Decreasing concentration of textile dye congo red using Fenton reagent/TiO2/UV

Industrial growth in Indonesia is increasing along with the development of science and technology, for example is the textile industry. Generally the wasted produced by the textile industry is in the form of colored liquid waste which contains various textile coloring agents. One of the substances that lead to pollution in wastewater is the congo red content in it. A method that can be used to treat textile wastewater is AOPS (Advanced Oxidation Processes) using Fenton reagent which are a mixture of hydrogen peroxide and ferro ions based on the formation of hydroxyl radicals (•OH). The hydroxyl radical can be maximized by adding UV light to the H2O2/Fe2+ system and adding TiO2 photocatalysts. The results showed that TiO2 in the Fenton/UV system could increase the decrease in concentration of congo red. The decrease in concentration of congo red with the fenton/TiO2 system was 97,32% with the contribution of 100 ppm H2O2, FeSO4.7H2O 20 mg, and TiO2 0.2 gram.


Introduction
The material business in Indonesia will furthermore construct individuals' necessity for clothing. The amount of material endeavors in Indonesia comes to 4,652 of each 2018. The amount of material organizations in Indonesia isn't like the amount of real liquid waste dealing with. Material tone waste ought to be managed first before it discarded. Receptive tones are colors that by and large worn in concealing in the material business. Congo Red is either the responsive shadings which is routinely used by the material business. Ecosystem imbalances can occur due to the existence of Congo Red in nature. These tones are particularly dissolvable in water and can't be corupted naturally [1]. Designed shadings are one of the top poisons because of their personality, which interfaces light and lead to pollution and impact biological change [2]. Thusly, elective strategies have been made to oversee colors from batik wastewater.
The creative advances to debase Congo red is the Advanced Oxidation Processes(AOPs) technique, with an innocuous, eco-accommodating, and CO2 and H2O final product. AOPs are frameworks dependent on the exceptionally solid oxidative properties of hydroxyl reactives (•OH). These reactives can be created from a mix of H2O2 with a ferrous particle (Fe 2+ ) normally alluded to as the Fenton reagent [3].
Also, different attributes of TiO2 have stood out as climate cleansing catalyst, and the substance are as per the following. In any case, the decay response of polluted materials is for the most part an oxidative response, and is dependent upon the VB of the photocatalyst. Thusly, the oxidation response further creates when the VB holes have higher oxidative power and there is a more certain electrochemical potential concerning the conventional hydrogen terminal (NHE) potential. The band opening of TiO2 is generally an extent of 3.0-3.2 eV, frequency is around 400 nm. This suggests that UV light brightening with a frequency lower than 400 nm begins a photograph response [4]. Therefore, when TiO2 is enlightened with UV light under 400 nm, its surface is presumably going to achieve heat higher than 30,000 o C, and this extraordinarily high temperature oxidizes all materials. Along these lines, regular blends are rotted absolutely into CO2 and H2O [6].
The joined technique for H2O2, TiO2, and UV light is the most focused on methodology and endeavored to cultivate various kinds of liquid waste. H2O2 is an expert that has strong oxidizing properties that talented to oxidizing mix of salt and not salt in liquid media. UV light is moreover prepared for setting off the breaking of bonds in regular blends. The mix of the two medicines, H2O2, TiO2, and UV light can achieve a more capable and speedier cycle for dealing with the issues of toxins [7].
Fe 2+ in the fenton reagent goes probably as a force to accelerate the decay of H2O2 to outline a •OH. The system of the fenton response is shown in the circumstance under [8] : The photo-Fenton association is a headway of the fenton cycle by adding splendid lights to accelerate and copy the •OH shaped. This cooperation (Fe 2+ /H2O2/UV) captures •OH course of action by H2O/UV and fenton (Fe 2+ /H2O2) response. The presence of recognizable light causes the Fe 3+ shapedin the fenton response to being changed over indeed into Fe 2+ particles with the course of action of another hydoxyl reactive [9]. Fe 3+ + H2O + hⱱ → Fe 2+ + •OH + H + (7) Exactly as superficies of the TiO2 impetuses setteled in H2O are enlightened with UV light, the light actuated electrons in the CB partake in the lessening processes, which routinely respond with crumbled O2 in air to make superoxide reactive anions (O2•). the light actuated holes in the VB assimilate to the TiO2 superficies and react with adsorbed H2O, shaping •OH. Taking everything into account, the •OH is essential as a significant dynamic species categories types during the photocatalytic oxidation reaction [10].

Impact of H2O2 level
An amount of 100 mL of Congo red specimen entered into measuring utencil glass, trailed by H2O2 course of action with a focus varieties of 10 until 140 ppm. The specimen mixed during 1 hours in dim room, after that quantify the Congo red level at most extreme frequency. Do the H2O2 framework with enlightenment during 1 hours. Henceforth, the ideal level of H2O2 got.

