Characterization and behaviour of fluoride-containing semiconductor wastewater with the presence of calcium chloride (cacl2) for optimization treatment processes / Noorul Amilin Saipudin
Air sisa semikonduktor mengandungi sebatian organik dan bukan organik yang terhasil daripada beberapa proses yang sangat kompleks dan rumit. Air sisa dari industri ini secara amnya dibahagikan kepada tiga aliran utama iaitu yang mengandungi fluorida, berasaskan asid dan dari proses gilapan kimia. Kajian awal telah dijalankan untuk menganalisis julat optimum pH melalui interaksi air sisa semikonduktor yang mengandungi fluorida dan koagulan dari segi potensi zeta dan pengukuran diameter hidrodinamik berdasarkan fungsi pH (pH 2-12). Pada setiap pH yang ditentukan, caj permukaan dan saiz zarah diukur menggunakan teknik serakan cahaya dinamik. pH awal air sisa semikonduktor dicatatkan pada pH 5.5, +15.54 mV bagi potensi zeta dan 1952 d.nm bagi pengukuran diameter hidrodinamik. pH titik sifar caj ditemui pada pH 7.1 dengan saiz zarah 4500 d.nm. Analisis ciri pada CaCl2 menunjukkan bahawa pada awalnya pH 5.7, potensi zeta memberikan nilai negatif -8. MV dengan purata saiz zarah adalah 770 d.nm. Seterusnya, julat dos optimum melalui interaksi (proses pengagregatan dan pengasingan) antara air sisa semikonduktor yang mengandungi florida dan koagulan (CaCl2) pada nilai pH yang berbeza secara sistematik dengan menggunakan pHPZC bagi air sisa sebagai titik rujukan. Eksperimen dijalankan dalam tiga keadaan pH iaitu pada keadaan i) pH pHPZC. Set ujian eksperimen yang dijalankan adalah untuk mengukur kecekapan penyingkiran fluorida dalam air sisa semikonduktor dalam dos koagulan yang optimum. Apabila CaCl2 ditambah, peratus penyingkiran fluorida untuk ketiga-tiga keadaan adalah 13.9%, 35.5% dan 18.6%. Ini dibandingkan dengan analisis yang dilakukan menggunakan ujian balang di mana peratusan penyingkiran adalah sebanyak 21.0%, 54.9% dan 32.4%. Walau bagaimanapun, kedua-dua analisis dalam eksperimen ini menunjukkan bahawa keadaan pH = pHPZC memberi peratusan terbesar penyingkiran fluorida. Keputusan dos yang digunakan untuk ketiga-tiga keadaan pH ialah 140 mg / L, 35 mg / L dan 35 mg / L masing-masing.
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Semiconductor wastewater contains high organic and inorganic compounds generated from several highly complex and delicate processes. The wastewater is generally divided into three different main streams, i.e. fluoride containing, acid base and chemical mechanical polishing. In this research, a preliminary study was conducted to analyse the optimum pH range via characterization of fluoride-containing semiconductor wastewater and coagulant (CaCl2) in terms of zeta potential and hydrodynamic diameter measurements as a function of pH (pH 2-12). At each adjusted pH, the surface charge and particle size were measured using the dynamic light scattering technique. The initial pH of semiconductor wastewater suspensions were recorded at pH 5.5, +15.54 mV and 1952 d.nm for zeta potential and hydrodynamic diameter measurement respectively. The pH of point of zero charge was found at pH 7.1 with a particle size of 4500 d.nm. Characteristic analysis on CaCl2 indicated that at initial pH 5.7, zeta potential gave a negative value of -8. mV with an average particle size of 770 d.nm. The subsequent stage were optimum dosage range via interaction (aggregation and disaggregation process) between fluoride-containing semiconductor wastewater and coagulant (CaCl2) at different pH values in a systematic way by using the pHPZC of the wastewater as a point of reference. Experiment were carried out in three pH regions which are experiments set conducted were, i) pH < pHPZC, ii) pH = pHPZC and iii) pH > pHPZC. The final experiment set conducted were to measure the removal efficiency of fluoride in fluoride-containing semiconductor wastewater within the coagulant optimum dosage. When CaCl2 were added the percentage of fluoride removal for the three conditions were 13.9%, 35.5% and 29.9% respectively. These were compared to the analysis done by jar test where by the removal percentage were notes as 21.0%, 54.9% and 18.6 %. However, in experiments both analysis show that the condition pH=pHPZC gives the biggest percentages of fluoride removal. The dosage determined for the three pH region were 140 mg/L, 35 mg/L and 35 mg/L respectively.
Characterization and behaviour of fluoride-containing semiconductor wastewater with the presence of calcium chloride (cacl2) for optimization treatment processes / Noorul Amilin Saipudin
Characterization and behaviour of fluoride-containing semiconductor wastewater with the presence of calcium chloride (cacl2) for optimization treatment processes_Noorul Amilin Saipudin _A9_2017_MYMY