Air hujan di kawasan industri dan perumahan bandar kebiasaannya dicemari Oleh kompaun hidrokarbon aromatik polisiklik (PAH); naftalena (NAP), fluorantena (FLT), dan pyrene (P YR), manakala racun perosak organo klorin (OCP); lindane (LIN) dan dichloro-difenil-trikloroetana (DDT), adalah dominan di kawasan pertanian dan perumahan luar bandar. Kehadiran bahan pencemar ini tidak diingini dan perlu dirawati sebelum boleh digunakan air hujan sebagai sumber alternatif air minuman. PAHs dan OCPs dipilih untuk diselidik dalam kajian ini menggunakan Ti02/sistem suria sebagai rawatan proses pengoksidaan lanjutan (AOP). Air hujan sintetik telah digunakan mengikut keadaan kajian yang berbeza seperti tempoh rawatan, pH, kepekatan titanium dioksida (Ti02), dan kepekatan awal bahan pencemar. Semasa kajian awal, NAP telah menunjukkan keputusan pengurangan yang tidak konsisten berikutan kompaun ini sangat mudah menguap dalam persekitaran berair. Oleh itu, NAP telah dikecualikan untuk diselidik dengan lebih Ianjut dalam kajian ini. Dalam usaha untuk memaksimumkan kecekapan proses, kaedah permukaan gerak balas (RSM) telah digunakan dengan mengambil kira tiga pembolehubah bebas iaitu pH, kepekatan Ti02, dan kepekatan awal bahan pencemar. Peratus pengurangan optimum yang diperolehi bagi FLT (88%), PYR (90%), LIN (66%), dan DDT (79%) didapati pada keadaan; pH = 7, kepekatan Ti02 = I .54 g/L, dan kepekatan awal bahan pencemar 125 ug/L, pada masa rawatan selama 30 minit. Persetujuan yang baik antara data eksperimen dan data ramalan mengesahkan tentang kecukupan dan kualiti model polinomial kuadratik yang padan. Proses fotopemangkin FLT, P YR, LİN, dan DDT mengikuti kadar tindak balas pseudo tertib pertama melalui Langmuir-Hinshelwood (L-H) model kinetik. Selain itil, penyingkiran bahan pencemar yang diperolehi dalam kajian ini mengesahkan bahawa penggunaan semula jadi sistem suria sebagai sumber UV boleh digunakan untuk proses fotopemangkin.
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Rainwater in industrial and urban residential areas were commonly contaminated with polycyclic aromatic hydrocarbons (PAHs); naphthalene (NAP), fluoranthene (FLT), and pyrene (P YR), while organo chlorine pesticides (OCPs); lindane (LIN) and dichloro-diphenyl-trichloroethane (DDT), were predominant in agricultural and rural residential areas. The presence of these pollutants are undesirable and must be treated prior to the usage of rainwater as an alternative source of drinking water. PAHs and OCPs were chosen to be investigated in this study using Ti02/solar system as an advanced oxidation process (AOP) treatment. Synthetic rainwater was used under different experimental conditions such as treatment period, pH, titanium dioxide (Ti02) dosage, and initial concentration of pollutant. During preliminaries, NAP showed unsuitable results since it evaporates very easily in the aqueous environment, hence, was excluded to be further investigated in this study. In order to maximize the process efficiency, response surface methodology (RSM) was used by considering three independent variables of pH, Ti02 concentration, and initial concentration of pollutant. The optimum percentage removals obtained for FLT (88%), PYR (90%), LIN (66%), and DDT (79%) were achieved at condition; pH = 7, Ti02 concentration = 1.54 g/L, and initial concentration of pollutant 125 pg/L, at 30 minutes of treatment period. Good agreement between the experimental and predicted data verified the adequacy and the quality of fit of the quadratic polynomial models. The photo-degradation process of FLT, P YR, LIN, and DDT followed pseudo first order rate of reaction through Langmuir-Hinshelwood (L-H) kinetic model. Besides, the degradation of pollutants obtained in this study confirmed the feasible use of natural sunlight as the UV source for the photocatalysis process to take place.
Removal of selected pahs and ocps from synthetic rainwater using heterogeneous photocatalysis (t102 solar)_Nurul Alln Binti Ab Aziz_A9_2017_NI