Pengaruh Aerasi Bertingkat dengan Kombinasi Saringan Pasir, Karbon Aktif, dan Zeolit dalam Menyisihkan Parameter Fe dan Mn dari Air Tanah di Pesantren Ar-Raudhatul Hasanah

Groundwater if allowed to form a yellow precipitate indicates that contains high levels of Fe and Mn are high, so we need a method that is good in quality and economical way to improve the quality of groundwater. Experimental research that aims to determine the effect of aeration is terraced with a combination of sand, activated carbon and zeolite filter. Examination of the samples is done continuous sampling every 1 hour within 5 hours of the treatment 1 (aeration 2 levels followed by a sand, activated carbon, and zeolite filter), the treatment 2 (aeration 2 levels with a combination of zeolite followed by a sand, activated carbon, and zeolite filter), and the treatment 3 (sand, activated carbon, and zeolite filter). The best decreased levels of Fe is to use the treatment 1 with an efficiency decrease of 47,22 %. Whereas decreased levels of Mn best is on each treatment with the efficiency of a decrease of 100 %. Statistical analysis showed that there are differences in the levels of Fe in the tool 1, tool 2 and the tool 3 p (0.028 < 0.05). There is no difference in the levels of Mn on treatment 1, treatment 2, and treatment 3 p (0146 > 0.05).Keywords : Groundwater, Fe, Mn, Multilevel aeration, Sand activated carbon zeolite filterAbstrakAir tanah yang jika dibiarkan membentuk endapan kuning menunjukkan bahwa masih mengandung kadar Fe dan Mn yang tinggi, sehingga diperlukan suatu metode yang baik dalam kualitas dan ekonomis untuk meningkatkan kualitas air tanah. Penelitian yang bersifat eksperimen ini bertujuan untuk mengetahui pengaruh aerasi bertingkat dengan kombinasi saringan pasir, karbon aktif dan zeolit. Pemeriksaan sampel dilakukan secara continuous sampling setiap 1 jam sekali dalam 5 jam pada alat 1 (aerasi 2 tingkat dilanjutkan dengan saringan pasir, karbon aktif, dan zeolit), alat 2 (aerasi 2 tingkat dengan kombinasi zeolit dilanjutkan dengan saringan pasir, karbon aktif, dan zeolit), dan alat 3 (saringan pasir, karbon aktif, dan zeolit). Penurunan kadar Fe yang tertinggi ialah menggunakan alat 1 dengan efisiensi penurunan sebesar 47,22 %. Sedangkan penurunan kadar Mn yang terdapat pada setiap alat dengan efisiensi penurunan sebesar 100 %. Hasil uji statistik menunjukkan bahwa ada perbedaan konsentrasi Fe pada alat 1, alat 2 dan alat 3 p (0.028 < 0.05). Tidak ada perbedaan konsentrasi Mn pada alat 1, alat 2 dan alat 3 p (0.146 > 0.05). Kata Kunci: Aerasi Bertingkat, Air Tanah, Fe, Mn, Saringan Pasir Karbon Aktif Zeolit

Formation of an Iron(III) Oxo Cubane Core Fe4(μ4-O)4 from FeCl3 and the Unsymmetrical Tripodal Ligand N[(CH2CH2NH2)(CH2CH2OH)(CH2CH2CH2OH)]

The coordination chemistry of the unsymmetric, aliphatic, tetradentate tripodal ligand N[(CH2CH2NH2)(CH2CH2OH)(CH2CH2CH2OH)] H4-1 with iron chlorides was investigated. The disodium salt of the deprotonated ligand Na2(H2-1) reacts with FeCl3 to yield a yellow precipitate which upon recrystallization from DMSO/CH2Cl2 gives red crystals of the octanuclear iron(III) complex [{FeIIICl(H2-1)}4FeIII4(μ4-O)4Cl4] 2 ・ 4CH2Cl2 containing a central Fe4(μ4-O)4 cubane core. Crystals of 2 ・4DMF were obtained by slow oxidation of the green iron(II) complex obtained from ferrous chloride and Na2(H2-1) after recrystallization from DMF. The structure determination of 2 ・4CH2Cl2 also revealed the presence of the iron(III) oxo cubane core. The core is surrounded by four iron atoms each coordinated by η4-(H2-1)2- and Cl- ligands.

Microwave Oven Drying in the Gravimetric Phosphorus Method

The gravimetric quinolinium molybdophosphate method for determining P2O5 in fertilizers, AOAC 2.026–2.028, has been modified to permit the precipitate to be dried in a microwave oven rather than a conventional drying oven. After the yellow quinolinium molybdophosphate precipitate is formed, cleaned up, and washed, it is placed in a microwave oven at 600 watts until dry. The quantity of precipitate remaining after microwave drying was equal to that obtained by drying according to AOAC 2.028 for several fertilizer samples. A distinct advantage of the described method is that the yellow precipitate will not char with reasonably excessive drying. Also, much less energy is expended with the microwave oven than with the drying oven.

Reactions of copper in molten alkali-metal nitrite

When molten NaNO2 is electrolysed between copper electrodes, a yellow precipitate which contains copper(1) forms at the cathode.It seems probable that a cuprite with the empirical formula Na2O,Cu2O,H2O is initially formed and is then slowly oxidized either by species present in the melt or by air. If sufficient Na2O2 is added to saturate the melt (i.e., solid Na2O2 is present),the precipitate partly dissolves to form an orange-red solution which forms a green solid on freezing. This may contain a copper(11) or copper(111) cuprate.

Stoichiometry of the Volumetric Ammonium Phosphomolybdate Method for P2O5

A study was made to determine the stoichiometry of this method with particular reference to solubility losses and ammonia content of the precipitate. Studies show that the recovery of ammonia by distillation from a caustic solution is depressed by the presence of molybdic acid. Recovery was reduced to as little as 99% at the stoichiometric ratio of MoO3 to IN. The mechanism of this phenomenon is unknown. However, after standardizing the method for ammonia in the presence of molybdic acid, the yellow precipitate was found to contain 99.5% of the theoretical ammonia according to the formula (NH4)3PO4:12MoO3

SULPHINIC ACIDS AS ANALYTICAL REAGENTS

The "specific" action of sulphinic acids with metal ions is not limited to compounds in which there is direct attachment of the —SO2H group to an aromatic ring. Since both aliphatic and aromatic sulphinic acids react similarly the assumption that an aromatic group is necessarily co-ordinated to the metal atom through its π system is not valid; the precipitated products are simple salts of the acids. Ferric iron yields at least two products with sulphinic acids. Ceric cerium is reduced in acid solution but an orange-yellow precipitate containing cerium is obtained from acetate-buffered solutions. Naphthalenesulphinic acid may be used to quantitatively precipitate [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text] [Formula: see text].[Formula: see text] [Formula: see text]