The mercury contamination associated with the former intense illegal gold mining activities is suspected in the watershed of Krueng Cot Satu, Nagan Raya Regency, Aceh Province, Indonesia. The aim of this study was to evaluate the mercury contamination residue in the water, soil, and vegetable fern (Pityrogramma calometanos (L)) The samples were collected from locations in the already closed artisanal gold mining sites. The sampling locations were purposively determined by considering their closeness to the previous gold mining activities sites. The content of mercury was analyzed using flow injection for atomic spectroscopy – atomic absorption spectroscopy. The method used was validated by linearity, Limit of Detection (LoD), Limit of Quantification (LoQ), Relative Standard Deviation (RSD), and recovery. The validation test showed that this method is well linear, sensitive, accurate, and precise with a correlation coefficient, LoD, LoQ, RSD and recovery of 0.9999, 0,0477 µg/L, 0,1447 µg/L, 2,96 % and 95-105 %, respectively. Herein, it was found that the concentrations of mercury contents in the water samples were below the detectable range. However, a high range of mercury concentration of 0.236 – 0.328 µg/g was found in soil, with the highest concentration obtained in the sample collected from the riverbank. The fern sample collected near the riverbank contained mercury in all its parts and concentrated in the root (0.408 µg/g in the leaves, 0.276 µg/g – stalks, and 9.994 µg/g – roots). Meanwhile, the absence of mercury contamination was obtained in the leaves and stalks of the fern samples collected far from the riverbank. The roots, however, were detected with mercury contamination with the highest concentration reaching 27.660 µg/g. Despite its disappearance in the water, mercury contamination residue from the former artisanal gold mining activities still could be traced in the soil and heavy metal accumulating plant – P. calometanos (L).

This research has successfully fabricated ion selective electrode (ISE) for Pb²⁺ using castor oil (Ricinus communis L.)-based polyurethane (PU) membrane with 1,10-phenanthroline as the active agent. The sensitivity of the Pb²⁺ ISE obtained is 27.25 mV/decade with a linear range of [Pb(NO₃)₂] of 10⁻¹⁰–10⁻⁵ M and a coefficient of determination (R²) of 0.959. The system response reaches stability after 25 s of measurement. The Pb²⁺ has a detection limit of 10⁻¹⁰ M and gives a stable response at pH 7–8 with a 15-day lifetime. The investigation of the selectivity of the ISE was performed using the mixed solution method with log Kij values of Ca²⁺ > K⁺ > Mg²⁺ > Cu²⁺ > Fe³⁺ > Cr³⁺> Zn²⁺ > Cd²⁺. The Pb²⁺ ISE shows acceptable reproducibility and repeatability with standard deviation values of 0.065 and 0.0079, respectively. Fourier transform infrared (FT-IR) spectra confirmed that 1,10-phenanthroline was responsible for the formation of the Pb²⁺ ion entrapment via complexation. Other characterizations (crystallinity, micro-surface morphology, and mechanical strength) suggest the degradation of the membrane structure integrity after the application. The analysis results of Pb levels using the Pb²⁺ ISE in artificial and wastewater samples were not significantly different from the atomic absorption spectroscopy (AAS) measurement.

Development of drug delivery systems (DDS) has been widely carried out using safe biopolymers – starch and κ-carrageenan. However, for optimal use, the foregoing polymers still suffers from mechanical weakness. Combining both polymers could enhance the properties of each of the polymer. This research aimed of improving the applicability of starch and κ-carrageenan as DDS by means of polyelectrolyte complexation to form a polymer film. The composition ratio of starch:κ-carrageenan was optimized using response surface method (RSM) on Design Expert 11.0 based on water swelling, tensile strength, and disintegration time of the film. Fourier transform infrared spectrometry was performed on the prepared starch—κ-carrageenan film and suggested the successful film preparation. The bulk characteristics of the film are dependent on the starch or κ-carrageenan composition ratio, where starch has been associated with higher thickness, while κ-carrageenan — rigidity. From the RSM, the optimized composition was revealed to be 2.95 and 2.84 g for starch and κ-carrageenan, respectively, in a 60 mL aqueous solvent. The predicted optimum properties of the film were 160.21%, 3.26 MPa, and 17.47 min for swelling degree, tensile strength, and disintegration time, respectively. Taken altogether, the characteristics of starch or κ-carrageenan individually could be modified by polymeric combination, where they could be optimized by means of RSM.

