scholarly journals Electrohydrodynamic, oven and natural drying of mint leaves and effects on the physiochemical indices of the leaves

2020 ◽  
Vol 66 (No. 3) ◽  
pp. 89-96
Author(s):  
Chibuzo Nwankwo ◽  
Chigozie Francis Okoyeuzu ◽  
Ikpeama Ahamefula
Keyword(s):  
Carbon Dioxide ◽  
Food Waste ◽  
High Efficiency ◽  
Biogas Production ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Liquefied Petroleum Gas ◽  
Physico Chemical ◽  
Efficiency Performance ◽  
Natural Drying

The efficiency of three modified plastic digesters (3.6 m<sup>3</sup> each) using food waste for biogas generation in cooking food was evaluated. The experiment was laid out based on a completely randomised design. A plastic tank was modified as a biodegradation system for food waste digestion to generate a biogas. The biochemical and chemical oxygen demand ranged from 44.58 to 49.62% and 130.42 to 139.20%, respectively, before digestion, but decreased significantly (P &lt; 0.05) after digestion. The pH of the fermenting slurry fluctuated (6.24–6.86) and an average biogas of 0.574 m<sup>3</sup> (505–601 L·day<sup>–1</sup>) per day was generated from the three experimental waste proportions which would be sufficient to cook three meals per day for 3 to 4 people. The methane gas significantly increased (P &lt; 0.05) while the carbon-dioxide significantly decreased (P &lt; 0.05) at the peak of the biogas production. The generated biogas significantly cooked (P &lt; 0.05) faster than kerosene, but not faster than liquefied petroleum gas. The flammable biogas generation and high significant (P &lt;0.05) percentage change in the physico-chemical properties of the wastes after digestion implied high efficiency performance of the digesters modified from the plastic tanks.

scholarly journals Natural Drying of Astringent and Non-Astringent Persimmon “Rojo Brillante”. Drying Kinetics and Physico-Chemical Properties

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 647
Author(s):  
Cristina M. González ◽  
Rebeca Gil ◽  
Gemma Moraga ◽  
Alejandra Salvador
Keyword(s):  
Chemical Properties ◽  
Drying Kinetics ◽  
Added Value ◽  
Diospyros Kaki ◽  
Drying Characteristics ◽  
Water Diffusivity ◽  
Physico Chemical ◽  
Drying Treatment ◽  
Effective Water ◽  
Natural Drying

Persimmon (Diospyros kaki L.f.) crop has markedly increased in Spain, and “Rojo Brillante” persimmon is the main cultivated variety. This astringent cultivar requires de-astringency treatment before commercialization, which may involve an extra cost. Its short commercial season implies handling large volumes of fruits with consequent postharvest losses. Therefore, the development of derived added-value products is of much interest. In this study, astringent and non-astringent “Rojo Brillante” persimmons were dehydrated by following a natural drying method used in Asia. The drying kinetics and physico-chemical properties were analyzed for 81 days. The results indicated subsequent reductions in weight, water content, and water activity throughout the drying process, and the equatorial diameter decreased. All the employed thin-layer mathematical models were suitable for representing the drying characteristics of both products with similar behavior. The effective water diffusivity values were 5.07 × 10−11 m2 s−1 and 6.07 × 10−11 m2 s−1 for astringent and non-astringent persimmon samples, respectively. The drying treatment significantly decreased the soluble tannins content, and the astringent samples obtained similar values to those obtained for the non-astringent samples in 20 days. The external and internal flesh of the astringent fruit remained orange through the drying period, while brown coloration in the non-astringent fruit was observed after 57 drying days. Therefore, prior de-astringency treatment would not be necessary.

scholarly journals Improved Food Waste Stabilization and Valorization by Anaerobic Digestion Through Supplementation of Conductive Materials and Trace Elements

2020 ◽  
Vol 12 (12) ◽  
pp. 5222 ◽  
Author(s):  
A. Sinan Akturk ◽  
Goksel N. Demirer
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Value Added ◽  
Electron Transfer Mechanism ◽  
Conductive Material ◽  
Positive Effects ◽  
Waste Stabilization ◽  
Environmentally Safe

