Journal of Environmental Treatment Techniques  
2020, Volume 8, Issue 2, Pages: 818-826  
J. Environ. Treat. Tech.  
ISSN: 2309-1185  
Journal weblink:  
Thermal Catalytic Treatment (Thermolysis): An  
Effective Process for the Removal of COD and  
Color from Industrial Wastewater  
Mohit Nigam , Sunil Rajoriya , Shraddha Rani Singh , Pradeep Kumar  
Raja Balwant Singh Engineering Technical Campus, Agra-283105, India  
Meerut Institute of Engineering and Technology, Meerut-250005, India  
Indian Institute of Technology (BHU), Varanasi-221005, India  
Received: 03/02/2020  
Accepted: 13/04/2020  
Published: 20/05/2020  
Nowadays, water pollution control is one of the global concern areas of scientific research. To meet stringent regulating measures  
set by various regulatory authorities for effluent discharge, it is a challenging task for various industries. Various processes such as  
adsorption, biological process, thermal catalytic, membrane technology, electrochemical etc. are reported for the treatment of industrial  
wastewater. Amongst all the above processes, thermal catalytic process has appeared as an advance process for the treatment of highly  
polluted wastewater originating from various industries. In this paper, mechanism of thermal catalytic (thermolysis) process towards the  
pollutant removal has been discussed. This paper provides information about the recent research on thermal catalytic process for the  
treatment of synthetic and real industrial wastewater. In addition to this, a case study on the treatment of tannery wastewater using  
thermolysis process has also been investigated. The obtained results showed that maximum 65.25% COD and 72.65% color were reduced  
using copper sulphate salt with catalyst mass loading of 2 kg/m at pH of 4.  
Keywords: Chemical oxygen demand, Color, Wastewater treatment, Tannery wastewater, Thermal catalytic process  
catalytic process has gained attention for the treatment of  
wastewater discharge from different industries. This novel  
process not only creates the desirable transformation but also  
decreases the total processing cost and has been found to be  
more energy efficient in comparison to many other  
conventional techniques. Thermal catalytic treatment offers  
immense potential for the removal of hardly degradable organic  
pollutant from various industrial effluents (17). Thermal  
catalytic process is an attractive destruction process for the  
treatment of wastewater in which organic and/or inorganic  
substances in aqueous/synthetic solutions gets decomposed and  
form precipitate at moderate or an elevated temperatures and  
self (autogenous) pressure in the absence of air/oxygen with or  
without metal salt catalysts like copper sulphate, copper oxide,  
magnesium oxide, ferric chloride etc. (18, 19). Due to its ease  
in operation, relatively simple equipment design, less  
maintenance and low energy consumption, thermal catalytic  
process can be applied almost all types of waste water. The  
main advantages and disadvantages of thermal catalytic process  
are given in Table 1. This process has been successfully applied  
in different type of industries such as pulp and paper mills (20),  
textile (21-22), alcohol distillery (17-18,23) waste water,  
Petrochemical wastewater (19), sugar industry waste water  
Water is one of the most precious compounds of nature for  
living life on earth. All living organism must have water in  
order to survive. There would be no life on earth without water.  
It covers more than 71% of the earth surface, whereas less than  
% of water is for drinking purpose as per international  
standards. Thus, major global challenge for the 21 century to  
have drinkable water (1, 2). Human health is affected by water  
quality typically due to the presence of contaminants in  
drinking water from highly polluted wastewater. With Strictest  
regulation standards set by different regulatory authorities and  
increasing environmental awareness industries faces  
challenges, it requires appropriate waste water treatment  
technologies (3-4). Several industries such as food processing,  
textiles, distilleries, pulp and paper industries, tanneries and  
many other industries are continuously polluting aquatic  
medium in numerous different ways, either discharge directly  
and/or from the treatment plants of wastewater that do not  
fulfill their obligation; as they contains hardly degradable  
organics substances. Traditional biological treatment methods  
are incapable to treat such larger complex compounds (5, 6). In  
the past years, several researchers have studied on the various  
treatment technologies such as electrochemical methods (7-9),  
Adsorption (10, 11), biological process (12), membrane  
processes (13), Advance oxidation process (14) and  
combination of biological and advance oxidation process (15,  
24). Further thermal catalytic treatment process may be used  
as a pre-treatment, post-treatment, or even as the main  
treatment of wastewater because of versatility of the treatment  
process (25).  
6) for the treatment of wastewater. In the recent years, thermal  
Corresponding author: (a) Sunil Rajoriya, Meerut Institute of Engineering and Technology, Meerut-250005, India. E-mail:; and (b) Pradeep Kumar, Indian Institute of Technology (BHU), Varanasi-221005, India. Email: