical Oxygen Demand ◽  
Nitrogen Removal ◽  
Biochemical Oxygen Demand ◽  
Oxygen Demand ◽  
Dairy Manure ◽  
Ammonium Oxidation ◽  
Two Stage ◽  
Sand Filters ◽  
Soluble Chemical Oxygen Demand ◽  
Anaerobically Digested Dairy Manure

High concentrations of ammonium and phosphate present a challenge to cost-effective treatment of anaerobically digested dairy manure. This study investigated the efficacy of a two-stage biofiltration system for passive treatment of digested dairy manure. The first stage pebble filters were batch loaded. When the slurry-like digested dairy manure was retained on pebble beds, soluble contaminants were removed before liquid infiltrated over 8–17 days. The pebble filters removed 70% of soluble chemical oxygen demand, 71% of soluble biochemical oxygen demand, 75% of ammonium, and 68% of orthophosphate. Nitrogen removal was attributed to the conventional nitrification – denitrification process and novel nitritation – anammox process. Aerobic ammonium oxidizing and anammox bacteria accounted for 25 and 23% of all bacteria, respectively, in the filtrate of the pebble filters. The longer it took for filtration, the greater the removal efficiency of soluble contaminants. The second stage sand filters had removal efficiencies of 17% for soluble chemical oxygen demand, 45% for soluble biochemical oxygen demand, 43% for ammonium, and 16% for orthophosphate during batch operations at a hydraulic retention time of 7 days. Aerobic ammonium oxidation and anammox were primarily responsible for nitrogen removal in the sand filters. Vegetation made an insignificant difference in treatment performance of the sand filters.

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.

scholarly journals PENGARUH PENAMBAHAN ZEOLIT ALAM TERMODIFIKASI SEBAGAI MEDIA IMOBILISASI BAKTERI TERHADAP DEKOMPOSISI MATERIAL ORGANIK SECARA ANAEROB

2017 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Melly Mellyanawaty ◽  
Chandra Wahyu Purnomo ◽  
Wiratni Budhijanto
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Oxygen Demand ◽  
Total Solid ◽  
Volatile Solid ◽  
Spent Wash ◽  
Distillery Spent Wash ◽  
Soluble Chemical Oxygen Demand

Penelitian ini bertujuan untuk mengetahui pengaruh penambahan zeolit alam termodifikasi sebagai media imobilisasi terhadap dekomposisi material organik pada proses anaerobic digestion. Modifikasi yang dilakukan adalah dengan cara mengimpregnasi ion besi(Fe2+)ke dalam zeolit yang telah dibentuk menjadi cincin Raschig. Impregnasi yang dilakukan adalah impregnasi basah. Dalam penelitian ini digunakan 3 variasi konsentrasi larutan Fe2+ yaitu 10 mg/L; 100 mg/L dan 2000 mg/L. Dari hasil impregnasi zeolit menggunakan ketiga konsentrasi tersebut diperoleh kadar Fe2+ yang terdeposit ke dalam zeolit berturut-turut: 0,0016 mgFe2+/gZeo; 0,0156 mgFe2+/gZeo; 0,3125 mgFe2+/gZeo dan 0 mgFe2+/gZeo digunakan sebagai kontrol. Zeolit termodifikasi Fe2+ kemudian ditambahkan ke dalam reaktor anaerobik yang dijalankan secara batch. Perbandingan volume media zeolit dan cairan adalah 1:1. Substrat yang digunakan berupa campuran limbah distillery spent wash dengan konsentrasi soluble Chemical Oxygen Demand (sCOD) 10.000 mg/L dan keluaran dari digester aktif kotoran sapi sebagai inokulum. Perbandingan volume distillery spent wash terhadap inokulum sebesar 2:1. Proses anaerobik dijalankan selama 28 hari.Jika dibandingkan dengan data Total Solid (TS) dan Volatile Solid (VS), hasil percobaan menunjukkan bahwa data analisis sCOD memberikan data yang lebih akurat dan konklusif untuk mengukur perubahan material organik dalam proses peruraian anaerobik menggunakan media imobilisasi. Dari keempat variasi kadar Fe2+ yang digunakan dalam penelitian ini, Fe2+ dengan kadar 0,0156 mgFe/gZeo memberikan efisiensi penurunan material organik (sCOD) tertinggi yaitu 66,73%. Sedangkan Fe2+ dengan kadar 0,3125 mgFe/gZeo mampu meningkatkan produksi biogas sebesar 43%. Namun secara keseluruhan proses peruraian anaerobik yang menggunakan zeolit termodifikasi Fe2+ menghasilkan biogas lebih banyak daripada kontrol (zeolit tanpa Fe2+).

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