The positive effects of conductive material supplementation on anaerobic digestion have been mainly investigated for single synthetic substrates, while its significance for real and complex organic wastes such as food waste has not been sufficiently investigated. This study investigated the effect of conductive material (biochar and magnetite) and trace metal supplementation on the anaerobic digestion of food waste by means of biochemical methane potential assays. The results indicated that the supplementation of biochar and trace metals improved both total biogas production and methane yields. A biochar dose of 2.0 and 5.0 g/L resulted in 11.2 ± 6.5 and 27.3 ± 9.5% increase in biogas and 8.3 ± 6.8 and 33.2 ± 2.8% increase in methane yield, respectively. Moreover, the same reactors demonstrated high food waste stabilization performance of over 80% chemical oxygen demand removal efficiency. These results indicate that biochar supplementation leads to more enhanced anaerobic digestion operation that could be through increased surface area for microbial growth and/or direct interspecies electron transfer mechanism. In turn, food waste will not only be stabilized but also valorized by anaerobic digestion at higher efficiencies that support sustainable waste management through both environmentally safe disposal and value-added generation.

Biogas production from cheese whey wastewater: laboratory- and full-scale studies

2014 ◽  
Vol 69 (6) ◽  
pp. 1320-1325 ◽  
Author(s):  
K. Stamatelatou ◽  
N. Giantsiou ◽  
V. Diamantis ◽  
C. Alexandridis ◽  
A. Alexandridis ◽  
...  
Keyword(s):  
High Efficiency ◽  
Cheese Whey ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Full Scale ◽  
Laboratory Scale ◽  
Phase System ◽  
Two Phase ◽  
Set Up ◽  
Cheese Production

A two-phase system for biogas production from cheese whey wastewater (CWW) was designed, set up and operated at laboratory and full scale for a whole cheese production season (8–9 months). The high efficiency and stability of the laboratory-scale system was demonstrated under various organic loading rates (OLRs) reaching 13 g chemical oxygen demand (COD) L−1d−1 and producing up to 9 L L−1d−1 of biogas (approximately 55% in methane). The COD removal was above 95% and the pH was maintained above 6.3 without any chemical addition. The full-scale system was operated at lower OLRs than its normal capacity, following the good response and high stability in disturbances of the laboratory-scale unit.

scholarly journals Physico-chemical properties of water of Ramshagar dighi, the largest man made historical reservoir in northern Bangladesh

2018 ◽  
Vol 23 ◽  
pp. 29-37
Author(s):  
Ashaduzzaman ◽  
MJ Hossain ◽  
S Akther
Keyword(s):  
Carbon Dioxide ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Air Temperature ◽  
Water Depth ◽  
Chemical Properties ◽  
Current Status ◽  
Chemical Parameters ◽  
Monthly Average ◽  
Physico Chemical

Ramshagar dighi is a larger historical man made reservoir (Dighi, Bengali meaning) situated at Tajpur village in Dinajpur, Bangladesh. This study was aimed to estimate current status of physico-chemical variables of water of Ramshagar dighi at Dinajpur District, Bangladesh. Monthly average changes in physico-chemical parameters such as water temperature, total dissolved oxygen, air temperature, humidity, rainfall, water depth and pH of water were analyzed for the period of 11 months from May 2011 to March 2012. The average air temperature (°C) at the study area of Ramshagar dighi at Dinajpur District was determined as 24.97 ± 4.92. Our present study showed that physico-chemical properties of water in Ramshagar dighi were monthly average of water temperature (°C) as 24.68 ± 4.77, air temperature (°C) 24.97 ± 4.92, humidity as 82.075 ± 4.14, rainfall as 1534.5 mm, water depth as 9.10 m ± 1.286, pH as7.67± 0.48 and carbon dioxide as 0.85 ± 0.92 as well as dissolved oxygen as 4.65 ± 0.62 respectively during the period of May 2011 to March 2012. Therefore, present study was conducted to assess physico-chemical properties of water of Ramshagar dighi, Dinajpur, Bangladesh.J. bio-sci. 23: 29-37, 2015

scholarly journals Anthropogenic pollution impact on physico-chemical characteristics of Lake Kivu, Rwanda

2012 ◽  
Vol 12 (53) ◽  
pp. 6517-6536
Author(s):  
OJ Olapade ◽  
◽  
BO Omitoyin ◽  
Keyword(s):  
Dissolved Oxygen ◽  
Lake Water ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Total Dissolved Solids ◽  
Total Alkalinity ◽  
Dissolved Solids ◽  
Physico Chemical ◽  
Lake Kivu ◽  
The Mean

