scholarly journals Application of the Initial Rate Method in Anaerobic Digestion of Kitchen Waste

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Lei Feng ◽  
Yuan Gao ◽  
Wei Kou ◽  
Xianming Lang ◽  
Yiwei Liu ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Initial Rate ◽  
Anaerobic Fermentation ◽  
Gas Production ◽  
Kitchen Waste ◽  
First Order ◽  
Hydrolysis Constants ◽  
Reaction Orders ◽  
Rate Method ◽  
Kinetics Of

This article proposes a methane production approach through sequenced anaerobic digestion of kitchen waste, determines the hydrolysis constants and reaction orders at both low total solid (TS) concentrations and high TS concentrations using the initial rate method, and examines the population growth model and first-order hydrolysis model. The findings indicate that the first-order hydrolysis model better reflects the kinetic process of gas production. During the experiment, all the influential factors of anaerobic fermentation retained their optimal values. The hydrolysis constants and reaction orders at low TS concentrations are then employed to demonstrate that the first-order gas production model can describe the kinetics of the gas production process. At low TS concentrations, the hydrolysis constants and reaction orders demonstrated opposite trends, with both stabilizing after 24 days at 0.99 and 1.1252, respectively. At high TS concentrations, the hydrolysis constants and the reaction orders stabilized at 0.98 (after 18 days) and 0.3507 (after 14 days), respectively. Given sufficient reaction time, the hydrolysis involved in anaerobic fermentation of kitchen waste can be regarded as a first-order reaction in terms of reaction kinetics. This study serves as a good reference for future studies regarding the kinetics of anaerobic digestion of kitchen waste.

The mechanism of the oxidation of thiocyanate ion by peroxomonosulphate in aqueous solution. II. Kinetics of the reaction

1966 ◽  
Vol 19 (8) ◽  
pp. 1365 ◽  
Author(s):  
RH Smith ◽  
IR Wilson
Keyword(s):  
Aqueous Solution ◽  
Initial Rate ◽  
Stopped Flow ◽  
Thiocyanate Ion ◽  
First Order ◽  
Conductance Method ◽  
Rate Of Reaction ◽  
Kinetics Of

Initial rates of reaction for the above oxidation have been measured by a stopped-flow conductance method. Between pH 2 and 3.6, the initial rate of reaction, R, is given by the expression R{[HSO5-]+[SCN-]} = {kb+kc[H+]}[HSO5-]0[SCN-]20+ka[H+]-1[HSO5]20[SCN-]0 As pH increases, there is a transition to a pH-independent rate, first order in each thiocyanate and peroxomonosulphate concentrations.

Kinetics of NO2 air space absorption in isolated rat lungs

1992 ◽  
Vol 73 (5) ◽  
pp. 1939-1945 ◽  
Author(s):  
E. M. Postlethwait ◽  
S. D. Langford ◽  
A. Bidani
Keyword(s):  
Steady State ◽  
Tidal Volume ◽  
Gas Phase ◽  
Initial Rate ◽  
Quasi Steady State ◽  
Closed Chamber ◽  
First Order ◽  
First Order Kinetics ◽  
Rat Lungs ◽  
Kinetics Of

We previously showed, during quasi-steady-state exposures, that the rate of inhaled NO2 uptake displays reaction-mediated characteristics (J. Appl. Physiol. 68: 594–603, 1990). In vitro kinetic studies of pulmonary epithelial lining fluid (ELF) demonstrated that NO2 interfacial transfer into ELF exhibits first-order kinetics with respect to NO2, attains [NO2]-dependent rate saturation, and is aqueous substrate dependent (J. Appl. Physiol. 71: 1502–1510, 1991). We have extended these observations by evaluating the kinetics of NO2 gas phase disappearance in isolated ventilating rat lungs. Transient exposures (2–3/lung at 25 degrees C) employed rebreathing (NO2-air) from a non-compliant continuously stirred closed chamber. We observed that 1) NO2 uptake rate is independent of exposure period, 2) NO2 gas phase disappearance exhibited first-order kinetics [initial rate (r*) saturation occurred when [NO2] > 11 ppm], 3) the mean effective rate constant (k*) for NO2 gas phase disappearance ([NO2] < or = 11 ppm, tidal volume = 2.3 ml, functional residual capacity = 4 ml, ventilation frequency = 50/min) was 83 +/- 5 ml/min, 4) with [NO2] < or = 11 ppm, k* and r* were proportional to tidal volume, and 5) NO2 fractional uptakes were constant across [NO2] (< or = 11 ppm) and tidal volumes but exceeded quasi-steady-state observations. Preliminary data indicate that this divergence may be related to the inspired PCO2. These results suggest that NO2 reactive uptake within rebreathing isolated lungs follows first-order kinetics and displays initial rate saturation, similar to isolated ELF.(ABSTRACT TRUNCATED AT 250 WORDS)

