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Activated carbon (AC) is an effective and inexpensive adsorbent material for dye removal, but it cannot always be used repeatedly. Furthermore, the adsorbed dyes with toxicity usually remain on its surface. In this study, a thermal air oxidation process was used to modify the surface of AC and decompose adsorbed methylene blue (MB). The behavior of this process on spent AC was investigated using TGA-DTA, while the degradation of MB before and after the regeneration process was analyzed using a carbon, hydrogen, nitrogen, sulfur (CHNS) analyzer. It was discovered that thermal air oxidation could promote the formation of oxygenated functional groups on AC produced from steam-activated carbon coconut shell (SACCS), which when treated at 350 °C (denoted as SACCS-350), demonstrated an adsorption capacity 2.8 times higher than the non-air-oxidized AC (SACCS). The key parameters for the MB adsorption of SACCS and SACCS-350, such as kinetics, equilibrium, and thermodynamics, were compared. Moreover, the SACCS-350 could be reused at least 3 times for the adsorption of MB. Based on these results, thermal air oxidation treatment could successfully improve the adsorption performance of AC and regenerate spent AC through a reasonable and environmentally friendly process compared to other regeneration methods.

XRD data

Batik is a piece of woven cloth decorated with beautiful patterns and designs and has become a signature product of the Malay Archipelago, including Malaysia and Indonesia. Batik industry consumes a large volume of water and produces a large amount of wastewater during the boiling process and dyeing process, both for hand-drawn (batik lukis) and block-printed (batik cap) batik. The release of colored effluents that contain a large number of dyes and chemicals can harm the environment and become a human health concern, particularly in south east Asian countries. Therefore, treatments of batik effluent are very crucial and have caught a lot of attention from researchers. The color removal is a major challenge, especially from this industry, as up until now there is no single and cost-effective treatment that can effectively decolorize as well as treat the dye effluent. Since batik is part of the textile industry, most treatment methods have been adapted from textile effluent treatment. Here, we review a variety of textile wastewater treatment techniques to make a good consideration of selecting the most appropriate method to be applied in batik wastewater. First, we briefly review the batik process, including the potential dyes that are mostly used in batik processing. Secondly, we describe all possible techniques and their performance to reduce dye concentration and decolorization. Finally, we review all advantages and disadvantages of these techniques for domestic and industrial applications.

The Biological Sulfur Recovery Unit (BSRU) with Thiobacillus as biocatalysts is believed to be suitable for handling soluble sulfur in wastewater. The purpose of this study is to evaluate the effect of nutrient (SO42−, PO43−, and Fe2+) concentration on BSRU performance, particularly on the conversion of sulfide to elemental sulfur. This study shows that the variation of SO42− concentration does not significantly affect the conversion process, while a small increment of PO43− (KH2PO4 1.7 g/L and K2HPO4 1.36 g/L) results in a higher yield of elemental sulfur production. Fe2+ also significantly affected the formation and conversion rate of elemental sulfur.

The production of sustainable diesel without hydrogen addition remains a challenge for low-cost fuel production. In this work, the pyrolysis of unsaturated fatty acid (UFA) basic soaps was studied for the production sustainable diesel (bio-hydrocarbons). UFAs were obtained from palm fatty acids distillate (PFAD), which was purified by the fractional crystallization method. Metal hydroxides were used to make basic soap composed of a Ca, Mg, and Zn mixture with particular composition. The pyrolysis reactions were carried out in a batch reactor at atmospheric pressure and various temperatures from 375 to 475 °C. The liquid products were obtained with the best yield (58.35%) at 425 °C and yield of diesel fraction 53.4%. The fatty acids were not detected in the pyrolysis liquid product. The gas product consisted of carbon dioxide and methane. The liquid products were a mixture of hydrocarbon with carbon chains in the range of C7 and C20 containing n-alkane, alkene, and iso-alkane.

