Chitosan was modified by maleic anhydride, and it was then functionalized using heterogeneous and blending method to obtain the membrane.

Montmorillonite was functionalized by (3-glycidyloxypropyl) trimethoxy silane (GPTMS). Subsequently, chitosan (CS) membranes filled by GPTMS-modified

Methylene blue (MB) is a dye in wastewater from textile industries that pollutes the water environment. Reduction of its content is necessary for protecting humans and the surrounding environment. This study fabricated chitosan/Fe3O4 nanocomposite through the mixture of chitosan from crab shell waste and magnetite (Fe3O4) from local sand iron with sodium tripolyphosphate (STPP)-sulfate crosslinker as an adsorbent to reduce methylene blue content. The obtained composite was characterized by Fourier Transform Infrared (FTIR) Spectrophotometer and X-Ray Diffraction (XRD) instrument. The contents of methylene blue before and after applying adsorbent-based nanocomposite were determined using an ultraviolet-visible (UV-Vis) spectrophotometer. FTIR characterization results show that chitosan and chitosan/Fe3O4 nanocomposite had successfully synthesized based on the typical vibrational peaks. The deacetylation degree of chitosan was 69.79%. Fe3O4, and chitosan/Fe3O4 nanocomposite, were confirmed by XRD patterns. The chitosan/Fe3O4 nanocomposite adsorption capacity reached 45.37 mg/g when adsorption occurred with 20 mg adsorbent, pH 9, and contact time of 1.5 h. Hence, the chitosan/Fe3O4 nanocomposite in this study has potency and is applicable to adsorb MB effectively.

The Leaching of Low-GradeNickel Laterite Ore Using Atmospheric Acid Leaching Method in Hydrochloric Acid. Nickel laterite extraction using the hydrometallurgical method is more efficient in energy consumption with less exhaust gas than the pyrometallurgical method. This method causes the extraction of lowgrade nickel laterite ore using hydrometallurgy could be more effective. One of the hydrometallurgical methods to extract nickel from its ore is atmospheric acid leaching. This research aims to determine the percentage of nickel recovery through the leaching process, determine the most influenced leaching factor, and determine the optimum leaching condition. The main factors that influence the leaching process are temperature, acid concentration, and leaching time. Atomic adsorption spectroscopy was chosen to analyze the leaching solution. This research showed that the lowest recovery of nickel leaching was 9,40% of Ni, and the highest was 75,76% of Ni. Analysis of variance (ANOVA) was used to determine the most influenced factor of leaching. The most influenced factor was temperature (A), followed by acid concentration (B), duration (C), interaction of acid concentration-temperature

Secularism has become a new trend in various parts of the world. Many people seem to no longer believe in the role of religion in the Society. Religion does not need to interfere with the situation that occurs in society. These problems rise different opinions and responses from various figures. Harvey Cox is one of the theologians who discusses secularization through his book entitled “The Secular City.” Harvey Cox argues that secularization does not need to be rejected. Secularization is a process that occurs in society, where religious affairs are separated from community affairs. Secularization is clearly different from secularism. In secularism, people see religion as a stranger and God is seen as a barrier. Through the book “The Secular City”, Harvey Cox offers a new perspective on secularization including how the Church should respond to secularization. This paper will also briefly mention the secularization that has occurred in Indonesia. Nurcholish Madjid’s thoughts equip the challenges and hopes for the Indonesian.