Judul: Integration of Photosynthesis Microbial Fuel Cell using  Citrobacter freundii GBH253 and Chlorella sp ICBB9005 in Tofu Wastewater
Abstrak: Photosynthesis Microbial Fuel Cell (PMFC) integration covering wastewater treatment, electricity production, and microalgae biomass production has prospects to be applied. Electricity production can be increased by combining wastewater as substrate and sodium acetate as co-substrate to increase exoelectrogen microbial activity in transferring extracellular electrons. This study aims to optimize electricity production by combining tofu wastewater as a substrate with sodium acetate as a co-substrate in the growth medium for Citrobacter freundii GBH253 at the anode. Chlorella sp. ICBB9005 is an electron acceptor, utilizing tofu wastewater as a carbon source with photosynthesis at the cathode. The treatment is given in this study various concentrations of sodium acetate co-substrate (0, 10, 20, 30 mM) in tofu wastewater. The research design used was a completely randomized design with an analysis of variance and Tukey's test to determine the significance of the effect between treatments (p<0,05). The results showed that 30 mM sodium acetate co-substrate was added into tofu wastewater 40% (v/v) as a growth media for C.freundii GBH253 5% (v/v) was able to produce maximum output voltage and power density 785,5 mV and 273,43 mW.m-2 at the anode PMFC. Each treatment differs significantly (P<0.05). Chlorella sp. ICBB9005, as an electron acceptor, produced O2 utilizing tofu wastewater as a carbon source with photosynthesis and reduced COD at the cathode PMFC. Utilizing tofu wastewater while producing biomass of Chlorella sp. ICBB9005 is 0.748 g.mL-1 at the cathode PMFC. Based on this study's results, the PMFC uses C. freundii GBH253 and Chlorella sp. ICBB9005 has the integrated to reducing COD and optimizing bioelectricity and biomass microalgae.
Keyword: Citrobacter freundii GBH253, Chlorella sp, ICBB9005, Power Density, Biomass, Photosynthesis Microbial Fuel Cell

Judul: Bioelectricity in Microalgae-Microbial Fuel Cell  (MMFC) using Different Ratios between Activated Sludge and Fish Processing Wastewater
Abstrak: Sistem microalgae-microbial fuel cell (MMFC) dilakukan dengan memanfaatkan proses fotosintesis Spirulina platensis dan reaksi metabolisme bakteri yang terdapat dalam lumpur aktif untuk menghasilkan energi listrik dan biomassa mikroalga. Penelitian bertujuan menentukan pengaruh rasio lumpur aktif dengan limbah pemindangan ikan dalam menghasilkan bioelektrisitas pada MMFC, menentukan kurva pertumbuhan dan biomassa S. platensis serta menentukan perubahan kualitas air limbah pada MMFC. Rasio lumpur aktif dan limbah pemindangan yang digunakan, yaitu 1:10 (MMFC-1), 2:10 (MMFC-2), dan 3:10 (MMFC-3). Perbedaan rasio berpengaruh terhadap elektrisitas yang dihasilkan. Perlakuan MMFC-1 menghasilkan elektrisitas tertinggi (rata-rata tegangan 577,03±18,71 mV; arus 3,16±0,17 mA; dan power density 55,35±4,45 mW/cm2 ), perlakuan MMFC-3 menghasilkan pertumbuhan S. platensis tertinggi (optical density 0,55±0,04) serta MMFC-1 dapat menurunkan chemical oxygen demand sebesar 4,89%; biological oxygen demand 31,12%; dan total ammonia nitrogen 28,79% sedangkan nilai pH dan total plate count mengalami kenaikan. Sistem MMFC berpotensi untuk dikembangkan dalam menghasilkan elektrisitas, menurunkan beban polutan, dan menghasilkan biomassa., Microalgae-microbial fuel cell (MMFC) system is carried out by utilizing the photosynthesis process of Spirulina platensis and metabolic reactions with bacteria contained in activated sludge to result in electrical energy and biomass microalgae. The study aims to determine the effect of the ratios of activated sludge to boiled fish processing wastewater in producing bioelectricity in MMFC, determine the growth curve and biomass of S. platensis, and changes in wastewater quality at the MMFC process. The ratios of activated sludge and wastewater used in the study were 1:10 (MMFC-1), 2:10 (MMFC-2), and 3:10 (MMFC-3). The difference in ratios affected to resulting electrical power. The MMFC-1 treatment produced the highest electrification (average voltage 577.03±18.71 mV; current 3.16±0.17 mA; and power density 55.35±4.45 mW/cm2 ), MMFC-3 resulted in the highest growth of S. platensis (optical density of 0.55±0.04) and MMFC-1 system can reduce chemical oxygen demand 4.89%; biological oxygen demand 31.12%; and total ammonia nitrogen 28.79% while pH and total plate count values increased. The MMFC system has the potential to be developed both in producing electrical power, reducing pollutants, and producing biomass.
Keyword: activated sludge, biomass, pollutant, power

Judul: Karakteristik Barisan Eksak Pendek HomR(N, ) dan HomR( ,N)
Abstrak: Module merupakan generaIisasi dari ruang ve}ctor, dimana pada ruang vektor skalar-skalamya berasal dati suatu lapangan (field) sedangkan pada module skaJar-skalamya merupalam unsur-unsur dan suatu ring R dengan unsur satuan. Dari suatu grup komutatif yang unsur-unsumya dipadukan dengan unsur-unsur dart suatu ring R, maka akan mengbastlk.an yang namanya R-module. Himpunan seroua fungsi homomorfisma yang memetakan dati R-module M ke R-module N dinotasikan sebagai HomiM,N), dimana HomiM,N) juga merupakan suatu R-module.
Keyword: