Kehinde, Fagbenro Oluwakemi (2015) Removal Of Color, Suspended Solids And Cod From Textile Wastewater Using Clinoptilolite And Persulfate, In Batch System. PhD thesis, Universiti Sains Malaysia.
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Abstract
Bekalan air bersih semakin terhad disebabkan oleh berbagai bentuk pencemaran seperti disebabkan oleh industri pencelup dan tekstil. Kajian terdahulu menunjukkan bahawa air sisa tekstil adalah toksik, karsinogen dan mutagen. Cirinya yang ketara adalah warna yang pekat, serta mengandungi nilai Keperluan Oksigen Kimia (COD) dan pepejal terampai yang tinggi disebabkan oleh pencelup berlebihan yang hadir dalam air-sisa selepas produksi. Salah satu industri tekstil di kawasan utara Malaysia sedang menghadapi masalah untuk mematuhi piawai pelepasan efluen terhadap tiga parameter di atas. Sehubungan itu, parameter tersebut dipilih sebagai fokus kajian ini. Disebabkan air sisa tekstil adalah recalcitrant terhadap teknik olahan konvesional, proses pra-olahan berasas kimia telah dicadangkan untuk membolehkan penguraian biologi dilakukan di mana sesuai. Lanjutan itu, potensi olahan oleh clinoptilolite (CPL), persulfat (PS) dan gabungan keduanya diselidiki dalam kajian ini melalui proses-proses penjerapan, pengoksidaan dan penjerapan-pengoksidaan. Beberapa siri pra-eksperimen kelompok dilakukan untuk menentukan julat pembolehubah proses tidak bersandar yang cenderung terhadap ketiga-tiga proses (olahan oleh; CPL, PS, and CPL/PS). Setelah julat setiap pembolehubah bekerja (operasi) ditentukan, mereka dioptimumkan dalam siri eksperimen berikutnya menggunakan kaedah klasik. Kaedah Tindakbalas Permukaan (RSM) diaplikasikan bagi membuktikan saling tindak balas antara pembolehubah bersandar dan tidak bersandar. Berikutnya, pembolehubah-pembolehubah proses, seperti dos media, pH awal dan masa tindakbalas juga dioptimumkan seiring dengan parameter tindakbalas (warna, SS, dan COD). Kesan pengaktifan haba PS pada suhu 40°C, 50°C dan 60°C dikaji dalam proses pengoksidan PS. Dalam analisis akhir, keupayaan setiap sistem yang telah dioptimumkan dibandingkan untuk menentukan sistem yang paling berkesan. Keputusan menunjukkan bahawa pada keadaan optimum yang telah ditentukan (saiz zarah: <75μm-250μm, kelajuan adukan: 150rpm, pH: 2, dos: 8g dan masa tindakbalas: 100minit) olahan oleh CPL, penyingkiran optimum warna, SS dan COD adalah masingmasing 90%, 90% dan 79%. Manakala, untuk pengoksidaan PS (pada suhu bilik), 90%, 78% dan 50% warna, SS dan COD berjaya disingkirkan pada keadaan optimum (kelajuan adukan: 150rpm, dos: 1/4 (i.e. nisbah pencemar/pengoksida), pH: 3 dan masa tindakbalas dalam minit: 360 (warna), 420 (SS) dan 60 (COD). Kombinasi olahan CPL/PS menghasilkan masing-masing 98%, 99% dan 74% penyingkiran untuk warna, SS dan COD pada keadaan optimum (CPL dos: 8g, dos PS: 1/4, pH: 4 dan masa tindakbalas dalam minit: 300 (warna), 210 (SS) dan 30 (COD). Perbandingan ketiga-tiga proses menunjukkan pencapaian yang lebih baik untuk proses kombinasi CPL/PS yang hampir menyahkan keseluruhannya warna dan pepejal terampai. Walaubagaimanapun, ia kurang berkesan untuk penyingkiran COD, berbanding penggunaan CPL. Penyingkiran oleh PS teraktif haba didapati lebih baik berbanding pengoksidaan PS pada suhu bilik. Keputusan kajian ini menunjukkan bahawa kombinasi clinoptilolite/persulfat adalah proses terbaik diantara ketiga-tiga proses yang telah dikaji dan mempunyai potensi yang lebih baik untuk digunakan dalam menyingkirkan SS, warna, dan COD dari air sisa tekstil mentah. Walaubagaimanapun, rawatan yang lebih lanjut adalah dicadangkan untuk menyingkirkan COD sepenuhnya. ________________________________________________________________________________________________________________________ The supply of clean water is limited by various sources of pollution such as the dye and textile industries. Previous studies have shown that