Characterization of Dioctyl terephthalate biodegradation by food waste composting

2019 ◽  
Vol 33 (14n15) ◽  
pp. 1940048 ◽  
Author(s):  
Sung Tse Lee ◽  
Huu Tuan Tran ◽  
Chitsan Lin ◽  
Hong Giang Hoang ◽  
Thi Dieu Hien Vo ◽  
...  

Dioctyl terephthalate (DOTP), a plasticizer is used as an additive in many plastic products. Disposal of DOTP into environment has been of concern because it is hardly biodegradable in nature. Therefore, the aim of this study is to investigate the biodegradation of DOTP by aerobic composting processes without bioaugmentation. The initial DOTP concentration in the compost mixture was 11,882 mg/kg, after 35-day incubation, the removal efficiency of the compost reactor was 98%. The degradation was found to follow the first-order kinetic with the half-life of 5.2 days. Food waste composting was demonstrated as a technically robust and economically competitive process for the degradation of DOTP, and that of other similar plasticizers are expected.

2020 ◽  
Vol 58 (3A) ◽  
pp. 1
Author(s):  
Hu Tap Van

Catalytic ozonation is one of the promising treatment methods for removal of persistent organic compounds from water and wastewater. In this study, some metal slags such as: iron slag, lead slag, zinc slag, cadmium slag and copper slag originated from solid waste of Thai Nguyen Non-ferrous Metals Limited Company, Vietnam were used as heterogeneous catalysts for ozonation process to remove organic compounds from pulp wastewater. The effects of the initial pH (pHi) of pulp wastewater and the metal slag dosage on efficiency of decolorization and mineralization of pulp wastewater, in term of COD were investigated. The results indicated that iron slag was the most suitable catalyst for treatment of pulp wastewater by ozonation process with the highest removal efficiency of COD, namely, after 120 min of ozonation (with flowrate of O3 of 3.038 g/h) of the pulp wastewater (initial COD 1809 mg/L), COD removal efficiency, respectively, reached 91,16%; 84%; 83,83 %; 83,91%; 83,41% and 83,14% in the presence of iron, copper, zinc, lead, cadmium slag and ozone alone. Simultaneously, the color was almost completely removed (95.55 – 98.79%) by ozonation processes with using all before-mentioned metal slags as heterogeneous catalysts and ozone alone. Maximum COD and color removal efficiency obtained at pH 7 for ozonation alone and its combinations with iron slag. Moreover, an increase in the iron slag dosage from 0.125 g/L to 2.0 g/L for O3/iron slag could enhance COD and color removal of pulp wastewater. The K values (apparent first-order rate constant values) showed that the COD removal rate followed the pseudo-first-order kinetic model. This study also indicated that the main constituent FeO presence in iron slag reaction with O3 in heterogeneous catalytic ozonation system enhances removal efficiency of color and COD of pulp wastewater.


2011 ◽  
Vol 183-185 ◽  
pp. 401-405 ◽  
Author(s):  
Hua Nan Guan ◽  
De Fu Chi ◽  
Jia Yu

The ultraviolet protectant (UV protectant) properties of different natural and synthetic compounds were investigated for a biopesticide based on ecdysone. This study examined the photostabilization of ecdysone when exposed to ultraviolet light in the presence of some ultraviolet protectants. Ecdysone solutions with and without UV protectants in methanol were applied onto the surface of glass slides. At particular intervals, the remaining concentration of ecdysone was analyzed by HPLC. Using first-order kinetic equation, the dissipation half-life values (DT50) for the degradation of ecdysone under ultraviolet radiation were obtained. The larvicidal activity was evaluated against the larvae of Martianus dermestoides Chevrolat. It indicated that the addition of congo red, yeast, starch and arabia gum provided moderate degree of photostabilization of ecdysone and that addition of lignin provided the best photostabilization of ecdysone, among these UV protectants studied. Toxicity of the ecdysone with UV protectants was higher to the larvae of M. dermestoides Chevrolat compared to the ecdysone alone as indicated by the lower EC50 value. The dissipation half-life values of ecdysone after irradiation under ultraviolet light and the larvicidal activity suggested that the addition of lignin (in 1:l mol ratio) can provide better photostabilization of ecdysone molecule.


2015 ◽  
Vol 13 (3) ◽  
pp. 437-445 ◽  
Author(s):  
Shweta Garg ◽  
Vimal Chandra Srivastava ◽  
Seema Singh ◽  
Tapas Kumar Mandal

Abstract Present study reports parametric and kinetic study for catalytic per oxidation (CPO) of pyrrole by Cu/SBA-15 catalyst using H2O2 as an oxidant. Brunauer-Emmett-Teller surface area, Fourier transform infra-red spectroscopy and thermo gravimetric-differential thermal analyses were used for the characterization of catalyst. Effects of various operating variables such as initial concentration of pyrrole (Co): 48.3–386.8 mg/L, catalytic dose (Cw): 0.5–2 g/L, stoichiometric ratio of hydrogen peroxide/pyrrole: 1–4, and reaction temperature (T): 50–60°C were studied. More than 85% pyrrole mineralization was observed at the optimum conditions of Cw = 1.5 g/L, stoichiometric ratio of hydrogen peroxide/pyrrole = 3, T = 55°C at pH = 6.1. A two-step pseudo-first-order kinetic model well-described the pyrrole mineralization by the CPO process.


2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Samira Norzaee ◽  
Edris Bazrafshan ◽  
Babak Djahed ◽  
Ferdos Kord Mostafapour ◽  
Razieh Khaksefidi

Penicillin G (PG) is one of the most widely consumed antibiotics around the world. Release of PG in environment may lead to contamination of water resources. The aim of the present work is to assess feasibility of applying UV-activated persulfate process in removal of PG from aquatic environments. The study examined the effect of pH (3–11), persulfate initial concentration (0.5–3 mM), reaction time (15–90 minutes), and initial concentration of PG (0.02–0.14 mM) on PG decomposition. Also, the pseudo-first-order kinetic model was used for kinetic analysis of PG removal. The results indicated that UV-activated persulfate process can effectively eliminate PG from water. The highest PG removal efficiency was obtained as 94.28% at pH 5, and the decomposition percentage was raised by increasing persulfate dose from 0.5 to 3 mM and the reaction time from 15 to 90 minutes. Besides, the removal efficiency decreased through increasing the initial concentration of PG. UV-activated persulfate process effectively decomposes PG and eliminates it from water.


2020 ◽  
Vol 31 (2) ◽  
pp. 171-179
Author(s):  
Umi Laila ◽  
◽  
Rochmadi Rochmadi ◽  
Sri Pudjiraharti ◽  
Rifa Nurhayati ◽  
...  

Previous study successfully conducted encapsulation of the purple-fleshed sweet potato’s anthocyanin but the study has yet to reveal the stability of encapsulated anthocyanin. Therefore, this research aims to observe the stability of encapsulated anthocyanin regarding the characteristic of low anthocyanin stability, which depends on environmental factors, such as temperature, pH, humidity, and water activity. The kinetic parameters of stability, including kinetic constant (k), reaction order, and half-life (t1/2), were also studied. Stability testing was conducted in high water activity of 0.75 and various in-cubation temperatures at 16, 25, 35, and 45°C. Un-encapsulated anthocyanin extract was also tested for its stability in the same condition in order to be compared with encapsulated anthocyanin. This study re-vealed that the encapsulated anthocyanin had lower stability than un-encapsulated anthocyanin extract. It was proven by higher kinetic constant and lower half-life of encapsulated anthocyanin for every incubation temperature which was induced by higher pH of encapsulated anthocyanin compared with anthocyanin extract. Besides, high water activity reduced glass transition temperature (Tg), in which encapsulated anthocyanin was in rubbery state. Both encapsulated anthocyanin and anthocyanin extract were degraded following the first order kinetic. Using the Arrhenius equation, it was obtained that the degradation kinetic constant of encapsulated anthocyanin was stated as k= 420.44 exp (-23.33/RT). Meanwhile, k= 1.12x106 exp (-46.70/RT) described degradation of kinetic constant of anthocyanin extract. The stability test re-vealed that the application of encapsulated anthocyanin was not suitable for wet-type food product.


2020 ◽  
Vol 10 (2) ◽  
pp. 35-40
Author(s):  
Marjana Simonič ◽  
Mirjana Čurlin ◽  
Lidija Fras Zemljič

Large quantities of leachate are generated from the water release during the decomposition of the biodegradable waste. The composition of compost leachate is very complex and its treatment is necessary before releasing into the environment. The possibilities of treating compost leachate by electrocoagulation have been extensively studied. The scope of this work was to investigate applicability of the first order kinetic model for degradation of metal and organic compounds from compost leachate by electrocoagulation process. Experimental results showed 75 % removal efficiency of Cu2+ and 65 % of Zn2+, while chemical oxygen demand was reduced by 36 %. According to obtained kinetic parameters, simulation of metal removal efficiency was performed in batch reactor. This way optimal electrocoagulation time which is needed for 95 % efficiency of metal removal was determined at 120th min for Zn2+ and 102nd min for Cu2+.