The shell of cocoa beans is one of the cocoa industry byproducts that currently still become waste. Through this research, utilization of cocoa bean shell for producing alkalized fiber powder was observed. The aim of the study is producing fiber powder from the shell of cocoa beans. The shell of cocoa beans was obtained from the chocolate industry and directly used without any pretreatment. The shell of cocoa beans was alkalized to adjust the pH and remove the possible heavy metal. At the end of the alkalization process, the solid material was measured by atomic absorption spectroscopy (AAS). Later, the solid material was crushed into 30–200 mesh. The possibility for this powder to substitute other fiber powders (oat and whole wheat) was tested by texture profile analysis (TPA) and panelists test for cookies produced of those powders. The experiment shows that an increase in temperature will cause the product’s color to be more red and yellow, lowering the powder yield, and also increase the coarse fiber content of the alkalized-product. Powder size analysis, TPA, and acceptance test show that the produced cocoa powder can be utilized for a substitution or mixing flour as there is no significant difference observed among them. It contains rich fiber that is important for dietary food.

Acid gas enrichment unit (AGEU) involves selective separation of H2S from acid gas mixture, for example using absorption with an NaOH solvent solution. Sodium carbonate (Na2CO3) and sodium bicarbonate (NaHCO3) buffer addition to NaOH solution suppresses CO2 absorption, thereby increasing the selectivity of H2S absorption. This study evaluated the effect of buffer addition to increase H2S absorption selectivity using an NaOH solution. It was shown that both buffer addition and L/G ratio decrease could increase H2S selectivity by limiting CO2 absorption. Based on the simulation results, in the 0.006 to 0.030 L/G ratio range and NaOH solvent concentration greater than 2%-mass, the addition of NaHCO3 with mass ratio greater than 1.5:1 to NaOH and the addition of Na2CO3 at 1.26 times NaHCO3’s mass increased H2S absorption selectivity up to 17.3%. The combination of an L/G ratio of 0.006 and solvent with a composition of 5%-mass NaOH, 15%-mass NaHCO3, and 18.9%-mass Na2CO3 produced the highest H2S selectivity of 23.1 (379.7% H2S selectivity increase).

This work studied the oxidative degradation performance of manganese gluconate as a liquid redox sulfur recovery (LRSR) agent. The degradation of gluconate in an aerated sulfide containing 0.1 M manganese/0.8 M gluconate/pH 13 solution was 11% in 47 h and 20% in 100 h of reaction time. With the total price of chelates being more or less comparable, these were superior to the degradation resistance of EDTA chelate in a solution of 0.1 M iron/0.2 M EDTA/pH 8 which degraded by about 30% in 47 h, and NTA in Fe-NTA (0.1 M metal/0.2 M chelate/pH 6.5), which was degraded by 40% in 100 h of reaction time. At pH of 13, 0.1 M Metal, and 0.8 M gluconate, manganese degraded gluconate more severely than iron and copper. At a lower chelate to metal molar ratio (RCM) of 2 and as well as at a lower pH of 10, the manganese gluconate degradation, expressed as relative concentration to its initial concentration, was faster than at RCM of 8 and pH of 13. All of these observations can be explained among others by the well-known Fenton reaction hydroxyl radicals mechanism as the main cause of the degradation process., Manganese gluconate; Sulfur recovery; Natural gas; LRSR; NTA; EDTA; Degradation.

Biological Sulfur Recovery Unit (Bio-SRU) with Thiobacillus as biocatalysts is believed to be suitable for handling hydrocarbon feed gas with moderate to low-H2S concentration. The purpose of this study is to evaluate the effect of SO4 2-, PO4 3-, and Fe2+ concentration on Bio-SRU performance particularly on the conversion of sulfide to elemental sulfur. Biological pathway of sulfur recovery from natural gas-treating facility wastewater was then studied by measuring the pH and redox potential of the sample. It shows that the variation of SO4 2- concentration does not significantly affect the conversion process, while a small increment of PO4 3- (KH2PO4 1.7 g/L and K2HPO4 1.36 g/L) results in a higher yield of elemental sulfur production. Fe2+also gave a significant effect on sulfur formation and conversion rate.

The presence of mercury in crude oil creates problems in oil processing in refineries, both in terms of operations and health. The previous removal process of mercury has not yet optimally removed mercury in the product, due to ionic and metallic mercury species. In this study, to obtain optimum results, the process of removal of mercury begins with the process of converting ionic (non-metallic) mercury into metallic mercury thermally in the liquid phase, followed by the transfer of metallic mercury to the gas phase by instant evaporation (flashing) and reinforced by gas stripping using internal gas cone from the evaporation of an instant. The results of the optimization of the process carried out can eliminate mercury with an efficiency of more than 95%.