Anthropogenic activities such as industrial effluent, domestic and agricultural waste disposal constitute major sources of pollution in water. The effects of these pollutants on the physico- chemical properties of Lake Kivu, Rwanda were investigated at three locations (Gisenyi, Kibuye and Cyangugu) between February 2005 and December 2006. Water samples used for physico- chemical analysis were collected from 12 stratified points on the lake. Samples collected were analysed and interpreted using appropriate international procedures. The physico -chemical properties measured were temperature, conductivity, pH, transparency, salinity, total alkalinity, dissolved organic matter (DOM), total dissolved solids (TDS), dissolved oxygen (DO), biological oxygen demand (BOD), nitrate – nitrogen, phosphate – phosphorus and sulphate. Mean water temperature measured (24.7 + 0.58 o C) was highest in Kibuye and lowest (24.5 + 0.31 o C) in Cyan gugu. The lake water was moderately hard with mean total alkalinity values of 88.1 ± 1.63mgL -1 ; 79.7 ± 2.36mgL -1 and 81.0 ± 2.46mg L -1 recorded in Gisenyi, Kibuye and Cyangugu respectively; salty and alkaline with mean pH values of 8.87 ± 0.07 in Gisenyi; 8.86 ± 0.06 in Kibuye and 8.91 ± 0.06 in Cyangugu. Total dissolved solids (TDS) level in the lake was above the 500mg L -1 prescribed by WHO while the mean biochemical oxygen demand (BOD) reading was within the range for unpolluted or moderately polluted lake. Water from the lake showed mineralization with mean conductivity values ranging from 1058 - 1184μS cm -1 in Gisenyi; 1058 - 1147μS cm -1 in Kibuye and 1031 - 1116μS cm -1 in Cyangugu. The mean dissolved oxygen values were below the 5mgl -1 limit recommended by WHO for fresh water fish species. SO 4- -2 and NO 3 – N concentration in the lake water does not constitute any serious health risk to both man and the aquatic organisms it supports. However, there is the need to constantly monitor the lake water to mitigate any build up of the ions to a hazardous level.

scholarly journals Effect of Low-Temperature Conditioning of Excess Dairy Sewage Sludge with the Use of Solidified Carbon Dioxide on the Efficiency of Methane Fermentation

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 150
Author(s):  
Joanna Kazimierowicz ◽  
Izabela Bartkowska ◽  
Maria Walery
Keyword(s):  
Carbon Dioxide ◽  
Sewage Sludge ◽  
Low Temperature ◽  
Chemical Oxygen Demand ◽  
Biogas Production ◽  
Nitrogen Concentration ◽  
Oxygen Demand ◽  
Ammonia Nitrogen ◽  
Methane Fermentation ◽  
Dissolved Phase

This study aimed to determine the effect of the low-temperature conditioning of excess dairy sewage sludge using solidified carbon dioxide on the efficiency of methane fermentation. An increase in the solidified carbon dioxide to excess dairy sewage sludge volumetric ratio above 0.3 had no significant effect on chemical oxygen demand concentration in the dissolved phase. The highest chemical oxygen demand values, ranging from 490.6 ± 12.9 to 510.5 ± 28.5 mg·dm−3, were determined at solidified carbon dioxide to excess dairy sewage sludge ratio ranging from 0.3 to 0.5. The low-temperature conditioning caused ammonia nitrogen concentration to increase from 155.2 ± 10.2 to 185.9 ± 11.1 mg·dm−3 and orthophosphates concentration to increase from 198.5 ± 23.1 to 300.6 ± 35.9 mg·dm−3 in the dissolved phase. The highest unitary amount of biogas, reaching 630.2 ± 45.5 cm3·g o.d.m.−1, was produced in the variant with the solidified carbon dioxide to excess dairy sewage sludge volumetric ratio of 0.3. Methane content of the biogas produced was at 68.7 ± 1.5%. Increased solidified carbon dioxide dose did not lead to any significant changes in biogas and methane production. The efficiency of biogas production from unconditioned excess dairy sewage sludge was lower by 43.0 ± 3.2%. The analysis demonstrated that the low-temperature conditioning is an energetic viable technology aiding the methane fermentation process.

scholarly journals Impact of Industrial Effluent Discharge on the Physico-chemical Properties of Aleto Stream, Eleme, Rivers State, Nigeria

2020 ◽  
pp. 79-89
Author(s):  
S. L. Gbarakoro ◽  
T. N. Gbarakoro ◽  
W. L. Eebu
Keyword(s):  
Electrical Conductivity ◽  
Industrial Effluent ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Total Hardness ◽  
Permissible Limits ◽  
Physico Chemical ◽  
Effluent Discharge ◽  
Rivers State ◽  
The Impact

