On the other hand it can accelerate the electrode reaction with stirring and shaking which decreased concentration polarization. Other than that the electrode performance of the cathode can be improved by adding a catalyst to promote the electrochemical activity of the electrode reaction. 3.6 Iron activation time The surface of iron should be activated before using it because there is a passivation layer of oxide film on the surface of iron. Studies have shown that K vaule has the stability of the reaction with activating by diluted hydrochloric acid after 20min. Therefore, the appropriate activation time may be 20min.
Many chemical compounds are sensitive to ozonation process. So this process can have a large impact in decrease the concentration of AOX in pulp wastewater and other colored/colorless chemical compounds. Biological Treatment Performance Works Cited Treatment of pulp and paper mill wastewater—a review
The chloroform extract was highly effective as free radical scavengers, electron-donating agents and reducing molybdate ions except for reducing lipid peroxidation. The highest total phenol content was also exhibited by chloroform and benzene extracts. Antioxidant potential expressed by C. caesia in the sequential extracts could be effectively utilized for identification of the bioactive compounds for future phytopharmacological applications. Key words: Curcuma caesia, antioxidants, reactive oxygen species, total phenols Free radicals, which are molecules with unpaired electrons, play a key role in the development of various degenerative diseases, including aging, cancer, inflammation, diabetes, Alzheimer’s disease and other neurodegenerative disorders[1,2]. They are formed as intermediates of various biochemical reactions, but when generated in excess can result in oxidative damage to DNA, proteins and lipids.
In technology, some important advantages of H2 are (i) its high specific enthalpy or reaction with O2 per gram (Eq. 1.) (ii) that the reaction H2 with O2 is ignited simply by a spark and produces only water. 2H2(g) + ... ... middle of paper ... ...face modification of standard Pt catalysts with oxophilic elements such as Ru, Os, Sn, Sb, Pb, Mo, and W helps improve the CO tolerance of low-temperature fuel cell systems which process CO contaminated H2 feed gases at anode. For ORR (oxygen reduction reaction) Se-modified Ru-C catalysts have recently been applied by Lopnov et al.
Natural zeolites have shown good ion-exchange capacities for cations, such as ammonium and heavy metal ions. In order to have high adsorption capacity for organic matter and anions, modification of natural zeolites can be performed by several methods, such as acid treatment, ion exchange, and surfactant functionalization. Besides the removal of heavy metals, natural zeolites are used to to remove ammonia and humic acid from the suface waters. The removal of the contaminants depends on pH value, initial concentration of humic acid and ammonia, temperature and contact time. Zeolite shows best performance of ammonia and humic acid removal at the pH close to natural water.
However, for some application acetic acid is more preferable compared to sulphuric acid or hydrochloric acid due to it non-toxic and biodegradable characteristics. Besides, alkaline waste can also be neutralised through bubbling of carbon dioxide gases to form carbonic acid. One of the advantages of carbon dioxide gas is that it is readily available in the exhaust gas at any combustion process. On the top of that, chemical precipitation is also one of the techniques that can be applied to liquid waste stream that contained hazardous compounds. It is very effectively in removing or eliminating the heavy metals that dissolved in the waste stream.
These sensors are inexpensive and are based on the principle of conductance change which arises due to the chemical adsorption of molecules of the ammonia gas on a sensing layer. Selectivity and sensitivity of these sensors towards the ammonia gas can be enhanced by using additives which will drive the adsorption of the gas molecules. Using additives like Au and MoO3 ammonia sensors can achieve the detection limit of 1 ppm. Metal oxides sensors have a detection limit in the range of 1 to 1000 ppm and operates at above 400 0C. In applications like environmental monitoring and detection of combustion gases these sensors are quite helpful.
Sol-gel process is convenient synthetic approach for preparation to metal oxide applied in a wide variety of fields including structural ceramics [1, 2], electronics [10, 11], sensors [3–5], optics [8, 9], and catalysts [6, 7] due to their hardness, high melting point, non-volatility, chemical inertness, and resistance to oxidation and corrosion [1-4]. The sol-gel method is based on phase transformation of a sol obtained from metallic alkoxides or molecular modified alkoxide. The suspended particles in the sol are polymerized at low temperature to form a wet gel [16-19]. Metal alkoxide, being the good precursors in sol-gel process, is purified by vacuum distillation or crystallization and addition pure water yields the metal oxide with high purity and the volatile by-product. A great advantage of this method of oxide preparation is in its absence of ionic impurities .
Chlorine dioxide (ClO2) additionally has oxidative capabilities for color elimination. Further, UV in aggregate with ClO2 is a likely treatment for the reduction of colored effluent from textile dyeing facilities. Ozone is one of the most powerful oxidizers commercially to be had and famous for huge complex organic molecules of dyes, detergents, phenols etc. it may be broken the compounds into easier one. It can also oxidize organics and inorganics compounds, hence the disposal of color and odors.
The most recent catalyst used in the modern petroleum refinery is zeolites which is a complex compound of aluminosilicates with large lattices of aluminium, oxygen atoms and silicon which carrying negative charge. It is desired for FCC catalyst because it has good stability to high temperature, high activity, low coke production... ... middle of paper ... ...tion and also hydrogenation process. It is an active carrier to do the complementary reaction. High-purity alumina as a carrier with acid functionality can be moderate by controlling amount of chloride added to the support. By combining acid with metal components, it form a dual-function catalytic system that potentially convert low-octane naphtha and paraffins into high-octane gasoline.