bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of C/N ratio on anaerobic decomposition of industrial tempeh wastewater for optimizing methane production
Authors: Fransiscus Y , Simangunsong T L 
Published: January 2022

Abstract
Considering its high organic contents, A biological process, in particular anaerobically decomposition is considered to be the most suitable treatment for industrial tempeh wastewater. Among the important parameters that determine the success level of the process, C/N ratio was mentioned to play a significant role. Thus, this study was carried out to investigate the effects of different C/N ratios (10; 20; 30 and 40) on the decomposition process to produce methane gas. The experiment was conducted using 1L batch reactors with sludge from active cow manure biogas digester as inoculum. Several parameters such as pH, COD, BOD, VFAs and methane gas were monitored during the process to understand the mechanism. The experimental results confirmed that the C/N ratio significantly affected the anaerobic decomposition of tempeh wastewater, giving the best achievement for C/N = 30, with organic removal as high as 89% (COD) and total methane produced as much as 1240 mL in 14 days of observation. The balanced composition between carbon and nitrogen is important for the anaerobic process, higher organic loading (C/N = 40) will potentially lead to VFAs accumulation, meanwhile higher nitrogen concentration (C/N = 10) will stimulate complex transition, mainly denitrification and free ammonia formation. Both conditions will block the methanogenesis stage, resulting in a nonoptimal decomposition process and minimum methane production.
The effect of pH, initial concentration, and salinity on the biosorption process of chromium (VI) ions using microalgae Chlorella sp.
Authors: Wanta K C , Saptoaji D , Miryanti Y I P A , Kristijarti A P 
Published: January 2022

Abstract
The chromium (VII) (Cr6+) ions are carcinogenic substances, and thus the presence of these substances in water is hazardous for the environment and humans. Therefore, removing Cr6+ ions in water is required before the water is utilized or discharged into the environment. One of the processes that can be used is the biosorption process which involves microalgae as biosorbents. In this study, a synthetic solution of potassium dichromate (K2Cr2O7) and living microalgae Chlorella sp. was applied in this experiment. The study focused on studying pH, initial solution concentration, and salinity level on removing Cr6+ ions from the solution. The pH of the solution was varied at 2–6; the initial concentration of the solution was varied at 10-30 ppm; while the salinity level was varied at 2,000–16,000 ppm. The biosorption process was carried out in a batch reactor for 48 hours using white light. Samples were taken and analyzed periodically using a UV-Vis spectrophotometer to determine the decrease of Cr6+ ions in the solution and a haemocytometer to calculate the number of microalgae in the system. The results showed that 91.79% of Cr6+ ions could be removed from the solution.
Potential of natural sunlight for microalgae cultivation in Yogyakarta
Authors: Habibah E , Suyono E A , Koerniawan M D , Suwanti L T , Siregar U J , Budiman A 
Published: January 2022

Abstract
The study of microalgae is widely developed on a laboratory scale. The large-scale applications of microalgae such as large photo-bioreactors or commercial ponds are not well established due to some obstacles. The high cost of artificial lighting in microalgae cultivation is one of the obstacles. Markedly, the natural sunlight intensity is high every month for a whole year in Indonesia. This natural sunlight may serve as a low-cost lighting source for microalgae cultivation in a tropical country such as Indonesia. However, the basic knowledge of whether the natural sunlight in Indonesia is sufficient or not for microalgae cultivation is poorly understood. This study was performed to investigate whether sunlight in Indonesia, particularly in Yogyakarta, is sufficient or not for microalgae cultivation in the absence of artificial lighting. The sun lighting period data from January 2019 to June 2020 were collected from BMKG (Badan Meteorologi Klimatologi dan Geofisika) website. The sun lighting period data were converted into solar radiation data. The Liliefors test was performed to evaluate the distribution of the solar radiation data. To confirm whether the sun lighting in Yogyakarta is sufficient for microalgae cultivation or not, the parametric statistical test namely single sample T-test was used in this study. The Liliefors test showed that solar radiation in Yogyakarta (January 2019 to June 2020) was normally distributed. The calculated Liliefors value (0.14) was less than Liliefors table value (2.00). The T-test results revealed that the solar radiation in Yogyakarta is equal to or higher than the sufficient solar radiation (reference) for microalgae cultivation (795 kWh/m2). The calculated t value (0.65) was higher than the t table value (-1.74). When taken together, our findings suggest that natural sunlight in Yogyakarta is sufficient as a lighting source for microalgae cultivation.
The extraction and purification of squalene from Nyamplung (Calophyllum Inophyllum L) leaves
Authors: Ardhyni D H , Aparamarta H W , Widjaja A , Ibrahim R , Gunawan S 
Published: January 2022

