ANALISIS PENGARUH ADSORBEN LIMBAH KULIT KOPI PERTANIAN JEMBER PADA PROSES ADSORPSI LOGAM TEMBAGA (Cu)

Suatu aktivitas industri termasuk industri pertanian dapat menimbulkan dampak, baik dampak positif ataupun negatif. Salah satu dampak negatif yang ditimbulkan dari aktivitas industri adalah permasalahan limbah padat yang dihasilkan. Salah satu limbah padat yang dihasilkan oleh industri pertanian adalah kulit kopi. Penelitian ini merupakan penelitian awal dalam pemanfaatan limbah padat industri pertanian yang ada di Kabupaten Jember sebagai material adsorben untuk menyerap limbah cair yang mengandung logam berat Cu. Limbah padat yang digunakan sebagai adsorben adalah limbah kulit kopi. Adsorben dari kulit kopi merupakan salah satu material potensial yang dapat dikembangkan dan telah terbukti dapat menyerap logam berat. Terdapat dua tahapan dalam penelitian ini yaitu tahap adsorpsi dan tahap uji Unvariate Two Way Anova menggunakan bantuan software SPSS. Pada tahap adsorpsi, dilakukan proses adsorpsi dengan waktu kontak 30, 60, dan 90 menit, dan kecepatan pengadukan 100, 200, dan 300 RPM. Pada tahap uji Unvariate Two Way Anova, data yang dihasilkan terlebih dahulu harus memenuhi uji prasyarat sebagai data terlebih dahulu diuji dengan uji normalitas dan homogenitas data. Uji normalitas menggunakan uji Kolmogorov Smirnov sedangkan uji homogenitas menggunakan levene test. Setelah itu kemudian dilanjutkan dengan uji Unvariate Two Way Anova dan uji pos hoc. Penelitian ini bertujuan untuk menganalisis proses adsorpsi logam tembaga (Cu) menggunakan adsorben dari limbah kulit kopi, dan menganalisis pengaruh waktu kontak dan kecepatan pengadukan pada proses adsorpsi. Berdasarkan hasil penelitian dan pembahasan, dapat disimpulkan bahwa (1) proses adsorpsi logam tembaga (Cu) menggunakan adserben yang terbuat dari limbah kulit kopi terbukti dapat menurunkan konsentrasi Cu, dan (2) terdapat pengaruh yang signifikan pada semua variabel waktu kontak dan kecepatan pengadukan kecuali antara kecepatan pengadukan 100 RPM dan 300 RPM. Kata kunci: Adsorben, adsorpsi, anova, Cu, kopi. The industrial activity including the agricultural industry can have an impact, both positive and negative impacts. One of the negative impacts caused by industrial activities is the problem of solid waste produced. One of the solid wastes produced by the agricultural industry is coffee skin. This research is an initial study in the utilization of agricultural industrial solid waste in Jember Regency as an adsorbent material to absorb liquid waste containing heavy metals Cu. Solid waste that is used as an adsorbent is coffee skin waste. Coffee skin adsorbent is one of the potential materials that can be developed and has been proven to absorb heavy metals. There are two steps in this research, namely the adsorption stage and the Unvariate Two Way Anova test using SPSS. In the adsorption stage, the adsorption process is carried out with contact times of 30, 60 and 90 minutes, and stirring speeds of 100, 200, and 300 RPM. In the Unvariate Two Way Anova test, the data generated must first fulfill the prerequisite test as the data is first tested by normality and homogeneity test. The normality test uses the Kolmogorov Smirnov while the homogeneity test uses the levene test. After that, it was followed by the Unvariate Two Way Anova test and the post hoc test. This study aims to analyze Cu adsorption process using adsorbents from coffee skin waste, and analyze the effect of contact time and stirring speed on the adsorption process. Based on the results of research and discussion, it can be concluded that (1) Cu adsorption process using adserbens made from coffee skin waste has been proven to reduce Cu concentration, and (2) there is a significant effect on all contact time variables and stirring speeds except between stirring speed of 100 RPM and 300 RPM. Keywords: Adsorbent, adsorption, anova, coffee, Cu.

Preparation of New Sargassum fusiforme Polysaccharide Long-Chain Alkyl Group Nanomicelles and Their Antiviral Properties against ALV-J

Avian leukosis virus subgroup J (ALV-J) is an immunosuppressive virus which has caused heavy losses to the poultry breeding industry. Currently, there is no effective medicine to treat this virus. In our previous experiments, the low-molecular-weight Sargassum fusiforme polysaccharide (SFP) was proven to possess antiviral activity against ALV-J, but its function was limited to the virus adsorption stage. In order to improve the antiviral activity of the SFP, in this study, three new SFP long-chain alkyl group nanomicelles (SFP-C12M, SFP-C14M and SFP-C16M) were prepared. The nanomicelles were characterized according to their physical and chemical properties. The nanomicelles were characterized by particle size, zeta potential, polydispersity index, critical micelle concentration and morphology. The results showed the particle sizes of the three nanomicelles were all approximately 200 nm and SFP-C14M and SFP-C16M were more stable than SFP-C12M. The newly prepared nanomicelles exhibited a better anti-ALV-J activity than the SFP, with SFP-C16M exhibiting the best antiviral effects in both the virus adsorption stage and the replication stage. The results of the giant unilamellar vesicle exposure experiment demonstrated that the new virucidal effect of the nanomicelles might be caused by damage to the phospholipid membrane of ALV-J. This study provides a potential idea for ALV-J prevention and development of other antiviral drugs.

Water sorption on coal: effects of oxygen-containing function groups and pore structure

Coal-water interactions have profound influences on gas extraction from coal and coal utilization. Experimental measurements on three coals using X-ray photoelectron spectroscopy (XPS), low-temperature nitrogen adsorption and dynamic water vapor sorption (DVS) were conducted. A mechanism-based isotherm model was proposed to estimate the water vapor uptake at various relative humidities, which is well validated with the DVS data. The validated isotherm model of sorption was further used to derive the isosteric heat of water vapor sorption. The specific surface area of coal pores is not the determining parameter that controls water vapor sorption at least during the primary adsorption stage. Oxidation degree dominates the primary adsorption, and which togethering with the cumulative pore volume determine the secondary adsorption. Higher temperature has limited effects on primary adsorption process.The isosteric heat of water adsorption decreases as water vapor uptake increases, which is found to be close to the latent heat of bulk water condensation at higher relative humidity. The results confirmed that the primary adsorption is controlled by the stronger bonding energy while the interaction energy between water molecules during secondary adsorption stage is relatively weak. However, the thermodynamics of coal-water interactions are complicated since the internal bonding interactions within the coal are disrupted at the same time as new bonding interactions take place within water molecules. Coal has a shrinkage/swelling colloidal structure with moisture loss/gain and it may exhibit collapse behavior with some collapses irreversible as a function of relative humidity, which further plays a significant role in determining moisture retention.

Enhanced removal of cadmium from wastewater with coupled biochar and Bacillus subtilis

Shortcomings of individual biochar or microbial technologies often exist in heavy metal removal from wastewater and may be circumvented by coupled use of biochar and microorganisms. In this study, Bacillus subtilis and each of three biochars of different origins (corn stalk, peanut shell, and pine wood) were coupled forming composite systems to treat a cadmium (Cd, 50 mg/L) wastewater formulated with CdCl2 in batch tests. Biochar in composite system enhanced the activity and Cd adsorption of B. subtilis. Compared with single systems with Cd removal up to 33%, the composite system with corn stalk biochar showed up to 62% Cd removal, which was greater than the sum of respective single B. subtilis and biochar systems. Further analysis showed that the removal of Cd by the corn stalk composite system could be considered to consist of three successive stages, that is, the biochar-dominant adsorption stage, the B. subtilis-dominant adsorption stage, and the final biofilm formation stage. The final stage may have provided the composite system with the ability to achieve prolonged steady removal of Cd. The biochar-microorganism composite system shows a promising application for heavy metal wastewater treatment.

Carbon Dioxide (CO2) Adsorption Behaviour and Its Relationship with Nano-Structure in an Organic-Rich Shale: A Case Study of the Longmaxi Shale in Southeast Chongqing

Carbon capture and storage (CCS) technologies in shale reservoirs have attracted increasing interest in recent years. To study the CO2 adsorption behaviour in the Longmaxi shale, isothermal adsorption experiments, scanning electron microscopy (SEM) and other techniques were employed in this study. The results show that when the pressure is less than 7.37 MPa, the Langmuir model fits well with the experimental CO2 adsorption data in the shale. In contrast, when the pressure is greater than 7.37 MPa, the D+R-K model fits better with the experimental data. From low pressure to high pressure (>20 MPa), the CO2 adsorption isothermal curves can be divided into four stages: rapid adsorption stage, slow adsorption stage, linear decreasing stage and slightly decreasing stage. With increases in temperature, the CO2 adsorption capacity decreases as expected. In addition, the effects of the Longmaxi shale nano-structure on the CO2 adsorption behaviour were also investigated. It was found that organic matter has a greater influence than clay and quartz on the CO2 adsorption behaviour. Based on the SEM observations, large numbers of nanoscale organic pores were found in the shale samples, and these nanoscale organic pores may control the CO2 adsorption behaviour in organic-rich Longmaxi shale. With increasing total organic carbon (TOC) content, the CO2 adsorption capacity increases linearly. In this study, the characteristics of the CO2 adsorption in shale and its relationship with the shale nano-structure were studied, which may be helpful for understanding CCS technologies and their application in enhanced shale gas recovery.

