China 
Africa 
Explore chapters and articles related to this topic
Processes for the Treatment of Industrial Wastewater
Published in Sreedevi Upadhyayula, Amita Chaudhary, Advanced Materials and Technologies for Wastewater Treatment, 2021
Nimish Shah, Ankur H. Dwivedi, Shibu G. Pillai
Electrolytic precipitation is a method using electric current for removal of dissolved metal particles. In this process electric current passed through wastewater by using electrodes. With electro-chemical reactions, the finely dispersed particles and dissolved metal ions coalesce with each other and get precipitated. Time required for this reaction is longer (Das, 2000; Process Water Treatment by Oxidative and Electrolytic Processes, n.d.; Rajasulochana & Preethy, 2016). Incineration or thermal evaporation is an eco-convivial technic. This high-energy–consuming method uses sodium persulfate as oxidizing agent and evaporate liquid. This method does not generate heavy sludge or toxic fumes. (Ananthashankar, 2013; Das, 2000; Rajasulochana & Preethy, 2016).
Remediation
Published in Daniel T. Rogers, Urban Watersheds, 2020
Chemical oxidation involves the addition of an oxidizing agent to contaminated soil that results in either the complete destruction of the contaminants or can be used as a source of oxygen to more rapidly induce bioremediation as long as the correct dosage is used. This technology can be very effective at remediating many organic compounds, including some DNAPL compounds as long as the correct dosages are applied and that the chemicals can be delivered to the location where the contaminants reside in the subsurface. Common oxidizing agents used include (USEPA 2007): OzoneHydrogen peroxideSodium percarbonateSodium permanganatePotassium permanganateSodium persulfate
Synthesis and Engineering of Polymeric Latex Particles for Hemodialysis Part I—A Review
Published in Wolfgang Sigmund, Hassan El-Shall, Dinesh O. Shah, Brij M. Moudgil, Particulate Systems in Nano- and Biotechnologies, 2008
S. Kim, H. El-Shall, R. Partch, B. Koopman
In the initiation stage, free radicals are created from an initiator by heat or an ultraviolet radiation source. The initiator with either peroxide groups (-O-O-) such as sodium persulfate, or azo groups (-N=N-) such as azobisisobutyronitrile, is commonly used for emulsion polymerization. The primary free radicals created from initiator react with the monomer for initiation of polymerization. In the propagation stage, the polymer chain grows by monomer addition to the active center, a free radical reactive site. There are two possible modes of propagation: head-to-head addition and head-to-tail addition. The head-to-tail mode is the predominant configuration of the polymer chain, a result of steric hindrance of the substituted bulky group. In the termination stage, polymer chain growth is terminated by either coupling of two growing chains forming one larger polymer molecule or by disproportionation, which involves moving a hydrogen atom from one growing chain to another, forming two polymer molecules, one having a saturated end-group and the other with an unsaturated end-group.
Highly efficient oxidative-alkaline-leaching process of vanadium-chromium reducing residue and parameters optimization by response surface methodology
Published in Environmental Technology, 2022
Hao Peng, Qian Shang, Ronghua Chen, Liuying Zhang, Ya Chen, Jing Guo
Thus, VCRR has attracted extensive research interests in recent years. Generally, there are three routes to recover vanadium from the VCRR, which are roasting-leaching, acid leaching, and alkaline leaching. The roasting-leaching route has been extensively studied [24,25]. It is like the traditional vanadium slag treatment process, using Na2CO3, Na2SO4, or NaCl as additives to convert the vanadium to water-soluble vanadate at high temperature. Unfortunately, the consumption of sodium salt of this technique is rather higher and substantial hazardous gases are emitted during the sodium roasting process, which limits the application of this technology. Acid leaching has drawn much research interest to avoid high-temperature roasting [26,27]. Sulfuric acid is used to treat the VCRR directly mostly and the nearly 90% vanadium can leach out. Acid leaching can avoid the problem of exhaust gas pollution during roasting, and is a low-cost vanadium extraction method. However, the consumption of acid is extremely high. The acid corrosion to the leaching equipment is also a major obstacle for its industrial application. The VCRR is a type of alkaline slag which contained much ammonium sulfate [20,28], so alkaline leaching can effectively avoid the leaching of most impurity elements. Meanwhile, in order to improve the leaching efficiency, some enhancing technologies are applied, like H2O2 [29,30], MnO2 [22], electric field [31,32] and so on. Sodium persulfate (Na2S2O8) has strong oxidative ability and widely used in the oxidation of the metal and solid waste [33,34]. Low valence vanadium could be oxidized to high valence by sulfate radical, which was formed by the heating of sodium persulfate [35,36]. Thus, sodium persulfate acted as the oxidant is applied to enhance the leaching process in this paper.
Modeling of NO mass transfer characteristics absorbed in sodium persulfate solution with a bubble reactor
Published in Journal of Environmental Science and Health, Part A, 2023
Jing Liu, Chang Li, Xiaoyang Zhang, Hao Zhang, Jiyun Tang, Yong Dong
In recent years, many methods with various oxidants have been shown to synchronously absorb NO in coal-fire flue gas effectively. With several advantages such as high stability, low cost, friendly environment and excellent oxidation performance, Sodium persulfate (Na2S2O8) has previously been used to remove the organic toxic gases, treat the groundwater with organic contaminants and remediate diesel-contaminated soil.[13–20] Therefore, Na2S2O8 can also be used as a candidate oxidant for removing NO in marine diesel engine emissions to satisfy the special requirements of navigation. Zhou et al.[11,21,22] performed experiments with bubble column reactor to investigate the effects of sodium persulfate concentration, temperature, initial pH value and oxidation degree of nitrogen oxides on removal efficiency of NOx and discussed the reaction mechanism of denitrification. The experimental results showed that the optimal pH range of the reaction solution is suggested between 6.5 and 8.5,[23] and the final products of the simultaneous absorption were nitrate.[24,25] In order to improve the effect on the removal of NOx, hydrogen peroxide and sodium hypochlorite are used to as the additives together with Na2S2O8 to form complex solutions.[26,27] Most of these studies have focused on the study of the laws affecting the wet denitrification and their improvement, however, they have concentrated more on the effects on the results and seldom in-depth discussions about the effects of these factors on the mass transfer process and how they affect the results.