ABSTRAKPestisida adalah substansi kimia dan bahan lain yang digunakan untuk mengendalikan berbagai hama yang terbukti mengganggu. Pestisida dapat dibuat dari bahan alam yang salah satunya dari daun pepaya dan umbi bawang putih. Hal ini diiringi dengan mudahnya didapatkan bahan alam tersebut sehingga muncullah ide untuk membuat pestisida dari bahan tersebut. Tujuan dari penelitian ini adalah mempelajari pengaruh variasi waktu perendaman bahan baku dengan variasi pelarut, menghitung rendemen dari variasi waktu perendaman bahan baku dan menguji senyawa metabolit sekunder dari rendemen maksimum lalu menguji toksisitas ekstrak yang diperoleh terhadap larva nyamuk. Penelitian ini dilakukan dengan metode ekstraksi maserasi menggunakan pelarut metanol dan etanol. Variasi waktu perendaman 3,5,7 hari dengan suhu lingkungan, nisbah larutan padatan sebesar 1 : 4, setelah proses perendaman dilakukan penyaringan dan hasil saringan berupa filtrat didestilasi dengan kondisi operasi temperatur 80o C selama 50 menit. Lalu ekstrak diuji senyawa metabolit sekundernya, diukur pHnya dan toksisitas terhadap hewan uji. Kondisi operasi maksimum diperoleh pada waktu perendaman selama 7 hari dengan kadar rendemen sebesar 41,35 % dengan pH 5,79 untuk hasil ekstrak metanol dan 36,06 % dengan pH 5,86 untuk hasil ekstrak etanol. Metabolit sekunder yang berhasil diidentifikasi adalah alkaloid, flavonoid, saponin, tanin dan sulfur. Konsentrasi maksimum yang membunuh larva nyamuk adalah sebesar 3000 ppm dengan rata-rata kematian larva 95 % untuk ekstrak etanol dan 97,5 % untuk ekstrak metanol.Kata kunci: pestisida alami, daun pepaya dan umbi bawang putih, ekstraksiABSTRACTPesticides are chemicals and other substances used to control pests that could prove disruptive. Pesticides can be made from natural materials, one of which from the leaves of papaya and garlic bulbs. It is accompanied by easily obtained natural materials that came the idea to create pesticide of these materials. The purpose of this research was to study the effect of variations in the time of immersion of raw materials with a variety of solvents, calculate the yield of raw material variation of soaking time and the test compounds secondary metabolites of maximum yield and test the toxicity of exstracts obtained against mosquito larvae. The research was done by maceration extraction method using methanol and ethanol. 3,5,7 days soaking time variation with temperature, the solid solution ratio 1 : 4, after immersion do filtering was done and filter the results in the form of the filtrate is distilled at 80o C temperature operating conditions for 50 minutes. Then extract secondary metabolites were tested, measured their pH and toxicity towards the test animals. Maximum operating conditions obtained at the time of immersion for 7 days with high levels of yields at 41.35 % with a pH of 5.79 for methanol extract and 36.06 % with a pH 5.86 to extract the ethanol. Secondary metabolites that were succesfuly identified are alkaloids, flavonoids, saponins, tannins, and sulfur.Maximum concentration that killed mosquito larvae is equal to 3000 ppm with an average of 95 % larval mortality for ethanol extract and 97.5 % for methanol extract.Keyword : natural pesticides, papaya and garlic bulbs, extraction

Mikroalga Chlorella sp. memanfaatkan nutrien yang terdapat di dalam POME sebagai sumber nutrisi untuk pertumbuhannya. Pada penelitian ini dilakukan penyisihan nutrien yaitu kandungan COD dan Nitrogen Total dengan memanfaatkan POME sebagai medium kultivasi di dalam flat-fotobioreaktor. Imobilisasi sel dilakukan untuk membentuk beads dikarenakan sel Chlorella sp. yang mikroskopis, berat jenis rendah, dan sulit dipisahkan dari medium. Untuk mendapatkan efisiensi penyisihan terbaik dilakukan variasi konsentrasi bead alga di dalam flat-fotobioreaktor sebesar 6, 8, 10, 12, dan 14 beads/mL air limbah serta waktu kontak 0, 1, 3, 5, dan 7 hari. Hasil penelitian menunjukkan efisiensi penyisihan COD dan Nitrogen Total terbaik terdapat pada flat-fotobioreaktor dengan konsentrasi bead alga sebesar 12 beads/mL air limbah pada hari ketujuh sebesar 77,8 % dan 83,5 %.

Background: The utilization of microalgae as a renewable energy is an important aspect in solving shortage of future oil reserve in 15 years. One of the renewable energy sources is microalgae biodiesel. Palm oil mill effluent (POME) is a wastewater that has a high content of organic materials. These organic materials can be used as growth nutrients for microalgae. Chlorella pyrenoidosa is one of the most potential microalgae used as a raw material for the production of biodiesel since it contains lipids (8%-35%). Methods: Chlorella pyrenoidosa was cultured on the POME medium with concentrations of 0%, 25%, 50%, 75%, and 100%v with addition of synthetic nutrients (urea: TSP) at the ratios of 2:1 ; 1:2 ; 0.5:1 in a 500 mL Erlenmeyer flask, at pH 6-8, aeration using aquarium pumps, and using LED lights (3000 lux). Results: It was revealed that at POME concentration of 25% and with addition of urea: TSP at a ratio of 2:1, the optimum specific growth rate (0.306/day) with the highest number of cells was 3.530 × 107 cells/mL and the highest lipid content was 36% of its dry weight. The removal efficiency of POME could be obtained from the removal efficiency of chemical oxygen demand (COD), total nitrogen, and orthophosphate (P-PO4 ), which was 70, 90.42, and 81.12%, respectively. Conclusion: According to the results, under appropriate culture conditions, C. pyrenoidosa can produce lipids with good use of nutrients contained in the POME medium.

