scholarly journals Plant growth and total Nitrogen absorption rate in leachate with water hyacinth (Eichhornia crassipes)

2019 ◽  
Vol 3 (2) ◽  
pp. 117-126
Author(s):  
Dyah Wahyu Wijayanti

Phytoremediation is a simple technique of wastewater  processing by utilizing the plant activity to vanish, replace and stabilize or destroy the pollutant either organic compound or inorganic. This research utilizes Eichhornia crassipes as the biofilter in handling the leachate produced from organic waste degradation. The purposes of this research are to find out the plant growth rate and total Nitrogen (N) absorption in leachate by the Eichhornia crassipes. The experiment shows that the concentration of leachate affects the absorption rate of total N and wet weight of the plant. The model was fit to the experimental data. The metabolism reaction rate constant ( ) and absorption rate constant ( ) at leachate concentration 5%, 10%, 15%, 20%, 25% and 30% were measured. The highest reaction rate constant and absorption rate constant were  5% of leachate concentration where = 0.008042/day and = 2.30811/day, whilst at the leachate concentration of 30% reaction rate constant and absorption rate constant were the lowest where it reached = 0.00029/day and = 0.04576/day. The absorption ability of water hyacinth to absorb the N which contained in the leachate was affected by the metabolism reaction rate of nitrogen in the plant and the reaction rate of nitrogen degradation into ammonia (NH4) and nitric ion (NO3) in the plant root. The leachate concentration affected the efficiency of N absorption by the water hyacinth. The efficiency of N absorption at leachate concentration of 5; 10; 15; 20; 25 and 30 were 89.81%, 68.99%, 49.51%, 36.32%, 30.28% and 21.64% respectively. Overall, this technique presents a simple technique approach and the utilization of elements contained in the leachate as the nutrition for plant.

2013 ◽  
Vol 864-867 ◽  
pp. 194-200
Author(s):  
Juan Wen ◽  
Chun Xiu Huo ◽  
Bin Zhang

The kinetics of CO2absorption in unloaded aqueous MEA, MDEA, DETA single amine solutions and MEA+DETA blende amine solutions was studied with the amine concentrations of 3.0 kmol/m3and at temperatures ranging between 298K and 338K. A dynamic model of CO2absorption rate on the basis of the static absorption experimental results was established. The reaction rate constant of CO2absorption in blended amine solutions MEA+DETA is , and its activation energy is 32.89KJ/mol.


2019 ◽  
Vol 292 ◽  
pp. 01063
Author(s):  
Lubomír Macků

An alternative method of determining exothermic reactor model parameters which include first order reaction rate constant is described in this paper. The method is based on known in reactor temperature development and is suitable for processes with changing quality of input substances. This method allows us to evaluate the reaction substances composition change and is also capable of the reaction rate constant (parameters of the Arrhenius equation) determination. Method can be used in exothermic batch or semi- batch reactors running processes based on the first order reaction. An example of such process is given here and the problem is shown on its mathematical model with the help of simulations.


2007 ◽  
Vol 544-545 ◽  
pp. 95-98 ◽  
Author(s):  
Jong Tae Jung ◽  
Jong Oh Kim ◽  
Won Youl Choi

The purpose of this study is to investigate the effect of the operational parameters of the UV intensity and TiO2 dosage for the removal of humic acid and heavy metals. It also evaluated the applicability of hollow fiber microfiltration for the separation of TiO2 particles in photocatalytic microfiltration systems. TiO2 powder P-25 Degussa and hollow fiber microfiltration with a 0.4 μm nominal pore size were used for experiments. Under the conditions of pH 7 and a TiO2 dosage 0.3 g/L, the reaction rate constant (k) for humic acid and heavy metals increased with an increase of the UV intensity in each process. For the UV/TiO2/MF process, the reaction rate constant (k) for humic acid and Cu, with the exception of Cr in a low range of UV intensity, was higher compared to that of UV/TiO2 due to the adsorption of the membrane surface. The reaction rate constant (k) increased as the TiO2 dosage increased in the range of 0.1~0.3 g/L. However it decreased for a concentration over 0.3 g/L of TiO2. For the UV/TiO2/MF process, TiO2 particles could be effectively separated from treated water via membrane rejection. The average removal efficiency for humic acid and heavy metals during the operational time was over 90 %. Therefore, photocatalysis with a membrane is believed to be a viable process for humic acid and heavy metals removal.


2013 ◽  
Vol 544 ◽  
pp. 426-430
Author(s):  
Dong Dong Jing ◽  
Yu Liu ◽  
Ruo Yu Liu ◽  
Hua Fan ◽  
Guo Feng Li ◽  
...  

The aim of this study was to observe the absorption enhancing effect of sodium dodecyl sulfate on metformin hydrochloride in colon of rat. Using in vivo intestinal loop model in rat while the ileum was took as blank group and colon as the experiment groups with different concentration of sodium dodecyl sulfate (1%, 2%, 4%). The colon/ileum ratio of the absorption rate constant of metformin hydrochloride was evaluated through calculating the residual dose of circulating solution in presupposition time points. Intergroup absorption rate constant and the rising percent of the absorption rate constant were different significantly (P<0.05). The absorption rate constant of colon were -0.22±0.03, -0.37±0.06, -0.89±0.09, -0.86±0.05μg•h-1•cm-1 (n=6) and the rising percent of the constant absorption value were 68.66 ± 8.28%, 304.88 ± 28.76%, 293.75 ± 33.19% (n=6), respectively. The result showed that the absorption of metformin hydrochloride was increased with the concentration of sodium dodecyl sulfate. However, the absorption rate constant reached maxium when the concentration of sodium dodecyl sulfate was 2%, this may be because the circulating metformin hydrochloride solution could be more viscous which affect the absorption of metformin hydrochloride when sodium dodecyl sulfate was raised. In conclusion, the absorption of metformin hydrochloride can be promoted by sodium dodecyl sulfate in the colon of rat and this can provide biophamaceutics data for novel pharmaceutical preparation.


1990 ◽  
Vol 95 (D9) ◽  
pp. 13981 ◽  
Author(s):  
Gaunlin Shen ◽  
Masako Suto ◽  
L. C. Lee

Author(s):  
Shigenori Togashi ◽  
Yukako Asano ◽  
Yoshishige Endo

The chemical reaction yield was predicted by using Monte Carlo simulation. The targeted chemical reaction of a performance evaluation using the microreactor is the consecutive reaction. The main product P1 is formed in the first stage with the reaction rate constant k1. Moreover, the byproduct P2 is formed in the second stage with the reaction rate constant k2. It was found that the yield of main product P1 was improved by using a microreactor when the ratio of the reaction rate constants became k1/k2 >1. To evaluate the Monte Carlo simulation result, the yields of the main products obtained in three consecutive reactions. It was found that the yield of the main product in cased of k1/k2 >1 increased when the microreactor was uesd. Next, a pilot plant involving the numbering-up of 20 microreactors was developed. The 20 microreactor units were stacked in four sets, each containing five microreactor units arranged. The maximum flow rate when 20 microreactors were used was 1 × 104 mm3/s, which corresponds to 72 t/year. Evaluation of the chemical performance of the pilot plant was conducted using a nitration reaction. The pilot plant was found to capable of increasing the production scale without decreasing the yield of the products.


2020 ◽  
Vol 15 (1) ◽  
pp. 280-289
Author(s):  
Ratnawati Ratnawati ◽  
Nita Indriyani

K-carrageenan is a natural polymer with high molecular weight ranging from 100 to 1000 kDa. The oligocarrageenan with low molecular weight is widely used in biomedical application. The aim of this work was to depolymerize k-carrageenan in an acidic solution with the assistance of ultrasound irradiation. The ultrasonication was conducted at various pH (3 and 6), temperatures (30-60 °C), and depolymerization time (0-24 minutes). The results show that the depolymerization reaction follows pseudo-first-order kinetic model with reaction rate constant of 1.856×10-7 to 2.138×10-6 s-1. The reaction rate constant increases at higher temperature and lower pH. The Q10-temperature coefficients of the depolymerization are 1.25 and 1.51 for pH 6 and 3, respectively. The enthalpy of activation (ΔH‡) and the Gibbs energy of activation (ΔG‡) are positive, while the entropy of activation (ΔS‡) is negative, indicating that the activation step of the ultrasound-assisted depolymerization of k-carrageenan is endothermic, non-spontaneous, and the molecules at the transition state is more ordered than at the ground state. The ΔH‡ and the ΔS‡ are not affected by temperature, while the ΔG‡ is a weak function of temperature. The ΔH‡ and ΔS‡ become smaller at higher pH, while the ΔG‡ increases with the increase of pH. The kinetics and thermodynamics analysis show that the ultrasound-assisted depolymerization of k-carrageenan in acidic solution is possibly through three mechanisms, i.e. bond cleavage due to cavitational effect of microbubbles, hydroxyl radical and hydrogen peroxide, as well as proton. Copyright © 2020 BCREC Group. All rights reserved 


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