Ale-ale are popular clams in the coastal area of Ketapang. The local community uses the clams as food, one of which is in the form of fermented products. In the fermentation process, the nutritional content of course will be different from fresh ale-ale because it has gone through the preservation process. One of the goals of processing it into fermented products is to increase the product's durability. Essential mineral contents (Fe, Mn, Zn) in fermented products is different and tends to decrease. Essential mineral testing used the Atomic Absorption Spectroscopy (AAS) method. The water content and ash content of fresh ale-ale were 63.1% and 15.8%, respectively. While the water content and ash content of the fermented ale-ale were 68.69% and 17.2%, respectively. The essential mineral contents of fresh ale-ale obtained Fe 23 mg/kg, Zn 1.70 mg/kg and Mn 0.138 mg/kg. In fermented ale-ale, the content of Fe is 9.76 mg/kg, Zn is 0.740 mg/kg and Mn is 0.387 mg/kg.

Fotokatalis TiO2 terdoping Fe3+ telah disintesis menggunakan titanium tetraisopropoksida (TTIP) sebagai prekursor serta dopan Fe3+ dari Fe(NO3)3 dengan metode sol-gel. Fotokatalis TiO2 didoping menggunakan Fe3+ bertujuan untuk memperlebar serapan dari sinar Ultra Violet (UV) hingga sinar tampak pada berbagai variasi persentase Fe3+ 0,05%; 0,125%; 0,25% (b/v). karakterisasi fotokatalis dilakukan dengan metode spektrofotometri UV-Vis/DRS, FT-IR, XRD  dan diuji aktivitasnya terhadap degradasi rhodamin B. Hasil pengukuran UV-Vis/DRS dari setiap variasi memberikan energi celah pita (Eg) masing-masing sebesar 1,33 eV, 2,11 eV, 2,53 eV. Spektra Infra merah (FT-IR) menunjukkan serapan Fe-O yang merupakan interaksi antara TiO2 dengan dopan Fe3+ dalam struktur TiO2. Hasil pengukuran x-ray difraction (XRD) Fe-TiO2 memberikan difragtogram pada 2θ 25,4773°, 37,9223°, 48,0159° mengindikasikan bahwa Fe3+ telah tersubsitusi kedalam struktur TiO2. Dopan Fe3+ yang telah tersubsitusi juga dapat dibuktikan dari penurunan ukuran rata-rata kristalit dan jarak antar kisi. Hasil Uji Aktivitas konsentrasi dopan Fe3+ 0,125% memiliki aktivitas tertinggi yaitu sebesar 25,605%. Hasil penelitian tersebut menunjukkan bahwa Fe-TiO2 memiliki potensi dalam mendegradasi rhodamin B menggunakan sinar tampak.

The Ag/N-TiO 2 nanotube arrays photocatalyst have been successfully fabricated by in-situ anodization method and followed by calcining at 450 o C under N 2 atmospheric condition. The inner diameter, wall thickness, and length of the nanotube arrays are approximately 65 nm, 15 nm, and 900 nm, respectively. Ag nanoparticles with diameter around 20-30 nm are deposited on the surface of the N-TiO 2 by an electrochemical deposition method. Compared with the TiO 2 nanotube arrays, the Ag/N-doped TiO2 showed a significant enhancement of photoelectrocatalytic (PEC) degradation on methylene blue (MB), was about 92% for 240 min under visible light irradiation. The kinetic constant of Ag/N-doped TiO 2 electrode was about 9 times higher than TiO 2. The enhanced photocatalytic activity under visible light irradiation of Ag/N-doped TiO 2 is a synergistic effect of N-doping and Ag nanoparticles deposited. Furthermore, the kinetic constant PEC degradation of MB is a contribution of photo-generated electron-hole separation efficiency, due to bias potential which was applied to the surface of the electrode. The Ag/N-TiO 2 is a promising photocatalyst for organic pollutant degradation which is visible light responsive.

In this work, undoped and Fe-doped TiO2 immobilized on kaolinite surface was successfully synthesized by sol-gel method with various Fe concentrations (0.05, 0.125, and 0.25 wt%). The effects of Fe doping into TiO2 lattice were thoroughly investigated by a diffuse reflectance UV-visible (DRS) spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, and X-ray diffraction (XRD). The optical band gap of undoped and Fe-doped TiO2/kaolinite is red shifted with respect to the incorporation of Fe3+ into the structure of TiO2 resulted band gap. The FTIR spectra shows a shift of peak at the wave number at 586 cm−1 and 774 cm−1 which is attribute of the Fe−O vibration as an indication of the formation of Fe-TiO2 bonds. Incorporation of Fe3+ cation into the TiO2 lattice replacing the Ti4+ ions, which induced a perturbation in anatase crystal structure, causes the change in the distance spacing of the crystal lattices dhkl(101) of 8.9632 to 7.9413. The enhanced photocatalytic performance was observed for Fe-doped TiO2/kaolinite compared with TiO2/kaolinite with respect to Escherichia coli growth inhibition in solution media under visible light irradiation. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Gastropoda adalah salah satu biota yang sering digunakan sebagai indikator lingkungan suatu perairan. Lokasi Bakau Besar Laut memiliki 3 rona lingkungan yaitu pemukiman, ekowisata, dan tambak udang. Sebagai dasar dari penelitian ini membutuhkan informasi terkait kualitas lingkungan dengan gastropoda sebagai indikator. Penelitian ini bertujuan untuk mengetahui komposisi dan distribusi gastropoda di Desa Bakau Besar Laut Kecamatan Sungai Pinyuh, Kabupaten Mempawah. Masing-masing stasiun dibuat 1 garis transek sepanjang 23 m. Setiap transekterdiri dari 3 plot berukuran 1 x 1 m dengan jarak antar plot 10 m. parameter lingkungan yang diukur meliputi suhu, pH, salinitas, dan jenis substrat. Berdasarkan hasil penelitian ditemukan komposisi dari jenis-jenis gastropoda yaitu Cerithidea cingulata, C. obtusa, C. weyersi, Littoria scabra, L. undolata, Nerita violacea, Strombus mutabilis dengan pola distribusi mengelompok.