Ng, Yin Sim (2018) Performance Of Spirodela Polyrhiza, Salvinia Molesta And Lemna Sp. In Phytoremediation Of Fish Farm Wastewater. Masters thesis, Universiti Sains Malaysia.
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Abstract
Air sisa ternakan ikan adalah tinggi dalam nutrien terlarut dan pepejal terampai hasil daripada pengumpulan makanan yang berlebihan dan perkumuhan ikan. Pemendapan mengurangkan pepejal terampai tetapi tidak efisien dalam menyingkirkan nutrient terlarut manakala rawatan termaju menghadapi kos yang tinggi dan permintaan tenaga yang besar. Penggunaan makrofit dalam fitopemulihan dapat menyelesaikan isu-isu tersebut disebabkan kos penyelenggaraan yang rendah dan penyingkiran nutrien yang ketara. Oleh itu, kajian ini bertujuan untuk menunjukkan keupayaan penyingkiran nutrient sebenar makrofit dalam keadaan aseptik serta menilai prestasi rawatan makrofit ke atas air sisa ternakan ikan. Dalam hal ini, makrofit Spirodela polyrhiza, Salvinia molesta dan Lemna sp. telah ditaksir dalam air sisa sintetik di bawah keadaan aseptik. Penyingkiran ammonia adalah pantas bagi S. polyrhiza dan Lemna sp., dengan kecekapan penyingkiran 60% dan 41% masing-masing dalam masa 2 hari. S. polyrhiza boleh mengurangkan 30% nitrat manakala Lemna sp. mencapai pengurangan fosfat tertinggi, sebanyak 86% pada hari ke-12. Profil yang diperolehi membolehkan pemilihan makrofit yang sesuai dalam rawatan air sisa ternakan ikan. S. polyrhiza dan Lemna sp. dipilih untuk merawat air sisa mentah ternakan ikan melalui rig kolam raceway (dalam sistem monokultur dan polikultur). Air sisa tersebut diperoleh dari ladang ikan keli tempatan, dengan tahap ammonia, fosfat, TSS dan COD sehingga 28.10 mg NH3-N/L, 5.80 mg PO43-/L, 175 mg/L and 322 mg/L masing-masing. Kolam raceway mempunyai dimensi 50cm x 25cm x 9 cm dan sistem boleh menakung 12 L air sisa. Sistem monokultur S. polyrhiza mengatasi sistem lain dalam penyingkiran nitrogen dan fosforus di mana 81% ammonia dikurangkan kepada 3.90 mg NH3-N/L dalam 2 hari manakala aras nitrat, nitrit dan fosfat diturunkan secara ketara. Hal ini disebabkan keupayaan pengambilan yang tinggi terhadap pelbagai spesies nitrogen dan fosfat. Penurunan tajam paras TSS, kekeruhan dan COD (sehingga 75%, 88% dan 71% dalam 2 hari) dicatatkan. Semua sistem makrofit menunjukkan produktiviti biojisim yang tinggi (peningkatan sehingga 112%) dan keunggulan dalam kandungan protein (peningkatan sehingga 12%). Kesan fed batch dan penuaian secara berkala terhadap kapasiti dan prestasi rawatan sistem monokultur S. polyrhiza juga dinilai. Sistem dengan fed batch dan penuaian dapat merawat isi padu air sisa yang lebih banyak, menyingkirkan amaun bahan pencemar yang lebih tinggi sementara mencapai had efluen yang ditetapkan. Kajian ini mencadangkan sistem monokultur S. polyrhiza dengan fed batch dan penuaian yang optimum boleh dilaksanakan dan berkesan untuk merawat air sisa ternakan ikan dan menghasilkan biojisim yang berguna untuk pelbagai aplikasi seperti suplemen makanan ikan, diet unggas, baja dan biofuel. _______________________________________________________________________________________________________ Fish farm wastewater is high in dissolved nutrients and suspended solids due to accumulation of uneaten feed and fish excretions. Sedimentation reduces suspended solids but not efficient in removing dissolved nutrients while advanced treatment suffers from high cost and huge energy demand. Phytoremediation using macrophytes could solve these issues owing to low maintenance cost and significant nutrients removal. Therefore, this study intended to show the true nutrients removal capabilities of macrophytes under axenic condition and to evaluate the treatment performance of macrophytes on fish farm wastewater. In this regard, Spirodela polyrhiza, Salvinia molesta and Lemna sp. macrophytes were assessed axenically in synthetic wastewater. The ammonia removal was rapid for S. polyrhiza and Lemna sp., with 60% and 41% removal efficiency respectively within 2 days. S. polyrhiza could reduce 30% of the nitrate while Lemna sp. achieved the highest phosphate reduction, of 86% at day 12. The acquired profiles allow selection of suitable macrophytes in fish farm wastewater treatment. S. polyrhiza and Lemna sp. were chosen to treat raw fish farm wastewater via raceway pond rig (in monoculture and polyculture system). The wastewater was sourced from a local catfish farm, of ammonia, phosphate, TSS and COD levels up to 28.10 mg NH3-N/L, 5.80 mg PO43-/L, 175 mg/L and 322 mg/L respectively. The raceway pond had dimensions of 50cm x 25cm x 9 cm and the system could hold 12 L wastewater. S. polyrhiza monoculture system surpassed other systems in nitrogen and phosphorus removal where 81% ammonia was reduced to 3.90 mg NH3-N/L in 2 days whilst the nitrate, nitrite and phosphate levels were significantly lowered. It was attributed to its high uptake capabilities of various nitrogen species and phosphate. Steep decline of TSS, turbidity and COD levels (up to 75%, 88% and 71% in 2 days) were recorded. All macrophyte systems demonstrated high biomass productivity (up to 112% increment) and superiority in protein content (up to 12% increment). The effect of fed batch and periodic harvesting on treatment capacity and performance of S. polyrhiza monoculture system were also evaluated. The system with fed batch and harvesting could treat more volume of wastewater, remove higher amount of pollutants while meeting effluent limits. This study suggested that S. polyrhiza monoculture system with fed batch and optimal harvesting is feasible and effective in treating fish farm wastewater and produces useful biomass for various applications such as fish feed supplement, poultry diet, fertiliser and biofuel.
| Item Type: | Thesis (Masters) |
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| Additional Information: | Full text is available at http://irplus.eng.usm.my:8080/ir_plus/institutionalPublicationPublicView.action?institutionalItemId=4731 |
| Subjects: | T Technology T Technology > TP Chemical Technology > TP1-1185 Chemical technology |
| Divisions: | Kampus Kejuruteraan (Engineering Campus) > Pusat Pengajian Kejuruteraan Kimia (School of Chemical Engineering) > Thesis |
| Depositing User: | Mr Mohd Jasnizam Mohd Salleh |
| Date Deposited: | 19 Jun 2019 09:31 |
| Last Modified: | 19 Jun 2019 09:31 |
| URI: | http://eprints.usm.my/id/eprint/44678 |
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