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Lead (Pb) is known as one of the dangerous heavy metals which may spread in the environment due to industrial, domestic, agricultural and other human activities. The use of plants for cleaning up contamination which is known as phytoremediation requires information on the ability of plants to tolerate heavy metal exposure. The aim of this study was to determine the adaptation pattern of trembesi ( Samanea saman Jacq. Merr) seedlings to lead (Pb) exposure based on the characteristics of organic acids content. Trembesi seedlings were grown on nutrient culture with Pb treatment of 0.5,1.5 and 2.5 mM for 7 days. The percentage of seedling life was counted and the organic acids content was observed using High Performance Liquid Chromatography (HPLC). The results showed that the life percentage of trembesi seedling exposed to lead up to 1.5mM reached 100%, but it decreased to 60% when it was exposed to 2.5 mM of lead. Trembesi seedlings produced all three organic acids investigated as oxalic, malic and citric acid. The increase of lead exposure from 0.5 to 1.5 and 2.5 mM, caused a significantly increase of oxalic acid exudation from 0.346 to 0.545 and 0.668 µg/mL respectively. At the same time, they also induced the accumulation of citric acid from 46.4481 to 63,668 and 83,516 µg/g respectively. This shows that trembesi has the adaptability to lead by a combination of external and internal mechanisms involving organic acids accumulation.

Fe is one of the microessential plants needed in low concentrations. The purpose of this study was to examine the growth response of three forest seedlings to iron exposure in water culture media. This study used a completely randomized design (CRD) with Fe dose treatment and consisted of 9 levels, namely 0, 0.5, 0.1, 1.5, and 2, with 3 replications each and each replication consisting of 3 plant units. The plants used consisted of Ochroma bicolor , Shorea macrophylla , and Senna siamea. The results of this study showed that Fe exposure treatment had a significant effect on the three seedlings on all growth parameters (height, root length, root dry weight, shoots, and total dry weight). Increasing the concentration of Fe can reduce all growth parameters. The three seedlings have different tolerance levels. Fe exposure treatment had a significant effect on the SPAD index only on O. bicolor and S. seamea seedlings. S. macrophylla seedlings had the highest tolerance index value compared to the other two seedlings. This indicated that S. macrophylla seedlings had higher resistance than the other two seedlings to Fe exposure.

This paper present the conversion of cellulose based on water hyacinth into hydrogel. The water hyacinth cellulose was prepared using acid-alkaline treatment and bleaching. The cellulose properties was optimized by varying the extraction condition such as solvent concentration and temperature. The analysis method of FTIR and XRD were used for characterizing the functional groups and crystallinity of cellulose. The effective condition of extraction were achieved at solvent concentration 17.5% w/w of NaOH, 8% v/v of H2O2 as bleaching agent and temperature of 80°C. The extracted cellulose was used to produced hydrogels using polyvinyl alcohol and glutaraldehyde as crosslinker agent. The research revealed that adding of glutaraldehyde with ratio 1:2 at 25°C give the highest water absorption capacity of 285%.

The Sumatran tiger is one of the endemic species in Indonesia which has been driven to extinction. This species has been categorized as critically endangered by IUCN and as Appendix I by CITES. Loss of prey is one of the threats to the Sumatran tiger’s population. It is an essential factor to maintain the existence of the Sumatran tiger. The study aimed to reveal the abundance of the Sumatran tiger prey using the camera trap method in Way Kambas National Park where one of the Sumatran tiger’s habitats. Our study was conducted from March until August 2020. We used 16 Camera traps which were divided into 2 Sites, Resort Pengelolaan Taman Nasional (RPTN) Sekapuk and Way Kanan. We found five species of Preys. They are wild boar ( Sus scrofa ), Sambar deer ( Rusa unicolor ), pigtail macaques ( Macaca nemestrina ), red muntjac ( Muntiacus muntjac ), and Mouse deer ( Tragulus kanchil ). The highest number of abundance was Sus scrofa (63%), and the lowest number of abundance was Rusa unicolor (0,94%). Our findings concluded that the potential preferred prey was Sus scrofa and Muntiacus muntjac.

The utilization of leather industry solid waste as adsorbent to separate oil from water emulsions of surfactant flooding process is a solution that is relatively inexpensive. This study was conducted aiming to obtain a mathematical model that is appropriate for the adsorption process of crude oil by buffing dust in emulsion phase with a continuous adsorption method. Variations in the column adsorption experiments were carried out, such as: flow rate of feed of water-crude oil-surfactant, the concentration of crude oil in the feed, and mass of adsorbent used. Data were evaluated using three models: Adams Bohart, Thomas and Yan. Best results are obtained on the following conditions, the feed flow rate of 60 mL/minute, the crude oil concentration in feed is 1.5% volume and the mass of adsorbent used was 10 g. The values of kinetic constant and adsorption capacity obtained from Yan Model was 21.7774 mL/mg/minute and 220.9581 mg/g with the relative error obtained is 5.4424%.

