Search

In this study, activated rice straw modified with duck egg white (RSA-DEW) was tested extensively to increase the adsorption capacity of Cr(VI) ions. The parametric study was carried out in a batch system, and the results showed that the maximum adsorption capacity of Cr(VI) ions using RSA-DEW was 94.904 mg g−1, far greater than using RSA of 60.204 mg g−1, in studies that have been reported. This optimum condition was achieved at pH 2, initial concentration of Cr(VI) 1000 mg L−1, contact time 30 min, particle size ≤ 36 µm, and stirring speed 100 rpm at 298 K. The principle of equilibrium follows the Freundlich isotherm model, which shows a multilayer adsorption process. Meanwhile, the adsorption kinetics follows a pseudo-second-order model, which indicates a chemical interaction between the adsorbent and the adsorbate. The thermodynamic evaluation showed that the adsorption of Cr(VI) ions onto RSA-DEW was exothermic and spontaneous. Prediction Adsorption mechanisms include pore filling, electrostatic interactions, reduction, ion exchange, and complexing. After five adsorption-desorption cycles were carried out to evaluate the reusability of the adsorbent, the efficiency of RSA-DEW did not change significantly, indicating good reusability. The application of RSA-DEW succeeded in removing Cr(VI) ions from river water contaminated with Cr(VI) ions, with a removal efficiency of up to 100 %. In conclusion, the novelty of this study presents the selection of Duck Egg White (DEW) as a new effective, low cost and advantageous modifier for removing Cr(VI) ions in solution.

This study discusses kapok husk (KH) activated by HNO3 as a biosorbent for methylene blue dye and analyses its adsorption ability. The adsorption capacity of KH is 330.161 mg g-1 with optimum conditions at pH 9, concentration 5500 mg L-1, contact time 15 min, and biosorbent temperature 25ºC. The isotherm study followed the Langmuir isotherm model, as seen from the R2 value of 0.9993 and maximum adsorption capacity of 312.5 mg g-1, which indicated a monolayer in the adsorption process. The kinetic data show that KH followed the pseudo-second-order model. The results of the TGA analysis show that thermal stability affects the performance of biosorbents in the adsorption process. FTIR and SEM-EDS characterisation results showed that electrostatic interactions, cation exchange, and pore filling regulate the methylene blue dye adsorption mechanism on the surface of the KH. The reusability of KH through adsorption–desorption cycle analysis was achieved five times. This indicates that the biosorbent can be economically feasible for real wastewater treatment based on its good reusability and simple preparation and activation.

Microplastic (MP) is one of the most dangerous contaminants due to its ecotoxicological impact on the aquatic environment, aquatic biota, and human health. Defined as particles less than 5 mm, these contaminants originates from either primary or secondary source. Therefore, this study aimed to analyze the abundance, shape, color, size, and type of microplastic (MP) polymers. In the process, water samples were collected from 3 distinct points in the Batang Anai River, to obtain MP. Subsequently, analysis was conducted using a microscope and Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR). The results showed that the abundance of MP in the water samples ranged from 37-77 particles/L, and the most dominant shapes, colors, and sizes identified were fragments (49.44%), black (48%), and sizes >1,000 µm (33%), respectively. Characterization and interpretation of functional groups in the FTIR spectrum indicated the presence of cellulose polymer, ethylene-propylene copolymer, neoprene, and polyester. In conclusion, this report can be used as initial information to help control plastic waste pollution.

Corn husk waste (CHW) was evaluated as an alternative simple treatment strategy to remove methylene blue dyes (MB). Various experimental factors, such as pH, concentration, contact time, and temperature, were studied during the adsorption process. Optimum conditions were obtained at pH 6, initial concentration of 800 mgL−1, contact time of 60 min, and temperature 298 K with an adsorption capacity of 41.06 mgg−1. The kinetics study was analyzed using pseudo-first-order, pseudo-second-order, intra-particle diffusion, and Elovich models. Moreover, the pseudo-second-order process model can characterize the MB chemisorption kinetics. The experimental results were fitted to the Langmuir isotherm model. The obtained thermodynamic parameters (ΔHo,ΔSo,ΔGo) revealed that MB adsorption was spontaneous and exothermic. The optimum conditions for removing MB on laboratory wastewater was 99.79 %, while for MB on batik industry water was 51.40 %. CHW had an excellent capability to be used for 4 times cycle.

Semakin bertambahnya tingkat konsumsi masyarakat maka semakin bertambah sampah plastik yang dihasilkan, sehingga sampah plastik menjadi permasalahan lingkungan pertama di Indonesia khususnya di Kelurahan Kampung Jua Nan XX, Kecamatan Lubuk Begalung, Kota Padang. Sampah plastik membutuhkan waktu yang cukup lama untuk hancur dan dapat terurai menjadi mikroplastik yang dapat tersebar ke tanah dan perairan. Kehadiran mikroplastik di tanah dan di perairan dapat mengontaminasi tumbuh-tumbuhan, kerang, ikan, dan bahkan garam yang akhirnya terakumulasi ke tubuh manusia melalui siklus rantai makanan. Oleh karena itu perlu solusi agar keberadaan sampah plastik dapat ditangani dengan baik dan dilakukan pengelolaan yang maksimal. Salah satu solusi dari pemanfaatan sampah plastik yaitu dengan pembuatan produk ecobrick yang bermanfaat dan bernilai jual tinggi serta dapat menjadi peluang mata pencaharian. Tujuan dari kegiatan ini adalah untuk meningkatkan kesadaran dan kepedulian masyarakat terhadap lingkungan guna terciptanya lingkungan yang bersih dan sehat melalui pengelolaan dan pengolahan sampah plastik. Kegiatan ini dilaksanakan di Kelurahan Kampung Jua pada tanggal 27 Oktober dan 9 Desember 2022 dengan dihadiri peserta dalam kegiatan ini adalah ibu-ibu PKK Kelurahan Kampung Jua Nan XX. Metode yang digunakan yaitu penyuluhan mengenai ancaman sampah plastik dan mikroplastik dan pelatihan secara demonstrasi pembuatan kursi dari ecobrick. Hasil kegiatan ini dapat meningkatkan kesadaran masyarakat akan bahaya limbah plastik, membatasi pemakaian kantong plastik dan pengelolaan limbah plastik di sumbernya sebagai upaya mengurangi timbulan sampah plastik serta memberdayakan masyarakat untuk memaksimalkan nilai ekonomi dari limbah yang ada secara berkelanjutan.

Sampah kertas merupakan sampah yang paling banyak dihasilkan dari aktivitas akademik di lingkungan kampus Universitas Andalas. Selama ini sampah kertas dibiarkan menumpuk dan kemudian dijual oleh petugas kebersihan kepada pengepul sampah atau dibakar. Tujuan dari kegiatan ini adalah dapat meningkatkan sumber daya dan potensi perempuan melalui teknologi Qulling Paper dengan peluang usaha yang menjanjikan terutama bagi para petugas kebersihan. Kegiatan ini dilaksanakan mulai dari bulan Juli sampai September 2022 dengan sasaran peserta adalah para petugas kebersihan yang berhubungan langsung dengan sampah kertas. Metode yang digunakan adalah penyuluhan tentang bahaya sampah kertas terhadap lingkungan dan kesehatan, yang di akhiri dengan diskusi dan wawancara untuk mengetahui tingkat pengetahuan petugas kebersihan tentang pengelolaan dan pengolahan sampah kertas. Kegiatan dilanjutkan dengan pelatihan pengolahan sampah kertas melalui teknologi paper quilling dengan mempraktekkan secara langsung sampai peserta dapat menghasilkan suatu produk kerajinan. Kegiatan pendampingan terhadap peserta juga dilakukan dengan membimbing peserta sampai terampil menghasilkan produk kerajinan yang layak jual. Pada kegiatan pelatihan ini semua peserta kegiatan dapat menghasilkan produk kerajinan yang bernilai jual tinggi, dan ekonomis. Pelatihan pengolahan sampah kertas kepada petugas kebersihan merupakan salah satu solusi paling tepat dalam mengurangi jumlah sampah kertas di kampus Universitas Andalas dan sekaligus dapat meningkatkan ketrampilan. Diharapkan kegiatan ini dapat meningkatkan pengetahuan dan ketrampilan serta mengurangi jumlah sampah kertas di lingkungan kampus Universitas Andalas.