2020 ◽  
Author(s):  
Jien Ye ◽  
Yi Wang ◽  
Qiao Xu ◽  
Hanxin Wu ◽  
Jianhao Tong ◽  
...  

Abstract BackgroundNanoscale zerovalent iron (nZVI) is a promising material for removing heavy metals from wastewater. However, passivation of nZVI hinders its efficiency in water treatment. Loading another catalytic metal has been found to improve the efficiency significantly. In this study, Cu/Fe bimetallic nanoparticles were prepared by liquid-phase chemical reduction for removal of hexavalent chromium (Cr(VI)) from wastewater. Purpose of this study was to clarify the effects and mechanisms of Cu loading on the removal efficiency of Cr(VI).ResultsThe results showed that Cu loading can significantly enhance the removal efficiency of Cr(VI) by 29.3% to 84.0%, and the optimal Cu loading rate was 3% (wt%). The removal efficiency decreased with increasing initial pH and Cr(VI) concentration. It was found that Cr(VI) removal followed a pseudo-first-order kinetic model. When the Cu loading rate was 3%, the initial concentration of Cr(VI) was 100 mg/L, the observed first-order rate coefficient (kobs) was 0.016 min-1 for Cu/Fe bimetallic nanoparticles at pH of 3.5, which was twice than that of nZVI (0.008 min-1). X-ray photoelectron spectroscopy (XPS) analysis indicated that Cr(VI) was completely reduced to Cr(Ⅲ) and precipitated on the particle surface as hydroxylated Cr(OH)3 and CrxFe1-x(OH)3 coprecipitation.ConclusionsIn this study, it was found that the loading of Cu can significantly increase the specific surface area and the Cr(VI) remove efficiency of nZVI, and the removal efficiency decreases with increasing pH and Cr(VI) initial concentration. Therefore, Cu loading can alleviate the passivation of nZVI effectively and can be beneficial for the application of iron-based nanomaterials in remediation of wastewater.


2021 ◽  
Author(s):  
André Eckhardt ◽  
Martin-Louis Riu ◽  
Peter Müller ◽  
Christopher Cummins

Phosphoryl nitride (NPO) is a highly reactive intermediate, and its chemistry has only been explored under matrix isolation conditions so far. Here we report the synthesis of an anthracene (A) and phosphoryl azide-based molecule (N3P(O)A) that acts as a molecular synthon of NPO. Experimentally, N3P(O)A dissociates thermally with a first order kinetic half-life that is associated with an activation enthalpy of ΔH⧧ = 27.5 ± 0.3 kcal mol–1 and an activation entropy of ΔS⧧ = 10.6 ± 0.3 cal mol–1 K–1 that are in good agreement with calculated DLPNO-CCSD(T)/cc-pVTZ//PBE0-D3(BJ)/cc-pVTZ energies. In solution N3P(O)A undergoes Staudinger reactivity with tricyclohexylphosphine (PCy3) and subsequent complexation with tris(pentafluorophenyl)borane (B(C6F5)3, BCF) to form Cy3P-NP(A)O-B(C6F5)3. Anthracene is cleaved off photochemically to form the frustrated Lewis pair (FLP) stabilized NPO complex Cy3P⊕-N=P-O-B⊖(C6F5)3. Intrinsic Bond Orbital (IBO) analysis suggests that the adduct is zwitterionic, with a positive and negative charge localized on the complexing Cy3P and BCF, respectively.


2010 ◽  
Vol 7 (1) ◽  
pp. 65-72 ◽  
Author(s):  
Reza Shokoohi ◽  
Vahid Vatanpoor ◽  
Mansuor Zarrabi ◽  
Akram Vatani

Adsorption process by activated carbon is widely used for removal of dyes. Because of economical limits, activated carbon derived from low cost materials seem to be economical. The aim of this work is preparation of activated carbon from poplar wood and investigation of its ability to removal of (AR18) dye. In this work, we prepared the activated carbon by chemical activation method in electric furnace. In addition we have investigated effect of various parameters such as pH, contact time, dye concentration and adsorbent dosage on dye removal. Langmuir and Freundlich isotherm models have been investigated. Pseudo-first order, pseudo-second order and modified pseudo-first order kinetic models have been used for experimental data. The results showed that removal efficiency was increased with increasing of adsorbent dosage, contact time and decreasing of pH, but with increasing of dye concentration, the removal efficiency was decreased. Adsorption isotherm models showed that Langmuir isotherm model was best fitted onto collected data (r2>0.978). In addition, kinetic models showed that sorption of AR18 onto activated carbon prepared from poplar wood follows the pseudo-first order model (r2>0.9758).


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