Theses (Department of Environmental Engineering)

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Theses collection of the Faculty of Engineering.

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Theses (Department of Environmental Engineering) Szerző szerinti böngészés "Hassanzad, Mohammad"

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    A Comprehensive Study on the Investigation of Microplastic Removal in Greywater Treatment Using Adsorbent Materials and Coagulants
    Hassanzad, Mohammad; Bodnár, Ildikó; DE--Műszaki Kar
    The issue of water shortage has emerged as a significant worldwide threat, leading to research on viable strategies for sustainable water utilization, such as the recycling of rainwater and wastewater [47]. Domestic wastewater is classified into two distinct categories: greywater and blackwater, with greywater comprising the majority of the discharge. Greywater, which is free of toilet residues and comprises domestic wastewater from sources such as baths, laundry, and bathroom basins, is distinguished by its minimal presence of organic and harmful pollutants [68]. On a daily basis, various detergents, personal care products, and clothing laundering significantly contribute to the MP content of domestic greywater that reaches wastewater treatment plants [35]. MP is an emerging pollutant that prompts alarm because of its pervasive presence in the environment. Wastewater treatment plants are a significant contributor to the presence of microplastics in the environment and water bodies owing to their limited ability to fully eliminate these tiny particles [28]. Therefore, it is critical to develop an innovative and effective treatment method for eliminating MP particles and other organic and inorganic pollutants from GW. Initially, synthetic greywater (SGW) was prepared using combining equal amounts of GW from laundry and bathrooms, each accounting for 50% of the content. Then LDPE-MP with a constant concentration of 0.1 g/L and fraction sizes of 50 to 500 µm spiked to the SGW. Two types of coagulants were used in this study: iron(III) chloride (ferric chloride) and Cationic Polyelectrolyte (ACEFLOC 80902). In the CFS method as a pretreatment technique, the pH, turbidity, and Zeta Potential measurements were conducted for all samples to find the optimum dosage and also MP removal efficiency in this phase. The aim of using coagulants was to understand the effects of coagulants on water quality and the potential for reducing the MP load in the pretreated samples. The pH was determined using a SenTix combination pH-electrode and the WTW Multi 3320 apparatus. Turbidity was measured using a WTW Turb 555IR light scattering photometer. The BOD5 was determined at a consistent incubation temperature of 20 °C using an OxiTop IS12 measuring head. TOC was calculated using the Shimadzu TOC-Vcpn total organic carbon analyzer. COD was assessed using NANOCOLOR COD test kits. The Zeta potential was measured using the Zetasizer Nano Z Zen 2600 instrument (Malvern Instruments Ltd., UK). Moreover, the study analyzed elemental concentrations of Raw SGW and treated water samples using an ICP-OES 5110 Vertical Dual View instrument and a double pass spray chamber. The efficiency of microplastic removal and water quality parameters in treated samples was examined using two columns made of the same adsorbent material across all column types. The GAC and NZ materials were used to prepare the columns. The materials ratio in columns were 100% GAC, 100% NZ, and 50% GAC and 50% NZ namely MIX filter medium. In total, we had 6 columns. To determine the efficacy of microplastic removal and water quality parameters, one column was devoted to the water quality parameters and one column to examine the MP removal. The treatment process involved determining the optimal dosage of coagulant, a coagulation-flocculation-sedimentation method, and a column-based filtration system. To investigate the effectiveness of a pre-treatment method using CFS in removing microplastics from water, MP removal efficiency was determined using a weight-based approach to determine the effectiveness of the CFS method. The coagulation process neutralized charges on particles, while flocculation amalgamated them for removal. The optimum concentration of coagulant was determined by monitoring the zeta potential and comparing it with the concentration of iron(III) chloride and Cationic Polyelectrolyte. To evaluate the MP removal efficiency of the adsorbent-column-based filtration system as a main treatment system, different techniques were used. Indeed, MP was identified using an optical microscope by counting the residual on the 0.45 µm filter paper, Raman spectroscopy to identify the polymer type by a light scattering technique, Scanning Electron Microscope (SEM) to examine the MP shape and surface morphology of adsorbent materials and their elemental composition, and a light microscope to evaluate the floc appearance and also MP counting. Results showed that the addition of LDPE-MPs to SGW increased turbidity, zeta potential, COD, and BOD5 values. The optimal dosage of FeCl3 was determined to separate unstable colloids and absorb MP particles. The optimal dosage resulted in a significant reduction in turbidity levels and pH levels. The optimum coagulant dosage for FeCl3 was 275 mg/L and for the combination effect, the optimum dosage for CPE was 15 mg/L in a constant amount of 275 mg/L FeCl3. The highest MP removal with the CFS method by FeCl3 was 16.60% and by the combination coagulants was 97.47%. In the first approach (Raw SGW-MP) the analysis of water quality parameters utilizing different filter media indicates varied effectiveness in pollutant removal. While all samples maintain pH levels within acceptable ranges for irrigation, the GAC filter showed superior turbidity reduction, though not meeting agricultural standards. Additionally, GAC and MIX filters demonstrated substantial reductions in TOC, COD, and BOD5, with the latter showing promising potential, particularly in organic pollutant removal. Moreover, elemental analysis revealed varying concentrations of trace elements, with all samples that can meet irrigation standards. The second approach revealed notable trends and effectiveness in pollutant removal. While the NZ filter medium shows a decrease in pH, other media maintain pH levels suitable for irrigation. All filter media exhibit a positive trend in ZP values, with NZ and MIX showing comparable or better outcomes. Turbidity decreases significantly across all media, with GAC demonstrating the most substantial reduction, meeting agricultural standards. Regarding TOC, GAC and MIX show significant improvements. In terms of COD and BOD5, GAC performs well for COD, while MIX excels for BOD5 compliance with EU regulations. Elemental analysis showed varied effects on trace elements, with all media meeting irrigation standards. The last approach showed consistent trends and efficacy in pollutant removal. Despite a slight decrease in pH for the NZ filter medium, all pH values fell within the recommended range for agricultural use. While NZ exhibited the highest EC value, all media showed improvement. Turbidity reduction was notable across all filters, particularly with GAC and MIX, meeting agricultural standards. GAC and MIX showed significant reductions in TOC, with GAC proving the most effective. For COD and BOD5, GAC demonstrated superior performance, meeting both EPA and EU guidelines. Moreover, Elemental analysis revealed trace element concentrations within acceptable limits for irrigation across all filter media. Overall, this part of the study highlights the effectiveness of different filter media in improving water quality for agricultural purposes, aligning with regulatory standards, particularly GAC and MIX filter media. In the case of MP removal efficiency, an optical microscope quantified MP particles on filter paper surfaces. Initially, the GAC filter medium showed an average of 10.67 MP particles/L, while the NZ filter medium displayed 32.00 MP particles/L, and the MIX filter medium exhibited 10.67 MP particles/L. This indicates comparable efficacy between GAC and MIX, primarily attributed to GAC's superior adsorption capacity. In the second approach with pre-coagulation using FeCl3, GAC had an average of 2.67 MP particles/L, while NZ had 10.67 MP particles/L, and MIX had 8.00 MP particles/L, again emphasizing GAC's effectiveness. In the third approach with pre-coagulation using CPE and FeCl3, no MP was detected on GAC, while NZ had 5.33 MP particles/L, and MIX had 2.67 MP particles/L, further highlighting GAC's superior MP removal capability.