Pembudidaya ikan pada umumnya mengalami kesulitan dalam menyediakan pakan buatan (pellet) yang berkualitas karena kurangnya pengetahuan dan keterampilan dalam teknologi pengolahan dan pembuatan pakan alternatif. Disamping itu biaya yang dikeluarkan untuk pengadaan pakan relatif besar mencapai 70 – 80 % dari total biaya produksi. Namun penyediaan pakan sering menjadi kendala karena selain harganya yang semakin hari semakin mahal, juga kualitas pakan yang tersedia tidak selalu sesuai dengan kebutuhan nutrisi yang dibutuhkan oleh ikan. Pemberian pakan berkualitas pada ikan nila yang dibudidayakan secara intensif sangat berpengaruh terhadap pertumbuhan dan produktivitas yang dihasilkan. Semakin tinggi kualitas pakan maka produksi yang dihasilkan juga akan semakin meningkat. Salah satu teknologi yang dapat diterapkan untuk mengatasi hal tersebut adalah pembuatan pakan formulated diet alternatif dengan menggunakan bahan baku lokal. Metode yang digunakan dalam kegiatan ini adalah transfer ilmu pengetahuan yang disajikan dalam kegiatan sosialisasi berupa: 1) pengenalan jenis-jenis bahan pakan ikan alternatif yang bersumber dari daerah tersebut, (2) Penyusunan formulasi pakan buatan ikan nila, (3) pelatihan teknologi pembuatan pakan buatan (pellet) serta, 4) pemantauan dan pendampingan. Sosialisasi dilakukan dalam bentuk ceramah dan dilanjutkan dengan sesi tanya jawab. Hasil kegiatan peternak mengenal jenis-jenis pakan lokal yang dapat digunakan sebagai pakan ikan, mengetahui formula pakan dan teknologi pembuatan pakan buatan alternatif. Pengetahuan dan keterampilan yang telah dimiliki pembudidaya ikan diharapkan dapat mengatasi kesulitan pembudidaya ikan dalam menyediakan pakan sehingga produksi dan usaha budidaya ikan meningkat.

Fungisida, seperti mankozeb, banyak digunakan dalam bidang pertanian berkelanjutan dan akan meninggalkan residu pada bahan pangan. Proses oksidasi lanjutan (AOPs) ozon treatment (ozonolisis dan air ozon), sonokimia (sonolisis) serta kombinasi keduanya (sonozolisis) merupakan salah satu teknik potensial dalam mendegradasi residu mankozeb pada cabe hijau. Perbandingan metode degradasi dilakukan pada kondisi yang sama yakni 50 g cabe hijau, 100 mL air dengan waktu treatment 10 menit mampu mendegradasi residu mankozeb sebesar 69,63±1,60 air ozon; 58,83±2,57 sonozolisis; 56,51±2,29 ozonolisis; dan 23,70±1,60 sonolisis. Penambahan waktu perendaman selama 20 menit air ozon meningkatkan persentase degradasi sebesar 83,80±2,54. Beberapa parameter yang mempengaruhi proses degradasi dipelajari seperti waktu treatment, volume air, dan massa cabe hijau. Proses degradasi dengan waktu treatment 10-15 menit, volume air 100 mL dan 50 g cabe hijau mampu mereduksi residu mankozeb sebesar 25-58%. Data hasil analisis spektrofotometer-HPLC menunjukkan bahwa residu mankozeb pada cabe hijau telah berhasil didegradasi.

3-Dimensional Roll Work technology training by processing waste paper into high-value handicraft products has been carried out in Nagari Lareh Nan Panjang, Padang Pariaman Regency. Most of the productive age groups in this area were unemployed women who depend on their husband's income for a living. In other hand, the activities of women's farmer groups, youth groups and (Family Welfare Movement) PKK were not productive. This activity aims to foster and empower community groups, especially women, in managing and processing paper waste into high selling value products with 3-Dimensional Roll Work technology that can be used as business opportunities so as to increase household income. The activity began with counseling on the dangers of paper waste for health and the environment, and continued by 3-dimensional Roll Work training. The indicator of the achievement of the targeted community service program was the management and processing of paper waste where each participant can produce quality handicraft products, namely key chains and accessories, while for other handicraft products, it was continued for group activities such as tissue, accessories, and cake boxes. This activity can be used as a sustainable empowerment effort through increasing community participation, self-financing and community self-help so as to create economically independent women in Nagari Lareh Nan Panjang.

