Fertilizer from dried human urine added to ash and lime – a potential product from eco-sanitation system

2016 ◽  
Vol 74 (6) ◽  
pp. 1436-1445 ◽  
Author(s):  
Shanta Dutta ◽  
Björn Vinnerås
Keyword(s):  
Mass Balance ◽  
Human Urine ◽  
Low Temperatures ◽  
Evaporation Rate ◽  
Nitrogen Loss ◽  
Urea Hydrolysis ◽  
Drying Process ◽  
High Ph ◽  
Feasible Option ◽  
Rate Of Evaporation

This research explored the possibility of making fertilizer at a laboratory from source separated and untreated human urine added to ash and lime by drying at low temperatures. A mixture of ash and lime (1:1) was used as drying agent and human urine was applied as undiluted and fresh. Ash and lime were chosen as drying agents for maintaining a pH > 10 during the drying process, which should inhibit urea hydrolysis in urine, and thereby urea should be retained in the drying agent. The drying technique was developed and drying capacity of the system was quantified; three specific temperatures (20 °, 35 °, 60 °C) and two airflow rates (1 L/min and 5 L/min) were used in the experiment. A mass balance for nitrogen in the system was obtained. It was evident from the experiment that urea can be retained by maintaining a high pH (>10). Urine drying at 20 °C was not a feasible option, since rate of evaporation was very low. The highest retention of inflow nitrogen at 35 °C and 60 °C were 74% and 54%, respectively, in the produced fertilizer. Reduced evaporation rate, flooding of urine over drying agent, and blockage in airflow influenced nitrogen loss and concentration of nitrogen in the final product.

scholarly journals Drying fresh human urine in magnesium-doped alkaline substrates: Capture of free ammonia, inhibition of enzymatic urea hydrolysis & minimisation of chemical urea hydrolysis

2021 ◽  
pp. 131026
Author(s):  
Anastasija Vasiljev ◽  
Prithvi Simha ◽  
Natnael Demisse ◽  
Caroline Karlsson ◽  
Dyllon G. Randall ◽  
...  
Keyword(s):  
Human Urine ◽  
Urea Hydrolysis ◽  
Free Ammonia ◽  
Ammonia Inhibition

An experimental assessment of the evaporation correlations for natural, forced and combined convection regimes

2011 ◽  
Vol 226 (1) ◽  
pp. 145-153 ◽  
Author(s):  
A Jodat ◽  
M Moghiman
Keyword(s):  
Mixed Convection ◽  
Forced Convection ◽  
Evaporation Rate ◽  
Density Variation ◽  
Convection Regime ◽  
Combined Convection ◽  
Wide Range ◽  
The Difference ◽  
Rate Of Evaporation ◽  
Evaporation Models

In the present study, the applicability of widely used evaporation models (Dalton approach-based correlations) is experimentally investigated for natural, forced, and combined convection regimes. A series of experimental measurements are carried out over a wide range of water temperatures and air velocities for 0.01 ≤ Gr/Re2 ≤ 100 in a heated rectangular pool. The investigations show that the evaporation rate strongly depends on the convection regime's Gr/ Re2 value. The results show that the evaporation rate increases with the difference in vapour pressures over both forced convection (0.01 ≤ Gr/Re2 ≤ 0.1) and turbulent mixed convection regimes (0.15 ≤ Gr/Re2 ≤ 25). However, the escalation rate of evaporation decreases with Gr/ Re2 in the forced convection regime whereas in the turbulent mixed convection it increases. In addition, over the range of the free convection regime ( Gr/Re2 ≥ 25), the evaporation rate is affected not only by the vapour pressure difference but also by the density variation. A dimensionless correlation using the experimental data of all convection regimes (0.01 ≤ Gr/Re2 ≤ 100) is proposed to cover different water surface geometries and airflow conditions.

scholarly journals Characteristics of Black Ginseng (Panax ginseng C.A. Mayer) Production Using Ginseng Stored at Low Temperature after Harvest

