Penelitian ini dilakukan untuk mengetahui pengaruh lama iradiasi sinar UV dan penambahan H2O2 terhadap karakteristik mikroplastik limbah disposable face mask (DFM). DFM atau masker sekali pakai terbuat dari bahan polipropilen memiliki sifat hidrofobik yang tinggi sehingga proses degradasi tidak dapat berlangsung secara maksimal. Fotodegradasi UV dan penambahan H2O2 merupakan salah satu metode yang dapat digunakan untuk memodifikasi struktur kimia dari mikroplasatik dengan membentuk gugus fungsi aktif seperti gugus karbonil dan gugus hidroksil. Fotodegradasi sinar UV dilakukan dengan memvariasikan lama waktu iradiasi sinar UV yaitu 24; 36; 48; 60; 72 jam untuk sampel tanpa dan dengan penambahan H2O2 1% v/v. Hasil proses fotodegradasi dikarakterisasi berdasarkan kandungan dari sampel, yaitu perubahan struktur kimia yang dianalisa menggunakan Fourier Transform Infrared (FTIR), perubahan morfologi permukaan mikroplastik dianalisa menggunakan mikroskop binokuler dan persentase penurunan berat mikroplastik dianalisa menggunakan metode gravimetri. Penelitian ini didapatkan hasil terbaik fotodegradasi tanpa H2O2 terjadi pada waktu 36 jam dan hasil terbaik fotodegradasi dengan kombinasi penambahan H2O2 terjadi pada waktu 60 jam berdasarkan penurunan persen transmitansi terbesar gugus karbonil (C=O) yang dianalisis menggunakan FTIR sehingga terjadi penurunan hidrofobisitas pada DFM walaupun tidak siginifikan. Penambahan H2O2 1% v/v tidak memberikan pengaruh signifikan terhadap perubahan karakteristik sampel yang difotodegradasi yang dibuktikan dengan hasil analisis FTIR, perubahan struktur permukaan sampel DFM dan berat yang hilang dari sampel DFM setelah proses fotodegradasi. Berat yang hilang dari sampel setelah proses fotodegradasi sebesar 0,43% tanpa penambahan H2O2 dan 0,29% dengan penambahan H2O2 dengan waktu iradiasi selama 72 jam(α < 1%).
{"title":"Pengaruh kombinasi antara fotodegradasi dan H2O2 terhadap karakteristik mikroplastik dari limbah disposable face mask","authors":"Feerzet Achmad, Devita Amelia, Arie Sabdi Sembiring, Novia Putri Ananda, Melbi Mahardika","doi":"10.22146/jrekpros.76141","DOIUrl":"https://doi.org/10.22146/jrekpros.76141","url":null,"abstract":"Penelitian ini dilakukan untuk mengetahui pengaruh lama iradiasi sinar UV dan penambahan H2O2 terhadap karakteristik mikroplastik limbah disposable face mask (DFM). DFM atau masker sekali pakai terbuat dari bahan polipropilen memiliki sifat hidrofobik yang tinggi sehingga proses degradasi tidak dapat berlangsung secara maksimal. Fotodegradasi UV dan penambahan H2O2 merupakan salah satu metode yang dapat digunakan untuk memodifikasi struktur kimia dari mikroplasatik dengan membentuk gugus fungsi aktif seperti gugus karbonil dan gugus hidroksil. Fotodegradasi sinar UV dilakukan dengan memvariasikan lama waktu iradiasi sinar UV yaitu 24; 36; 48; 60; 72 jam untuk sampel tanpa dan dengan penambahan H2O2 1% v/v. Hasil proses fotodegradasi dikarakterisasi berdasarkan kandungan dari sampel, yaitu perubahan struktur kimia yang dianalisa menggunakan Fourier Transform Infrared (FTIR), perubahan morfologi permukaan mikroplastik dianalisa menggunakan mikroskop binokuler dan persentase penurunan berat mikroplastik dianalisa menggunakan metode gravimetri. Penelitian ini didapatkan hasil terbaik fotodegradasi tanpa H2O2 terjadi pada waktu 36 jam dan hasil terbaik fotodegradasi dengan kombinasi penambahan H2O2 terjadi pada waktu 60 jam berdasarkan penurunan persen transmitansi terbesar gugus karbonil (C=O) yang dianalisis menggunakan FTIR sehingga terjadi penurunan hidrofobisitas pada DFM walaupun tidak siginifikan. Penambahan H2O2 1% v/v tidak memberikan pengaruh signifikan terhadap perubahan karakteristik sampel yang difotodegradasi yang dibuktikan dengan hasil analisis FTIR, perubahan struktur permukaan sampel DFM dan berat yang hilang dari sampel DFM setelah proses fotodegradasi. Berat yang hilang dari sampel setelah proses fotodegradasi sebesar 0,43% tanpa penambahan H2O2 dan 0,29% dengan penambahan H2O2 dengan waktu iradiasi selama 72 jam(α < 1%).","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48377500","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rachma Tia Evitasari, Hana Rofiqoh, Putri Alfina Damayanti, F. Chusna
Purple sweet potato (Ipomoea batatas L.) is one of the tubers or roots that is widely grown in Indonesia that contain high antioxidants. One type of flavonoid that functions as an antioxidant is a natural dye called anthocyanin. In the process of extraction of anthocyanin, the solvent has an important role. In this research, the deep eutectic solvent was used because it is more economical and environmentally friendly. This research will optimize the microwave assisted extraction of anthocyanin content in purple sweet potato (Ipomoea batatas L.) using a deep eutectic solvent with the variation of material to solvent ratio, microwave power, and extraction time. Optimization is done by using the statistical method Response Surface Method (RSM) with Total Anthocyanin content as a response. The optimum operating conditions for the extraction of anthocyanins from purple sweet potato using the deep eutectic solvent were obtained at a solid to solvent ratio of 1:29 at a microwave power of 270 watts for 193 s, with an optimum TAC value of 311.64 mg/L and an antioxidant value of 44.85%. The use of DES can increase the extraction yield and is environmentally friendly.
{"title":"Microwave assisted extraction of anthocyanin from purple sweet potato (Ipomoea batatas L.) using deep eutectic solvent (DES) based on citric acid","authors":"Rachma Tia Evitasari, Hana Rofiqoh, Putri Alfina Damayanti, F. Chusna","doi":"10.22146/jrekpros.72046","DOIUrl":"https://doi.org/10.22146/jrekpros.72046","url":null,"abstract":"Purple sweet potato (Ipomoea batatas L.) is one of the tubers or roots that is widely grown in Indonesia that contain high antioxidants. One type of flavonoid that functions as an antioxidant is a natural dye called anthocyanin. In the process of extraction of anthocyanin, the solvent has an important role. In this research, the deep eutectic solvent was used because it is more economical and environmentally friendly. This research will optimize the microwave assisted extraction of anthocyanin content in purple sweet potato (Ipomoea batatas L.) using a deep eutectic solvent with the variation of material to solvent ratio, microwave power, and extraction time. Optimization is done by using the statistical method Response Surface Method (RSM) with Total Anthocyanin content as a response. The optimum operating conditions for the extraction of anthocyanins from purple sweet potato using the deep eutectic solvent were obtained at a solid to solvent ratio of 1:29 at a microwave power of 270 watts for 193 s, with an optimum TAC value of 311.64 mg/L and an antioxidant value of 44.85%. The use of DES can increase the extraction yield and is environmentally friendly.","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44849056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-30DOI: 10.37037/jrftsp.v12i1.150
Lisa Risna, Melinda Noer, Rizki Aziz
