Semakin maraknya aktivitas Penambangan Emas Tanpa Izin (PETI) di Kabupaten Kuantan Singingi mengakibatkan munculnya beragam permasalahan, terutama pencemaran air Sungai Kuantan yag menjadi lokasi aktivitas penambangan . Oleh karena itu pada penelitian kali ini dilakukan analisis kualitas air Sungai Kuantan khususnya di Desa Bandar Alai Kari Kecamatan Kuantan Tengah Kabupaten Kuantan Singingi yang meliputi derajat keasaman ( pH) dan kadar Hg atau logam merkuri yang kita ketahui sangat berbahaya bagi tubuh yang merupakan hasil limbah dari pengolahan emas secara amalgamasi. Metode yang digunakan dalam penelitian ini yaitu metode survei dengan penentuan titik sampling secara purposive berdasarkan lokasi maraknya aktivitas PETI. Pengambilan sampel dilakukan pada 3 titik mulai dari daerah hulu, tengah dan hilir. Dari hasil penelitian didapatkan nilai pH berkisar diatas pH 6 antara 6,46 - 6,50, nilai ini masih memenuhi angka baku mutu yang ditetapkan, kemudian untuk kadar logam berat merkuri 12,67 ppb - 13,60 ppb (µg/L) dan kadar merkuri ini sudah melampaui angka baku mutu yang diizinkan. Kata Kunci : Limbah PETI, analisis kadar air, logam berat

This service activity aims to increase teacher digital literacy in blended learning. The method used in service activities was the assistance carried out by observation, preparation, implementation, and evaluation. The dedication partner was Rumbio Jaya State Senior High School 4. The instrument for evaluating this activity used a questionnaire which was analyzed descriptively. The results of the community service that had been carried out and evaluated showed an increase in teacher digital literacy. This increase was shown by the teacher's understanding before the activity, from an average score of 3.11 to an average of 3.30 after the activity was carried out. However, even though there has been an increase, teachers still need to maximize their ability to use technology to support the implementation of blended learning better.

SOCIALIZATION AND EDUCATION ON THE UTILIZATION OF BANANA SKIN WASTE AS ANTIOXIDANT-RICH NATURAL FACE MASKS IN MARPOYAN DAMAI DISTRICT, PEKANBARU. The fact at this time is the increasing level of consumer consumption of beauty products. It does not only occur among adult women but also teenager. But the consumptive level not accompanied by purchasing power of quality products. Based on interviews with residents of the village of East Sidomulyo, most of the citizens are among adult women and teenagers that they mostly use ready-made masks that are sold in the market because it is more practical and faster in the process of use without considering the possibility of its contents which are harmful to skin health. The problem of the partners is to encourage service in the form of socialization and education to the local community to be able to take advantage of the banana peel waste that is widely available in the environment because it is now became popular a variety of processed banana products, but in terms of waste has not been utilized at all. This education is based on several studies that banana peels contain high antioxidants so it is very good if it can be processed as a mask for a facial skin care. In addition, the utilization of waste will be able to reduce pollution that might occur in the environment due to banana peels that are not treated. The existence of this activity was very welcomed by residents, this can be seen from the enthusiasm of residents asking questions regarding the problems presented and the impression of some residents who want this activity to be carried out continuously, so that more people feel the benefits and they are very enthusiastic to directly apply the knowledge.

Kulit pisang mengandung  komponen aktif yang dapat dijadikan bahan baku pengembangan produk berpotensi antioksidan, selain itu dapat mengatasi pencemaran limbah kulit pisang. Pada penelitian ini dilakukan uji efektivitas beberapa jenis pelarut polar dan non polar  dalam mengidentifikasi metabolit sekunder pada simplisia kulit pisang .Dengan tujuan menjadi landasan bagi penelitian lainnya dalam proses ekstraksi kulit pisang, sehingga akan didapatkan kandungan senyawa aktif dalam jumlah maksimal jika pelarut yang digunakan dapat menarik komponen aktif dengan optimal. Penelitian ini menggunakan empat jenis pelarut yakni etanol, metanol, etanol dicampur aseton, dan n-heksan. Kemudian keefektifan nya dilihat dari kemampuannya dalam mengidentifikasi metabolit sekunder pada simplisia kulit pisang. Hasil penelitian ini menunjukan ketiga jenis pelarut yakni, metanol, etanol dan campuran etanol dan aseton dapat mengidentifikasi metabolit sekunder kulit pisang , namun pelarut n-heksan tidak dapat mengidentifikasi metabolit sekunder kulit pisang. Kemudian dari ketiga pelarut tersebut yang mempunyai efektivitas paling besar adalah metanol. Metanol dapat mengidentifikasi empat jenis metabolit sekunder yakni flavonoid, fenolik, tanin dan saponin dengan lebih cepat dan menunjukan perubahan warna yang lebih signifikan. Berdasarkan hasil ini dapat dikatakan bahwa simplisia kulit pisang berpotensi antioksidan karena positif mengandung beberapa metabolit sekunder dan untuk mendapatkan ekstrak yang maksimal dapat digunakan metanol sebagai pelarut untuk proses ekstraksi

Many first semester students in University struggle to study chemistry, it proven by low achievement of students in learning general chemistry. This study investigated student's difficulties to understand in term of chemistry material characteristics (fundamental concept, advanced concept, mathematical concept and misconception) and learning process in the class. This investigation includes a coginitve test and a difficulty questionnaire were given to 92 first semester students in Biology program Universitas Islam Riau-Indonesia who took general chemistry course. Research questions in this study were: 1) What topics did students find difficult?; 2) Which chemistry material indicators did students feel difficult?; 3) How did student's perceptions about learning chemistry before and after learning process in college?. The result gave information that student's difficulties mostly existed in average level in chemical bonding about 84 students, stoichiometry around 52 students and higher level of barrier in colligative properties topics reached 52 students. Furthermore, students felt higher difficult in three indicators in term of mathematical concept, advanced concept and misconception with number reached 46%, 65% and 61% respectively. Difficulty questionnaire showed the slightly dropping around 9% before and after learning process. Overall, the difficulties encountered in average level and higher level. Topic that sudents felt difficult were: chemical bonding, stoichiometry and colligative properties, which each topic contained higher skill such as advanced concept, mathematical skill and misconception. The minor dip in student's perception can give us information about quality changes after learning process.