IPTEKS berbasis dosen dan masyarakat (IbDM) bertujuan untuk mengaplikasikan atau mendiseminasikan teknologi pakan buatan alternatif untuk pengembangan budidaya ikan gurame intensif dalam upaya meningkatkan produktivitas perikanan dan meningkatkan pengetahuan serta keterampilan petani ikan (masyarakat) di Kelurahan Limau Manis, Kecamatan Pauh, Kota Padang dalam bidang usaha budidaya ikan di Sumatra Barat. Di samping itu, juga diharapkan petani ikan di Sumatra Barat dapat melakukan pemeliharaan dengan teknik yang baik dan ramah lingkungan. Dengan demikian kegiatan IbDM ini juga diharapkan mampu menekan biaya operasional dalam budidaya ikan gurami intensif dan pada akhirnya dapat meningkatkan pendapatan para petani/ masyarakat Kelurahan Limau Manis melalui pengembangan usaha budidaya ikan yang berkelanjutan. Untuk mencapai hasil diseminasi teknologi yang optimal maka sasaran utama IbDM di Kecamatan Pauh ini adalah kelompok tani ikan dan para pembina/pemuka masyarakat Kelurahan Limau Manis yang diharapkan mampu memberikan motivasi kepada petani untuk mensosialisasikan metode pembuatan pakan formula alternatif untuk pengembangan budidaya ikan gurame secara intensif dan ramah lingkungan. Metode yang digunakan dalam kegiatan ini adalah (1) Penyuluhan (ceramah), dengan materi utama: (a) pengenalan berbagai jenis bahan baku (raw material) yang dapat digunakan untuk makanan ikan gurame, (b) memberikan pengetahuan tentang penyusunan formulasi pakan buatan dengan metode kuadrat, (c) memberikan pengetahuan tentang proses pembuatan makanan buatan (d) menambah pengetahuan masyarakat tentang cara menyimpan pelet yang baik agar lebih tahan lama dan (e) pemberian materi tentang pengujian mutu pakan, baik secara fisika, kimia dan biologis; dan (2) Peragaan pembuatan pakan buatan alternatif untuk budidaya ikan gurame. Dari hasil kegiatan IbDM ini didapatkan bahwa pengetahuan dan keterampilan kelompok tani Kelurahan Limau Manis Kecamatan Pauh, Padang sebelum dilaksanakan kegiatan IbDM ini masih sangat rendah. Namun demikian motivasi atau keinginan masyarakat kelompok tani mitra IbDM untuk melakukan usaha budidaya atau pemeliharaan ikan sangat besar. Hal ini terlihat dari keinginan masyarakat kelompok tani mitra IbDM untuk menguasai teknologi pembuatan pakan alternatif ikan gurame dari hasil limbah daun dan batang talas yang diproses menjadi tepung relatif cukup tinggi. Lebih jauh dari hasil kegiatan IbDM pada masyarakat ini dapat menambah pengetahuan dan keterampilan masyarakat dalam mencari pakan alternatif untuk pakan ikan gurame sehingga kegiatan budidaya dapat berjalan dengan baik di daerah mitra IbDM. Agar kegiatan budidaya berjalan dengan baik di daerah mitra IbDM perlu dilakukan kegiatan IbDM secara berkelanjutan tentang teknik pembuatan pelet ikan alternatif dan teknik pemeliharaan ikan yang efisien dan efektif. Di samping itu perlu dukungan dana atau pemberian kredit oleh pihak yang berwenang kepada masyarakat atau petani ikan untuk modal pengembangan usahanya.

A selective and sensitive adsorptive stripping voltammetric (AdSV) procedure for the simultaneous determination of cadmium, copper and lead in the sea water was conducted. The aim of this research is to get optimum condition for simultaneous determination of cadmium, copper and lead. Adsorptive stripping voltammetry has been used for determination of trace amount of Cd(II), Cu(II) and Pb (II) by using calcon as a complexing agent. The parameters studied were variation of calcon concentration, pH, accumulation potential and accumulation time. In this study, the optimum conditions were calcon concentration of 0.6 mM, pH = 4.0, accumulation potential of -0.7 V and accumulation time of 80 sec. At the optimum conditions, the relative standard deviation were 8.78%, 3.12%, and 4.02% for Cd(II), Cu(II) and Pb(II) respectively for eight replicates (n = 8) measurements of 10 μg/L mixed standard solution of Cd(II), Cu(II) and Pb(II). The method was applied to the direct simultaneous determination of Cd(II), Cu(II) and Pb(II) in sea water around Bungus, Padang City. Concentration of Cd(II), Cu(II) and Pb(II) in samples were equal to 1.8 μg/L for Cd(II), 38.6 μg/L for Cu(II) and 0.7 μg/L for Pb(II) with recovery of 87.03%, 98.80%, and 95.73%, respectively.