Persoalan kumuh menjadi bagian permasalahan kumuh bagi kota-kota besar di Indonesia dan menjadi tanggung jawab semua pihak dalam penanganannya. Berbagai upaya dilakukan dalam penanganannya untuk terciptanya lingkungan yang sehat, bersih, aman, tertib, layak huni, dan nyaman bagi penghuninya. Kelurahan Batang Arau Kota Padang salah satu kelurahan kumuh di Kota Padang sesui SK Kumuh tahun 2014. Penanganan kumuh telah dilakukan oleh beberapa pihak sejak 4 tahun terakhir sehingga perlu dianalisis efektifitas penanganan permukiman kumuh yang dilakukan. Penelitian ini dilakukan dengan menggunakan metode penelitian kualitatif dan kuantitatif. Pengumpulan data dilakukan dengan observasi lapangan, wawancara secara bebas. Data yang digunakan mencakup data kualitatif seperti data kondisi fisik wilayah, penggunaan lahan sedangkan data kuantitatif berupa data demografi, data sarana dan prasarana lingkungan, data numerik 7 aspek kumuh, dan data investasi kegiatan penanganan kumuh. Pengolahan data menggunakan analisis terhadap data baseline yang bersumber dari Program KOTAKU dan data kolaborasi kegiatan investasi penanganan kumuh tahun 2016-2019. Program Kota Tanpa Kumuh (KOTAKU) salah satu program nasional yang fokus pada pencapaian pengurangan luasan kumuh. Hasil penelitian menginformasikan bahwa 3 kriteria yang dinilai efektivitasnya yaitu upaya/usaha (effort) yang dilakukan oleh pemerintah dalam melaksanakan program sesuai dengan tujuan yang ingin dicapai dinilai tidak efektif, hasil (result) dari pelaksanaan program dibandingkan dengan hasil yang ditetapkan sebelumnya, dinilai tidak efektif serta dampak (impact) yang dirasakan langsung oleh masyarakat dari pelaksanaan program dinilai efektif. Berdasarkan hal tersebut, dapat disimpulkan bahwa efektivitas penanganan permasalahan permukiman kumuh di Kelurahan Batang Arau dinilai tidak efektif.
{"title":"EFEKTIVITAS PENANGANAN PERMUKIMAN KUMUH DI KELURAHAN BATANG ARAU KOTA PADANG","authors":"Lisa Risna, Melinda Noer, Rizki Aziz","doi":"10.37037/jrftsp.v12i1.150","DOIUrl":"https://doi.org/10.37037/jrftsp.v12i1.150","url":null,"abstract":"Persoalan kumuh menjadi bagian permasalahan kumuh bagi kota-kota besar di Indonesia dan menjadi tanggung jawab semua pihak dalam penanganannya. Berbagai upaya dilakukan dalam penanganannya untuk terciptanya lingkungan yang sehat, bersih, aman, tertib, layak huni, dan nyaman bagi penghuninya. Kelurahan Batang Arau Kota Padang salah satu kelurahan kumuh di Kota Padang sesui SK Kumuh tahun 2014. Penanganan kumuh telah dilakukan oleh beberapa pihak sejak 4 tahun terakhir sehingga perlu dianalisis efektifitas penanganan permukiman kumuh yang dilakukan. Penelitian ini dilakukan dengan menggunakan metode penelitian kualitatif dan kuantitatif. Pengumpulan data dilakukan dengan observasi lapangan, wawancara secara bebas. Data yang digunakan mencakup data kualitatif seperti data kondisi fisik wilayah, penggunaan lahan sedangkan data kuantitatif berupa data demografi, data sarana dan prasarana lingkungan, data numerik 7 aspek kumuh, dan data investasi kegiatan penanganan kumuh. Pengolahan data menggunakan analisis terhadap data baseline yang bersumber dari Program KOTAKU dan data kolaborasi kegiatan investasi penanganan kumuh tahun 2016-2019. Program Kota Tanpa Kumuh (KOTAKU) salah satu program nasional yang fokus pada pencapaian pengurangan luasan kumuh. Hasil penelitian menginformasikan bahwa 3 kriteria yang dinilai efektivitasnya yaitu upaya/usaha (effort) yang dilakukan oleh pemerintah dalam melaksanakan program sesuai dengan tujuan yang ingin dicapai dinilai tidak efektif, hasil (result) dari pelaksanaan program dibandingkan dengan hasil yang ditetapkan sebelumnya, dinilai tidak efektif serta dampak (impact) yang dirasakan langsung oleh masyarakat dari pelaksanaan program dinilai efektif. Berdasarkan hal tersebut, dapat disimpulkan bahwa efektivitas penanganan permasalahan permukiman kumuh di Kelurahan Batang Arau dinilai tidak efektif.","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76330240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-25DOI: 10.37037/jrftsp.v12i1.113
Vivi Ariani, F. Roza, Embun Sari Ayu