Abstract
Squalene is a natural organic compound that is primarily found in shark liver oil. It can act as a skin moisturizing, anticancer, antivirus, and drug delivery agent. The advantages of people consuming healthy oil which contains squalene can lower the risk of heart disease. Due to the high market demand for squalene, it becomes a severe threat to shark existence. Therefore, investigation to find a new source of squalene is deemed necessary. Squalene is present in the leaves of nyamplung (Calophyllum inophyllum), a species of mangrove plant commonly found along Indonesia’s coast. This study aims to extract and purify squalene from nyamplung leaves. First, nyamplung leaves were crushed and extracted with n-hexane. The extract was designated as a crude extract of nyamplung leaves. After that, squalene was purified from the crude extract by the multistage adsorption-desorption method at 3°C. The crude extract was dissolved in hexane, and silica gel was then added at 30 min. The mass ratios of silica gel to crude extract were varied at 1:1, 2:1 and 4:1 (g/g). N-hexane fraction was separated from silica gel by filtration paper. N-hexane fraction was designated as a non-polar fraction (NPF), while silica gel fraction was designated as a polar fraction (PF). The dark-colored of PF was employed for the desorption process using methanol until its color became colorless. Meanwhile, NPF was extracted with fresh silica gel until it reached the 10th stage of extraction. NPF and PF were then quantitatively and qualitatively analyzed using TLC and GC, respectively. The best result was obtained from silica gel to crude extract mass ratio of 1:1 (g/g) at the 5th stage with squalene purity of 35.96% (45.82% recovery).
The effect of ultrasonic extraction methods on extract quality from Strobilanthes crispus L.
Authors: Arbianti R , Ningsih H , Utami T S , Muharam Y , Slamet  
Published: January 2022

Abstract

Strobilanthes crispus L. leaves are known to have many health benefits that have been proven both traditionally and in scientific research. To achieve more benefits from the leaves of Strobilanthes crispus L., the ultrasonic extraction (53 kHz) method was carried out using various ways. The variations of the ultrasonic method being carried out are UAE (Ultrasound-Assisted Extraction), UAEE (Ultrasound-Assisted Enzymatic Extraction), UAE-ATPE (Ultrasound-Assisted Enzymatic Aqueous Two-Phase Extraction) sequence and simultaneously. Extraction was carried out at 27 °C for 1hour, enzymatic hydrolysis reaction for 2 hours with a cellulose concentration of 7% w/w dry leaves, and the ATP (Aqueous Two-Phase) system of ethanol-ammonium sulfate of 33-14% w/w. The extract parameters measured were the yield, TPC (Total Phenolic Content), and TFC (Total Flavonoid Content) values. The highest yield was obtained by the Hydrolysis/UAE-ATPE method simultaneously, namely 80.94% w/w dry biomass. The highest TPC and TFC values were obtained from the extraction using the Hydrolysis/UAE-ATPS method simultaneously, i.e. 5.517 and 3.332 mg/g dry biomass respectively. Thus, it can be concluded that the simultaneous use of hydrolysis enzymatic with the cellulase enzyme and the ATP system in the ultrasonic extraction method can increase the quantity and quality of Strobilanthes crispus L. leaves extract.
Glucose production from oil palm empty fruit bunch (OPEFB) using microwave and fungal treatment method
Authors: Juliastuti S R , Hendrianie N , Sabar K R , Anggita S 
Published: January 2022