ABSTRAKDalam penelitian dilakukan pengolahan limbah cair Hotel yang bersumber dari dapur dan laundri dengan metode Multi Soil Layering (MSL). Tujuan penelitian ini untuk menentukan efisiensi penyisihan COD dan mempelajari pengaruh faktor variasi material organik dalam campuran tanah pada lapisan anaerob dan variasi Hydraulic Loading Rate (HLR) terhadap efisiensi pengolahan limbah cair hotel dengan metode MSL. Dua buah reaktor MSL berdimensi 50 x 15 x 100 cm dengan lapisan batuan yang sama pada kedua reaktor berupa kerikil berukuran 35 mm serta lapisan anaerob berupa campuran tanah dengan arang (reaktor 1) dan campuran tanah dengan serbuk gergaji (reaktor 2) dengan rasio komposisi 2 : 1. Limbah dialirkan pada masing-masing reaktor dengan variasi HLR 500, 750, dan 1.000 l/m2hari. Konsentrasi COD sebelum diolah adalah 132,600201,240 mg/l, setelah diolah dengan MSL konsentrasi berubah menjadi 12,48088,920 mg/l. Secara umum, variasi material organik dalam campuran tanah tidak begitu berpengaruh pada penyisihan COD. Variasi HLR cukup berpengaruh, dimana HLR 500 l/m2hari memberikan efisiensi penyisihan COD yang lebih tinggi. Efisiensi penyisihan COD yang diperoleh pada penelitian ini berturut-turut pada reactor 1 berkisar antara 55 -90 % dan pada reactor 2 berkisar antara 56-89%. Hasil menunjukkan bahwa kedua reaktor mampu menyisihkan COD pada limbah cair hotel.Kata Kunci: COD, limbah cair hotel, multi soil layering (MSL)ABSTRACTResearch COD removal from hotel wastewater stemmed from laundry and kitchen with Multi Soil Layering method (MSL) was conducted. The aim were to observe COD removal efficiency and to study the effect of organic material variation in soil as the anaerob layer as well as the effect of various hydraulic loading rate (HLR). In this research, there were two MSL reactors with dimension of 50 x 15 x 100 cm. Aerob layers of both reactors in the form of gravel 3-5 mm sized while anaerob layers are composed from soil mixed with charcoal (reactor 1) and soil mixed with sawdust (reactor 2) with ratio 2:1. HLR of wastewater for each reactor are 500, 750, and 1.000 l/m2day. Concentration of COD was 132,600-201,240 mg/l. COD concentration successively reduced to 12,480-88,920 mg/l.This result indicated both reactors can cast aside COD and also neutralize hotel liquid waste pH. In general, organic material variation of in soil mixture, that is sawdust and charcoal did not show any significant influence. HLR of 500 l / m2/day allowed the best removal efficiency at each contaminant parameters. As a whole efficiency removal of COD at this research successively at reactor 1 ranged from 55-90%, and 56-89%.Key Words:COD, hotel wastewater, multi soil layering (MSL)

Heavy metals which is mostly contained in electroplating wastewater is Cr, in the form of Cr (VI) and Cr (III). Cr (III) is relatively unstable but tends to be dangerous, Cr (VI) is very stable and has a high level of toxicity which is dangerous for the environment. This study aims to determine the ability of microalgae Chorella sp immobilized with calcium alginate in removing metals Cr (VI) and Cr (III) in electroplating wastewater with variations cell density in beads 0; 1.53×108; 1.76×107 and 1.54×106 cells / bead, pH 3, 5, 7, and 9 with contact time 0; 12; 24; 36 and 48 hours. Allowance carried out by microalgae Chlorella sp immobilized in reducing Cr (VI) and Cr (III) metals in electroplating wastewater with initial concentrations of Cr (VI) 24.78 mg/l and Cr (III) 0.91 mg/l with highest efficiency value of 50.28% at pH 3, cell density 1.54×106 cells/bead within 48 hours

Electroplating industry is one of the industries producing liquid waste containing heavy metals. Among the heavy metals contained in the liquid waste is Chromium (Cr) which has a high toxicity. One technology that can be applied to eliminate Cr metal in liquid waste is by the method Biosorption using biomass derived from yeast bread (Saccharomyces cerevisiae). This study aimed to study the ability of bread yeast biomass (saccharomyces cerevisiae) in removing Cr metal on variations in biosorbent weight of 0.25; 0.5 and 0.75 grams, mesh size 80; 100 and 140 and contact time 1; 2; 3 and 4 hours. The results showed that the highest Cr removing efficiency occurred at 0.75 g biosorbent weight at 80 mesh and 4 hours contact time with efficiency of 54.7%. The biosorption process indicates that the adsorption isotherm type obtained is Langmuir isotherms assumed that the layer formed is monolayer with R2 value of 0.8819. The SEM analysis results show the difference of the morphological shape on the sample surface before and after the biosorption process

Mikroalga memiliki kandungan lemak (lipid) dan asam lemak (fatty acid) yang dapat dikonversi menjadi salah satu energi alternatif biodiesel. Biodiesel adalah bahan bakar alternatif yang tidak beracun dan dapat terurai secara alami. Kelimpahan dan pertumbuhan mikroalga Chorella sp. yang sangat cepat dinilai ideal dan potensial untuk dijadikan sebagai bahan baku produksi bioenergi. Disisi lain mikroalga membutuhkan nutrisi seperti karbon dan nitrogen untuk pertumbuhannya.

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