In the present work, the oxidation stabilities of oil biodiesel fuel from Jatropha curcas L were investigated by using both Rancimat and PetroOXY test method. Three types of conventional antioxidan...

This study investigates the mechanism of aromatic formation from acetylene over zeolite catalyst. The mechanism of reaction was focused following continuous acetylene addition scheme at two differe...

Aqueous amino solvents, such as monoethanolamine (ETA/MEA), methyl diethanolamine (MDEA) or amine blends, are the most widely used solvents in commercial CO2 or acid gas separation applications. Th...

This study aims to produce terpineol from α-pinene by direct one-stage hydration reaction mechanism. The study was focused to investigate the influence of organic acids and mixture acid catalyst between organic acid and phosphoric acid. Based on the experimental results and depending on the acid strength and affinity of catalyst to the carbocation mechanism, p-toluensulfonic acid was shown to have a better result compared to acetic and formic acid. The presence of phosphoric acid could boost the performance of acetic acid in term of acidity strength that increased the conversion of the reaction. The highest yield of terpineol from α-pinene in this hydration reaction in this study was 53.5 wt% using mixed phosphoric and acetic acid.

The catalytic effect of magnesium and magnesium–zinc or copper(II), iron(III), aluminium(III), chromium(III) metal combination on ratio of the alkane to 1-alkenes and carbon number distribu...

Devolatilization is the release of volatile compounds from coal matrix by thermal decomposition. During coal devolatilization, fragmentation could occur due to pressure built up of accumulated volatiles. A fragmentation model is necessary to ensure the safe operation of coal combustion and optimum process condition. In this study, the refinement of fragmentation model of coal devolatilization was done. In order to obtain a comprehensive model, a fluidized bed combustion experiment using two Indonesian coals (Musi Banyuasin and Berau) was conducted and the results were then compared with the model simulation. Using coal diameter of 0.8-17 mm at combustion temperature of 850°C, it shows that the fragmentation probability and number of fragments could be affected by the coal particle diameter, convective pore diameter, and porosity. The developed model predicted closely to the experimental fragmentation data with an error range of less than 5.1%.

Pathogenic microorganisms are the primary agents of waterborne disease that is responsible for high global mortality rate. Although conventional disinfectants are effective in inactivating common waterborne pathogens, they still bear a risk of generating harmful disinfection by-products. Since its discovery in 1991, carbon nanotube (CNT) has been renowned for its high adsorption capacity and has been utilized to remove a wide range of contaminants including biological contaminants in water. In recent times, antimicrobial activity of CNTs has been also documented in a number of studies that have paved the way for their applications in water disinfection systems. This chapter reviews biocidal effect and adsorption ability of two types of CNTs: single-walled carbon nanotubes and multi-walled carbon nanotubes, as well as some of their composites with other materials such as metal nanoparticles, polymers, and other antimicrobial agents. Toxicological and environmental concerns of CNTs and future challenges that still limit the optimal utilization of CNTs in waterborne pathogen control are also discussed.

The rise of global population has resulted in an impressive growth in food production, which has been attributed to the overly increased use of agrochemicals such as pesticides and fertilizers. However, unthoughtful use of agrochemicals also leads to deterioration of environmental quality and pose severe threats to terrestrial and aquatic ecosystems. Even though persistent and harmful chemicals have been phased out and replaced by less persistent and biodegradable chemicals, legacy residues from the past and recent residues are still a painful challenge to solve. In this chapter the advances of nanotechnology and their application for remediations of agrochemicals are discussed. Depending on the decontamination process, these techniques have been classified into two categories: reactive and adsorptive treatments. This review covers the utilization of various nanomaterials including metal- and metal-based silica, carbonaceous, and polymeric nanomaterials for remediation techniques. Besides, ecotoxicological concerns associated to the application of nanomaterials in the environment is also included.

