A novel air plasma electrolysis with direct air injection in plasma zone to produce nitrate in degradation of organic textile dye

Abstract

Nitrogen is one of the essential nutrients for plants. Even though its availability in the air is abundant, it cannot be utilized yet due to its structure. Plasma electrolysis by air injection is effectively degrade organic textile dyes waste. In this study we propose a novel air plasma electrolysis (APE) where direct air injection into plasma zone inside electrolysis plasma can converts air into nitrate, while simultaneously the degradation of dyes waste produces organic nitrogen. Degradation of organic textile dye by APE can also transform nitrogen-rich organic wastewater into nitrogen fertilizers. In this experiment, Remazol red as a compound in the azo dye group was used as a model for organic textile dye wastewater. Air plasma electrolysis reactor equipped with a stainless-steel cathode, a tungsten anode, with various air injection rates and electric power. The results show 99.82% Remazol red degradation and 41.41 mmol of nitrate production. Preliminary efficacy tests on tomato plants showed that the nitrogen fertilizers produced from Remazol red produce the best plant growth. This study shows that APE simultaneously reduces organic textile dye waste, transforms them into potential organic fertilizer, and at the same time, synthesizes nitrates.

Fixation of air nitrogen to ammonia and nitrate using cathodic plasma and anodic plasma in the air plasma electrolysis method

“…35 According to the results of previous studies, air injection can significantly reduce electrical power consumption. 19,31 As shown in Figure 2b, the electrical power of cathodic plasma at a voltage of 625 V decreased by 17.9%, from 586 to 481 W. In contrast, the electrical power of anodic plasma at a voltage of 850 V decreased by 15.7%, from 654 to 551 W.…”

“…In the recently developed air plasma electrolysis method, plasma is produced in the aqueous liquid phase with the simultaneous injection of air. 19,20 This method is effective in directly producing NO 3 À in the liquid phase. 21 The initial formation of plasma involves the activation of N 2 and O 2 from the air by plasma to form ˙N and ˙O, while the H 2 O vapor in the plasma zone is converted to ˙H and ˙OH, as shown in Equations ( 1)-( 4) 22 :…”

“…˙N and ˙O form NH 3 and NO 3 , while ˙H and ˙OH can be recombined to form H 2 and H 2 O 2 , as shown in Equations ( 5)-( 9) 19,22 :…”

“…The process began with the formation of NO x gas in the plasma zone, which was then diffused into the solution as soluble NO and NO 2 gases that were subsequently oxidized by ˙OH into NO 3 À . 19,22 The injection of air into the plasma zone increases performance and reduces energy consumption. 31 The addition of O 2 and N 2 molecules from the air has the potential to produce new reactive species in the form of N and O radicals 32,33 that can form NO 3 À , NO 2…”

The Effect of Power on Nitrate Synthesis and The Emission Intensities of Reactive Species Using Anodic Plasma Electrolysis

“…This is because the diffusion process of NO and NO2 gases produced from air plasma into the liquid phase to form NO3is still low. In addition, the reactive species of •OH and •H needed for nitrate formation are relatively small (Farawan et al, 2021). Air plasma technology which produces a low nitrate yield in the liquid phase, encourages the use of the plasma electrolysis method.…”