Judul: Pemanfaatan Kiambang (Salvinia molesta) dalam Mereduksi Bahan Pencemar pada Limbah Cair Tapioka.
Abstrak: Tapioca wastewater may cause unbalance aquatic ecosystem. It contains cyanide, high organic matter, and acid water. Free floating aquatic plants such as kiambang (Salvinia molesta) can be applied as biological treatment for tapioka wastewater. Kiambang can utilize organic matter from water and from sediment. Therefore, water height could affect utilization of organic matter by kiambang. This research aimed to study the utilization of kiambang to reduce contaminant material in tapioca wastewater with different water height. Result showed that treatment with 10 cm water height decreased cyanide concentration and organic matter more than 20 cm. Wastewater treatment of 10 cm without aquatic plants decreased cyanide and organic matter the most, i.e 70% and 50%, respectively. This was because oxygen diffusion from atmosphere into water was blocked by the plant, causing organic material reduction was blocked as well. Aquatic plants acclimatization in wastewater should be done in a particular time span, so that aquatic plants ability to reduce cyanide and organic matter could be more visible.
Keyword: water height, tapioca wastewater, Salvinia molesta, kiambang

Judul: Phytoremediasi Greywater dengan Tanaman Kayu Apu (Pistia stratiotes) dan Tanaman Kiambang (Salvinia molesta) serta Pemanfaatannya untuk Tanaman Selada
Abstrak: Waste are residue from certain efforts of human activities in solid, liquid or gas form and have less economical value. Liquid waste often dispose to sewage water so it could decrease water quality. Domestic waste known as prominant contaminant of water environments. Usage water for domestic requirement is much higher than industrial where organic contents in domestic waste is basicly “biodegradable”. Domestic wastewater is devided into blackwater and greywater. Blackwater is waste from toilets, faecal matter including industrial product, whereas greywater is none industrial wastewater generated from domestic processes such as bathing, dishing and kitchen washing. These research particularly focuse on greywater (bath waste) because it much easy to treat and recycle than blackwater, due to lower levels of contaminant. The aim of the research were to find out the most effective treatment using phytoremediation approach with Pistia and Salvinia and to study the influence of treatment on lettuce growth. The research consists of initial the research and main research. The initial research begin with determined waste concentration and biomass water plant used, while main managed greywater with circulation system using remediation vessel and water plant as phytoremediator. These research were designed according to Complete Randomized Factorial Experimental Design (SK = 95%) with two factors including remediation vessel (B1 and B2) and water plant (Control, Pistia and Salvinia), which every treatment were repeated for three times. The research result showed chemical characteristic that is Chemical Oxygen Demand (COD) were exceed standard quality of level waste. COD level significantly decrease (P<0,05) at 0 and 1 weeks after planting tend (WAP) by water plant treatment, while COD level at 3 WAP significantly decrease by remediation vessel. Phosphorus level significantly decrease at 0, 2 and 3 WAP by remediation vessel, while nitrate level significantly decrease at 1 WAP by water plant treatment, remediation vessel and both of combination. Pistia treatment more effective than Salvinia to recycling water quality. Phosphorous and nitrate level content in effluent 1 were low than nutrient requirement for normal lettuce growth on hydroponic system. Deficiency element nutrient for lettuce make it low weight of harvested and has caused died level of lettuce at the research were approximately 32%.
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Judul: Determinan dan Invers Matriks Leslie Ganda dengan Formula Schur
Abstrak: Matriks Leslie ganda merupakan bentuk umum dari matriks Leslie, matriks companion, dan matriks companion ganda. Bentuk khusus komplemen Schur dapat digunakan pada formula Schur untuk mendapatkan rumus determinan dan invers. Tujuan dari penulisan karya ilmiah ini adalah mengkaji secara teoritis pembuktian formulasi determinan dan invers matriks Leslie ganda berdasarkan formula Schur. Pembuktian formula determinan dan invers matriks Leslie ganda dilakukan dengan mensubstitusi formula determinan dan invers matriks persegi menggunakan komplemen Schur., The doubly Leslie matrix is generalized of the Leslie matrix, the double companion matrix, and the companion matrix. The unique form of Schur complement can be used in Schur’s formula to obtain a formula of the determinant and inverse of doubly Leslie matrix. In this article, the proof of those formulation are discussed theoretically based on Schur’s formula. Proof of the determinant and inverse formulation perform by substitute the determinant and inverse of square matrix with Schur Complement.
Keyword: Komplemen Schur, Formula Schur, Determinan, Invers, Matriks Leslie Ganda