Phosphate as an essential compound in every plantation is largely produced in the form of fertilizer. Despite its usefulness, phosphate discharge into water body in excessive amount causes eutrophication that leads to ecosystem disturbances. Aside from the aforementioned negative effect, phosphate itself is deemed as an unsustainable resource. Thus its recovery has attained considerable attention from both academician and industrial societies. In this book chapter, simultaneous phosphate recovery by converting it into some type of salts that constitute either calcium and fluorine ions is being considered. In addition, the effect of Ca and F ions removal to phosphate conversion into struvite (magnesium ammonium phosphate hexahydrate) as a valorized by product is deeply considered. This salt formation and crystallization are reported to be well affected by both Ca and F ions. Since both aforementioned ions are reported as potent inhibitors for struvite crystallization, their removal can potentially reduce the settling time of struvite and eventually capital and operation costs.

Wastes are unavoidable by-products of human production and consumption activities and have been a primary cause of environmental issues. The release of wastes such as pesticides, textile dyes, and heavy metals that end up polluting environment have endangered not only human health but also biodiversity in general. According to recent developments, the use of nanotechnology for environmental cleanup is evidently promising. Enhanced properties of nanoparticles attributed to their larger surface area enable them to perform in a number of remediation methods such as absorption, adsorption, filtration, chemical reaction, and photocatalysis. This chapter focuses on the applications of four groups of nanomaterials: zero-valent iron nanoparticles, carbon nanotubes, zeolites, and metal oxide nanoparticles for environmental remediation. As a growing research priority, the development of nanotechnology for environmental cleanup has also raised significant concerns on nanoparticle production routes that can be technically challenging. Various fabrication methods ranging from conventional pathways such as physical, chemical, and electrochemical to novel production technique involving biosynthesis are discussed in this review. Despite the useful application, exposures to nanomaterials in the environment also bring potential hazards to plants, animals, and humans. This chapter discusses possible solutions for the aforementioned issue and provides a summary of recent developments of nanoparticle utilization for textile dye and toxic pollutant removals.

The Rate Determining Step (RDS) in adsorption proses plays a key role in order to understand the correct adsoption mechanism. In this experiment, a simple method used for distinguishing the RDS of liquid adsorption on solid adsorben was studied by an experiment based on Shrinking-Core Diffusion-based Model (SCM). RDS determination was done by comparing experimental data of two SCM Models: (1) Pore-Surface Model Diffusion (PSDM) and (2) Film-Pore Diffusion Model (FPDM). The adsorption of methylene blue by activated carbon obtained from Jatropha curcas L. was used as a case study. The result of experiment by three variated parameters: initial concentration (C0), pH, and type of adsorben shows that PSDM has more accuration compared to FPDM in representating the characterstic of mass transport of metil red adsorption on activated carbon.

Dalam rangka meningkatkan komoditas susu di Indonesia, pemerintah menargetkan sapi perah lokal harus mampu menyuplai 41% produksi susu dalam negeri pada 2022. Salah satu cara untuk menaikkan produksi susu sapi adalah memberikan suplemen pakan berupa sabun kalsium. Sabun kalsium telah banyak digunakan di luar negeri, namun tidak di Indonesia, untuk menaikkan produksi susu sekaligus fertilitas ruminansia. Sabun kalsium dapat dibuat melalui reaksi fusi termodifikasi antara Palm Fatty Acid Distillate ( PFAD ) sebagai sumber asam lemak bebas dengan sumber kalsium. Penelitian ini mengevaluasi pengaruh jenis PFAD terhadap kualitas produk sabun kalsium. PFAD yang digunakan berasal dari beberapa industri pengolahan kelapa sawit di Indonesia, yaitu Kabupaten Sidoarjo, Kabupaten Bekasi, Kota Bekasi, dan Kabupaten Pelalawan dengan rentang angka asam 195 – 221 mg KOH/g sampel. Produk sabun kalsium yang dihasilkan kemudian dianalisis nilai angka asam untuk menguantifikasi kualitasnya. Keempat produk sabun kalsium secara keseluruhan memiliki angka asam di bawah 1 mg KOH/g sampel. Rendahnya angka asam pada produk membuktikan bahwa keempat sumber PFAD dapat digunakan sebagai bahan baku pembuatan sabun kalsium dengan kualitas baik. Kata kunci: angka asam, kalsium oksida, PFAD, pakan ruminansia, sabun kalsium . Abstract . Calcium Soap from PFAD for Ruminant Feed: Quality of PFAD as a Source of Free Fatty Acids. In order to increase the milk commodity in Indonesia, the government targets local dairy cattle to be able to supply 41% of domestic milk production by 2022. One way to increase the production of cow's milk is to provide a dietary supplement in the form of calcium soap. Calcium soap has been widely used overseas, but not in Indonesia, to increase milk production as well as ruminant fertility. Calcium soaps can be made by modified fusion reactions between PFAD as a source of free fatty acids with a calcium source. This study evaluated the effect of PFAD type on the quality of calcium soap products. PFAD used were obtained from several palm oil processing industries in Indonesia, namely Sidoarjo regency, Bekasi regency, Bekasi city, and Pelalawan regency with the acid number 195 – 221 mg KOH/g sample. The resulting calcium soap product is then analyzed for the acid number to quantify its quality. The four calcium soap products had an acid number below 1 mg KOH / g sample. The low acid number in the product indicates that the four sources of PFAD can be used as raw material for producing calcium soap with good quality. Keywords: acid value, calcium oxide, calcium soap, PFAD, ruminant feed.

