Kemampuan PAC dan Tawas dalam Menurunkan COD dan TSS Air Limbah Penatu

Habsari, Teresa Saras Nugraheni Putri (2026) Kemampuan PAC dan Tawas dalam Menurunkan COD dan TSS Air Limbah Penatu. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Air limbah laundry merupakan salah satu sumber pencemar domestik yang mengandung senyawa organik, surfaktan, dan padatan tersuspensi dalam konsentrasi relatif tinggi. Jika dibuang tanpa pengolahan yang memadai, limbah ini dapat menurunkan kualitas badan air dan mengganggu keseimbangan ekosistem perairan. Parameter utama yang digunakan untuk mengevaluasi tingkat pencemaran adalah Chemical Oxygen Demand (COD) dan Total Suspended Solids (TSS). Hasil karakterisasi awal menunjukkan konsentrasi COD dan TSS masing-masing sebesar 1600 mg/L dan 72 mg/L, yang melebihi baku mutu berdasarkan Peraturan Menteri Lingkungan Hidup Nomor 11 Tahun 2025, yaitu 100 mg/L untuk COD dan 50 mg/L untuk TSS. Oleh karena itu, diperlukan metode pengolahan yang efektif untuk menurunkan kedua parameter tersebut.
Penelitian ini bertujuan untuk menganalisis efektivitas Poly Aluminium Chloride (PAC) dan aluminium sulfat (tawas) dalam menurunkan COD dan TSS serta menentukan dosis optimum yang menghasilkan efisiensi penyisihan terbaik. Penelitian dilakukan secara eksperimental skala laboratorium menggunakan metode jar test melalui proses koagulasi, flokulasi, dan sedimentasi. Variasi dosis digunakan untuk mengevaluasi kinerjanya. Analisis COD dilakukan dengan metode refluks tertutup, sedangkan TSS menggunakan metode gravimetri sesuai standar yang berlaku. Hasil penelitian menunjukkan bahwa kedua mampu menurunkan COD dan TSS secara signifikan. PAC menunjukkan kinerja lebih baik dan stabil dibandingkan tawas, dengan dosis optimum 150 mg/L yang menghasilkan efisiensi penyisihan COD sebesar 89,29% dan TSS 94,44%. Sementara itu, tawas pada dosis optimum 200 mg/L menghasilkan efisiensi COD 82,14% dan TSS 88,89% pada waktu pengendapan 25 menit. Pada kondisi optimum, penurunan kekeruhan mencapai 98,45% (PAC) dan 96,42% (tawas), serta MBAS turun dari 4,4 mg/L menjadi 1,5 mg/L (PAC) dan 1,8 mg/L (tawas). Efluen PAC telah memenuhi baku mutu COD dan TSS, sedangkan pada tawas COD masih melampaui batas. Nilai pH kedua (5,7 untuk PAC dan 5,2 untuk tawas) masih di bawah rentang baku mutu 6,0–9,0 sehingga diperlukan penyesuaian dengan penambahan alkali. Selain itu, dirancang unit pengolahan berupa bak pembubuh koagulan, pengaduk cepat, dan pengaduk lambat sesuai debit pengolahan. Berdasarkan hasil tersebut, proses koagulasi–flokulasi menggunakan PAC maupun tawas berpotensi diterapkan sebagai teknologi pengolahan air limbah laundry yang sederhana, efektif, dan aplikatif untuk skala kecil dan menengah.
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Laundry wastewater is one of the domestic pollutant sources containing organic compounds, surfactants, and suspended solids in relatively high concentrations. If discharged without adequate treatment, this wastewater can degrade water body quality and disrupt the balance of aquatic ecosystems. The main parameters used to evaluate the level of pollution are Chemical Oxygen Demand (COD) and Total Suspended Solids (TSS). Initial characterization results showed COD and TSS concentrations of 1,600 mg/L and 72 mg/L, respectively, exceeding the quality standards set by Minister of Environment and Forestry Regulation No. 11 of 2025, namely 100 mg/L for COD and 50 mg/L for TSS. Therefore, an effective treatment method is needed to reduce both parameters. This study aims to analyze the effectiveness of Poly Aluminium Chloride (PAC) and aluminum sulfate (alum) in reducing COD and TSS, as well as to determine the optimum dose that produces the best removal efficiency. The research was conducted experimentally at laboratory scale using the jar test method through coagulation, flocculation, and sedimentation processes. Dose variations were used to evaluate performance. COD analysis was performed using the closed reflux method, while TSS was analyzed using the gravimetric method in accordance with applicable standards.
The results show that both coagulants were able to significantly reduce COD and TSS. PAC demonstrated better and more stable performance than alum, with an optimum dose of 150 mg/L achieving a COD removal efficiency of 89.29% and a TSS removal efficiency of 94.44%. Meanwhile, alum at an optimum dose of 200 mg/L achieved a COD efficiency of 82.14% and a TSS efficiency of 88.89% at a settling time of 25 minutes. Under optimum conditions, turbidity reduction reached 98.45% (PAC) and 96.42% (alum), while MBAS decreased from 4.4 mg/L to 1.5 mg/L (PAC) and 1.8 mg/L (alum). The PAC effluent met the COD and TSS quality standards, whereas the alum effluent still exceeded the COD limit. The pH values of both effluents (5.7 for PAC and 5.2 for alum) remained below the quality standard range of 6.0-9.0, requiring adjustment through alkali addition. In addition, treatment units were designed, comprising a coagulant dosing tank, a rapid mixer, and a slow mixer, sized according to the treatment flow rate. Based on these results, the coagulation-flocculation process using either PAC or alum has the potential to be applied as a simple, effective, and applicable laundry wastewater treatment technology for small- and medium-scale operations.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Air limbah laundry, COD, koagulasi–flokulasi, PAC, TSS, COD, Coagulation-flocculation, Laundry wastewater, PAC, TSS
Subjects:	T Technology > TD Environmental technology. Sanitary engineering > TD455 Chemical precipitation. Coagulation. Flocculation. Water--Purification--Flocculation.
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Environmental Engineering > 25201-(S1) Undergraduate Thesis
Depositing User:	Teresa Saras Nugraheni Putri Habsari
Date Deposited:	26 Jul 2026 03:50
Last Modified:	26 Jul 2026 03:50
URI:	http://repository.its.ac.id/id/eprint/137360

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