textile wastewater is toxic, carcinogenic and mutagenic. Its most obvious characteristics are the strong color, high chemical oxygen demand (COD) and suspended solid (SS) caused by unfixed dyes and stuff remaining in the wastewater after production. One of the textile industries in the northern region, Malaysia, is experiencing difficulties in complying with the standard discharge limit of effluent against these parameters. Hence they were selected as the focus of this study. Because textile wastewater is recalcitrant to conventional treatment techniques, chemical based pretreatment have been suggested to degrade and make treatable by biological means, where necessary. In the light of this, the treatment potential of each of clinoptilolite (CPL), persulfate (PS) and a combination of both were investigated in this study by adsorption, oxidation, and adsorption-oxidation processes. A series of batch preliminary experiments were conducted to determine the range of each independent process variable that favours, the three processes (treatments via; CPL, PS, and CPL/PS). Having predetermined the range of each working (operational) variable, they were optimized in another series of main experiments using the classical method. The response surface methodology (RSM) was applied to show the interrelationship between the dependent and independent process variables. Also, the process variables, especially dosage of media, initial pH of reaction and reaction time were optimized alongside the response parameters (color, SS, and COD). The effect of thermal activation of PS at temperatures of 40°C, 50°C and 60°C was investigated in the PS oxidation process. In the final analysis, the performances of each optimized system were compared to determine the most efficient system. Results indicated that, at the predetermined optimum conditions (particle size: <75μm-250μm, agitation speed: 150rpm, pH: 2, dosage: 8g and contact time: 100minutes) of treatment via CPL, the optimum removals for color, SS and COD in terms of percentages (%) were; 90, 90 and 79 respectively. While PS oxidation (at room temperature) had 90%, 78% and 50% removal of color, SS and COD respectively at the optimum conditions (agitation speed: 150rpm, dosage: 1/4 (i.e. contaminant/oxidant ratio), pH: 3 and contact time in minutes: 360 (color), 420 (SS) and 60 (COD). The combined CPL/PS treatment achieved 98%, 99% and 74% for removal of color, SS and COD at t optimum conditions (CPL dosage: 8g, PS dosage: 1/4, pH: 4 and contact time in minutes: 300 (color), 210 (SS) and 30 (COD). A comparison of the three processes showed a better performance of the combined CPL/PS which achieved an almost complete decolorization and SS removal. However, it achieved less for COD removal while the sole CPL performed best in COD removal. The performance of thermal activated PS was found better than the PS oxidation at room temperature. The findings of this study have shown that the combination of clinoptilolite/persulfate is the best of the three processes that were investigated and potential to be used to remove SS, color and COD from raw textile wastewater. However, since all parameters except COD met the discharge limit, a further treatment is suggested to completely remove the COD.
| Item Type: | Thesis (PhD) |
|---|---|
| Additional Information: | Full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=2866 |
| Subjects: | T Technology T Technology > TA Engineering (General). Civil engineering (General) > TA1-2040 Engineering (General). Civil engineering (General) |
| Divisions: | Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraan Awam (School of Civil Engineering) > Thesis |
| Depositing User: | Mr Mohd Jasnizam Mohd Salleh |
| Date Deposited: | 12 Jul 2018 08:07 |
| Last Modified: | 16 Aug 2018 08:14 |
| URI: | http://eprints.usm.my/id/eprint/41024 |
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