Abstract
Palm oil is one of the plants that can be used to produce cooking oil, industrial oil, and fuel. Indonesia itself was one of the largest palm oil-producing countries in the world. OPEFB includes lignocellulose biomass, whose main content is 46.5% cellulose, 33.8% hemicellulose, and 32.5% lignin. This research method used 3 stages, namely microwave pretreatment, Fungal Treatment 1 (FT 1), and Fungal Treatment 2 (FT 2). The raw materials used are OPEFB, while the fungi used are Phanaerochaete chrysosporium, Tricodherma harzianum, Aspergillus niger, and Tricodherma viride. The first step to be prepared in this study was to prepare OPEFB powder measuring 20 mesh. OPEFB powder was then put in the microwave for 20, 40, and 60 minutes. OPEFB that had been heated in the microwave was then converted into a slurry with the addition of water with a ratio of 3:5 (w/w). The second and third phases were Fungal Treatment for ±10 days. The parameters analyzed were the introduction of OPEFB, product of microwave pretreatment, product of fungal treatment 1, and product of fungal treatment 2. The content to be analyzed were lignin, cellulose, hemicellulose, and glucose. The result of pretreatment revealed that microwave-based pretreatment with the addition of alkaline solution could eliminate lignin by 83.45% and increase holocellulose levels by up to 41.907% at 300 W power and 60 minutes. As for the result for fungal treatment, the best treatment for FT 1 was treatment ratio TH:PC 1:2, which could eliminate lignin for 47.55% and FT 2 with treatment ratio TV:AN 1:2 that could increase glucose up to 84.9%.
Characteristic of oil palm empty fruit bunch after ethanol-organosolv pretreatment catalyzed by acid
Authors: Mondylaksita K , Budhijanto W , Taherzadeh M J , Millati R 
Published: January 2022

Abstract
The increasing growth of palm oil industry results in an increase in the accumulation of waste generated from the industry, such as oil palm empty fruit bunches (OPEFB). OPEFB is a good source of renewable raw materials if a pretreatment process can overcome the recalcitrance of OPEFB and allows the fractionation of all carbohydrates and lignin. In this work, the effectiveness of organosolv pretreatment to deconstruct OPEFB and to recover high purity of lignin and glucan was studied. The pretreatment experiments were carried out at 210 °C for 90 minutes with a solid to liquid ratio of 1/10. Ethanol 50% (v/v) was used as solvent. The effect of H2SO4 0.07% (w/w) as catalyst was also studied. The results showed that organosolv pretreatment with the addition of acid increased the purity of glucan and lignin by 36 and 5%, respectively. A total of 65% lignin was recovered, which was 3.6 times higher than lignin from pretreatment without acid catalyst. After organosolv pretreatment with an acid catalyst, the crystallinity index (CRI) decreased by 54%, while the decrease in CRI was only 14.4% after pretreatment without an acid catalyst. The water retention value of the pretreated OPEFB with acid catalyst increased by 8%. It can be concluded that organosolv pretreatment using ethanol as a solvent with the addition of acid catalyst succeeded in fractionating OPEFB with high purity and reducing recalcitrant OPEFB.
Microcrystalline cellulose production by acid hydrolysis of hydrotropic rice straw pulp
Authors: Raudhatussyarifah R , Sediawan W B , Azis M M , Hartati I 
Published: January 2022

Abstract
Rice straw is a by-product of the production of rice. Most of this material is considered as agricultural waste, used only for fodder, left or burned on the fields after harvest. Rice straw contains 35-50% cellulose, making it promising as raw material for microcrystalline cellulose production. The production of microcrystalline cellulose consists of three stages, namely delignification, bleaching, and hydrolysis. Those processes can be conducted at relatively high temperatures by both oven or microwave irradiation. The objective of this study was to compare the performances of those processes (oven and microwave irradiation) by evaluating the cellulose content and the crystallinity index of the microcrystal cellulose. The rice straw pulp was successively pre-treated with hydrotropic delignification and was bleached. Those pretreatments are intended to significantly remove unwanted substances such as lignin, coloring materials, and hemicellulose before the hydrolysis. The hydrotropic delignification was performed using a 20% urea solution with a liquid solids ratio of 1:10 at 80°C for 60 minutes. The bleaching process was carried out at 70°C for 60 minutes using hydrogen peroxide, an environmentally friendly bleaching agent. The hydrolysis was performed using hydrochloric acid and sulphuric acid in an oven for 10 to 50 minutes. The product was analyzed using Chesson-Datta method and FTIR. The FTIR analysis result shows that the highest crystalline cellulose fraction was 63,23%, which was obtained from hydrolysis using 1,5 M sulfuric acid for 50 minutes, the yield content is 55,91%. The same condition using hydrochloric acid resulted in a crystalline cellulose fraction of 60,70% with 59,16% yield content.
Utilization of sodium silica from coal fly ash and trimethylchlorosilane as self-cleaning coating on glass
Authors: Maharsih I K , Ernawati L , Welltina  , Dani W P 
Published: January 2022

