Judul: Pemulihan Perak dari Limbah Cair Hasil Analisis Kebutuhan Oksigen Kimiawi.
Abstrak: Limbah cair laboratorium banyak mengandung logam berat, seperti perak, merkuri, kromium, dan besi dalam konsentrasi tinggi dan berpotensi mencemari lingkungan. Tujuan penelitian ini adalah memulihkan Ag dari limbah cair hasil analisis kebutuhan oksigen kimiawi (COD) menggunakan beberapa macam pereaksi dan membandingkan hasil pengolahan limbah tersebut dengan baku mutu sesuai dengan Peraturan Pemerintah Republik Indonesia No. 5 tahun 2014. Jumlah konsentrasi total logam Ag dalam limbah sisa analisis COD ialah 432 ppm. Nilai tersebut sangat melebihi standar baku mutu yang telah ditetapkan oleh pemerintah yang menyatakan bahwa batas maksimum logam Ag dalam perairan adalah 0.5 ppm. Logam dalam limbah COD diukur kadarnya menggunakan spektrofotometer serapan atom. Meskipun dengan menambahkan NaOH, kadar logam Ag yang diperoleh masih belum memenuhi baku mutu yang telah ditetapkan, sehingga diperlukan penanganan lebih lanjut.
Keyword: limbah analisis COD, pemulihan logam, pengolahan limbah, perak, presipitasi

Judul: Pengolahan Limbah Cair Laboratorium Bekas Pengujian Kebutuhan Oksigen Kimiawi (KOK) dengan Metode Presipitasi
Abstrak: Determination of chemical oxygen demand (COD) parameter in water samples produce laboratory waste which are still harmful to be dumped to the environment. It is because COD testing still use several reagents containing heavy metals such as Ag, Cr, and Hg. This research was focused on Hg removal, because of its higher toxicity compared with the two others. The initial COD waste contained 5241.4 mg/L of Hg, whereas the quality standard of Hg according to PP No. 82/2001 is 0.002 mg/L. Precipitation method was studied in this research to treat this COD waste, especially to reduce the Hg content. The precipitation was carried out with hydroxide and carbonate. From several methods tested, 5 of which decreased significant amount of Hg, which were hydroxide precipitation with acid addition (HA), multilevel hydroxide precipitation (HB), carbonate precipitation with addition of hydroxide and acid (KHA), multilevel hydroxide precipitation with acid addition (HBA), and multilevel hydroxide precipitation with addition of salt and acid (HBGA). Those five methods could decrease the Hg content up to 99.96%, into 2.1939, 2.7513, 2.0185, 2.5858, and 2.1683 mg/L, respectively. However these results had not yet fulfilled the quality standard
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Judul: Distribution and Diversity of Ectoparasite Mites on Geckos in Indonesia
Abstrak: Data on the diversity and dispersal of parasitic mites on house geckos in Indonesia are very scarce. In this work, the distribution and diversity of mites living on three species of house geckos, namely Cosymbotus platyurus, Hemidactylus frenatus, and H. garnotii collected throughout Indonesia, has been elaborated. Geckos and mites were captured and immediately preserved in 70% ethanol. Whole mount of the mites was prepared by clearing in lactophenol followed by mounting on polyvinyl lactophenol solutions. The SEM preparation was conducted to examine the detail morphological characters of the mites. The results showed that among 448 individuals of geckos, 221 geckos were infected by Geckobia mites. Prevalences of C. platyurus, H. frenatus, and H. garnotii infested by mites were 14.8%, 50.69%, and 79.6%, respectively. Three different spesies of Geckobia (G1, G2, and G3) could be differentiated; and based on similarities of their morphological characters to ones described in published literatures, Geckobia G2 is Geckobia glebosum and Geckobia G3 is Geckobia bataviensis while G1 could not be identified to the species level. The highest mean intensity of Geckobia G1 infestation was found on H. garnotii (I=7.0), G. glebosum infestation on H. frenatus (I=3.5), and G. bataviensis infestation on H. garnotii (I=11.8). In general, C. platyurus was infested by the least number of mites. Geckobia G1 were found living on the skin folds on the claws, G. glebosum were found mainly on the body and thigh, and G. bataviensis were found on almost all parts of the host’s body. Geckobia mites are distributed randomly throughout Indonesian Archipelago, following the pattern of distribution of their hosts. So it is concluded that Geckobia G1, G. glebosum, and G. bataviensis are sympatric.
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