Water Sorption on Coal: Effects of Oxygen Containing Function Groups and Pore Structure

Coal-water interactions has profound influences on gas extraction from coal and coal utilization. Experimental measurements on three coals using X-ray photoelectron spectroscopy (XPS), low-temperature nitrogen adsorption and dynamic water vapor sorption (DVS) were conducted. A mechanism-based isotherm model was proposed to estimate the water vapor uptake at various relative humidities, which was well validated with the DVS results. The validated isotherm model of sorption is further used to derive the isosteric heat of water vapor sorption. The pore specific surface area of coal is not the determining parameter that controls water vapor sorption at least during the primary adsorption stage. Oxygen containing degree dominates the primary adsorption, and togethering with the cumulative pore volume determine the secondary adsorption. Higher temperature has limited effects on primary adsorption process. The isosteric heat of water adsorption decreases as water vapor uptake increases, which was found to be close to the latent heat of bulk water condensation at higher relative humidity. The results confirmed that the primary adsorption is controlled by the stronger bonding energy while the interaction energy between water molecules during secondary adsorption stage is relatively weak. However, the thermodynamics of coal-water interactions are complicated since internal bonding interactions within the coal are disrupted at the same time as new bonding interactions take place with the water molecules. Coal has a shrinkage/swelling colloidal structure with moisture loss/gain and it exhibits collapse behavior with some collapses irreversible as a function of relative humidity, which plays a significant role in determining moisture retention.

Selection of the Activated Carbon Type for the Treatment of Landfill Leachate by Fenton-Adsorption Process

Sanitary landfill leachates usually have characteristics that depend on the region where they are generated and according to the age of the landfill, which is why a unique treatment for their sanitation has not been found. However, the adsorption preceded by the Fenton process has been proven to be highly efficient at removing contaminants. In this study, the adsorptive capacity of two types of activated carbon, granular and powdered, was analyzed to determine which was more efficient in the adsorption stage in the Fenton-adsorption process. Likewise, its behavior was analyzed using three isotherm models (Langmuir, Freundlich and Temkin), testing the raw leachate and the Fenton-treated one with both carbons. The adsorption that is carried out on the carbons is better adjusted to the Freundlich and Temkin models. It concludes that multilayers, through the physical adsorption, carry out the adsorption of pollutants on the surface of the carbons. The results show that, statistically, granular activated carbon is more efficient at removing chemical oxygen demand (COD), and powdered activated carbon removes color better. Finally, an adsorption column was designed for the Fenton-adsorption process that was able to remove 21.68 kgCOD/kg carbon. Removal efficiencies for color and COD were >99%.

Numerical study of the dynamics of synthesis gas adsorption separation

A numerical study of the dynamics of pressure swing adsorption process for synthesis gas separation and hydrogen concentration was carried out. The influence of regime parameters (compressor and vacuum pump outlet pressures, duration of the "adsorption-desorption" cycle, backflow coefficient) and design parameters (height of the adsorbent bulk layer and the internal bed diameter) on the recovery and purity of hydrogen, plant performance in a given range of changes in the temperature, composition and pressure of the initial gas mixture was studied. It is found that when the hydrogen content decreases from 68 to 48 vol. % and a simultaneous increase in the carbon dioxide content in the initial gas mixture from 27 to 47 vol. % required hydrogen purity value at 99.99 vol. % can be achieved by reducing the pressure at the outlet of the vacuum pump from 0.75?105 to 0.5?105 Pa. At the same time, the duration of the adsorption stage increases from 120 to 150 seconds, and the degree of hydrogen extraction decreases from 55 to 52% due to an increase in the proportion of the flow selected for the regeneration of the adsorbent. Increasing the temperature of the initial gas mixture from 293 to 323 K leads to the need to reduce the duration of the adsorption stage from 148 to 42 s due to a decrease in the equilibrium concentrations of carbon dioxide and monoxide in the adsorbent.

Creep behavior of laminated veneer lumber from poplar under cyclic humidity changes

Many academic studies over the years have confirmed that mechano-sorptive (MS) creep is an inherent characteristic of wood. Unlike solid wood, bond lines are introduced into laminated veneer lumber (LVL), creating a laminated structure with different hygroscopicity. What are the effects of these differences on the MS creep of LVL? In this study, three groups of well-matched LVL samples were subjected to four-point bending loading within different relative humidity cycles. For each group, the applied load ranged from 15% to 35% of the short-term fracture load. The results showed that after the first hygroscopic process, LVL showed irreversible expansion (0.11 mm) and a relatively slow moisture adsorption rate. These made it difficult for LVL to show partial creep recovery during the first adsorption process no matter how low the load level was, while solid wood showed partial creep recovery when the load level was ≤ 25%. The following creep behavior of LVL was similar to that of solid wood: partial creep recovery started from the second adsorption stage when a moderate load level was applied.