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 98
Author(s):  
Hyo Bin Oh ◽  
Ji Won Lee ◽  
Da Eun Lee ◽  
Soo Chang Na ◽  
Da Eun Jeong ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Panax Ginseng ◽  
Low Temperatures ◽  
Sugar Content ◽  
Base Material ◽  
Free Sugar ◽  
Drying Process ◽  
Heat Treated ◽  
Black Ginseng

Ginseng processing often involves multiple drying and heat treatments. Ginseng is typically processed within one week of harvesting or is stored at low temperatures to prevent spoilage. Black ginseng (BG) is manufactured by repeating the heat treatment and drying process of ginseng several times. We compared the suitability of low-temperature stored ginseng (SG) and harvested ginseng (HG) as the components for black ginseng production. SG and HG were processed into black ginseng and the appearance change, free sugar content, and benzo[a]pyrene (BAP) content were observed. Appearance observations showed the SG to be suitable in terms of quality when heat-treated at a temperature of 95 ℃ or higher. The BAP content of the SG increased significantly as the steaming process was repeated. A maximum BAP concentration of 5.31 ± 1.12 μg/kg was measured in SG steamed from 2 to 5 times, making it unsuitable for processing into BG. SG and HG showed similar trends in the content of sucrose, fructose, and glucose during steaming. This study aimed to facilitate the proper choice of base material to improve the safety of black ginseng by limiting BAP production during processing.

scholarly journals Evaluation of Bio-drying Process of Sewage Sludge using Mathematical Model of Heat and Mass Balance: Effects of Temperatures of Supplied Air and Exhaust Gas

2020 ◽  
Vol 42 (11) ◽  
pp. 580-591
Author(s):  
Jae-Ram Park ◽  
Dong-Hoon Lee ◽  
Kyung-Hyun Kim
Keyword(s):  
Sewage Sludge ◽  
Mass Balance ◽  
Air Temperature ◽  
Exhaust Gas ◽  
Moisture Removal ◽  
Mass Ratio ◽  
Gas Temperature ◽  
Drying Process ◽  
Exhaust Gas Temperature ◽  
Efficiency Indicators

Objectives : The effects of temperatures of supplied air and exhaust gas on moisture removal in the bio-drying process of sewage sludge were assessed by simulating the process. We also suggested performance and efficiency indicators for moisture removal in this process and identified their effectivity.Methods : The bio-drying process of sewage sludge was simulated by mathematical modeling of heat and mass balance under different combinations of supplied-air temperatures and control ranges of exhaust gas temperatures. The simulation results were analyzed by using some indicators for assessing the performance and efficiency of moisture removal.Results and Discussion : While BVS (biodegradable volatile solid) degradation was inhibited at a higher supplied-air temperature and a lower control range of exhaust gas temperature, moisture reduction was enhanced at the supplied-air temperature nearer to ambient and the controlled exhaust gas temperature for 45 to 50℃. The drying performance could be improved by the utilization of both metabolic heat and convective heat from hot supplied-air for the source of heat necessary for moisture removal. We suggested the moisture removal rate as a performance indicator, and both the moisture removing capacity of supplied-air and the mass ratio of moisture removal to BVS degradation as an efficiency indicator. We identified that this mass ratio could be an alternative for thermal efficiency of drying.Conclusions : It is effective to control the air-flow rate to keep the exhaust gas temperature within 45~50℃ during bio-drying of sewage sludge in terms of drying performance and efficiency. It is expected that a specified range or minimum required value for the performance and efficiency indicators in the bio-drying process which suggested in this study needs to be established.