A sensitive and selective absorptive stripping voltammetric (AdSV) method to determine Cd(II), Cu(II), Pb(II) and Zn(II) in sea water is proposed. The aim of this study was to get optimum condition for the determination of Cd(II), Cu(II), Pb(II) and Zn(II). Absorptive stripping voltammetry has been used for ultra trace determination of Cd(II), Cu(II), Pb(II) and Zn(II) using calcon as a complexing agent (ligand). In this case, the optimum conditions were reached at 0.1 M KCl supporting electrolyte, concentration of 0.5 mM calcon for Cd(II), Cu(II) 0.3 mM while 0.7 mM for Pb(II) and Zn(II), pH 6 for Cu(II) and pH 7 for Cd(II), Pb(II) and Zn(II), accumulation potential -0.5 V for Cu(II) and Pb(II) and -0.6 V for Cd(II) and Zn(II) and accumulation time 70 sec for Cd(II), 90 sec for Cu(II) and Pb (II) while 50 s for Zn(II). At the optimum condition the relative standard deviations were 7.80%, 4.25%, 8.70% and 0.86% for Cd(II), Cu(II), Pb(II) and Zn(II) respectively for eight replicates (n = 8) measurements of 10 μg/L Cd(II), Cu(II), Pb(II) and Zn(II). The method was applied for the direct determination of Cd(II), Cu(II), Pb(II) and Zn(II) in sea water around Bungus, Padang City. Concentration Cd(II), Cu(II), Pb(II) and Zn(II) in sample were 13.200 μg /L for Cd(II), 17.200 μg/L for Cu(II), 0.089 μg/L for Pb(II) and 62.000 μg/L for Zn(II) with recovery of 98.68%, 97.99%, 96.17% and 99.96% for Cd(II), Cu(II), Pb(II) and Zn(II), respectively.

The current learning paradigm is oriented to the XXI century learning and the development of the 4.0 Industrial Revolution. It is relevant to the emergence of the COVID-19 outbreak and the new normal era where the learning is held online. Conducting online learning needs a good readiness from educational institutions, teaching, e-learning quality, infrastructure, and many more to support the online learning implementation. The significance of this study was to analyze the needs for indicators of online learning instruments, to know the weakness and the strength levels of each required indicator as well as the accuracy of instruments for online learning assessment conducted later. This study aimed to analyze the needs assessment for the online learning program during the COVID-19 pandemic. This study was carried out by conducting a survey. A total of 128 samples were selected for this study consisted of 115 students and 13 lecturers from 6 study programs in the Faculty of Engineering, Universitas Negeri Padang. The data collection instrument was questionnaire adapted from Al-Shagran (2017), the need analysis of the evaluation of online learning programs. Data analysis was conducted descriptively. The result showed that the required indicators for assessment started from the design of the e-learning management system technology provider and then followed by teaching staff.

ABSTRACT Study of optimation cadmium(II) by adsorptive stripping voltammetry has been done. The aim of this study to get optimum conditions for determination of Cd(II). Parameters were done : potential accumulation, time accumulation, pH, supporting electrolite concentration and optimum of complex concentration. In this case, the optimum conditions were reached in potential accumulation -0.7 V, time accumulation 60 second, pH 7.0, NH4Cl 0.12 M, calcon concentration 0.12 mM. In the optimum condition was obtained with the relative standard deviation was 4.61% for eight replicates, measurements of 0.01 ppm. The method was applied to the direct determination of Cd(II) in water around Batang Air Dingin Lubuk Minturun and Muara Padang. Concentration Cd(II) in sample was equal to 7.359 μg/L and 3.659 μg/L with recovery of 99.04%. Keywords: cadmiun, adsorptive, stripping, voltammetry

ABSTRACT Study of optimation chromium (VI) in sea water by adsorptive stripping voltammetry has been done. The aim of this method to get optimum conditions for determination of Cr(VI). Adsorptive stripping voltammetry (AdSV) has been used for the ultra trace determination of chromium using 2,2’- bipyridin as ligand. Parameters were done, like accumulation time, concentration of ligand, pH, accumulation potential, electrolyte concentration and catalyst concentration. In this case, the optimum conditions were reached in accumulation time 80 second, pH 5.0, concentration of 2,2’- bipyridin 10 μM, accumulation potential -0,6 Volt and electrolyte concentration (NH4Cl) 0,1 M. In the optimum conditions, a linear calibration graph was obtained with correlation coefficient of 0.9971, the relative standard deviation was 15.06 % for eight replicates (n = 8) measurements of 10 μg/L of Cr(VI). The detection limit method was 0.1692 μg/L. The method was applied to the direct determination of Cr(VI) in sea water around Muara Padang water. Concentration Cr(VI) in sample was equal to 0.9684 μg/L with recovery of 90.23 %. Keywords : optimation, chromium, adsorptive, stripping, voltammetry

ABSTRACT The research about determination of Cu(II) by adsorptive stripping voltammetry (AdSV) was conducted. AdSV method was applied to the determination of copper in ultra trace concentration. The parameters of ligand, accumulation potential, accumulation time, pH and ligand concentration was studied. Calcon was found as complexing agent that give the highest peak current. The optimum condition are accumulation potential -0,7 V, accumulation time 60 s, pH 10, and calcon concentration 0.12 mM. The relative standar deviation (n=8) at 10 µg/L standard concentration were obtained 4,27 %. This method was applied to determination of Cu(II) in sample from Batang Air Dingin, Lubuk Minturun and Muara Padang. The sample concentration were 4,778 µg/L and 5,189 µg/L for Batang Air Dingin and Muara Padang, respectively. The recovery of this method was studied for sample from Muara Padang and 98,31 % was obtained. Key words : Adsorptive, Stripping, Voltammetry, Calcon and Copper

A selective and sensitive adsorptive stripping voltammetric (AdSV) method for simultaneous determination of lead(II) and cadmium(II) were proposed. The aim of this study was to get the optimum condition for simultaneuos determination of lead(II) and cadmium(II). The parameters were studied such as: variation of accumulation potential, accumulation time, pH, and variation of calcon concentration. In this case, the optimum conditions were reached at accumulation potential –0.7 V, accumulation time 80 s, concentration of 0.12 mM calcon, and pH 7.0. At the optimum conditions the relative standard deviation were 2.90% and 1.46% for Pb(II) and Cd(II) respectively for eight replicates (n = 8) measurements. The method was applied for the direct determination of Pb(II) and Cd(II) in sea water around Bungus, Padang City. Concentration Pb(II) and Cd(II) insample were 9.918 μg/L – 27.320 μg/L for Pb(II) and 7.997 μg/L - 32.521 μg/L for Cd(II), with recovery of 99.48%, and 103.28 for Pb(II), and Cd(II) respectively.

The present study investigated the capability of cassava peel (Manihot Esculenta Crantz) in Pb(II) and Cr(VI) removal. The comparative study was conducted using batch method observing some parameters. The results indicated that the optimum adsorption of Pb(II) occurred at pH 5, initial concentration of 1000 mg/L, and contact time of 50 min. On the other hand, the optimal adsorption of Cr(VI) was achieved at pH 2, initial concentration of 1200 mg/L, and contact time of 70 min. The adsorption isotherms of both metals tended to follow the Langmuir model, while the adsorption kinetics suited to pseudo-second-order model. Thermodynamic parameters indicated that the adsorption process was spontaneous (ΔG° negative), endothermic (ΔH° positive), and exhibited surface dispersion on the biosorbent (ΔS° positive). Characterization using Fourier Transform Infrared (FTIR), X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), and Thermogravimetry (TGA) provided evidence of both physical and chemical adsorption. The adsorption capacity of cassava peel was also tested on samples collected approximately 30 m from the bay shoreline, resulting in a removal percentage of 94.67% for Pb(II) and 82.28% for Cr(VI) under optimal pH and contact time conditions. [ABSTRACT FROM AUTHOR]

Dye water contamination was the main challenge that pressured textile industries tremendously. The present investigation aims to employ solid waste from fisheries industries to remove toxic dye contaminants in an aqueous solution. Shrimp shell waste (SSW) was fishery waste with good potential for adsorbing dyes, one of which is methylene blue. This research studied methylene blue's adsorption capacity using shrimp shell waste as a biosorbent. By studying several parameters, it was found that the adsorption capacity was 48.834 mg g−1 at pH = 10, with an optimum concentration of 550 mg L−1, a contact time of 105 min, and a heating temperature of the biosorbent 120 °C - the results of XRF characterisation shown the differences in the chemical composition percentage before and after adsorption process. The results suggested that SSW can be employed as and low-cost adsorbent for the removal of methylene blue dye from water effectively. [ABSTRACT FROM AUTHOR]

