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This study aimed to analyze the adsorption ability of black sand in the metal ions adsorb cadmium (Cd2+) with a concentration of 70 ppm to a solution with a pH of 4,5. The black sand is used is 40 mesh. This research was conducted by batch adsorption system naturally and adsorption kinetics modeling. Kinetics of adsorption reached equilibrium at time t = 120 minutes with the percentage concentration of adsorbed Cd2+ 18,5%. In the adsorption kinetics modeling correlation coefficient is almost the same between the equations of first order and second order in the amount of 0.98 and 0.99. The result indicated that the type of interaction Cd2+ ions on the surface of black sands occur in chemistry and physics. The adsorption kinetics of diffusion modeling of internal and external diffusion of the correlation coefficient of 0,85 and 0,71. From this data it can be seen that in this study is modeling kinetic internal diffusion trend that shows adsorbent particles are inter sand surface area that experienced internal inter-particle pore diffusion.

Lignin is one of the chemical components of wood beside cellulose, hemicellulose and extractive. Lignin contains phenolic hydroxyl group that are bound to phenyl propane unit, allowing lignin bonds with formaldehyde to be similar to the results of the reaction between phenol and formaldehyde. The catalytic process in lignin isolation is expected to convert lignin efficiently. Although many catalysts have been developed and shown to efficiently degrade lignin compositions, only a few catalyst can degrade lignin with good conversion. In this study we will discuss the effect of temperature and reaction time on lignin isolation from reeds and is expected to be applied later in the process of making surfactants. This research was carried out at temperatures of 70 °C, 80 °C, and 90 °C, and reaction times during (10, 20, 30, 40, and 50) minutes, with catalyst NaOH 10%. The observations of the most lignin yield obtained from the reaction temperature of 90 and the reaction time of 30 minutes as much as 30,93%. The product will be investigated by FTIR (Fourier Transform Infra Red).

During the COVID 19 virus impact to the most area in Indonesia, most of the teaching and research activities doing at home. The idea to force the activity at home by giving the idea to do research in drying natural operation. It is the sample of how students can apply the drying operation at their home. The idea to dry the Ginger as the material sample was applied and have given the result on the size or shape of the sample variation. The operation time and temperature impact on drying the sample. Drying at the open area and naturally were give the information have impacted the rate of drying. In this study, the type of shape was the most impacted in comparing the temperature and operation time.

This study aimed to analyze the adsorption ability of white sand in the metal ions adsorb cadmium (Cd2+) with a concentration of 70 ppm to a solution with a pH of 4.5. The white sand is used is 40 mesh. This research was conducted by batch adsorption operation naturally and adsorption kinetics modeling. Kinetics of adsorption reached equilibrium at time t = 120 minutes with the percentage concentration of adsorbed Cd2+ 30.7%. In the adsorption kinetics modeling correlation coefficient is almost the same between the equations of first order and second order in the amount of 0.97 and 0.99. The result indicated that the type of interaction Cd2+ ions on the surface of white sands occur in chemistry and physics. The adsorption kinetics of diffusion modeling of internal and external diffusion of the correlation coefficient has 0.95 and 0.85. From this data it can be seen that in this study is modeling kinetic internal diffusion trend that shows adsorbent particles are inter sand surface area that experienced internal inter-particle pore diffusion.

Ball mill is an operating unit used to grind various types of solid materials into finer particle sizes. The purpose of this study was to determine the best variation of operating conditions of mung bean milling in a ball mill by varying the grinding time, weight of raw materials and the number of balls used. In this study, the raw material used is mung bean. After grinding, the beans are then sifted through sieves 70, 140 and 200 mesh where the fraction of green beans that passes each sieve was obtained. From the studies, it can be concluded that the best operating conditions of mung bean milling in the ball mill are at 60 minutes grinding time, the weight of the raw material is 45 grams and the number of balls size is 8 medium balls and 6 small balls.