Aim: This research work aimed to determine the impact of industrial effluent discharge on the physicochemical properties of Aleto Stream, Eleme and Rivers State. Study Design: Random sampling technique was applied in this study. The study area was divided into three sites; upstream, downstream all of Aleto Stream and Agbonchia Stream which serves for the control experiment. Water samples for eleven physical and six chemical parameters were collected in a Completely Randomized Design. Place and Duration of Study: This study was carried out on Aleto and Agbonchia streams at Eleme, Rivers State, Nigeria from 2017 to 2018. Methodology: Two samples were collected; one sample at the Aleto stream where the industrial effluent is being channelled into the stream and the other sample was collected from Agbonchia stream, which was used as a control. In the Aleto Stream, sampling was made at two points; point A (upstream) point B (downstream) and each of these points had their Physico-chemical properties tested while only one sample was collected from the Agbonchia Stream. Physico-chemical properties were analyzed in the samples using pH meter for pH, Turbidity meter for turbidity, Conductivity meter for electrical conductivity, phosphate by colourimetric method, total dissolved solids (TDS) and total suspended solids (TSS) by gravimetric method, biochemical oxygen demand (BOD) and chemical oxygen demand (COD) by standard method, chloride, alkalinity, dissolved oxygen (DO), calcium hardness, total hardness by titrimetric method, colour, odour and taste by sensory method. Results: Results obtained on the Physico-chemical properties had varying concentrations of Temperature, Total hardness, Chloride, Alkalinity, DO and Phosphate that were within world health organization (24)  and Federal Ministry of Environment (1991) permissible limits on both upstream and downstream with values ranging from 29.0-23.7oC, 360-125 mg/l, 120-100 mg/l, 36-30 mg/l, 4.9-4.4 mg/l, 1.92-1.2 mg/l respectively while Electrical conductivity, Turbidity, TSS, TDS, Calcium hardness, COD, BOD, Colour, Taste and Odour were above permissible limits on both upstream and downstream with values ranging from 1660-1700 mg/l, 83-112NTU, 82-80 mg/l, 910-914 mg/l, 1590-1900 mg/l, 100-165 mg/l, 4.36-3.88 mg/l respectively. The pH values ranged from 9.0-6.3 mg/l showing a result on the upstream to be alkaline while the downstream was slightly acidic. The increase in the above parameters above their permissible limits is as a result of the impact of industrial effluent discharges drained into the stream. This indicates that the stream is unfit for both human and aquatic inmates. Conclusion: Therefore, proper management of this effluent should be ensured and an acute test with lethal concentration (LC50) as the endpoint is recommended to determine the degree of toxicity of the effluent waste.

scholarly journals Effect of vinasse (spentwash) on quality of soil and sugarcane- A review

2019 ◽  
Vol 34 (01) ◽  
Author(s):  
Vishal Goyal ◽  
M. R. Meena ◽  
Sukhdev Kumar
Keyword(s):  
Field Experiments ◽  
Chemical Properties ◽  
Oxygen Demand ◽  
Low Ph ◽  
Sugarcane Variety ◽  
Physico Chemical ◽  
Sugarcane Yield ◽  
Harvesting Method ◽  
Indian Law

Vinasse produced by fermentation of molasses has to be paid particular attention due to its potentially huge impacts. The chemical composition of vinasse differs depending upon the soil, sugarcane variety, harvesting method and industrial method of ethanol production. For obvious reasons, as per the Indian Law, there are restrictions on its disposal in water bodies. Detailed and extensive studies and field experiments on soil and crop mostly show that vinasse is excellent manure which not only positively affects the physico-chemical properties of the soil but also helps in increasing the sugarcane yield. But due to some objectionable characteristics (low pH, high biochemical oxygen demand etc.), its judicious use is essential.

Effect of Physico-Chemical Properties of Ceria-Based Supports on the Carbon Dioxide Methanation Reaction

2013 ◽  
Vol 1 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Myriam Frey ◽  
Gérard Mignani ◽  
Julien Jolly ◽  
Anne-Cécile Roger
Keyword(s):  
Carbon Dioxide ◽  
Chemical Properties ◽  
Methanation Reaction ◽  
Physico Chemical ◽  
Carbon Dioxide Methanation
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