Judul: Waktu Tinggal Hidraulik dan Resirkulasi Optimum Biofiltrasi dengan Media Bioball untuk Peningkatan Kualitas Air Baku
Abstrak: Pengembangan teknologi proses pengolahan air dan air limbah menjadi semakin menarik dengan terus teridentifikasinya berbagai kontaminan, pertumbuhan penduduk dan industri yang cepat, serta berkurangnya ketersediaan sumber air baku. Satu alternatif proses pengolahan air baku adalah biofiltrasi oleh aktivitas biologi dari biofilm. Penelitian ini bertujuan untuk memerbaiki kualitas air baku dengan biofiltrasi menggunakan bioball, mengukur tingkat kinerja optimasi proses biofiltrasi, serta mengetahui pengaruh perlakuan proses resirkulasi dan waktu tinggal hidraulik (WTH) optimal pada peningkatan kualitas air baku pada pengoperasian bioball biofilter skala reaktor 1000 L. Tahapan penelitian yaitu perancangan reaktor, aklimatisasi, dan uji optimasi. Optimasi pada penelitian ini dilakukan dengan menggunakan Response Surface Method (RSM) dengan rancangan central composite design/CCD. Proses aklimatisasi dicapai selama 35 hari. Solusi optimasi yang direkomendasikan yaitu WTH 2.41 jam dan resirkulasi 0.3 (Qr/Qi). Hasil prediksi titik optimum pada penyisihan parameter-parameter dari COD, KMnO4, ammonium, Total Suspended Solid (TSS) dan warna secara berturut-turut sebesar 62 %, 58%, 71%, 50%, dan 53%.
Keyword: air baku, bioball, biofiltrasi, resirkulasi, WTH optimum

Judul: Aplikasi Biofiltrasi Menggunakan Media Bio-ball untuk Menurunkan Polutan Air Baku
Abstrak: Pencemaran sumber air baku terus berlangsung akibat dari aktivitas manusia dalam berbagai bidang. Solusi efektif untuk mengurangi masalah krusial tersebut yaitu dengan teknologi proses biofiltrasi. Penelitian ini dilakukan untuk mengetahui hubungan waktu tinggal hidrolik (WTH) dan pengaruh mode arah aliran air (upflow dan downflow) di dalam bioreaktor dengan media bio-ball terhadap penurunan polutan air baku. Tahapan penelitian terdiri atas persiapan, aklimatisasi, dan pengujian pengaruh WTH terhadap efektivitas penyisihan polutan. Biofiltrasi yang dioperasikan dengan mode upflow mampu mengeliminasi TSS sebesar 41.01%, kekeruhan 48.06%, warna 46.47%, bahan organik (COD) 47,12%, amonium 35.87%, dan meningkatkan nitrat sebesar 30.13%. Sementara biofiltrasi yang operasikan dengan downflow mampu mengeliminasi TSS 45.13%, kekeruhan 50.85%, warna 55.13%, COD 51.77%, amonium 36.31%, dan meningkatkan nitrat sebesar 28.09%. Penyisihan polutan dalam air baku semakin meningkat dengan bertambahnya waktu tinggal dalam bioreaktor. Secara umum, efisiensi penyisihan parameter polutan biofiltrasi downflow lebih baik dibandingkan dengan reaktor upflow.
Keyword: Biofilter, bio-ball, downflow, upflow, pre-treatment of raw water, Raw water, Aklimatisasi, Waktu tinggal hidrolik, Biofilm

Judul: Systematics of Desmos (Annonaceae) in Malesia
Abstrak: Desmos is a woody climbing genus of Annonaceae which has been widely used as traditional medicine in several countries such as China, Indo-China, Thailand, and Peninsular Malaysia to treat dysentery, vertigo, fever, and postpartum. Phylogenetic studies on Desmos showed a close relationship between Desmos and Dasymaschalon. They share similar moniliform monocarpic fruits, but their flowers are different. It has been debated among Annonaceae researchers whether both genera should be treated as the same or distinct genus. Therefore, investigation on the taxonomic delimitation of Desmos species and Dasymaschalon will be necessary. Plastid genome (plastome) identification, leaf epidermal section of Desmos species and Dasymaschalon species, a taxonomic revision of Desmos in Malesia using morphological data, the spatial distribution of Desmos species in Malesia, and morphological and genetic variation in Desmos chinensis population using ISSR marker were used to investigate taxonomic delimitation of Desmos. Plastome study of Desmos chinensis and Dasymaschalon dasymaschalum was carried out to determine the origin, evolution, phylogenomics, and identify marker candidates for Desmos and Dasymaschalon or with other genera in Annonaceae. We discovered that the plastome of Desmos chinensis was circular with the size of 167,677 bp (smaller than Dasymaschalon dasymaschalum), consist of 111 genes, including 78 protein-coding genes, 29 transfer RNAs, and 4 ribosomal RNAs. The plastome showed a typical quadripartite structure, i.e., large single copy (LSC), small single copy (SSC), and two inverted repeats (IRs). The plastome of Dasymaschalon dasymaschalum was 191,488 bp in length, which also exhibited a typical quadripartite structure (LSC, SSC, and two IRs). Desmos chinensis and Dasymaschalon dasymaschalum showed different copies of accD, ndhD, ndhF, rps18, and ycf2. Protein coding genes of rpoB, rpoC1, rbcL, matK, rpl32, infA, and rpl36 were identified based on nucleotide diversity, sequence variability, and parsimony-informative sites. The genes are defined as molecular marker candidates of plastome for phylogenetic, barcoding, and population genetic research. We predicted that Desmos chinensis and Dasymaschalon dasymaschalum separated at ca. 64 million years ago during the Paleocene. Leaf anatomical feature study was carried to support the taxonomic delimitation of interspecific Desmos and intergeneric of Desmos and Dasymaschalon. Leaf anatomy in the paradermal section of 20 taxa (12 species of Desmos, eight species of Dasymaschalon) have been carried out. According to the leaf epidermal section, Desmos and Dasymaschalon are two distinct genera mainly distinguished based on the anticlinal wall undulation of epidermal cells and supported by variation of the crystal type and size. The anticlinal wall undulation of Desmos was almost straight to slightly wavy and never sinuous; meanwhile, Dasymaschalon varies from almost straight to deeply sinusoid. The crystals of Desmos consist of rhombohedral, druse type A, and druse type B crystals, whereas Dasymaschalon has prism, druse type A, druse type B, and druse type C crystals. The recent taxonomic revision using the morphological data was mainly based on the examination of about 1374 specimens from BO, L, WAN, ANDA, SING, SAN, K, P, HUH herbaria. The Desmos species in Malesia consists of eight species: D. acutus, D. chinensis, D. chryseus, D. dunalii, D. pedunculosus, D. subbiglandulosus, two new records: D. lawii and D. macrocarpus, and one
Keyword: Dasymaschalon, Desmoid clade, Magnoliid, plastid genome, phylogenomics analysis