The aims of this study are to know the adsorption ability of white sand from Medan Indonesia to adsorb cadmium ions (Cd2+) from the solution at pH 4.5. The variables were on different size of white sand, the rpm of shaker and Cd concentrations. The first step was to determine the optimum contact time and adsorption capacity. The adsorption capacity on 70 ppm Cd ions with 40 mesh sand size and stirring speed 150 rpm is 38% after 100 minutes operation time. Impact of sand size 10 mesh, 20 mesh and 40 mesh is possible to increase the adsorption capacity. Increasing the rpm will impact to interaction stability the Cd ion on sand surface. White Sand has ability to interact with metal ions dissolve in solution.

This study reports the turmeric of drying operation. Variables that have been compared are size or surface area of the sample, drying air rate and drying temperature. In this case it was found that the effect of increasing surface area would be able to increase the amount of water evaporated from the sample. The effect of drying air flow rate at the same temperature decreases the ability to evaporate air in turmeric samples. This is due to the reduced time of interaction of the drying air with the sample surface. Relatively small temperature variations do not show significant differences. The optimal drying rate is achieved by using drying air temperature at 39°C with drying flow of 4,5 m/s and the turmeric sample with surface area of 0,00525 m2. The effect of this drying variable obtained significantly on the size of the dried turmeric.

The inspiration of this investigation was to descript the output analysis of product plantation media from sand material from mount Sinabung eruption. The Sinabung volcanic sand with chicken manure and natural soil were mixed and used as materials to produce planting media. The experiment started from collecting the materials with pre-treatment then added by certain variation material prepared to make shape by mechanic pressure tool to construct the matrix media with cylindrical shape.The surface characteristic and hardness of the planting media products were analyzed to get the best variation of materials. The increasing percentage of Sinabung sand will decrease the strength of mixed materials plantation media from 61,9 N to 40,9 N and to 32,6 N for 20%,40% and 60% Sinabung volcanic sand. The product planting media can be used in the area that needed reforesting such as: around the mount Sinabung, toba lake, ect.

In this study, the interfacial properties of biosurfactant rhamnolipid were investigated and were applied to remove adsorbed heavy metal ions from sand surfaces with flushing operations. The surface tension-lowering activity, micelle charge characteristic, and foaming ability of rhamnolipid were identified first. For rhamnolipid in water, the negatively charged characteristic of micelles or aggregates was confirmed and the foaming ability at concentrations higher than 40 mg/L was evaluated. By using the rhamnolipid solutions in a batch washing approach, the potential of applying the interfacial properties of rhamnolipid to remove adsorbed copper ions from sand surfaces was then demonstrated. In rhamnolipid solution flushing operations for sand-packed medium, higher efficiency was found for the removal of adsorbed copper ions with residual type than with inner-sphere interaction type, implying the important role of interaction type between the copper ion and the sand surface in the removal efficiency. In addition, the channeling effect of rhamnolipid solution flow in the sand-packed medium was clearly observed in the solution flushing operations and was responsible for the low removal efficiency with low contact areas between solution and sand. By using rhamnolipid solution with foam to flush the sand-packed medium, one could find that the channeling effect of the solution flow was reduced and became less pronounced with the increase in the rhamnolipid concentration, or with the enhanced foaming ability. With the reduced channeling effect in the flushing operations, the removal efficiency for adsorbed copper ions was significantly improved. The results suggested that the foam-enhanced rhamnolipid solution flushing operation was efficient in terms of surfactant usage and operation time.

The potential of using the biosurfactant surfactin to remove adsorbed metal ions from sand surfaces with continuous flushing approaches was evaluated. With the surfactin solution flushing approach, low removal efficiency of 2–15% for copper ions was detected due to the contact of surfactin with copper ions occurring mainly in the inter-particle pore region. The channeling effect also contributed to the low removal efficiency. By incorporating foam in the flushing operation, the contact of surfactin with copper ions was enhanced due to reduced channeling effect. More copper ions with outer-sphere interaction type were thus available and the removal efficiency was increased. Increasing the surfactin concentration could increase the dynamic foaming capacity and lead to improved removal efficiency of 40%. The results demonstrated that the foam-enhanced solution flushing approach was efficient with a low usage of surfactin.