KINETIC STUDIES OF METHYL-BIS-β-CHLOROETHYLAMINE: III. THE KINETICS OF THE DIMERIZATION IN METHANOL

1948 ◽  
Vol 26b (2) ◽  
pp. 175-180 ◽  
Author(s):  
C. A. Winkler ◽  
A. W. Hay ◽  
A. L. Thompson
Keyword(s):  
Rate Constants ◽  
Initial Rate ◽  
Kinetic Studies ◽  
First Order ◽  
Rate Expression ◽  
Principal Reaction ◽  
Kinetics Of ◽  
Rate Controlling Step

The principal reaction of methyl-bis-β-chloroethylamine in methanol is dimerization, which results in one chlorine from each molecule becoming ionic, but this is accompanied by slight alcoholysis. The rate-controlling step is believed to be the first order formation of an ethylenimonium ion which reacts rapidly with one of its kind to form dimer. The rate expression as calculated from initial rate constants is k (initial) = 4.0 × 1013e−19600/RThr.−1.

Study of Methane Production by High Temperature Anaerobic Fermentation of Chicken Manure and Stalks

2020 ◽  
Vol 14 (4) ◽  
pp. 551-557
Author(s):  
Yongku Li ◽  
Xiaomin Hu ◽  
Lei Feng
Keyword(s):  
High Temperature ◽  
Anaerobic Digestion ◽  
Production Rate ◽  
Methane Production ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Gas Production ◽  
Chicken Manure ◽  
Biogas Slurry ◽  
Production Rates

The changing parameters, as the biogas production rate, the methane production rate, the cumulative biogas amount, the cumulative methane amount, the biogas composition, pH etc. in high temperature anaerobic fermentation of chicken manure and stalks were analyzed by experiments with different mass ratios of chicken manure or livestock manure and stalks with a high C/N ratio. The methane production mechanism of high temperature anaerobic digestion of chicken manure and stalks was discussed in detail. It showed that not only the biogas production rates but also the methane production rates of R1–R7 demonstrated the trend of initial increase and then decrease after 50 d of high temperature anaerobic digestion. Besides, the gas production of R1 with pure chicken manure stopped on the 30th d of the reaction. The gas production of other groups R2–R7 also stopped on the corresponding 34th, 36th, 36th, 37th, 37th, and 37th day, respectively. At the end of the reaction, the cumulative biogas amounts and the cumulative methane amounts of R1–R7 were 411.58 and 269.54, 459.91 and 314.41, 425.32 and 294.11, 401.85 and 272.54, 382.63 and 257.07, 363.04 and 218.16, and 257.15 and 160.10 N ml/(g VS). The biogas slurry pH of R1–R7 all demonstrated a trend of initial decrease and then increase, e. g., pH of R2 reached the minimum of 5.94 on the 5th day. pH values of other groups were between 6.01 and 6.39. After the addition of 4 g of sodium bicarbonate on the 7th day, biogas slurry pH of R1–R7 all increased. pH was maintained between 7.16 and 7.44 until the end of the reaction.

scholarly journals Kinetics of aflatoxin B1 and G2 adsorption on Ca-clinoptilolite

2000 ◽  
Vol 65 (10) ◽  
pp. 715-723 ◽  
Author(s):  
Aleksandra Dakovic ◽  
Magdalena Tomasevic-Canovic ◽  
Vera Dondur ◽  
Aleksandra Vujakovic ◽  
Predrag Radosevic
Keyword(s):  
Adsorption Process ◽  
Order Reaction ◽  
Active Centers ◽  
Fast Reaction ◽  
First Order ◽  
Ph Values ◽  
Zero Order Reaction ◽  
Rate Method ◽  
Adsorption Rates ◽  
Kinetics Of

The kinetics of aflatoxins B1 and G2 adsorption on Ca-clinoptilolite at pH2 and 7, in aqueous electrolyte at 37?C were studied. For both aflatoxins, the adsorption process begins with a fast reaction whereby most of the toxin is adsorbed in the first few minutes. This fast process is followed by the significantly slower process of aflatoxin bonding at active centers of mineral adsorbent. The initial rate method showed that the fast adsorption process of aflatoxin ?1 and G2, at both pH values is a first order reaction, while the slow adsorption process of these aflatoxins is a zero order reaction. The adsorption indexes and adsorption rates for both examined toxins were pH dependent. In the investigated initial toxins concentration ranges (500-3000 ?g/dm3), high adsorption indexes were achieved (> 80 %).