Penelitian ini merupakan kajian pustaka,berkaitan dengan bahan pembuatan plastik.Kajian bertujuan untuk memberikan informasi sumber-sumber bahan polimer alami,sebagai pembuatan plastik biodegradable. Plastik telah menjadi bagian tak terpisahkan dari kehidupan saat ini.Pada berbagai bidang.Dari alat rumah tangga sebagai kebutuhan hidup sehari-hari.Keadaan ini menimbulkan masalah bagi lingkungan,karena menghasilkan limbah.Limbah plastik dari minyak bumi merupakan limbah paling banyak dihasilkan,karena masa degradablenya sangat panjang.Untuk mengurangi limbah plastik yang sulit terdegradasi dengan menggunakan bahan biodegradable polimer alami sebagai bahan dasar pembuatan plastik Polimer alami digunakan dalam pembuatan plastik juga bisa digunakan sebagai alternative penganti polimer dari minyak bumi yang keberadaannya sangat terbatas, dan dapat bisa mengurangi limbah dari bahan polimer nonbiodegradable.Dari kajian ini diperoleh dua dasar sumber polimer alami sebagai bahan dasar pembuatan bahan plastik yaitu sumber nabati dan sumber hewani.Adapun sumber nabati yaitu kayu dan tanaman tahunan dan sumber Hewani yaitu kitin dan kitosan serta protein.

Even though phytoremediation is considered a green technology for remediating heavy metals, there are some problems with the application of this technology, particularly when it comes to managing the biomass that is used. So, processing biomass needs to be given a lot of attention. This study outlined the utilization of extracts obtained from the hyperaccumulator plant Brassica oleracea var. alboglabra to synthesize nickel oxide nanoparticles. Subsequently, the nanoparticle underwent testing to determine its suitability as an absorbent for heavy metals, specifically lead, as well as its efficacy as an antifungal agent against Fusarium sp. strain. The characterization of nickel oxide nanoparticles involved several measurements, such as scanning electron microscopy analysis, high- and low-resolution transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and hysteresis curve acquisition. The research findings indicate that the extract from hyperaccumulators can be utilized for the synthesis of NiO, which exhibits an absorption capacity exceeding 98% and serves as an efficient antifungal agent against Fusarium sp. pathogens. The approach utilized in this study not only prioritizes "green" and sustainability factors but also takes into account the economic aspects associated with the items being manufactured. The research has important implications in two areas. Firstly, it demonstrates the utilization of natural resources (B. oleracea var. alboglabra) in the production of nickel oxide, which serves as a safer and more eco-friendly substitute for dangerous chemicals. Furthermore, it aids in the advancement of novel techniques for effectively managing biomass hyperaccumulators.

Castor seed oil (Ricinus communis L) can be utilized for the manufacturing of membranes reacted with toluene diisocyanate (TDI). The aim of this study was to examine the effect and membrane characteristics of castor seed oil with a combination of silica used as an adsorbent, with a combination of silica (SiO2) 0.5 mg, 1 mg, 1.5 mg, and 2 mg. The initial analysis of the membrane was carried out with a swelling test of 1.5 mg of silica variation to obtain the most ideal result of 200%. The best chemical resistance characterization occurred at a variation of 1.5 mg of silica. Further characterization, particularly the FTIR test, thermal test, mechanical test, and SEM test, showed that there were Si-O groups and amine groups (NH2), and on the membrane there were groups OH, C=O, and NH. The thermal characterization of the silica membrane (1.5 mg) gave the greatest residue concentration, measuring 3.2%. In mechanical terms, the silica membrane has a higher elongation value than the membrane. In SEM characterization, the silica membrane has holes and is solid. This study indicated that the highest drop in Fe metal occurred at an immersion period of 6 hours with a combination of silica with a flux value of 9.25 L/m2 hour and a rejection value of 0.098%.