Mitigasi dampak limbah cair pengolahan batu apung :: Studi kasus air buangan PT. Surya Indah Cakratama Nusa Tenggara Barat

SAIDA, Suranto, Prof.Ir. Sukandarrumidi, MSc.,Ph.D

2004 | Tesis | S2 Teknik Geologi (Magister Geologi Pertambangan)

PT. Surya Indah Cakratama adalah satu-satunya perusahaan yang mengolah batuapung di Kabupaten Lombok Tengah, Propinsi Nusa Tenggara Barat, Indonesia. Perusahaan ini mulai beroperasi pada Agustus 2002 sampai sekarang. Batuapung dipasarkan ke propinsi lain dan keluar negeri. Pengolahan batuapung yang dilakukan menghasilkan limbah cair yang dibuang ke Sungai Babak. Limbah cair hasil pengolahan batuapung menyebabkan pencemaran fisik berupa perubahan warna sungai menjadi kekuning-kuningan dan berlumpur. Hal ini disebabkan tidak adanya instalasi pengolahan limbah cair oleh perusahaan. Pemeriksaan awal limbah cair di laboratorium menunjukkan kadar residu tersuspensi 7759 mg/lt. Penelitian dilakukan dengan menggunakan metode pengendapan dengan bak clarifier dan ijuk sebagai penyaring untuk mengurangi kadar residu tersuspensi. Hasil percobaan menunjukkan kadar residu tersuspensi pada variasi tanpa ijuk 7748,05 mg/lt, variasi 1 lembar ijuk 6988,33 mg/lt, variasi 3 lembar ijuk 3990,67 mg/lt dan pada variasi 5 lembar ijuk 88,67 mg/lt. Hasil penelitian menunjukkan penggunaan bak pengendapan dan ijuk sebagai penyaring dapat dijadikan alternatif mitigasi dampak limbah cair pengolahan batuapung. Selain itu, diperlukan “good will” pemerintah daerah untuk meningkatkan pengawasan pelaksanaan dokumen UKL/UPL perusahaan tersebut.

Surya Indah Cakratama Ltd. is a single industry processing of pumice in Lombok Tengah District, West Nusa Tenggara Province, Indonesia. This Company started to operate on August 2002 until now. Pumice has been marketed to other province and overseas. Processing of pumice yield liquid waste which thrown to Babak River. The liquid waste of pumice processing has caused to physical contamination of water river of Babak. The colour of river water changed into yellowish and muddy. It was caused that company does not has the liquid waste processing unit. Early observation for liquid waste in laboratory showed that suspended solid were 7759 Mg/lt. Research used a clarifier sedimentation basin and fibre of palmtree as a filter in order to reduce suspended solid of liquid waste. The result of experiment showed number of rate suspended solid at variation without fibre of palmtree were 7748,05 Mg/lt, variation one sheet fibre of palmtree were 6988,33 Mg/lt, variation three sheets fibre of palmtree were 3990,67 Mg/lt and at variation five sheets fibre of palmtree were 88,67 Mg/lt. The result of research showed that using the clarifier sedimentation basin and filter by palmtree fibre can be used as an alternative mitigation of impact liquid waste of pumice processing. On other hand, the role of government was needed in environmental requiring a ‘good will’ of local government to improve controlling the company for excution of the environmental management and the environmental control to the company.

Kata Kunci : Geomorfologi,Penambangan Batu Apung,Dampak Limbah Cair, Mitigation, suspended solid, fibre of palmtree