Klaim dalam industri konstruksi merupakan masalah yang dapat mengacu kepada permohonan terhadap pertambahan biaya dan pertambahan waktu serta memicu terjadinya perselisihan antara penyedia jasa ke pengguna jasa. Tujuan yang ingin dicapai dalam penelitian ini adalah untuk mengidentifikasi faktor penyebab timbulnya klaim pada proyek konstruksi oleh penyedia jasa ke pengguna jasa. Metodologi penelitian dalam penelitian ini adalah penelitian kuantitatif dengan penyebaran survey kuesioner kepada praktisi industri konstruksi khususnya kepada stakeholder proyek konstruksi untuk menjawab tujuan penelitian. Pengumpulan data survey kuesioner dilakukan kepada stakeholder proyek konstruksi di Kota Padang, meliputi pemilik proyek (owner), konsultan perencana, konsultan pengawas dan kontraktor. Teknik analisa data dilakukan dengan menggunakan statistik deskriptif yaitu: rata-rata (mean) dan standar deviasi. Mean digunakan untuk mengetahui nilai rata-rata dari jumlah respon untuk tiap jawaban yang tersedia. Dari hasil analisa, diperoleh 28 faktor penyebab terjadinya klaim konstruksi oleh penyedia jasa ke pengguna jasa. Luaran penelitian diharapkan dapat mempermudah proses pengajuan klaim proyek konstruksi.
{"title":"IDENTIFIKASI PENYEBAB TIMBULNYA PENGAJUAN KLAIM KONSTRUKSI DARI PENYEDIA JASA KE PENGGUNA JASA DI KOTA PADANG","authors":"Vivi Ariani, F. Roza, Embun Sari Ayu","doi":"10.37037/jrftsp.v12i1.113","DOIUrl":"https://doi.org/10.37037/jrftsp.v12i1.113","url":null,"abstract":"Klaim dalam industri konstruksi merupakan masalah yang dapat mengacu kepada permohonan terhadap pertambahan biaya dan pertambahan waktu serta memicu terjadinya perselisihan antara penyedia jasa ke pengguna jasa. Tujuan yang ingin dicapai dalam penelitian ini adalah untuk mengidentifikasi faktor penyebab timbulnya klaim pada proyek konstruksi oleh penyedia jasa ke pengguna jasa. Metodologi penelitian dalam penelitian ini adalah penelitian kuantitatif dengan penyebaran survey kuesioner kepada praktisi industri konstruksi khususnya kepada stakeholder proyek konstruksi untuk menjawab tujuan penelitian. Pengumpulan data survey kuesioner dilakukan kepada stakeholder proyek konstruksi di Kota Padang, meliputi pemilik proyek (owner), konsultan perencana, konsultan pengawas dan kontraktor. Teknik analisa data dilakukan dengan menggunakan statistik deskriptif yaitu: rata-rata (mean) dan standar deviasi. Mean digunakan untuk mengetahui nilai rata-rata dari jumlah respon untuk tiap jawaban yang tersedia. Dari hasil analisa, diperoleh 28 faktor penyebab terjadinya klaim konstruksi oleh penyedia jasa ke pengguna jasa. Luaran penelitian diharapkan dapat mempermudah proses pengajuan klaim proyek konstruksi. \u0000 ","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80503917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-25DOI: 10.37037/jrftsp.v12i1.129
Harne julianti Tou, M. Noer, Helmi
Tourism is not only done in urban areas but also has been in great demand in the countryside. This is due to the beauty of nature, cultural uniqueness, and other characteristics in rural areas that attract visitors. Besides aiming to reduce the fatigue of activities in the city, tourists also want to experience nature and the life of rural communities. This literature study research seeks to identify the main pillars of sustainable rural tourism development. Sustainable rural tourism development is the development of the tourism sector in the village by observing the sustainability of tourism, such as efficient use of environmental resources while preserving natural heritage and biodiversity, including respecting the socio-cultural authenticity of the local community in terms of inter-cultural tolerance and should provide socio-economic benefits to all stakeholders, using qualitative descriptive methods. The writer analyzed the objects of the study in terms of tourism development, rural tourism, sustainable rural tourism development, and the role of stakeholders in rural tourism development. The main pillars found are culture and community participation (socio-culture), ecology (environment), and policy (politics).