KINETICS OF EVAPORATION OF A MODEL SOLUTION OF DISTILLERY DREGS CONTAINING PROTEIN, OIL AND SUGAR

2021 ◽  
Author(s):  
А.С. ДАНИЛЬЧЕНКО ◽  
Т.Г. КОРОТКОВА ◽  
С.Ю. КСАНДОПУЛО
Keyword(s):  
Evaporation Rate ◽  
Experimental Studies ◽  
Petri Dish ◽  
Model Solution ◽  
Soluble Carbohydrates ◽  
Drying Process ◽  
Sugar Water ◽  
Oil Water ◽  
Drying Model ◽  
Kinetics Of

Рассмотрена кинетика сушки послеспиртовой барды при 60°С. Объектом исследований была модельная смесь, состоящая из воды, белков, жиров и растворимых углеводов. Представлены результаты исследований кинетики испарения воды и смесей вода–масло, вода–белок, вода–сахар, вода–масло–белок–сахар, помещенных в чашку Петри. Процесс испарения в изотермических условиях протекал в сушильном шкафу Memmert. Установлено, что добавление вещества в воду снижает скорость испарения воды в периоде постоянной скорости сушки, в периоде падающей скорости сушки продолжительность испарения возрастает. По результатам кинетики сушки модельных смесей можно определять коэффициенты активности компонентов и проводить исследование процесса сушки реальных смесей при проектировании сушилок. The kinetics of drying of the distillery dregs at 60°C is considered. The model mixture containing water, proteins, oils and soluble carbohydrates was the object of research. The results of experimental studies of the kinetics of evaporation of water and mixtures of water-oil, water-protein, water-sugar, water-oil-protein-sugar, placed in a Petri dish, are presented. Evaporation under isothermal conditions was carried out in a Memmert drying cabinet. It is established that the addition of the substance into the water reduces the evaporation rate of water in the period of constant drying speed, the duration of evaporation in the period of falling drying speed increases. According to the results of the kinetics of drying model mixtures, it is possible to determine the activity coefficients of the components and conduct a study of the drying process of real mixtures in the design of dryers.

Estimation of evaporation rate of water droplet group in spray drying process

2020 ◽  
Vol 227 ◽  
pp. 115938 ◽  
Author(s):  
Sayaka Okada ◽  
Shuji Ohsaki ◽  
Hideya Nakamura ◽  
Satoru Watano
Keyword(s):  
Spray Drying ◽  
Water Droplet ◽  
Evaporation Rate ◽  
Drying Process

Stabilization of source-separated human urine by chemical oxidation

2013 ◽  
Vol 67 (9) ◽  
pp. 1901-1907 ◽  
Author(s):  
Yang Zhang ◽  
Zifu Li ◽  
Yuan Zhao ◽  
Shuangling Chen ◽  
Ibrahim Babatunde Mahmood
Keyword(s):  
Hydrogen Peroxide ◽  
Ozone Concentration ◽  
Human Urine ◽  
Heterotrophic Bacteria ◽  
Inhibitory Effect ◽  
Chemical Oxidation ◽  
Urea Hydrolysis ◽  
Urine Test ◽  
Urine Concentrations ◽  
The One

The inhibitory effect of ozone and hydrogen peroxide (HP) on urea hydrolysis in stored urine was investigated and compared. Ozone showed less effect on urea hydrolysis due to the complicated composition of urine (including a large amount of urease-producing bacteria) and bacteria regeneration. Ozone concentration and total heterotrophic bacteria analysis demonstrated that residual ozone concentration decreased by 43% within 15 hr from 13.50 to 7.72 mg/L in the one-time ozonation urine test, and finally completely decomposed within 4 days. In addition, bacteria regenerated quickly after ozone completely decomposed. However, HP showed a significant effect on inhibiting urea hydrolysis not only in stored urine but also in fecal-contaminated urine. The suitable doses of applied HP to inhibit urea hydrolysis in stored urine, concentrations of 0.5 and 1.0 g feces per liter of fecal-contaminated urine, were 0.03, 0.16 and 0.23 mol/L, respectively. The urea concentrations after 2 months stored were 7,145, 7,109 and 7,234 mg/L, respectively.

