Utilization of Papaya Seeds as Natural Coagulant for Synthetic Textile Coloring Agent Wastewater Treatment

Abstract

Textile wastewater contains many pollutants which is hazardous if directly discharged. Various technologies such as adsorption, advanced oxidation processes, biological treatment, membrane technology, coagulation, and flocculation have been explored and utilized to treat textile wastewater. However, coagulation followed by flocculation is still widely used. Usually, inorganic salts such as alum, ferric chloride, PAC, are widely used to treat textile wastewater. However, utilization of inorganic salts poses some drawbacks, such as high coagulant cost, a large volume of sludge produced, and potential health problems if the water is consumed. In this study, we explore the utilization of natural coagulant as an alternative to inorganic salts to treat textile wastewater. This study describes the utilization of papaya seeds powder as a natural coagulant for synthetic textile wastewater of drimarene dark red (DDR) with an initial concentration of 10 mg/L. The effect of coagulant dosage and pH to the %removal of color in wastewater was studied using central composite design. The potential active functional groups in papaya seeds powder were characterized using Fourier Transform Infrared Spectroscopy (FTIR). It was found that papaya seeds powder contained-OH,-NH, C=O functional groups that indicate good potential as natural coagulant. The cubic model obtained was in a good fit with experimental data, which was shown in the R-squared value of 0.995. It was found that coagulant dosage, pH, and its interaction were significant to the removal of synthetic dye in wastewater. The decrease of pH gave higher %removal due to protonation of papaya seeds powder active coagulating agent resulting in better electrostatic interaction with dyes. The increase of dosage also gave an increase in %removal until its optimum condition. After optimum condition, the %removal decreased due to colloid re-stabilization. The optimum condition was obtained at a dosage of 0.57g/L, and pH 1.97 with 84.77% of predicted color removal and this result was in agreement with experimental response value.

Adsorption and coagulation in wastewater treatment – Review

“…The removal percentages for COD and TSS were up to 48.22 and 81.58%, respectively. Kristianto et al (2018) studied the use of papaya seed powder to remove color in synthetic textile wastewater. The result shows the percentage of removal of 84.77% with optimum conditions were found in coagulant dosage is 0.57 g L À1 , and pH 1.97.…”

Insights into Solar Disinfection Enhancements for Drinking Water Treatment Applications

“…The authors reported 90-99% removal of water bacteria after using this natural coagulant in addition to its coagulation role. Carica papaya seeds are another natural coagulant obtained from tropical trees and characterized by cystine protease proteins (water-soluble and positively charged proteins), which are also utilized as a putative natural coagulant [123]. In a study done by Unnisa et al [124], Carica papaya seeds were used as a pre-treatment for SODIS to reduce water turbidity and inactivate coliform bacteria.…”

Multi-response optimization of the coagulation process of real textile wastewater using a natural coagulant

“…Alum based sludge for example was described to be difficult to dewater (Gupta et al, 2011). Another potential problem is associated with health issues such as Alzheimer's, and dementia (Kristianto, Kurniawan, & Soetedjo, 2018).…”

“…They successfully reached 67.66%, 96.86% and 91.12% COD, turbidity and colour removal, respectively. Many researchers investigated the performance of other natural coagulants such as potato starch (Ahmad, 2018), papaya seeds (Kristianto et al, 2018), sago, chitin (Saritha, Karnena, & Dwarapureddi, 2019) and okra (Freitas et al, 2015) as possible alternatives to the chemical coagulants. Strychnospotatorum (Nirmali seeds) and Eirchorrniacrassipes (water hyacinth) were seen to give better reduction for total suspended solids (TSS), COD and biological oxygen demand (BOD) over alum (Prabhakaran, Manikandan, & Boopathi, 2020).…”

“…Most of the coagulation studies using natural coagulants were conducted on synthetic textile waste (Kristianto et al, 2018;Suresh et al, 2019;Obiora-Okafo & Onukwuli, 2017;Onukwuli, Obiora-Okafo, & Omotioma, 2019;Dalvand et al, 2016) or surface water (Adesina, Abdulkareem, Yusuff, Lala, & Okewale, 2019), yet little attention was given to real waste samples. Until recently, the new trends in the field were directed towards investigating the performance of these natural coagulants on real waste samples for the purpose of finding better alternatives for industrial applications (Dotto et al, 2019;Rambe, 2018;Dos Santos, 2018).…”