{"title":"Sustainable Pilar Of Rural Tourism Development","authors":"Harne julianti Tou, M. Noer, Helmi","doi":"10.37037/jrftsp.v12i1.129","DOIUrl":"https://doi.org/10.37037/jrftsp.v12i1.129","url":null,"abstract":"Tourism is not only done in urban areas but also has been in great demand in the countryside. This is due to the beauty of nature, cultural uniqueness, and other characteristics in rural areas that attract visitors. Besides aiming to reduce the fatigue of activities in the city, tourists also want to experience nature and the life of rural communities. This literature study research seeks to identify the main pillars of sustainable rural tourism development. Sustainable rural tourism development is the development of the tourism sector in the village by observing the sustainability of tourism, such as efficient use of environmental resources while preserving natural heritage and biodiversity, including respecting the socio-cultural authenticity of the local community in terms of inter-cultural tolerance and should provide socio-economic benefits to all stakeholders, using qualitative descriptive methods. The writer analyzed the objects of the study in terms of tourism development, rural tourism, sustainable rural tourism development, and the role of stakeholders in rural tourism development. The main pillars found are culture and community participation (socio-culture), ecology (environment), and policy (politics).","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77248659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The study aims to compare the effectiveness of chromium removal from water using adsorption by coal fly ash (CFA) and phytoremediation by vetiver grass (Vetiveria zizanioides L) as well as a combination of both CFA and vetiver grass. The experiment was carried out in four different reactors, having size of 100 cm (length) x 60 cm (wide) x 80 cm (height). One reactor was filled with gravel and CFA, without vetiver grass (RI), while another one was filled with gravel and vetiver grass, without CFA (RIV). The other two reactors were filled with gravel, CFA, and vetiver grass with the mass ratio of gravel/CFA of (25:2) and (25:1), denoted as RII and RIII, respectively. Fifty (50) L of synthetic wastewater containing 14.612 ppm of chromium was filled into the reactors and continuously recirculated for 15 days. Chromium accumulation in CFA and plants was analyzed on day 15. The results of plant development are indicated by the presence of new shoots and roots that grow during phytoremediation processes. In addition, there was an increase in weight and number of vetiver stems indicating the persistency of vetiver grass in such a harsh wastewater condition. The removal of Cr from wastewater in RI, RII, RIII and RIV at days 15 were 81%, 93.2%, 85.8% and 75.7%, respectively. It can be concluded that: (1) vetiver grass (Vetiveria zizanioides L) has high potential as phytoremediator plant, (2) Chromium adsorption by CFA plays important role in Cr removal from wastewater, and (3) combination of adsorption by CFA and a phytoremediation by vetiver grass significantly increases the removal of chromium from wastewater.