Abstract
Sodium silica is extracted from coal fly ash generated from the power plant. Furthermore, sodium silica is utilized as silica sol, and then it is added to the coating solution with trimethylchlorosilane (TMCS) as an additive. The coating solution is applied to the glass surface by the deep coating method in order to get a self-cleaning glass. This material is usually used as microfluidic devices for biotechnology or bioprocessing. This study aims to analyze the effect of various volume ratios of silica sol and silane sol from TMCS on the physicochemical characterization of the glass surface. The ratios used between silica sol and silane sol are 1:0, 1:1, 1:2, 1:4, and 1:8. Wettability, hysteresis, morphology, and functional group analysis are conducted on the coated glass. The best concentration ratio is 1:8 that produces a contact angle of 107.53°, contact angle hysteresis of 3.13°, and transparency of 99.04%. Moreover, the glass-coated by silica sol-silane sol has surfactant resistance. When Sodium Dodecyl Sulfate (SDS), at a concentration of 2 times of CMC, is dropped on the glass surface inclined at 10°, the droplet slides without leaving a trace. It can be concluded that the glass coated by sodium silica and TMCS has a self-cleaning characteristic.
Promising agricultural technologies for growing winter wheat for sustainable agricultural development
Authors: Zelenev A V , Chamurliev O G , Krivtsov I V , Kholod A A , Sidorov A N , Vorontsova E S 
Published: January 2022

Abstract
In the arid zone of light chestnut soils of the Lower Volga region, in order to increase the influx of organic matter and basic nutrients into the soil, winter rye and yellow two-year-old clover should be cultivated in occupied fallows as sideral crops. To increase the replenishment of potassium in the soil, it is also recommended to grow phacelia on siderate as a fallow crop. Plowing oats in the form of green fertilizer led to a decrease in the input of organic matter and mineral nutrition elements into the soil compared to the control. The highest content of nitrate nitrogen, mobile phosphorus and exchangeable potassium in the arable layer of the soil during the sowing of winter wheat, when its plants leave for winter and spring regrowth, as well as during harvesting, was provided by the predecessors of the occupied fallows by winter rye, two-year-old clover and phacelia for siderate. The highest yield of winter wheat was obtained by the predecessors the pure fallow and occupied fallows by winter rye, sweet clover and phacelia for siderate. According to the predecessors, the occupied fallows by spring ginger and oats for siderate showed a significant decrease in the yield of winter wheat.
Expert system for determining the technical condition of longterm operational structures of water management facilities of the agro-industrial complex
Authors: Arkov D P , Yastrebov A A , Matveev A S , Sukhov A A 
Published: January 2022

Abstract
This paper presents a promising solution to the issue of determining the category of technical condition of hydraulic structures in operation, namely, the collaboration of IT solutions and a set of current building codes and rules in the developed expert system. Most of the reclamation and hydraulic structures operating in the Volgograd region have exceeded their operational life of 25 years laid down in the design. Therefore, it is necessary to control and maintain such structures with the establishment of the technical condition. The developed expert system would contribute to the solution of the listed problems by the operational services of the organizations on the balance of which the structures are located, and the result should comply with all relevant norms and rules.
Effect of the structure of artificial rain on the soil
Authors: Bocharnikov V S , Kozinskaya O V , Denisova M A , Bocharnikova O V , Repenko T V , Pustovalov E V 
Published: January 2022