Salt produced from seawater evaporation contains harmful microplastics (MP). For this reason, a technology that can remove MP from seawater using coagulation and filtration techniques is needed. The purpose of this study is to utilize alum as a coagulant and sand as a filtration media to reduce MP pollution in seawater as a source of raw material for salt making. Seawater from Buo Bay, Padang City, Indonesia was taken as raw material for salt production. The MP abundance of salt made from seawater without alum and sand treatment was found to be 400 particles/kg. To reduce the abundance of MP in the salt, we varied the alum concentration (0.1; 0.3; and 0.5 g/L) and sand particle size (=2, =1-<2, and <1 mm). From the results obtained, the optimal condition is an alum concentration of 0.5 g/L and sand particle size is <1 mm. The optimal condition of salt made from seawater in treatment H obtained MP abundance from 400 particles/kg to 30 particles/kg with an MP reduction efficiency of 92.5%. Visual analysis using optical trinocular microscopy found 4 forms of MP, namely: fragments (51.13%), fibers (28.95%), films (15.41%), and pellets (4.05%). Rewith the most dominant MP size found was >100-300 µm. The results of ATR-FTIR analysis identified the types of MP as Polyethylene (14.28%), Polyethylene Terephthalate (42.85%), Polypropylene (14.28%), and Polyamide (28.57%). [ABSTRACT FROM AUTHOR]

Industrial processes are the main source of Pb(II) contamination of natural water bodies. Pb(II) is a non-biodegradable heavy metal and carcinogen. The recent study explored the ability of citric acid-modified-kepok banana peel (CA-BP) to remove Pb(II) from an aqueous solution using the batch method. The adsorption capacity of kepok banana peel (BP) was also investigated for comparison. The optimum conditions for Pb(II) removal using kepok banana peel were achieved at pH 5, initial concentration of 600 mg l-1, contact time of 75 min, and agitation speed of 100 rpm, with an adsorption capacity of 36.478 mg g-1. Meanwhile, the adsorption capacity of citric acid modified-kepok banana peel was 64.088 mg g-1, which was reached at pH 5, initial concentration of 850 mg l-1, contact time of 75 min, and agitation speed of 150 rpm. The adsorption of Pb(II) onto both sorbents followed the Langmuir isotherm model and pseudo-second-order model, indicating monolayer adsorption with chemical interaction as a rate-limiting step. A Fourier Transform Infra-Red (FTIR) analysis was conducted to identify the functional groups present in the biosorbent and demonstrate a change in the wave number. The surface morphology of the biosorbent was examined using Scanning Electron Microscopy (SEM) before and after the absorption of Pb2+ metal ions. The objective of Energy Dispersive X-ray (EDX) is to quantify the elemental composition of the biosorbent derived from the surface of the kepok banana peel. An X-ray fluorescence (XRF) analysis was conducted to determine the chemical composition of the surface of the kepok banana peel biosorbent. Thermogravimetric Analysis (TGA) was conducted to observe the decrease in mass of the biosorbent as the temperature increased. [ABSTRACT FROM AUTHOR]

BACKGROUND AND OBJECTIVES: Microplastics are plastic fragments measuring less than 5 millimeters which are formed from degraded plastic materials and have the potential to pollute the environment. Due to their widespread presence in the marine environment, microplastics have become a significant global threat. The presence of microplastics is often considered as causing pollution in various environments, especially aquatic ecosystems such as rivers and oceans. Microplastics contamination can even be found in consumed salt, thus raising concerns about its impact on human health. However, information on the presence of microplastics in salt is still very limited. This study aims to determine the abundance and characteristics of microplastics as contaminants in salt and assess the human exposure to microplastics in Indonesia. METHODS: A total of 21 samples of salt products were taken from various brands available in Padang City and Jambi City, Indonesia for analysis. Microplastics extraction was carried out by removing the organic materials contained in the salt samples using 30 percent hydrogen peroxide and then filtering them with a 0.45 micrometer pore filter. A stereomicroscope was used to detect the abundance, shape, size, and color of microplastics, while the Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy was utilized to identify the polymer type of the microplastics. Furthermore, human exposure to microplastics can be predicted by calculating the estimated dietary intake and taking into account the daily salt intake. FINDINGS: Microplastics were detected in significant amounts (p<0.05) in all salt samples, ranging from 33 to 313 particles/kilogram. The types of microplastics most commonly found in the samples were fragments (67.49 percent), fibers (23.82 percent), films (6.08 percent), and pellets (2.61 percent). The types of polymer identified include polyethylene, polypropylene, polyethylene terephthalate, and polyester. The dominant microplastics were 100-300 micrometers in size (47.3 percent) and black in color (52.88 percent). It is estimated that adults in Indonesia will be exposed to 60.225-571.225 microplastics/year if they consume 5 grams of salt/day or 120.45-1142.45 microplastics/year if they consume 10 grams of salt/day. CONCLUSION: Of the 21 salt samples analyzed, all were detected to contain microplastics. Inadequate and unhygienic salt production and contaminated seawater used as raw material contribute to microplastics contamination of salt, thus posing a risk to human health. By calculating of daily salt intake of the Indonesian population, it is possible to estimate their daily and annual exposure to microplastics. The results of this study contain useful information for the efforts to prevent microplastics contamination by relevant stakeholders and the provision of education and socialization about the proper salt production process in accordance with food safety standards as to reduce or even eliminate microplastics in salt. In addition, this study can provide valuable data on human exposure to microplastics in salt products that can assist policymakers in making standard references for microplastics. [ABSTRACT FROM AUTHOR]