{"title":"Study of chromium removal from wastewater using SSF-CW model: comparison between physical adsorption by coal CFA and phytoremediation by vetiver grass (Vetiveria Zizanioides L)","authors":"Titik Indrawati, S. Sarto, A. Prasetya","doi":"10.22146/jrekpros.69978","DOIUrl":"https://doi.org/10.22146/jrekpros.69978","url":null,"abstract":"The study aims to compare the effectiveness of chromium removal from water using adsorption by coal fly ash (CFA) and phytoremediation by vetiver grass (Vetiveria zizanioides L) as well as a combination of both CFA and vetiver grass. The experiment was carried out in four different reactors, having size of 100 cm (length) x 60 cm (wide) x 80 cm (height). One reactor was filled with gravel and CFA, without vetiver grass (RI), while another one was filled with gravel and vetiver grass, without CFA (RIV). The other two reactors were filled with gravel, CFA, and vetiver grass with the mass ratio of gravel/CFA of (25:2) and (25:1), denoted as RII and RIII, respectively. Fifty (50) L of synthetic wastewater containing 14.612 ppm of chromium was filled into the reactors and continuously recirculated for 15 days. Chromium accumulation in CFA and plants was analyzed on day 15. The results of plant development are indicated by the presence of new shoots and roots that grow during phytoremediation processes. In addition, there was an increase in weight and number of vetiver stems indicating the persistency of vetiver grass in such a harsh wastewater condition. The removal of Cr from wastewater in RI, RII, RIII and RIV at days 15 were 81%, 93.2%, 85.8% and 75.7%, respectively. It can be concluded that: (1) vetiver grass (Vetiveria zizanioides L) has high potential as phytoremediator plant, (2) Chromium adsorption by CFA plays important role in Cr removal from wastewater, and (3) combination of adsorption by CFA and a phytoremediation by vetiver grass significantly increases the removal of chromium from wastewater.","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42278864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Prasakti, Billy Dion Yogihaz, L. Subekti, Anton Sujarwo, A. Prasetya
This research aimed to examine the effect of NaCl concentration on the pH and Oxidation Reduction Potential (ORP) values of both EOW and ERW products. The experiment was conducted using distilled water. The electrolysis apparatus consisted of anode and cathode chambers. The chambers were connected by a tube filled with a cotton (or a fabric). Both electrodes (anode and cathode) were made of titanium and formed as a spiral. Electrolysis was performed for 780 minutes, and the pH and ORP values of both EOW and ERW were measured every time. Sodium chloride concentration was varied for 0, 100, and 200 ppm. Experimental results revealed that the higher the NaCl concentration, the higher ERW’s pH rise and the lower the EOW’s pH. Similar results were found for ORP. ERW’s ORP was lowered while EOW’s ORP rose with the increase in NaCl concentration. This study could also generate a mathematical model that correlates pH and time during the electrolysis process. The model was developed by connecting with a simple polynomial. A similar approach was used to develop the model that correlates pH and ORP value.
{"title":"Effect of salt concentration on the properties of electrolyzed reducing water (ERW) and electrolyzed oxidizing water (EOW): an empirical correlation study","authors":"L. Prasakti, Billy Dion Yogihaz, L. Subekti, Anton Sujarwo, A. Prasetya","doi":"10.22146/jrekpros.69673","DOIUrl":"https://doi.org/10.22146/jrekpros.69673","url":null,"abstract":"This research aimed to examine the effect of NaCl concentration on the pH and Oxidation Reduction Potential (ORP) values of both EOW and ERW products. The experiment was conducted using distilled water. The electrolysis apparatus consisted of anode and cathode chambers. The chambers were connected by a tube filled with a cotton (or a fabric). Both electrodes (anode and cathode) were made of titanium and formed as a spiral. Electrolysis was performed for 780 minutes, and the pH and ORP values of both EOW and ERW were measured every time. Sodium chloride concentration was varied for 0, 100, and 200 ppm. Experimental results revealed that the higher the NaCl concentration, the higher ERW’s pH rise and the lower the EOW’s pH. Similar results were found for ORP. ERW’s ORP was lowered while EOW’s ORP rose with the increase in NaCl concentration. This study could also generate a mathematical model that correlates pH and time during the electrolysis process. The model was developed by connecting with a simple polynomial. A similar approach was used to develop the model that correlates pH and ORP value.","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48982724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Himawan Novianto, Muhammad Mufti Azis, Hilya Mudrika Arini
Beberapa penelitian membahas penurunan konsentrasi polutan udara selama masa pandemi COVID-19, namun belum banyak penelitian yang membahas kaitan antara variabel kualitas udara dan tingkat mobilitas masyarakat. Penelitian ini menyelidiki keterkaitan hubungan antara variabel polutan udara, faktor meteorologi, dan tingkat mobilitas masyarakat di Kota Yogyakarta. Fenomena hubungan sistem kualitas udara dan mobilitas masa pandemi COVID-19 tahun 2020 terbagi dalam dua periode: (a) Pembatasan Aktivitas (April s.d. Juli 2020) dan (b) Normal Baru (Agustus s.d. Desember 2020). Kualitas udara Kota Yogyakarta sebelum dan pada masa pandemi COVID-19 menunjukkan perbaikan, dari kategori Baik: 31,85% menjadi 90,37% ISPU (chi-square asymp. sig. < 0,05). Polutan udara PM10, SO2, dan CO menurun sebesar 18%, 93%, dan 74%, sedangkan O3 meningkat sebesar 104% pada masa pandemi COVID-19 tahun 2020. Polutan udara primer PM10, SO2, dan CO berhubungan positif terhadap faktor meteorologi penyinaran matahari, tetapi berhubungan negatif terhadap polutan udara sekunder O3 serta faktor meteorologi suhu udara, kelembaban udara, curah hujan, dan kecepatan angin. Pembatasan aktivitas masyarakat di luar rumah secara umum menyebabkan perbaikan kualitas udara, di mana penurunan mobilitas transportasi menjadi variabel yang mempengaruhi penurunan polutan udara primer di Kota Yogyakarta. Pembatasan aktivitas mempengaruhi polutan udara sekunder, di mana kenaikan O3 terjadi ketika mobilitas dalam ruangan dan transportasi meningkat.
