Siti Syamsiah

Adsorption cycles and effect of microbial population on phenol removal using natural zeolit

Abstract Combination of adsorption and biodegradation is becoming more common to remove phenolic compounds from wastewater. Adsorption could reduce the inhibitory effect of the compounds for microorganisms, whereas biodegradation could, in some extend, freeing adsorption sites. This results in extending the life of adsorbent. Activated carbon is the adsorbent widely used for that purpose. This study deals with the use of Indonesian natural zeolite to remove phenol in a laboratory scale fixed bed system, in the presence of microbial growth. 50 mg/l of phenol solution was fed into the bed at the flow rate of 1 cm 3 /s. The bed was inoculated with Psudomonas putida . It was observed that the microbial mass has slowed down the adsorption, as it contributed in increasing mass transfer resistance. The effect was more significant at higher cycles. About 2% of adsorbed phenol was microbially degraded into carbon dioxide, whereas the rest could be converted into dissolved products and microbial mass, and/or irreversibly adsorbed. Comparison between the observed data with predicted data indicates that the system was much more complex than merely combination of adsorption and biodegradation processes. Further evaluation should be made.

Biogas production from traditional market waste to generate renewable energy

The increased energy consumption and limited fossil energy sources caused industry to find energy from renewable resources. Biogas is one of the renewable energy that has a good prospect in the near future. Traditional market wastes which were represented by green mustard and white mustard were undertaken in a laboratory experiment. To produce biogas, the raw material such as white mustard and cow manure, green mustard and rice straws were mixed until C to N ratio close to 20. Inoculums starter from biodigester effluent was put into digester then water was added until 350 ml. The initial pH was measured. Fermentation process was conducted at temperature of 35°C. Volume and pH of the biogas were observed daily. Methane, total solid and volatile solid were analyzed weekly. Fermentation process was observed for 7 weeks. The accumulation of biogas production at the day 42 for white mustard (S1), white mustard with cow manure (S2), and mixed of green mustard and rice straw (S3) were 0.111L, 0.901L and 0.390L respectively. The highest methane concentration in the biogas was achieved on the day 21, which were found of 62.18% and 63.15% for S2 and S3 respectively. Meanwhile for S1 (white mustard only without cow manure) no methane was observed. In the first 7 days, the pH level were observed decrease and increase after the day of 28. However, at the end of digestion period the pH will slightly decrease. It was also developed to conduct a pilot plant within the tubular digester to generate energy in batik home industry, Imogiri, Yogyakarta, Indonesia.

Effects of Various Pretreatment Variables on Hydrolysis of Lignocellulose to Produce Sugar in Bioethanol Production

This research intends to explore the effect of pretreatment on lignoselulose to be used as raw material for bioethanol production. Pretreatment prepares lignocellulose compounds to be more easily hydrolyzed. Several variables were tested on oil palm empty fruit bunch (OPEFB) i.e. temperature, NaOH concentration, and particle size. According to the method of size reduction, there are two types of pretreatment which were milling and cutting. The first pretreatment type consisted of milling and screening resulting -+10-30, -30+40, -40+80, and-80 mesh. Each size fractions were then soaked in water at 90 °C for 2 hours. Meanwhile the second type consisted of cutting to 1 cm length followed by soaking in NaOH solutions for 2 hours. The operating temperatures at the second type were varied at 90 °C, 120 °C, 150 °C, 170 °C while the NaOH concentrations applied were 0%, 0.5%, 1%, 2%, 5%, 10%.The pretreated OPEFB was then hydrolyzed using cellulase produced by Aspergillusniger grown in situ. It was revealed that the relatively good pretreatment condition was milling to-80 mesh followed by soaking in hot water at 90 °C. It gave the highest produced sugar concentration at 15 g/L while other type resulted only 5.8 g/L.

Utilization of Fruit Waste as Biogas Plant Feed and its Superiority Compared to Landfill

Fruit waste is a part of municipal solid waste which is typically disposed of directly to a landfill site. In order to utilize this valuable renewable resource, anaerobic biological processes can b ...

The influence of chicken eggshell powder as a buffer on biohydrogen production from rotten orange (Citrus nobilis var. microcarpa) with immobilized mixed culture

This research observed the influence of chicken eggshell on hydrogen production from anaerobic fermentation of rotten orange (Citrus nobilis var. microcarpa) using batch method at 36 °C and pH 7. Fermentation material were varied in several types, the first type was meat and peel of oranges with VS of 59.152 g.L−1 in A, B, C, and D compositions. The second type was orange meat added with peel (OMP) with VS of 36.852 g.L−1. The immobilized ingredients used in the experiment consisted of 2 % (w/v) alginate and active carbon with the ratio of 1:1. 3.2 g chicken eggshell powder was added to the first type of material (substrates A, B, C, and D). Results showed that pH during fermentation process using chicken eggshell as a buffer was constant at 5.5; however, without the use of chicken eggshell, the pH decreased to 3.8 and increased slightly before it stayed stable at 4.0. The total amount of gas produced in sample using the chicken eggshell was 46,35 mL.mg VS−1 and in sample produced without the eggshell, it...

Performance of continuous stirred tank reactor (CSTR) on fermentative biohydrogen production from melon waste

This research was meant to investigate performance of continuous stirred tank reactor (CSTR) as bioreactor for producing biohydrogen from melon waste through dark fermentation method. Melon waste are commonly generated from agricultural processing stages i.e. cultivation, post-harvesting, industrial processing, and transportation. It accounted for more than 50% of total harvested fruit. Feedstock of melon waste was fed regularly to CSTR according to organic loading rate at value 1.2 - 3.6 g VS/ (l.d). Optimum condition was achieved at OLR 2.4 g VS/ (l.d) with the highest total gas volume 196 ml STP. Implication of higher OLR value is reduction of total gas volume due to accumulation of acids (pH 4.0), and lower substrate volatile solid removal. In summary, application of this method might valorize melon waste and generates renewable energy sources.

Biohydrogen production from rotten orange with immobilized mixed culture: Effect of immobilization media for various composition of substrates

Enriched–immobilized mixed culture was utilized to produce biohydrogen in mesophilic condition under anaerobic condition using rotten orange as substrate. The process was conducted in batch reactors for 100 hours. Microbial cultures from three different sources were subject to a series of enrichment and immobilized in two different types of media, i.e. calcium alginate (CA, 2%) and mixture of alginate and activated carbon (CAC, 1:1). The performance of immobilized culture in each media was tested for biohydrogen production using four different substrate compositions, namely orange meat (OM), orange meat added with peel (OMP), orange meat added with limonene (OML), and mixture of orange meat and peel added with limonene (OMPL). The results show that, with immobilized culture in CA, the variation of substrate composition gave significant effect on the production of biohydrogen. The highest production of biohydrogen was detected for substrate containing only orange meet, i.e. 2.5%, which was about 3-5 times higher than biohydrogen production from other compositions of substrate. The use of immobilized culture in CAC in general has increased the hydrogen production by 2-7 times depending on the composition of substrate, i.e. 5.4%, 4.8%, 5.1%, and 4.4% for OM, OMP, OML, and OMPL, respectively. The addition of activated carbon has eliminated the effect of inhibitory compounds in the substrate. The major soluble metabolites were acetic acid, propionic acid, and butyric acid.