Silver nanoparticles are nano-sized particles ranging from 1-100 nm which are commonly used as antifungal and antibacterial agents in various products. In this study, silver nanoparticles were synthesized from a natural bioreductant, namely key orange peel extract. The silver nanoparticle phase which was successfully synthesized and then XRD test was carried out was cubic in shape with the highest peak at 2θ : 38.1959˚; 44.4038˚; 64.5491˚ The lattice parameter of silver nanoparticles is a=b=c= 4.0861 . The resulting crystal structure of silver nanoparticles is cubic with a crystallite size of 39.84 nm, in addition to XRD test, XRF test was conducted to determine the main constituent components of silver nanoparticles, while the main component of synthesized silver nanoparticles was Ag of 97.66%. Antibacterial activity of silver nanoparticles was indicated by the formation of inhibition against the growth of Staphylococcus aureus bacteria with a clear zone formed around 12.091 mm. Therefore, the antibacterial inhibition formed from the silver nanoparticles synthesized in this study can be classified as a strong antibacterial property.

The effect of deproteinization temperature on chitosan extraction process from shrimp shells waste used variation of temperature: 30, 60 and 90°C was studied. The results shown that the degree of deacetylation of chitosan (DD) decreased with increasing deproteinization temperature. This is probably due to excess polymerization reaction when the deproteinization temperature increases, thereby destroying the chitin structure. The highest chitosan DD achieved was up to 79.72% at temperature deproteinization of 30°C and the occurrence of deacetylation structurally demonstrated by the Fourier transform infrared characterization. The chitosan adsorption for zinc metal ions in Bangka post tin mining water shown that the systems of adsorption follow the pseudo second order kinetic model. Based on the equation of kinetics adsorption shown that the increase of chitosan DD causes the adsorption rate and maximum adsorption capacity increased. The increase of chitosan DD which is an indicator of the transformation of chitin into chitosan represents an increase in the number of amine groups which have a stronger metal ion adsorption. The highest of adsorption rate coefficient and maximum adsorption capacity was up to 1.215 g mg−1 min−1 and 0.15 mg g−1 respectively achieved at temperature deproteinization of 30°C.

Menipisnya cadangan sumber minyak bumi di Indonesia dapat menjadi penghambat pembangunan pertanian berkelanjutan. Potensi energi alternatif salah satunya adalah limbah biomassa tongkol jagung yang dihasilkan dari aktivitas produksi pertanian yang jumlahnya sangat besar. Tongkol jagung memiliki nilai kalor sebesar 4059.853 kal/gr sehingga semakin banyaknya tongkol jagung yang digunakan akan mempercepat proses pembakaran. Akan tetapi proses pembakaran yang dilakukan harus dibantu oleh serbuk kayu kering sebagai pemantik bagi api. Kayu kering yang memiliki nilai kalor lebih besar dari tongkol jagung akan terbakar lebih cepat dan membantu membakar tongkol jagung. Hasil dari nyala lampu terdapat pada massa tongkol jagung 400gr dengan variasi volume air 250ml menyala redup selama 1 menit. Pada massa 500gr lampu menyala redup selama 1 menit pada variasi volume air 150ml dan 200ml. Sedangkan lampu menyala terang selama 20 detik pada variasi 250ml air. Hal ini juga membuktikan bahwa banyaknya volume air yang digunakan dapat mempengaruhi nyala lampu.

Wound dressings act as wound protectors as well as drug delivery for wound healing. This article develops a PVA/alginate-based wound dressing material added with pepper extract to obtain its antibacterial properties. The sample preparation process consisted of several stages: the preparation of pepper extract by maceration method with ethanol solvent, preparation of PVA/Alginate hydrogel and addition of pepper extract, and testing. Antibacterial test using the paper disc method with the pathogen Staphyloccocus aureus showed that the extract had powerful antibacterial properties with an inhibition zone of about 22 m. Based on the FTIR analysis, it is known that the FTIR transmittance pattern of the PVA/alginate composite added with pepper is related to its constituent functional groups. The highest degree of swelling of the hydrogels prepared in this study was 188%.