This study demonstrated the abilities of negatively charged biosurfactants, surfactin and rhamnolipid, to remove adsorbed copper and cadmium ions from sand surfaces with the foam-enhanced solution flushing technique. A popular anionic surfactant, sodium dodecylsulfate (SDS), was used for the purpose of removal efficiency comparison. The role of surfactant foaming ability in the flushing approach was then identified. It was found that the surfactant solution flushing could only result in limited removal efficiency of 3–10% and 13–36% for copper ion and cadmium ion, respectively, after 24-pore volume (PV) flushing due to the channeling effect. As compared to the surfactin solution, a less pronounced channeling effect was detected for the rhamnolipid or SDS solution. With the presence of foam in the flushing approach, the channeling effect could be inhibited, and one could obtain improved removal efficiency of 10–30% and 20–46% for copper ion and cadmium ion, respectively, after 24-PV flushing. The removal efficiency was higher for cadmium ions than for copper ions, which could be explained by the significant adsorption of the cadmium ions in the inter-particle pore regions. Moreover, the cumulative removal efficiency variations with the foam-enhanced solution flushing could be correlated with the dynamic foam capacity of the surfactant solutions.

The effect of negative charge SDS monomer on its foam capacity with the presence of contaminants was investigated in foam generator. Generally, surfactant with higher concentration has higher foam capacity. The higher concentration will increase the number of monomer then increase the micelles in liquid phase. Increasing the number of monomer with the negative charge is a potential to increase interaction with metal ion with positive charge in solution. The presence of inorganic compound as metal ion with positive charge and organic compound (colloid) as particle of coffee impacting to generate the foam lamella with monomer is evaluated. Foam dynamic capacity of only SDS with variation of CMC, 1 x; 2 x; 3 x have the height 7.5, 8.0 and 8.3 cm respectively with the different range time were investigated. The Height of foam dynamic capacity with the presence of 20 ppm Cd2+ ion contaminant was 8.0, 8.3 and 8.4 cm at the same CMC variation of SDS. The presence of metal ion contaminant within the foam was conf...

Crushing is one of the operation units that aimed to convert the size of solid material to be smoother particle's size. The operation unit that can be used in this crushing is ball mill. The purpose of this study is to foresee the effect of raw material mass, grinding time, and the number of balls that are used in the ball mill tool related to the amount of raw material of coffee and cocoa beans. Solid material that has become smooth is then sieved with sieve mesh with size number: 50, 70, 100, and 140. It is in order to obtain the mass fraction that escaped from each sieve mesh. From the experiment, it can be concluded that mass percentage fraction of coffee powder is bigger than cocoa powder that escaped from the mesh. Hardness and humidity of coffee beans and cocoa beans have been the important factors that made coffee beans is easier to be crushed than cocoa beans.

Drying is widely used as a method to preserve food because of its convenience and affordability. Drying of ginger using tray dryer were carried out at various drying conditions, such as air-drying flow, air-drying temperature, and sample dimensions, to achieve the highest drying rate. Samples with various dimensions were placed in the tray dryer and dried using various air-drying flow and temperatures. The weights of samples were observed every 3 minutes interval. Drying was stopped after three times of constant weighing. Data of drying was collected to make the drying curves. Drying curves show that the highest drying rate is achieved using highest air flow and temperature.

The growing issue on firm value shows that firm value is not only determined by the firm ability to increase financial profit, but also by the company's concern in maintaining the environmental condition. The industrial development produces waste that pollutes the environment that has potential to serious impact on the next life. In addition to provide financial benefits, companies are increasingly facing pressure to be socially responsible for the survival of the company. However, past findings demonstrate that the effect of environmental performance, profitability, and asset utilization to the firm’s value are still unclear. This study aims to test whether environmental performance, firm profitability and asset utilization can effectively enhance firm value in two different conditions: intensive debt monitoring and less intensive debt monitoring. Sample of companies is taken from the list of Indonesia Stock Exchange during the period of 2013 to 2015. Using multiple regression analysis, discloses that: in intensive monitoring, managers tend to have high firm value when company has high environmental performance and or high profitability and high asset utilization. Monitoring system needs to be intensified especially for companies with the above characteristics.