Penyahwarnaan efluen kilang minyak kelapa sawit (POME) melalui proses pengoksidaan Fenton secara berterusan menggunakan limonit sebagai pemangkin

Industri minyak sawit mempunyai impak yang besar ke atas alam sekitar terutama di Malaysia. Efluen kilang minyak sawit (POME) merupakan air buangan yang mengandungi sebatian organik yang berasal daripada bahan boleh urai dan sedia direput oleh mikroorganisma. Teknologi rawatan POME masa kini banyak bertumpu kepada kaedah biologi untuk mengurangkan permintaan oksigen kimia (COD), permintaan oksigen bio-kimia (BOD) dan jumlah karbon organik (TOC). Walau bagaimanapun, kebanyakan proses biologi tidak dapat menguraikan warna yang terdapat dalam POME. Kajian ini mengkaji potensi teknologi pengoksidaan Fenton menggunakan biji limonit sebagai pemangkin kepada hidrogen peroksida untuk merawat POME selepas proses rawatan biologi yang diperoleh daripada kilang minyak kelapa sawit. Keputusan menunjukkan dengan hanya 50 mM H2O2 boleh menyahwarnakan POME sebanyak 800-1000 PtCo secara berterusan dengan pengekalan masa 1 jam pada pH 3

Properties of cellulose hydrogel from kenaf core prepared via pre-cooled dissolving method

Hydrogels were produced from cellulose derived from kenaf core powder with weight average molecular weight of cellulose was 1.68 × 105 and was dissolved in NaOH/urea solvent at -13oC. To obtain the optimal dissolving parameters, different percentage of NaOH, urea and kenaf core cellulose was used to study the degree of dissolution and formation of hydrogel. From the results obtained, it was found that the ratio of 6% NaOH/4% urea and 2% cellulose produced a good hydrogel. UV-Vis spectroscopy and XRD analysis were performed to analyze the transparency and crystallinity index of the cellulose solution and hydrogel, respectively. It showed that the hydrogel with the highest degree of solubility gave highest transparency due to the reduction of cellulose crystallinity as a result of the dissolution process. XRD analysis results showed the crystallinity of cellulose from kenaf core decreased by 70% after dissolution and hydrogel formation. Samples with 4% urea possess highest water content of 73% and decreased with increasing urea content

Methylene blue adsorption on graphene oxide

In this study, graphene oxide (GO), produced using the simple Hummer’s method, was used as adsorbent to remove methylene blue (MB) from aqueous solution. Characterizations using transmission electron microscope (TEM) and Fourier transform infrared (FTIR) spectroscopy were carried out on the GO before the MB adsorption experiments. The adsorption kinetics and isotherm studies were conducted under different conditions (pH = 3-7 and MB concentration = 100-400 mg/L) to examine the adsorption efficiency of the GO towards MB in aqueous solution. The adsorption kinetics data were analyzed using different kinetic models to investigate the adsorption behavior of MB on GO. The obtained results showed that the maximum adsorption capacity of the GO towards MB can achieve up to ~700 mg/g for the adsorption at 300 mg/L MB. The adsorption kinetic data were found to fit pseudo-second order model as compared with pseudo-first-order model. The intraparticle diffusion model suggested that the adsorption process of GO towards MB was dominated by the external mass transfer of MB molecules to the surface of GO