Judul: Composting of water treatment sludge with agricultural waste
Abstrak: Water treatment sludge (WTS) contains organic and inorganic solids including algae, pathogens such as bacteria and viruses, sand, clay, and sediment of chemicals that were formed during processing. The main concerns of direct disposal of WTS is the potential toxicity of iron and aluminum from alum and ferric chloride as the primary coagulant used, and also heavy metals content such as Pb, and Zn. Organic and inorganic materials, especially metals contained in sludge are generally labile / unstable which is a concern when exposed to the water bodies or soil. The purposes of this study were (1) to apply composting techniques to WTS as an alternative of sludge handling and to minimize negative impacts on the environment, (2) to analyze the influence of composting process on the quality of sludge in the form of compost material produced, (3) to analyze the quality of the produced compost based on national compost standard of SNI 19-7030- 2004. The composting process used three different WTS from three different water treatment plants. Natural static pile composting method that carried out for 60 days was used in this study. Temperature changes of compost piles which were monitored daily showed that the compost pile undergoing a process of well degradation by microorganisms. This degradation process was stabilizing the concentration of macro and micro elements including heavy metals in the compost pile. Those were shown by the increase and stabilization of macro elements such as C, N, K, and P. The results also showed that composting process can be used to decrease the concentration of metal such as Fe, Al, and Pb. The composting process worked well and produced composts which comply with the compost quality standard. Based on the results obtained, the produced compost can be justified to contain nutrient which is applicable as soil conditioner.
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Judul: Pengomposan Lumpur Pengolahan Air dengan Limbah Pertanian
Abstrak: Water treatment sludge (WTS) contains organic and inorganic solids including algae, pathogens such as bacteria and viruses, sand, clay, and sediment of chemicals that were formed during processing. The main concerns of direct disposal of WTS is the potential toxicity of iron and aluminum from alum and ferric chloride as the primary coagulant used, and also heavy metals content such as Pb, and Zn. Organic and inorganic materials, especially metals contained in sludge are generally labile / unstable which is a concern when exposed to the water bodies or soil. The purposes of this study were (1) to apply composting techniques to WTS as an alternative of sludge handling and to minimize negative impacts on the environment, (2) to analyze the influence of composting process on the quality of sludge in the form of compost material produced, (3) to analyze the quality of the produced compost based on national compost standard of SNI 19-7030- 2004. The composting process used three different WTS from three different water treatment plants. Natural static pile composting method that carried out for 60 days was used in this study. Temperature changes of compost piles which were monitored daily showed that the compost pile undergoing a process of well degradation by microorganisms. This degradation process was stabilizing the concentration of macro and micro elements including heavy metals in the compost pile. Those were shown by the increase and stabilization of macro elements such as C, N, K, and P. The results also showed that composting process can be used to decrease the concentration of metal such as Fe, Al, and Pb. The composting process worked well and produced composts which comply with the compost quality standard. Based on the results obtained, the produced compost can be justified to contain nutrient which is applicable as soil conditioner.
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Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix