Penurunan kandungan biological oksygen demand (BOD) chemical oksygen demand (COD), phosphat dan amoniak limbah cair tahu metode rotating biological contractors lokal :: Indikator biologis ikan

FAHRI, Sukmal, Dr.dr. Adi Heru Sutomo, M.Sc.DCN.DLSHTM

2002 | Tesis | S2 Ilmu Kesehatan Kerja

Penelitian ini bertujuan untuk mengetahui apakah ada penurunan BOD, COD, PO₄ dan NH₃ limbah cair tahu setelah diolah dengan Rotating Biological Contactors (RBC) lokal, sebagai unit pengolahan limbah secara biologis. Penelitian ini dilatarbelakangi pentingnya mengolah limbah cair tahu agar tidak menimbulkan dampak negatif terhadap lingkungan. Jenis penelitian ini adalah eksperimen dengan rancangan one group pre-test design. Sebelum penelitian dilaksanakan dilakukan aklimasi. Hasil penelitian menunjukkan bahwa limbah cair tahu setelah dilakukan pengolahan terdapat penurunan antara variasi waktu tinggal yang berbeda. Berdasarkan uji statistik penurunan yang terbesar terjadi pada variasi waktu tinggal 6 jam, rerata penurunan BOD 89%, COD 89%, PO₄ 85% dan NH₃ 25%. Penurunan BOD dan COD diakibatkan bakteri yang berasal dari oksidasi senyawa organik dalam limbah cair tahu diuraikan oleh mikroorganisme menjadi karbon dioksida dan amoniak untuk pembentukan sel baru. Penurunan phosphat diakibatkan bakteri menggunakan bahan organik sebagai bahan makanan dan amoniak turun karena kemampuan mikroorganisme bekerja mendegradasi amonia menjadi nitrit dan nitrat. Sedangkan rendahnya kematian ikan terbanyak pada waktu tinggal limbah cair tahu 1,5 jam dan 3 jam, ha1 ini diakibatkan limbah cair tahu belum memenuhi standard Baku Mutu Limbah Cair. RBC yang terbuat dari ijuk mampu menurunkan kandungan BOD, COD, PO₄ dan NH₃ limbah cair tahu, kemampuan terbesar pada waktu tinggal 6 jam .

This research has such purpose to know whether there are lowering of BOD, COD, PO₄ and NH₃ in the liquid waste of soybean curd, after treatment with local Rotating with Biological Contactors (RBC) as a biologically waste treatment unit, this research has a background about the important of soybean liquid waste treatment in order not to emerging negatif impact to environment, the type of this research is experiment with one group pre test design plan, before the research had performed, it was perform acclimation. The research result shows that soybean curd liquid waste after treatment had lowering between various retention time which different, based on statistic test, the great lowering occurs at 6 hours retention time, lowering average at BOD 89%, COD 89%, PO₄ 85%, and NH₃ 25%. The lowering of BOD and COD resulted from bacteria which origin from organic compound oxidation in soybean curd liquid waste, it will be decomposed by micro-organism to carbon dioxide and ammonia for new cell establishment, the lowering of phosphate was caused by bacteria that used phosphate as food material and ammonia lowering was caused by the micro-organism ability that had worked to ammonia’s degradation to nitrite and nitrate, while, the least of nila fish death, most at the treated soybean curd waste at 1.5 and 3 hours retention time, this is caused by soybean curd waste still has not met the requirement of the liquid waste quality basic standard. The RBC which made from palm fiber had could lowered the BOD, COD, PO₄ and NH₃ contents in soybean curd liquid waste, the most capability at 6 hours time retention.

Kata Kunci : Mikrobia, biofilm, waktu tinggal, Microbe, biofilm, retention, organic and RBC