There has been large interest to isomerize raw turpentine to produce a number of derivative products that has higher economic value. This process is often conducted using homogenous acid catalysts. Catalyst screening is often challenging to target a certain derivative product, such as cineole. The aim of present work is investigate various combination of strong and weak acid catalyst to obtain cineole. Strong acids used in this research were PTSA, hydrochloric acid, sulfuric acid. In addition, the weak acids were oxalic acid dihydrate, citric acid, and formic acid. Commercial turpentine was mixed with strong and weak acid with 4:1:6 ratio respectively, heated up to 85oC for 6 hours for each combination of strong and weak acid. The result from GC-MS analysis shows that combination of hydrochloric acid and formic acid gave the highest eucalyptol yield around 9.67% along with other valuable product such as camphene, limonene, and a-terpinolene.

Turpentine is a potential non-wood product from pine tree forest in Indonesia. Turpentine has a wide application in industry mainly as solvent. Isomerization of turpentine is an attractive route to obtain a higher value fine chemical such as cineole. Acid catalyst is often used for this purpose and screening of numerous combination of acid catalysts is often challenging. Therefore, an investigation of isomerization operating condition is important. The aim of present work is to investigate the influence of several acids ratios, and residence time. The raw turpentine was obtained from PT Perhutani Anugerah Kimia (PAK) Trenggalek, East Java. Here, we have investigated the influence of raw turpentine to acid catalyst ratios as well as residence time using central composite design (CCD) of 22 factorial design. In this work, the strong acid catalysts used is hydrochloric acid (HCl) and the weak acid catalysts is formic acid (HCOOH). The result from GC-MS analyses showed that isomerization of raw turpentine using combination of HCl and formic acid can produce cineole compound along with other valuable products such as camphene and limonene. Herein, we have reported the highest yield of cineole as high as 11.5% which is in close agreement with model prediction. It is expected that this work may provide a useful path for cineole production in a larger production scale.

Rosin is the major component of Pine sap that has a composition of up to 90%. Rosin is an organic compound that consists of diterpene tricyclic compounds with carboxyl functional group. The presence of this functional group makes rosin becoming acidic and corrosive. Furthermore, rosin also has double bonds that are prone to oxidation when exposed to air. To improve the weaknesses, modifications shall be done. Esterification reaction can be done through transforming into a more stable functional group, ie. ester, while Diels-Alder reaction will saturate the double bonds into more stable cyclic compounds. The results indicate that synthesizing maleic modified rosin ester could improve the properties of pine rosin. Esterification was done using a ratio of glycerol to rosin of 1:3 mol. Esterification was done for 6 hours at 250°C at room and vacuum pressure. The Diels-Alder reaction was done using maleic anhydride at 1:1 stoichiometric ratio to rosin, reacted at 150°C for 1 hour at vacuum condition.

Direct utilisation of biomass for energy application is less profound due to the problems of low calorific value, high water content, and low grindability of biomass. For this reason, pre-heating t...