Black grass jelly (Mesona palustris BL) is an Indonesian traditional food that is rich in antioxidants and believed to have potential for treating various diseases such as diabetes, hypertension, and cancer. The present study aimed to determine the antioxidant activity of black grass jelly leaf extract as well as fractions using ABTS, DPPH and FRAP methods. Following ethanol extraction and subsequent fractionations, total flavonoid level was determined, followed by antioxidant activity tests using the ABTS, DPPH and FRAP with vitamin C as references. The tests revealed the following order of antioxidant activities, ethyl acetate fraction>extract>water fraction>n-hexane fraction. All test substances had IC50 of <50 ppm, which categorized them as having very high antioxidant activities. In line with this data, on the basis of reducing power, ethyl acetate extract was shown to be the most potent antioxidant, having a value of 20.24 mgAAE/g sample. Overall, results of the present study suggest the potential use of black grass jelly as a part of the therapeutic armamentarium for oxidative stress-related diseases. [ABSTRACT FROM AUTHOR]

In this paper, the application of the Adsorptive Stripping Voltammetry-Response Surface Methodology (AdSV-RSM) in the simultaneous determination of copper ions in an aquaponics system has been studied. The effects of several parameters studied include variations in Calcein concentration, pH, accumulation potential, and accumulation time. The study design used was Response Surface Methodology (RSM) with 4 factors/variables, 3 levels and 31 treatment combinations. The results of the study, analysis of variance was carried out, and it was decided to accept the second-order model, which means that the independent variable has a significant effect on the response variable (peak current). Based on data analysis with the RSM, the determination of Cu(II) obtained the optimum conditions including peak current 349.196 (Ip); calcein concentration 0.616339 µg/L; pH 6.06208; potential accumulation −0.721104 V and time accumulation of 69.3744 s. The response surface method has been applied successfully for Cu(II) analysis in water, fish, and hydroponic plant aquaponics system, which is an integration between fish farming and hydroponic plant cultivation, with the relative standard deviation value was 1.12%, recovery of 99.23% and the detection limit of 0.75 μg/L. [ABSTRACT FROM AUTHOR]

Acid-activated corn husk waste (CHW) was used to investigate the adsorption mechanism of Indigo Carmine (IC) dye from an aqueous solution. The effect of different operating parameters such as pH (1-7), initial IC dye concentration (40-400 mg/L), contact time (5-75 min), and heating temperature (25–200 °C) was measured on the removal of IC dye by the CHW. The maximum uptake of IC dye was observed at an initial pH of 2. The maximum capacity of 13.57 mg/g and the maximum dye removal of 89.01 % in wastewater. The adsorbents were characterized using Fourier Transforms Infrared Spectrophotometry (FTIR), Scanning Electron Microscopy (SEM), Brunauer-Emmett-Teller (BET) surface area analysis, X-ray Fluorescence (XRF), and Thermogravimetry Analysis. The characterization process reveals the differences in adsorbent characteristics before and after the adsorption processes. The Langmuir showed the best fitting (R2 = 0.977) and described multilayer adsorption on diverse surfaces. The pseudo-second-order kinetic model best correlated with the experimental data (R2 = 0.981). Thermodynamics revealed that adsorption was favorable spontaneous and exotherm. The study's results indicated that using CHW as a low-cost adsorbent to treat IC dye was efficient and beneficial to the environment. [ABSTRACT FROM AUTHOR]