{"title":"Analisis perubahan sistem kualitas udara Kota Yogyakarta pada masa pandemi COVID-19","authors":"Himawan Novianto, Muhammad Mufti Azis, Hilya Mudrika Arini","doi":"10.22146/jrekpros.71888","DOIUrl":"https://doi.org/10.22146/jrekpros.71888","url":null,"abstract":"Beberapa penelitian membahas penurunan konsentrasi polutan udara selama masa pandemi COVID-19, namun belum banyak penelitian yang membahas kaitan antara variabel kualitas udara dan tingkat mobilitas masyarakat. Penelitian ini menyelidiki keterkaitan hubungan antara variabel polutan udara, faktor meteorologi, dan tingkat mobilitas masyarakat di Kota Yogyakarta. Fenomena hubungan sistem kualitas udara dan mobilitas masa pandemi COVID-19 tahun 2020 terbagi dalam dua periode: (a) Pembatasan Aktivitas (April s.d. Juli 2020) dan (b) Normal Baru (Agustus s.d. Desember 2020). Kualitas udara Kota Yogyakarta sebelum dan pada masa pandemi COVID-19 menunjukkan perbaikan, dari kategori Baik: 31,85% menjadi 90,37% ISPU (chi-square asymp. sig. < 0,05). Polutan udara PM10, SO2, dan CO menurun sebesar 18%, 93%, dan 74%, sedangkan O3 meningkat sebesar 104% pada masa pandemi COVID-19 tahun 2020. Polutan udara primer PM10, SO2, dan CO berhubungan positif terhadap faktor meteorologi penyinaran matahari, tetapi berhubungan negatif terhadap polutan udara sekunder O3 serta faktor meteorologi suhu udara, kelembaban udara, curah hujan, dan kecepatan angin. Pembatasan aktivitas masyarakat di luar rumah secara umum menyebabkan perbaikan kualitas udara, di mana penurunan mobilitas transportasi menjadi variabel yang mempengaruhi penurunan polutan udara primer di Kota Yogyakarta. Pembatasan aktivitas mempengaruhi polutan udara sekunder, di mana kenaikan O3 terjadi ketika mobilitas dalam ruangan dan transportasi meningkat.","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49382207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Penelitian ini bertujuan untuk melakukan analisis keekonomian pada skenario alternatif pengolahan sampah yang melibatkanan aerobic digestion (AD), pengomposan, dan landfilling. Penanganan sampah menggunakan beberapa metode alternatif selain dumping dan landfilling atau keduanya diperlukan untuk mengurangi dampak lingkungan yang ditimbulkan. Penelitian terdahulu menggunakan pendekatan life cycle assessment (LCA) menunjukkan bahwa skenario tersebut memberikan dampak potensi pemanasan global yang lebih rendah di TPA Gunung Panggung, Kabupaten Tuban. Analisis kelayakan ekonomi menunjukkan hasil positif dengan nilai benefit cost ratio (BCR), net present value (NPV), dan internal rate return (IRR) masing-masing sebesar 1,62, Rp34.893.409.826,37, dan 34,07%. Analisis sensitivitas dilakukan dengan memvaria- sikan harga produk dan biaya produksi. Adanya perubahan harga tidak menunjukkan perubahan yang signifikan terhadap nilai kelayakan investasi ini.
