Wardoyo, Iva Rustanti Eri (2018) Evaluasi Pengaruh Koagulan Alami dan Sintetis Proses Basa pada Pengendapan Selektif Pemurnian Reject Water SWRO dan Potensi Ekonomi Aplikasinya. Doctoral thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Brine water yang berasal dari reject water seawater reverse osmosis (SWRO) memiliki jumlah padatan terlarut (TDS) lebih dari 40.000 mg/L yang didominasi oleh ion-ion Ca2+, Mg2+, Na+, Cl-, SO42-dan HCO3-. Apabila dibuang langsung ke laut tanpa pengolahan terlebih dahulu dapat merusak lingkungan penerima. Brine water mengandung konsentrat NaCl, yang dalam jumlah besar memiliki nilai ekonomi antara lain sebagai bahan baku industri klor-alkali, regenerasi resin penukar ion dan sebagainya.
Tujuan penelitian adalah menemukan pengaruh koagulan alami dan sintetis dalam proses basa pada pemodelan pengendapan selektif pemurnian reject water SWRO, sehingga diperoleh kondisi optimum dalam proses memurnikan larutan NaCl dari mineral impurities. Penelitian dilakukan dalam skala laboratorium, menggunakan jar test. Untuk menentukan kondisi optimum penelitian, digunakan rancangan Response Surface Methodology (RSM) pada berbagai variasi penelitian yaitu konsentrasi NaOH, Na2CO3, jenis dan dosis koagulan serta gradien kecepatan (G) flokulasi.
Hasil penelitian ini menunjukkan bahwa ekstrak Moringa oleifera memiliki gugus aktif aliphatic primary amides dan aliphatic alcohol functional group, sedangkan koagulan sintetis poliakrilamida kationik (Cationic Polyacrilamide) memiliki gugus aktif aliphatic amines group dan aliphatic hydrocarbone group. Gugus aktif koagulasi MO memiliki kemampuan yang sama dengan CP 0,1% dalam menurunkan kation golongan II dan anion valensi 2. Hal ini terlihat dari persentase penurunan kation impurities (Ca2+, Mg2+ dan K+) dan anion SO42- dari kedua golongan ini yang hampir sama. Analisis menggunakan Response Surface Methodology (RSM) menghasilkan titik optimum model pengendapan selektif menghasilkan konsentrasi NaCl tertinggi (49090 mg/L) berada pada kosentrasi NaOH 28.714%, dosis koagulan 24.4283 g/L dan menggunakan koagulan ekstrak Moringa oleifera. . Hasil analisa hubungan perubahan pH selama waktu pengendapan (t, menit) mengikuti persamaan logaritmik pH = - 0,832 ln(t) + 12,079 , dengan nilai R2 = 83,08%. Proses pemurnian reject water SWRO menghasilkan larutan crude NaCl 5% (masih mengandung ion-ion bivalen impurities). Hasil analisa ekonomi menunjukkan bahwa pemurnian reject water SWRO menggunakan ekstrak MO sebagai koagulan layak dibangun dan menguntungkan dengan nilai Payout Time 2 tahun, Break Even Point 44,53 % dan Internal Rate of Return (IRR) 86,74%. Hal tersebut menunjukkan bahwa investasi pemurnian reject water SWRO sangat layak dan dapat memberikan manfaat ekonomi yang sangat besar.
Kata kunci: reject water membran SWRO, koagulan, NaCl
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Brine water - which is derived from seawater reverse osmosis reject water (SWRO), has an amount of dissolved solids (TDS) around 40000-61000 mg/L; which is dominated by ions Ca2+, Mg2+, Na+, Cl-, SO42-and HCO3-. If its directly discharged into the open public sea without having any specific process, it surely will damage the environment. Brine water contains NaCl concentrate, that in huge quantities has certain economic values ; as a raw material in chlor-alkali industry, the regeneration of resin-ion exchange and any other substantial benefits.
This research aims to discover the capability of natural coagulant and the synthesis of alkaline process within reject water SWRO selective precipitation purification modelling, so the optimum condition from NaCl purifying process from impurities mineral content can be obtained. The research was conducted in a laboratory scale, using a jar test, and applied the Response Surface Methodology (RSM) design on a wide variety of variables, which are concentrations of NaOH, Na2CO3, type and dosage of coagulants also flocculation velocity gradient (G).
The final result of this research shows that Moringa oleifera’s extract contains a cluster of active Primary aliphatic amides and Aliphatic alcohol functional group, while the Cationic Polyacrilamide synthetic coagulant contains a cluster of active aliphatic amines group and aliphatic hydrocarbone group. Active cluster of Moringa oleifera’s coagulation has the same ability with CP 0,1% in reducing type II cations and anions with a valence of 2. This can be determined from the percentages of cationic impurities decreased (Ca2+, Mg2+ dan K+) and anion of SO42- since both have similarities. The analysis using Response Surface Methodology (RSM) resulted optimum point of Reject Water SWRO Selective Precipitation Purification Modelling with highest NaCl concentrate (49090 mg/L) occurred in NaOH concentrate of 28.714%, coagulant dosage of 24.4283 g/L and using the coagulant extract of Moringa oleifera.
The result of analysis of pH change relationship during settling time (t, min) following logarithmic equation pH = - 0,832 ln (t) + 12,079, with value R2 = 83,08%. The process of purifying reject water SWRO yields a 5% crude NaCl solution (still containing bivalent impurities ions). Result of economic analysis show that investation in purification of reject water SWRO using MO extract as coagulant worthy built and profitable with value of IRR 86,74%, 2 years payout time and BEP 44,53%.
Keywords : Reject Water SWRO Membranes, Coagulants, NaCl
| Item Type: | Thesis (Doctoral) |
|---|---|
| Additional Information: | RDL 628.162 War e |
| Uncontrolled Keywords: | Reject water membran SWRO, Koagulan, NaCI |
| Subjects: | T Technology > TD Environmental technology. Sanitary engineering > TD433 Water treatment plants T Technology > TD Environmental technology. Sanitary engineering > TD455 Chemical precipitation. Coagulation. Flocculation. Water--Purification--Flocculation. |
| Divisions: | Faculty of Civil, Environmental, and Geo Engineering > Environmental Engineering |
| Depositing User: | IVA RUSTANTI ERI WARDOYO |
| Date Deposited: | 07 Oct 2020 07:20 |
| Last Modified: | 07 Oct 2020 07:20 |
| URI: | http://repository.its.ac.id/id/eprint/59445 |
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