Impact of FeSO4.7H2O Weight variation
An amount of 100 mL of Congo red specimen entered into measuring utencil glass, after that, entered with FeSO4.7H2O powder with a weight variety of 10; 20; 30; 40; and 60 mg and added with H2O2 optimum. The specimen mixed during 1 hours in dim room, after that quantify the Congo red level at most extreme frequency. Do the FeSO4/H2O2 framework with illumination during 1 hours. Henceforth, the ideal load of FeSO4.7H2O got.

Impact of TiO2 Weight Variation
An amount of 100 mL of Congo red specimen entered into measuring utencil glass, after that entered with TiO2 powder with a weight variety of 0.1; 0.2; 0.3; and 0.4 gram and added with FeSO4/H2O2 optimum. The specimen mixed during 1 hours in dim room, afterward centrifuged to isolate the congo red arrangement with TiO2. Later quantify the Congo red level at most extreme frequency. Do the TiO2/FeSO4/H2O2 framework with light during 1 hours. Subsequently, the ideal load of TiO2 got.

Variety of H2O2 Level
Decreased degrees of Congo red utilizing H2O2 framework and H2O2/UV framework respectively finished by fluctuating the level of H2O2. This framework is acted in dull spaces (without UV light illumination) and with UV illumination. The aftereffects of Congo red decolorization for H2O2 and H2O2/UV frameworks are displayed in Figure 1. In light of Figure 1, the results obtained that the more level of H2O2 is entered, the Congo red decolorization can increment the amount of OH is shaping. Nonetheless, the increase of a lot of H2O2 concentration makes Congo red decolorization be less effective, because it can reduce the amount of OH is shaping. HO2• is formed from the reaction between excees H2O2 and •OH [12]. The mechanism of HO2• shaping is displayed in the situation: H2O2 + •OH → HO2• + H2O HO2• + •OH → H2O + O2

Variety of FeSO4 Weight
FeSO4.7H2O utilized as a wellspring of Fe 2 + to catalyze the photo-decolorization process.  Figure 2. Impact of FeSO4 weight.
In light of Fig. 2, the results obtained that the more FeSO4 entered to the waste then the level of Congo red decolorization will be greater. The mechanism is happening in the FeSO4 system is displayed in the situation [13]: Fe 2+ and Fe 3+ particles fill in as coagulant that can bind to the Congo red design a complex. Regardless the proportion of FeSO4 entered, UV illumination can likewise assist with expanding the rate decrease in Congo red levels because of photograph Fenton responses that produce •OH. With oxygen in the climate and the framework, Fe 2+ particles will oxidize to Fe 3+ while oxygen will be decreased to H2O [9]. In light of Figure 2 the results obtained that the more FeSO4 entered to the FeSO4/UV framework, the more imperative the degree of Congo red decolorization. Be that as it may, assuming the expansion of FeSO4 an excessive amount of will diminish Congo red decolorization ability. The more FeSO4 entered after the ideal weight, Fe 3+ is produced from oxidized Fe 2+ residue, and Fe 3+ will form new compounds if it reacts with Congo red and lead decolorization cycles to less effective.

Variety of TiO2 Weight
The decolorization of Congo red or diminished Congo red level in this framework is finished by varying TiO2 weight. 10 20  Figure 3. Impact of TiO2 Weight In light of Figure 2, the results obtained that the more TiO2 entered into the waste can increase the decolorization ability. The mechanism is happening in the TiO2 framework is displayed in the situation [ TiO2 helped by the radiation of UV light brought about the excitation of electrons from the valence band to the conduction band. Electron excitation will cause holes in the valence band (h + vb) to respond with hydroxyl particles (OH -) to shape hydroxyl radicals which are solid and dynamic oxidizing specialists. In the interim, ecbwill bind to O2 in the environment to create O2• as diminishing specialists [10].
The addition of overabundance TiO2 will bring about an abatement in the decolorization ability. This is on the grounds that the addition of abundance TiO2 will make the TiO2 contained in the arrangement block the entrance of UV light to the outer layer of the TiO2 in it. Furthermore, it is evident that there is a recombination cycle on the catalyst so it can't form hydroxyl radicals. To make the decolorization activity decline [6].

Conclusion
In view of the research results, the decline of congo red substance utilizing fenton reagent/TiO2 all the more successfully with the guide of UV light illumination analyzed about without illumination of light. The ideal level of H2O2 was 100 ppm, the ideal FeSO4 was 20 mg, while the ideal TiO2 was 0.2 gram with the decrease of congo red level for H2O2, H2O2/UV, H2O2/FeSO4, H2O2/FeSO4/UV, H2O2/FeSO4/TiO2, and H2O2/FeSO4/TiO2/UV independently by 2.08%; 6