Application of Response Surface Methodology (RSM) for Optimizing Turbidity of Paper Recycling Wastewater Using Microwave Technology

Abstract

Aims: The aim of the study was to use Response Surface Methodology (RSM) to find optimal experimental design for wastewater treatments from office paper recycling. In this way, interactive effects of treatment factors were evaluated, including microwave power (MW) and durations with centrifuge time while turbidity of wastewater was chosen as the dependent output variable or an optimal response.
 Methodology: The RSM approach was utilized for optimization of the process parameters and identifying the optimal conditions for the removal of turbidity in paper recycling wastewater. In this regard, a three-factor RSM were selected, using MW irradiation power (Watts), durations (seconds) and centrifuge time (min). Statistical analysis of variance (ANOVA) was carried out to identify the adequacy of the developed model. In this case, specially prepared office papers (one-side laser printed) were subjected to standard paper recycling procedure for obtaining wastewater at laboratory conditions. The experimentally derived RSM model was validated using range of statistical parameters.
 Conclusions: The study revealed that under the RSM optimized conditions, a marked reduction in the turbidity of wastewater was observed for both groups studied. The R2, R2(adj) and R2(pred) values were indicates, the developed model was significant which revealed a well agreement between the experimental data and proposed model. In this approach, the R2=99.710% and lack-of-fit value were found to be 0.111 (p>0.05), which shows the model and the data consisted to each other. The lowest turbidity value was found with 150.000 Watts and 60.000 seconds in MW conditions with 15.000 minutes of centrifugation time, experimentally. With employing these variables, the turbidity value of 6.65 NTU was determined. However, the highest turbidity value of 18.013 NTU was found with MW power of 200.00 Watts with 40.000 seconds of durations and 1.591 minute of centrifugation time. It is important to note that with using optimized parameters, the turbidity value of 1.43 NTU was calculated while 1.47 NTU was found with experimentally.

A comparative study on paper recycling wastewater treatment using microwave irradiation and centrifuge technology

“…Besides visual analysis, it was suggested to measure the cloudiness-haziness (Turbidity) of wastewater using a turbidity method (Stephenson and Duff, 1996;Choy et al, 2016;Özkan and Sahin, 2023;Ozkan et al, 2023). The turbidity values of wastewater samples are shown in Table 2.…”

“…It mainly involves processes, including furnish preparation, pulp treatment, and paper web formation. Although the quantity of water consumption varies for each mill depending on the desired paper grade, it requires fresh water for every tonne of paper manufactured (Biermann, 1996;Ozkan et al, 2023).…”

“…It has gained much attention owing to the molecular level heating in various processes (Remya and Lin, 2011;Vialkova et al, 2021). Many researchers have conducted a comprehensive study of the existing state of MW technology for adopting wastewater treatment (Remya and Lin, 2011;Wang and Wang, 2016;Wei et al, 2020;Vialkova et al, 2021;Ozkan et al, 2023). It was reported to be used for complex oxidation of wastewater containing ammonia (Lin et al, 2009), phosphorous compounds (Jung 2011), phenols (Remya and Lin, 2011;Wang et al, 2021) pesticides (Cheng et al, 2015), medical preparations (Remya and Lin, 2011), and some other elements (Wang and Wang, 2016;Wei et al, 2020;Vialkova et al, 2021).…”

Treatment of paper recycling wastewater using microwave technology

“…Besides synthetic materials, various cost-effective natural adsorbents such as agricultural and forest residues have also been utilized as bio-absorbents for treatment purposes (Janoš et al, 2009;Zedan et al, 2022). It has suggested that the ash raw bagasse (Valix et al, 2004), plant stem (Bazrafshan and Kord Mostafapour, 2013), cellulose-based waste (Annadurai et al, 2002), red pine chips (Ozkan et al, 2023) have some of the natural absorbent that effective for removing various type of coloring matters from wastewater.…”

“…It has already been reported to be use MW irradiated to modify material's properties including; surface and bulk modification (i.e. permeability, wettability, dyeability and bonding ability), pyrolysis of lignocellulosics, phase separation and extraction, remediation of hazardous and radioactive wastes and sewage sludge treatments (Ozcelik and Sahin, 2021;Ozkan et al, 2023).…”