Danang Widjajanto
Sekretariat Unit Penelitian dan Pengabdian kepada Masyarakat (UP2M) Politeknik Negeri Jakarta Gedung Direktorat Lt.2, Telp.(021) 7270036 Psw. 236 Fax (021)7270034 Kampus Baru Universitas Indonesia Depok, DEPOK 16425 Email: politeknologi_pnj@yahoo.co

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Ketersediaan Air Tanah dan Karbon Organik pada Lahan Semak Belukar dan Budidaya Bawang Merah di Wilayah Tropika Kering Zainuddin, Rachmat; Widjajanto, Danang
Agroland: Jurnal Ilmu-ilmu Pertanian Vol 32 No 2 (2025): Agustus
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/agrolandnasional.v32i2.2690

Abstract

Konversi lahan semak belukar menjadi lahan budidaya intensif di daerah iklim kering tropika memengaruhi dinamika sifat fisik dan kimia tanah. Penelitian ini bertujuan untuk menganalisis perbedaan ketersediaan air tanah dan kandungan karbon organik pada dua jenis penggunaan lahan, yaitu semak belukar dan bawang merah. Sebanyak 21 sampel tanah dikumpulkan untuk dianalisis sifat fisik, seperti bobot isi, konduktivitas hidraulik jenuh, kadar air kapasitas lapang, dan kimia seperti kapasitas tukar kation (KTK) dan karbon organik. Hasil penelitian menunjukkan bahwa lahan semak belukar memiliki nilai ketersediaan air dan kandungan C-organik yang lebih tinggi dibandingkan lahan budidaya. Hubungan bobot isi tanah dengan air tersedia dan konduktivitas hidraulik mengikuti pola kuadratik (R² = 0,72 dan R² = 0,62), sementara hubungan antara C-organik dan KTK menunjukkan korelasi sangat kuat (R² = 0,78). Sebaliknya, tekstur tanah tidak menunjukkan hubungan yang berarti terhadap perilaku air dan KTK. Penurunan kualitas tanah akibat konversi lahan dapat ditekan melalui peningkatan kandungan bahan organik dan praktik konservasi. Hasil penelitian ini penting digunakan sebagai dasar pengetahuan pengelolaan tanah berkelanjutan di wilayah tropika kering.
PENURUNAN TINGKAT KEMATIAN IKAN GURAMI MELALUI PENURUNAN KEKERUHAN AIR KOLAM DENGAN PROSES ELEKTROKOAGULASI   Widjajanto, Danang; Saepudin, Endang
Jurnal Pepadu Vol 6 No 3 (2025): Jurnal Pepadu
Publisher : Universitas Mataram

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29303/pepadu.v6i3.7928

Abstract

The turbidity of the water used for cultivating gourami fish by the Mina Lestari Fish Farmers group reaches 68 NTU and oxygen solubility is about 2.5 mg/L, while the maximum turbidity permitted for fish farming is 50 NTU and oxygen solubility more than 5 mg/L. Insufficient oxygen can cause the death of fish. To reduce water turbidity can be treating water using electrocoagulation. This community service activity aims to implement aelectrocoagulation process to reduce water turbidity, thereby increasing dissolved oxygen levels and reducing gourami mortality in RW 05, Duren Mekar, Depok. The methods used include site surveys, problem identification, partner coordination, program outreach, water reservoir for electrocoagulation process construction, coagulant producer construction, elctrocoagulation processing and evaluation. The electrocoagulation water reservoir for electrocoagulation process is made from concrete with 3m long, 1.5 m wide, and 1.2 m high. It is equipped with one 4-inch PVC pipe for the inlet and three 3-inch PVC pipes for the outlet. The electrocoagulation process is carried out by flowing 5 liters per minute of coagulant from coagulant storage to the water in reservoir. The electrocoagulation process was able to reduce water turbidity from 68 NTU to 43 NTU and increase dissolved oxygen from 2.5 mg/L to 5.6 mg/L as well as reduce the gourami fish deaths from 20 to 5 from a cultivation of 100 fish for 5 months. The conclusion is that the electrocoagulation process of pond water is able to produce water with turbidity that meets the requirements for cultivating gourami fish.
Pengaruh Komposisi Media Tanam Terhadap Sifat Fisika Tanah dan Pertumbuhan Bibit Gaharu (Aquilaria malaccensis) Monde, Anthon; Rahman, Abdul; Widjajanto, Danang; Somba, Bunga Elim; Frahastuti, Frahastuti
Agroland: Jurnal Ilmu-ilmu Pertanian Vol 31 No 2 (2024): Agustus
Publisher : Universitas Tadulako

