Performance of conventional oxidation pond using integrated phytogreen system by aquatic plants for achivieng standard a effluent / Abdul Syukor Abd. Razak

Faculty of Civil Engineering Technology

Thesis (Doctor of Philosophy in Civil Engineering Technology) -- Universiti Malaysia Pahang – 2020

Includes bibliographical references

Phytogreen systems using phytoremediation technology have been identified as one of the high capacity technologies for processing domestic wastewater. This system is an alternative to conventional systems that are expensive, less efficient and have a long maintenance and long life especially in oxidation ponds. This integrated phytogreen system (IPS) consists of phytogreen zone (PZ), aeration zone (AZ) and incline plate clarification zone (IPC) which is able to remove organic contaminants, nutrients and heavy metals in the maturation pond in a compact arrangement and does not require large areas at 30oC. Therefore, the installation of this compact system can save maintenance costs and be more efficient. The main objective of this study is to develop an integrated phytogreen system that can produce wastewater effluent quality that meets standard A, Environmental Quality Act 1974 (EQA, 1974). Six types of aquatic plants were selected, namely Pistia stratiotes sp., Eichhornia crassipes sp., Typha angustifolia sp., Lepironia articulata sp., Monochoria vaginalis and Limnochoris flava. All of these plants were placed in a pilot plant-scale maturation pond with a population average of 5000 PE and a retention time of 13 days. Analysis of contaminants accumulation in roots, stems and leaves using Field Emission Scanning Electron Microcsophy (FESEM) together with Energy Dispersion X-ray (EDX) was conducted. Some parameters such as temperature, pH, biochemical oxygen demand @ 5 days (BOD5), chemical oxygen demand (COD), total suspended solids (TSS), oil and grease, ammonical nitrogen (NH3-N), phosphorus, nitrate, nitrite, turbidity and potassium have been tested to determine the effectiveness of these aquatic plants in wastewater treatment. All analytical measurements in this study were conducted according to the Standard Method for Water and Wastewater Examination (APHA, 2005). Statistical analysis was performed to determine the significant difference between the integrated system and the parameters. Experimental results show that aquatic plants in the phytogreen zone are able to get rid of 79.4% BOD5, 83.79% COD, 75.82% TSS, 49.23% oil and grease, 4.5% pH, 17.48% nitrate, 58.95% turbidity, 36.20% nitrite, 21.06% phosphorus and 27.35 % potassium from sewage. At the same time, the plant increased the DO value of wastewater by 58.95%. All parameters have achieved Standard A quality of effluent wastewater. Elimination efficiency for BOD5, COD, oil and grease, TSS, AN, nitrate, nitrite, phosphorus and potassium is 98.1%, 97.6%, 78%, 85%, 73%, 52%, 69%, 63%, 69%, 84% in the ventilation zone. The IPC zone also proved to be effective as a wastewater treatment medium in the final phase at an average temperature of 30oC and eliminated 97% BOD5, 97% COD, 89% TSS, 87% oil and grease, 85% NH3-N, 70% phosphorus, 58% nitrate , 75% nitrite, 55% potassium and 97% turbidity. Statistical analysis confirmed that there was a significant difference between the parameters and the sample taken. Based on the FESEM-EDX analysis, it was found that Lepironia articulata showed the highest aquatic plants in getting rid of heavy metals in maturation ponds with results in the range of 21.8% to 79.7% compared to other aquatic plants. The results of this study prove that the IPS is capable of being an alternative green technology that can improve the quality of domestic wastewater in the processed oxidation pond until it comply with Standard A, EQA, 1974.