This work was conducted to study the adsorption behaviour of bio adsorbent of alkali modified jackfruit wood sawdust and to investigate its possibility as adsorbent to remove heavy metals from wastewaters. The effects of sodium hydroxide concentration on the bio adsorbent adsorption capacity were investigated. The bio adsorbent prepared through chemical modification with solution of 2% sodium hydroxide showed the highest adsorption capacity with the value 3.32 mg/g at initial Pb(II) concentration 18.69 mg/L and percent removal Pb(II) ions was 88.86%. This study proved that adsorption process of Pb(II) ions onto bio adsorbent was perfectly illustrated by second order kinetic equation and adsorption isotherm of bio adsorbent was well represent by Freundlich isotherm model.

Arbuscular Mycorrhizal Fungi (AMF) is one of the fungi that can be found in almost every ecosystem including post-coal mining land. This study aims to analyze the diversity of AMF in different age of revegetation of post-coal mining land area. Soil samples were collected from six different age of revegetation of post-coal mining area (unrevegetated area, 0, 2, 4, 6 and 8 years) and from natural forest as comparison. AMF spore isolation was carried out using wet-sieving method, while spore identification was carried out based on several morphological characters according to INVAM guideline. The results of the observation showed that with increasing of revegetation age will be able to increase the number of AMF populations (R2= 84.96%). The highest AMF population was found at the age of 10 years after revegetation of land with the number of 492 spores per 20 grams soil, while the lowest AMF population was found in unrevegetated area with the number of 12 spores per 20 grams of soil. AMF genera found included Glomus, Acaulospora, Gigaspora, Scutellospora, and Dentiscutata. Glomus and Acaulospora were the dominant AMF in every land revegetation age (100% of frequency). AMF populations was correlated strongly with soil organic content (r = 0.79).

Increased human populations induce enhanced developments in industry, transportation, infrastructure and other areas. To date, the energy needed to supply these areas is still mainly derived from fossil fuels. Renewable fuels become an attractive alternative for replacing fossil fuels that are being on the skids. Bio oil is one of the alternative energy sources resulting from biomass pyrolysis process. The purpose of this study is to obtain the bio oil characteristics ofPinus Merkusii flower in vary of temperatures and sizes of biomass powder, those were temperatures of 450 - 550°C and sizes of 0.644 mm and 0.456 mm. Dry pine flower powder was inserted into a fixed bed reactor enclosed by furnace. Prior heating, the N2 gas was flown through the reactor to dissipate the O2 gas present in the reactor. After the N2 gas stream was stopped, the reactor was run in isolated condition. Pyrolysis run at heating rate of 15 °C/min and residence time for 3 hours. From the existing variations, the largest bio oil yield i.e. 45.2011% was obtained from the sample size of 0.644 mm at temperature of 550°C. The resulting bio-oil had the following properties: dark brown, pH of 2.682- 4.053; density of 1.01 - 1.145 gr.cm-3; viscosity of 58.544- 103.465 mm2.s-1; acetic acid content of 21 - 49.2 mg.cm-3and the heating value of 10.850 - 11.663 MJ.kg-1. The bio oil was potential to be biofuel and bio-chemical materials through upgrading process.

One of the ester product of glycerol and acetic acid is triacetin which has wide industrial aplication. In this study the esterification of glycerol with acetic acid over Lewatite catalyst to produce triacetin, were carried out. Lewatite is one of ion exchange resin, the use of ion exchange resins as catalyst will not produce waste, not corrosive, high thermal stability and has good selectivity. The esterification reaction of glycerol with acetic acid were performed in a three-neck flask with stirrer (175 rpm) at temperature (90 °C, 100 °C and 110 °C) and atmosphere pressure. A 9.66 % selectivity of triacetin with conversion (77.4 %) was achieved at 100 °C within 90 minutes of reaction time. This research aimed to report experimental data and kinetic modeling of glycerol esterification with acetic acid to evaluate and compare model performance and capability. A kinetic model was developed using a first order pseudo-homogeneous model according to the experimental data. The surface reaction of acetic acid with glycerol was assumed to be rate-controlling. The effect of temperature to rate of reaction constants can be expressed as follows: k r =8.138 x  10 11  exp( − 57,176.47 RT )( 1 s )

This study aims to examine the diversity of flora in various age classes of revegetation of post-mining coal. This research was conducted at PT. Berau Coal, Binungan block, East Kalimantan. Sampling plots were applied on revegetation land of post-mining coal aged 0, 2, 4, 6, 8 and 10 years, and natural forest as a control. Flora observations were carried out on sample plots of size 25m x 40m for sapling, poles and trees, while sub-plots 1m x 1m for seedlings and understorey. In natural forests observations were made on sample plots measuring 20m x 20m for trees with sub plot 2m x 2m for uderstorey and seedlings, 5m x 5m for saplings, 10m x 10m for poles. The analysis results show that the highest individual density per ha is found in natural forests (seedlings, saplings and poles). The highest of flora index of diversity, richness and evenness were found in natural forests. The flora from revegetation of eight-year has been able to approach to natural forests conditions. The species of plants that predominate in some revegetation age classes are Rhynchospora corymbose (understorey), Senna siamea (seedling, sapling, pole and tree). Acacia mangium and Macarangan hypleoca grow naturally in some revegetation age.