Effect of micro-oxygen pretreatment on gas production characteristics of anaerobic digestion of kitchen waste

2020 ◽  
Vol 22 (6) ◽  
pp. 1852-1858 ◽  
Author(s):  
Xiaofei Zhen ◽  
Xiaoyan Zhang ◽  
Shuaibing Li ◽  
Mingche Li ◽  
Jian Kang
Keyword(s):  
Anaerobic Digestion ◽  
Gas Production ◽  
Kitchen Waste ◽  
Production Characteristics

Redox reaction between an oxo-bridged diiron complex and hydrazine: A kinetic study

2020 ◽  
Vol 10 ◽  
Author(s):  
Sarvjeet Kumar Chandrabanshi ◽  
Ritam Mukherjee
Keyword(s):  
Initial Rate ◽  
Deprotonated Form ◽  
First Order ◽  
Rate Versus ◽  
Mechanistic Investigation ◽  
Profile Changes ◽  
Rate Method ◽  
Ph Range ◽  
Method Show ◽  
Reaction Profile

Objective: Mechanistic investigation of the reaction between the complex ion [FeIII2(μ-O)(phen)4(H2O)2] 4+ (1) (phen = 1,10-phenanthroline) and its hydrolytic derivatives [FeIII2(μ-O)(phen)4(H2O)(OH)]3+ (1a) and [FeIII2(μO)(phen)4(OH)2] 2+ (1b) which coexist in rapid equilibria in the range pH = 3.00 to pH = 5.00 (pKa1 = 3.71 ± 0.03, pKa2 = 5.28 ± 0.07) with N2H5 + ion to produce [Fe(phen)3] 2+ has been covered in this study. Methods: Rise in absorbance of the product with time was measured and rates have been determined using initial rate methods. Dependence of rate on pH and concentration of N2H5 + are studied in detail. Results: In presence of excess phenanthroline, the reaction follows simple first-order exponential profile. Interestingly, in absence of any added phenanthroline, the reaction becomes faster and the reaction profile changes to nearly linear with curvature near the end of the reaction. Slight autocatalytic nature has been observed only for the slower reactions. The observed rate constants obtained using initial rate method show first-order dependence on the concentration of N2H5 + . Increase in rate with increasing pH has been noticed. The plot of rate versus 1/[H+ ] shows saturation beginning near pH 4.6, suggesting that the mono-deprotonated form of the complex (i.e. 1a) is the active oxidant in this pH range. Conclusion: Presumably the reaction becomes faster in absence of added phenanthroline because ligand dissociation from the parent complex becomes facilitated when there is no external phenanthroline ligand present. This produces a coordinatively unsaturated Fe(III) species which is a faster oxidant.

KINETICS OF CATALYTIC REACTIONS ON A UNIFORM SURFACE AND SINGLE SITES: SIMILARITY AND DIFFERENCE

2009 ◽  
Vol 16 (05) ◽  
pp. 757-760 ◽  
Author(s):  
VLADIMIR P. ZHDANOV
Keyword(s):  
Reaction Scheme ◽  
Catalytic Reactions ◽  
First Order ◽  
Metal Atoms ◽  
Catalytic Sites ◽  
Reaction Orders ◽  
Similarities And Differences ◽  
Similarity And Difference ◽  
Kinetics Of ◽  
Kinetics Of Catalytic Reactions

To illustrate typical similarities and differences in the reaction kinetics occurring on a uniform surface and single sites (e.g. on single metal atoms incorporated into the inner walls of zeolite), we analyze a generic reaction scheme of N2O decomposition running in the presence of oxygen. In both cases, there are three reaction regimes, (i) controlled exclusively by the N2O -decomposition step, (ii) partly inhibited by oxygen, or (iii) limited by oxygen desorption. Regime (i) is kinetically similar (first order in N2O ) in the two cases. The states of the catalytic sites are however different. Regime (ii) exhibits different reaction orders in oxygen (-0.5 for the surface and -1 for single sites). Regime (iii) is fully identical in both the cases.

scholarly journals Prototype of a Biogas Anaerobic Digester from the Hostel Mess Kitchen Wastes

2019 ◽  
Vol 5 (2) ◽  
pp. 35-39
Author(s):  
Shivam Modi ◽  
Pooja Mahajan
Keyword(s):  
Solid Waste ◽  
Food Waste ◽  
Organic Waste ◽  
New Technologies ◽  
Anaerobic Fermentation ◽  
Energy Content ◽  
Research Work ◽  
Gas Production ◽  
Kitchen Waste ◽  
Biodegradable Waste

Biogas is a non-exhaustible of energy which can be formed from anaerobic fermentation of different types of biodegradable waste such as food waste, plant waste, animal waste sewage and other organic waste. The typical composition of Biogas includes CH4 (50–70%) which is responsible for maximum energy content along with CO2 (25–50%) that can be collected, stored and supplied. Biogas acts as a multipurpose and an eco- friendly sustainable resource of energy which can be utilized for cooking, electricity generation, lightning, heating etc. Biodegradable waste specifically produced in large amounts as a kitchen waste. In modern society, the solid waste per capita has been consistently increasing as of increase in population and change in socio-economic-cultural habits. The biogas production through the kitchen waste thereof provides a solution of disposal of solid waste. The bio gas production through anaerobic degradation pathways can be controlled and enhanced with the help of certain microorganisms and advancements of new technologies. In this research work, an attempt is being made to produce the biogas from kitchen and food waste collected from hostel mess of Chitkara University, Punjab and a novel method of production of microorganism has been also proposed for fast degradation of waste. Under this project, a survey for the estimation of daily production of organic waste from hostel mess has also been done for fifteen day. 

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