A mass balance study on nitrification and deammonification in vertical flow constructed wetlands treating landfill leachate

2007 ◽  
Vol 56 (3) ◽  
pp. 117-123 ◽  
Author(s):  
G. Sun ◽  
D. Austin
Keyword(s):  
Mass Balance ◽  
Total Nitrogen ◽  
Landfill Leachate ◽  
Nitrogen Loss ◽  
Organic Content ◽  
Vertical Flow ◽  
Ammoniacal Nitrogen ◽  
High Concentration ◽  
Balance Study ◽  
Mass Balance Study

A laboratory-scale, mass-balance study was carried out on the transformation of nitrogenous pollutants in four vertical flow wetland columns. Landfill leachate containing low organic matter, but a high concentration of ammoniacal-nitrogen, was treated under dissolved oxygen concentrations close to saturation. Influent total nitrogen (TN) comprised ammoniacal-nitrogen with less than 1% nitrate and nitrite, negligible organic nitrogen, and very low BOD. Nitrification occurred in three of the four columns. There was a substantial loss of total nitrogen (52%) in one column, whereas other columns exhibited zero to minor losses (<12%). Nitrogen loss under study conditions was unexpected. Two hypotheses are proposed to account for it: (1) either the loss of TN is attributed to nitrogen transformation into a form (provisionally termed α-nitrogen) that is undetectable by the analytical methods used; or (2) the loss is caused by microbial denitrification or deammonification. By elimination and stoichiometric mass balance calculations, completely autotrophic nitrogen-removal over nitrite (CANON) deammonification is confirmed as responsible for nitrogen loss in one column. This result reveals that CANON can be native to aerobic engineered wetland systems treating high ammonia, low organic content wastewater.

scholarly journals Influence of Fluid Motion on Evaporation in Drying Process and Estimation of the Evaporation Rate

Seikei-Kakou ◽  
2021 ◽  
Vol 33 (4) ◽  
pp. 135-141
Author(s):  
Takahiro Ono ◽  
Daisuke Suzuki ◽  
Keisuke Sato ◽  
Naoki Ono
Keyword(s):  
Evaporation Rate ◽  
Fluid Motion ◽  
Drying Process

scholarly journals Hydrochemical and Stable Isotope Analyses Show Limited Interactions Between Groundwater and Lake Water in the Lake Bosomtwi Impact Crater, Ghana.

2022 ◽  
Author(s):  
Yvonne Sena Akosua Loh ◽  
Obed Fiifi Fynn ◽  
Evans Manu ◽  
George Yamoah Afrifa ◽  
Millicent Obeng Addai ◽  
...  
Keyword(s):  
Lake Water ◽  
Evaporation Rate ◽  
Impact Crater ◽  
Spatial Relationship ◽  
Hierarchical Cluster ◽  
Water Isotopes ◽  
Stable Water Isotopes ◽  
Rate Of Evaporation ◽  
Δ18o And Δd ◽  
The Relationship

Abstract The relationship between groundwater and surface water in the Lake Bosumtwi impact crater has been assessed using hydrochemical data and stable water isotopes of δ18O and δD. This study aimed to define likely groundwater flow and recharge zones, estimate the rate of evaporation, and examine the relationship between the lake and groundwater in the study area. The results of Q-Mode hierarchical cluster analysis (HCA) clearly differentiate the lake water from the groundwater based on their spatial relationship. These preliminary results indicated that groundwater recharge occurs on the hilltops of the crater, where it is slightly acidic with low levels of dissolved minerals, characterized by short residence time and rapid unrestricted vertical infiltration and recharge. The groundwater becomes more mineralized with longer contact times and deeper circulation with the host rock, while it flows from the recharge areas towards the lake at lower elevations. Analyses of stable water isotopes of δ18O and δD showed a high evaporation rate on the lake surface, of ~90% with a relatively significant evaporative enrichment, whereas groundwater showed a relatively lower evaporation rate ranging between 54-60%. Both reservoirs do not appear to be hydraulically connected, and where such a connection exists, it is expected to favour the lake.

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