Penyisihan Fe, Warna, dan Kekeruhan pada Air Gambut Menggunakan Metode Elektrokoagulasi

Air gambut umumnya memiliki warna merah kecoklatan, pH asam, kekeruhan tinggi, dan logam besi tinggi yang konsentrasinya melebihi baku mutu air bersih. Elektrokoagulasi merupakan metode elektrokimia untuk pengolahan air dimana pada anoda terjadi pelepasan koagulan aktif berupa ion logam Aluminium ke dalam larutan. Tujuan penelitian ini mengetahui pengaruh waktu kontak dan jenis elektrolit pendukung terhadap penyisihan Fe, warna dan kekeruhan. Penelitian dilakukan dalam skala laboratorium dengan sistem batch dan kontinyu. Variasi yang digunakan adalah jenis elektrolit pendukung NaCl pro analisis 0,01M, NaCl teknis 0,01M, NH4Cl 0,01M dan K2SO4 0,01M serta waktu kontak 30 menit, 60 menit, 90 menit, dan 120 menit. Hasil penelitian menunjukkan bahwa proses elektrokoagulasi dengan penambahan elektrolit pendukung NH4Cl menghasilkan efisiensi terbaik dengan penyisihan Fe sebesar 90,92%, warna sebesar 84,93%, dan kekeruhan sebesar 99,94% dengan waktu pengolahan 120 menit. Aplikasi elektrokoagulasi menggunakan reaktor kontinyu dengan penambahan elektrolit pendukung NaCl teknis mampu menyisihkan warna sebesar 88,43%, kekeruhan 92,71%, dan logam Fe terlarut sebesar 91,30%. Hasil pengolahan tersebut telah memenuhi baku mutu air bersih

Shaping the growth behaviour of biofilms initiated from bacterial aggregates

Bacterial biofilms are usually assumed to originate from individual cells deposited on a surface. However, many biofilm-forming bacteria tend to aggregate in the planktonic phase so that it is possible that many natural and infectious biofilms originate wholly or partially from pre-formed cell aggregates. Here, we use agent-based computer simulations to investigate the role of pre-formed aggregates in biofilm development. Focusing on the initial shape the aggregate forms on the surface, we find that the degree of spreading of an aggregate on a surface can play an important role in determining its eventual fate during biofilm development. Specifically, initially spread aggregates perform better when competition with surrounding unaggregated bacterial cells is low, while initially rounded aggregates perform better when competition with surrounding unaggregated cells is high. These contrasting outcomes are governed by a trade-off between aggregate surface area and height. Our results provide new insight into biofilm formation and development, and reveal new factors that may be at play in the social evolution of biofilm communities

Erratum to Bacteria attachment to surfaces - AFM force spectroscopy and physicochemical analyses [J. Colloid Interf. Sci. 364 (2011) 213-218]

10.1016/j.jcis.2012.07.081Journal of Colloid and Interface Science3921470-JCIS

Bacteria attachment to surfaces - AFM force spectroscopy and physicochemical analyses

10.1016/j.jcis.2011.08.021Journal of Colloid and Interface Science3641213-218JCIS

PERANCANGAN FURNACE TEMPERATUR SEBAGAI PEMANAS SEAL TIMAH PADA SAMBUNGAN PIPA STAINLESS STEEL

Hlm. 101-10

Adhesion of B. subtilis spores and vegetative cells onto stainless steel - DLVO theories and AFM spectroscopy

10.1016/j.jcis.2013.05.031Journal of Colloid and Interface Science405233-241JCIS

Integrated treatment of submerged membrane and adsorption using dried Aphanothece sp for removing cadmium from synthetic wastewater

Water pollution from the discharge of wastewater containing toxic heavy metals such as cadmium (Cd) to the natural water bodies is one of the biggest problem affecting humanity. Different technologies such as sorption, membrane filtration etc. have been used to remove heavy metal from the polluted water. In this work, the effects of operational parameters on the ability of the submerged membrane adsorption hybrid system (SMAHS) to remove Cd2+ from synthetic wastewater using dried Aphanothece sp A15 as a suspended biosorbent was evaluated. This biomass originates from a cyanobacterium was cultivated in a photobioreactor system enriched with 15 % of CO2. The operational parameters investigated were filtration flux, biomass dosage, frequency of replacing biosorbent, and initial metal concentration. Of the various parameters, the filtration flux and the initial concentration of Cd were the most influential parameters concerning biosorption efficiency in this study. More than 95 % removal of Cd was achieved with initial Cd concentration of 4.89 mg/L at a filtration flux of 20 L/m2.h. The highest biosorption capacity (112.89 mg/g) was obtained with a flux of 60 L/m2.h.The biosorbent became saturated after 20 h of operation without biosorbent replacement. This suggests that the dried biomass of Aphanothece sp A15 has the potential to be implemented in the industrial wastewater treatment plant using SMAHS processes integrated within the CO2 bio-sequestration unit. Therefore, cadmium removal from wastewater can be coupled with the reduction of CO2 emissions from flue gas