Abstract
The quality of irrigation by sprinklers is determined not only by the uniformity of the distribution of the rain layer over the irrigated area. If the water permeability exceeds the intensity of precipitation, then surface runoff does not occur. With an increase in soil moisture, water permeability decreases, and surface runoff increases, contributing to the washout of the fertile layer. The sprinkling machine “Kuban-LS” is installed 18…20 km west of Volgograd, located on the western slope of the Volga Upland. The soil cover has a complex character and is represented by carbonate light chestnut varieties of varying degrees of washout. The data on the effect of artificial rain created by a sprinkler machine on the soil structure and absorption rate are presented. Due to the partial destruction of agronomically valuable soil aggregates, the density of the arable layer from sowing to harvesting the grass mixture after each irrigation increased from 1.10…1.28 to 1.26…1.35 t/m3. The quality of irrigation by sprinklers is determined not only by the uniformity of rain distribution, but also by the conditions for the absorption of irrigation water into the soil. Based on these studies, we offer certain recommendations to reduce the negative impact on the soil.
Calculation of the strength of water management facilities for the sustainable development of rural areas
Authors: Gureeva N A , Kiseleva R Z , Klochkov Yu V , Nikolaev A P 
Published: January 2022

Abstract
The physical relations are presented at the loading step of a bulk body in two variants. In the first version, the theory of plastic flow is used. In the second variant, to determine the increments of plastic deformations, a hypothesis is proposed about the proportionality of the increments of plastic deformations to the components of the deviator of stress increments, which made it more correct and easier to obtain the defining equations at the loading step. Variants of physically nonlinear defining equations in the calculation of three-dimensional elements of water management objects are implemented in the developed tetrahedral finite element with nodal unknowns in the form of displacement increments and stress increments.
Dynamics of various forms of manganese in the pond waters
Authors: Ch Kazanchev S , Getokov O O , Khashegulgov Sh B , Dolov M M , Yusupova L U 
Published: January 2022

Abstract
The forms of migration of manganese in pond waters are suspended matter and truly dissolved forms, including free manganese cations, as well as complex compounds formed by manganese with organic substances. The aim of the work was to study the dynamics of the content of various forms of manganese in the water of fish ponds. The content of individual forms of manganese was established according to the method developed by Linnik and Nabivanets. According to the methodology of Alekin, Semenov and Skopintsev determined hydrochemical parameters. It has been established that the dynamics of the content of manganese forms in different seasons depends mainly on the concentration of dissolved oxygen, pH value, inflow from sludge waters and the content of dissolved organic complexing substances in the water. In winter, free uncomplexed ions are the dominant form of migration. In other seasons, the content of complex forms exceeds the concentration of uncomplexed manganese. The dominant form of manganese migration in spring, summer, and autumn is Mn suspended, while in some periods of the same seasons, Mn dissolved predominates, which is explained by the influence of the intensity of water exchange, where suspended particles settle under conditions of slow runoff.
Promising technology of wastewater treatment with natural ameliorants
Authors: Bocharnikov V S , Denisova M A , Ovchinnikov A S , Bocharnikova O V , Kozinskaya O V , Meshcheryakov M P 
Published: January 2022

Abstract
The article presents the results of testing filter media with various natural sorbents. When studying the absorbing properties of zeolite, charcoal and gravel sand, their properties of removing heavy metals such as Zn, Ca, Cu, Fe, as well as ammonium nitrogen were studied. During experimental studies, all studied ion exchangers showed absorption properties to varying degrees. After calculating the static capacities of each of the studied sorbents, he showed that the best absorption properties are aluminosilicate (zeolite). After completing experimental studies within 48 hours, the best moisture-absorbing effect was observed with zeolite, after 12 hours of contact with poultry wastewater, it removed 64.7 percent of the total iron, and activated carbon and gravel sand only 15.4 percent. The result of research in the study of the absorption properties of heavy metals, ammonium nitrogen ions, showed that zeolite has the highest quality wastewater treatment. The removal of ions of chemical elements was more than 60 percent within 12 hours of being in the liquid phase, in contrast to charcoal and gravel sand.