{"title":"Analisis Keekonomian Skenario Pengelolaan Sampah di TPA Gunung Panggung Tuban Jawa Timur","authors":"Rahmah Arfiyah Ula, Iman Haryanto, Agus Prasetya","doi":"10.22146/jrekpros.69657","DOIUrl":"https://doi.org/10.22146/jrekpros.69657","url":null,"abstract":"Penelitian ini bertujuan untuk melakukan analisis keekonomian pada skenario alternatif pengolahan sampah yang melibatkanan aerobic digestion (AD), pengomposan, dan landfilling. Penanganan sampah menggunakan beberapa metode alternatif selain dumping dan landfilling atau keduanya diperlukan untuk mengurangi dampak lingkungan yang ditimbulkan. Penelitian terdahulu menggunakan pendekatan life cycle assessment (LCA) menunjukkan bahwa skenario tersebut memberikan dampak potensi pemanasan global yang lebih rendah di TPA Gunung Panggung, Kabupaten Tuban. Analisis kelayakan ekonomi menunjukkan hasil positif dengan nilai benefit cost ratio (BCR), net present value (NPV), dan internal rate return (IRR) masing-masing sebesar 1,62, Rp34.893.409.826,37, dan 34,07%. Analisis sensitivitas dilakukan dengan memvaria- sikan harga produk dan biaya produksi. Adanya perubahan harga tidak menunjukkan perubahan yang signifikan terhadap nilai kelayakan investasi ini.","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45303730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The first purpose of this study was to investigate the effect of operating variables and surfactant concentration in subcritical water to after ultrasonic process on the sugar-producing yield from coconut husk. The second purpose was to obtain the optimum operating condition of the subcritical water process. The sonication before the subcritical water process was done by dispersing 40 mesh coconut husk powder in water at 60°C, and 35 kHz. The effect of sonication time was studied by comparing the material crystallinity and composition after being treated for 30 minutes. In this research, the optimization was done by using a Box-Behnken response surface methodology (RSM) experimental design with 3 factors (temperature, time, and surfactant concentration). The designed lower and upper levels were 130°C and 170°C, 40, and 80 minutes, as well as 1 and 3% (w). The results showed that the quadratic response surface model predicted the maximum reducing sugar yield to be 12.0%, which was achieved at the optimum condition of 170°C, 77.5 minutes, and 2.3% SDS surfactant addition. The experiment run at the obtained optimum condition resulted in a reducing sugar yield of 11.7%, which was close to that obtained from the model prediction.
{"title":"Coconut Husk to Reducing Sugar Conversion Using Combined Ultrasound and Surfactant Aided Subcritical Water","authors":"Saiyyidah Tus Zuhroh, A. Fatmawati, A. Widjaja","doi":"10.22146/jrekpros.69231","DOIUrl":"https://doi.org/10.22146/jrekpros.69231","url":null,"abstract":"The first purpose of this study was to investigate the effect of operating variables and surfactant concentration in subcritical water to after ultrasonic process on the sugar-producing yield from coconut husk. The second purpose was to obtain the optimum operating condition of the subcritical water process. The sonication before the subcritical water process was done by dispersing 40 mesh coconut husk powder in water at 60°C, and 35 kHz. The effect of sonication time was studied by comparing the material crystallinity and composition after being treated for 30 minutes. In this research, the optimization was done by using a Box-Behnken response surface methodology (RSM) experimental design with 3 factors (temperature, time, and surfactant concentration). The designed lower and upper levels were 130°C and 170°C, 40, and 80 minutes, as well as 1 and 3% (w). The results showed that the quadratic response surface model predicted the maximum reducing sugar yield to be 12.0%, which was achieved at the optimum condition of 170°C, 77.5 minutes, and 2.3% SDS surfactant addition. The experiment run at the obtained optimum condition resulted in a reducing sugar yield of 11.7%, which was close to that obtained from the model prediction.","PeriodicalId":17711,"journal":{"name":"Jurnal Rekayasa Proses","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46867013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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