Combined Application of Coagulation/Flocculation/Sedimentation and Membrane Separation for the Treatment of Laundry Wastewater

Abstract

The wastewater from industrial laundries has a high quantity of contaminants from the washing process, as well as chemical additives. Aiming at the treatment of this type of wastewater, the present study evaluated the performance of a combined coagulation/flocculation/sedimentation process (C/F/S) and membrane separation to treat laundry wastewater in relation to physicochemical parameters of water quality. For this purpose, a Doehlert experimental design was applied to the C/F/S step using the natural coagulant Tanfloc POP® with maximum color and turbidity removal efficiency obtained of 80.27% and 86.50%, respectively, under conditions of pH of 6.4 and a coagulant concentration of 110 mg·L−1. The supernatant from the C/F/S step was used in the sequential microfiltration (MF) and ultrafiltration (UF) experiments. The maximum values of color, total nitrogen, dissolved solids, and turbidity removal were similar to MF and UF membranes at transmembrane pressure of 1.4 bar, with the greatest flow of permeates (92.2 L·h−1·m−2) presented by the MF membrane at 1.4 bar. The total efficiency of the combined C/F/S-MF process indicated the quality of the treated wastewater since it reduced 98.4% of the color, 99.1% of turbidity, 71.7% of the surfactants, and more than 55% of the total dissolved solids (TDS), chemical oxygen demand (COD), and total organic carbon (TOC) from the industrial laundry wastewater. This study showed that the C/F/S-MF combined process could be an efficient treatment of laundry wastewater.

Use of Natural Coagulants/Flocculants in the Treatment of Hospital Laundry Effluents

“…In agreement with these results, the scientific literature 171,190 reports that, in general, at pH close to 6, CS offers less turbidity/apparent colour and the increase in pH also causes a slight increase in residual turbidity. Another factor that may be weakly influencing the better performance of the C/F treatment at pH 6 is that the zeta potential of the CS surface in acidic environments is usually positive due to the protonation of the amino groups (-NH 3 + ) in these conditions.…”

Use of Natural Coagulants/Flocculants in the Treatment of Hospital Laundry Effluents

“…In agreement with these results, the scientific literature 171,190 reports that, in general, at pH close to 6, CS offers less turbidity/apparent colour and the increase in pH also causes a slight increase in residual turbidity. Another factor that may be weakly influencing the better performance of the C/F treatment at pH 6 is that the zeta potential of the CS surface in acidic environments is usually positive due to the protonation of the amino groups (-NH 3 +…”

Penggunaan Ferri Klorida dan Kitosan Cangkang Kepiting sebagai Alternatif Koagulan pada Pengolahan Air Limbah Laundry

“…Air limbah perkotaan pada umumnya terdiri dari air limbah rumah tangga, perusahaan komersial, dan air tanah atau air permukaan yang masuk ke dalam sistem pembuangan kotoran (Middleton, 1997). Industri laundry merupakan salah satu penyumbang air limbah perkotaan yangmemiliki kandungan COD, BOD5, dan surfaktan yang relatif tinggi sehingga menjadi penyebab tingginya tingkat pencemaran air sungai (Nascimento et al, 2019). kadar COD dan BOD5 tersebut disebabkan oleh tingginya beban organik.…”

“…Selain itu, konsentrasi residu ion ferri atau aluminium dalam air dapat meningkat karena peningkatan dosis koagulan kimia. Hal ini dapat meningkatkan risiko penyakit Alzheimer, anemia, hilangnya memori, dan gejala sakit kepala (Nascimento et al, 2019;Muthuraman dan Sasikala., 2014).Polimer sintetik seperti poli akrilamida dan poliamina merupakan koagulan alternatif yang dapat digunakan untuk proses pengolahan air limbah dengan koagulasi-flokulasi. Penggunaan kedua bahan kimia tersebut efektif dalam mengurangi kekeruhan air limbah tanpa peningkatkan volume lumpur karena tidak menghasilkan logam hidroksida.…”