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/agrolandnasional.v31i2.2222

Abstract

Gaharu merupakan komoditas hasil hutan non kayu yang bernilai komersial tinggi. Untuk mendukung tersedianya bahan tanam dalam upaya pembudidayaan tanaman Gaharu berkualitas, maka salah satu upaya dalam penyedian bibit perlu didukung oleh tersedianya media tanam bibit yang baik dan tepat Penelitian ini bertujuan untuk mengetahui pengaruh komposisi media tanam terhadap sifat fisika tanah dan pertumbuhan bibit gaharu. Penelitian ini dilaksanakan di Persemaian BPDASHL di Kampus Universitas Tadulako Palu. Penelitian dimulai Februari sampai Juni 2023. Penelitian ditata dan dianalisis dengan Rancangan Acak Kelompok (RAK), dengan perlakuan yang dicobakan adalah: M1 = tanah, sekam padi bakar, pupuk kandang kambing 1:0:0 v/v; M2 = dengan perbandingan 1:1,25:0,25 v/v; M3 = 1:1,5:0,5 v/v; M4 = 1:1,75:0,75 v/v; dan M5 = 1:2:1 v/v. dengan ulangan 4 kali. Pengamatan yaitu pertumbuhan tinggi tanaman, jumlah daun, berat kering tanaman, bobot isi tanah, porositas tanah dan kadar air kapasitas lapang. Hasil analisis menunjukkan perlakuan M3= 1:1,5:0,5 v/v, meningkatkan pertambahan tinggi tanaman hingga 27,47 cm, jumlah daun 12,33 helai, dan berat kering tanaman 5,13 g. Analisis sifat fisika tanah diperoleh bobot isi tanah perlakuan kontrol dengan kriteria berat (1,65 g/cm3) dan semakin tinggi dosis arang sekam maka bobot isi tanah menurun (M5 = 0,88 g/cm3), sebaliknya porositas tanah semakin meningkat (M5 = 66,47%), peningkatan dosis pupuk kandang meningkatkan kadar air kapasitas lapang tanah.
Effect of Changes Turbidity on Oxygen Solubility in Fish Pond Water Electrocoagulation Process Sutanto, Sutanto; Supriyanto, Toto; Widjajanto, Danang
Fluida Vol. 16 No. sp1 (2023): FLUIDA x IRWNS Special Edition
Publisher : Department of Chemical Engineering, Politeknik Negeri Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35313/fluida.v16isp1.5596

Abstract

The water used for fish farming by the Mina Lestari is very dirty, because many soil particles are dissolved in water. The water with high dirty in generally has very high turbidity. So that oxygen is difficult to dissolve in water and is not sufficient for fish life. So many fish die, due to insufficient oxygen for breathing. To reduce water turbidity is treated by electrocoagulation process combined with the aeration process. The aim of the research was to study the effect of changes in turbidity on dissolved oxygen in water. The study began by measuring the turbidity using a turbidimeter and dissolved oxygen using a DO meter. Furthermore, pour 10 liters of water into the electrocoagulation process tank. The electrocoagulation was carried out at 12 volt or 0,3 ampere for 10 minutes. The process was stopped, then the water flowed into the settling tank and left for 30 minutes to precipitate of the dirt. The water flowed into a holding tank and followed aeration process by flowing air at a rate of 500 cc per minute for 30 minutes. Then followed measuring turbidity by turbidimeter and dissolved oxygen by DO meter. Subsequent studies were carried out using the same procedure with an interval of 10 minutes processing time for electrocoagulation process. The results showed that an increase in processing time can reduce water turbidity from 68 NTU to 45 NTU or 33.82% and increase dissolved oxygen from 2.8 mg/L to 5.3 mg/L or 89.29% at 50 minutes processing.