Analisis Risiko Kesehatan Pajanan Pm10 pada Pekerja Industri Readymix PT. X Plant Kebon Nanas Jakarta Timur

Pajanan agen risiko kesehatan dari lingkungan kerja berdampak pada timbulnya risiko penyakit akibat kerja sehingga pekerja menjadi tidak produktif. Oleh karena itu, untuk mengestimasi risiko kesehatan dari pajanan agen risiko berupa PM10 dari lingkungan kerja, sebuah penelitian analisis risiko telah dilakukan pada 70 orang pekerja industri readymix PT. X Plant Kebon Nanas. Risiko kesehatan akibat pajanan PM10 dihitung dengan membandingkan asupan PM10 dengan dosis referensi. Konsentrasi PM10 diukur pada 6 titik dengan konsentrasi rata-ratayaitu 0,289 mg/m3.Perhitungan risiko yang diterima saat ini (realtime) terdapat 21,4% pekerja yang berada dalam kategori berisiko. Hasil estimasi risiko yang diterima seumur hidup (lifetime) hanya 2 orang pekerja yang dalam kategori tidak berisiko. Manajemen risiko yang dapat dilakukan adalah dengan menurunkan konsentrasi menjadi 0,08 mg/m3. Dengan konsentrasi tersebut pekerja diestimasikan aman bekerja selama 11 jam per hari dan 362 hari per tahun

Characterization of bio fouling in membrane bioreactor

Biofouling that formed in membrane bioreactor impacted the performance of membrane bioreactor. This study investigates the impact of biofouling in terms of the concentration of soluble microbial product on the characteristics and the fouling potential of lab scale membrane bioreactor. The performance of membrane bioreactor reduced significantly with reduction in the initial flux, and dramatic transformation in surface morphology and roughness occurred. The small size of residual organic substances further facilitates membrane fouling by pore blockage. It can be concluded that SMP influence fouling under certain condition of membrane bioreactor

Determination of potential level of Indonesian rhizomes as an antioxidant based on phenolic compound and antioxidant activity

Abstract This study was aimed to determined of the potential level of rhizomes from Indonesia as an antioxidant. The calculated of potential level rhizome based on the total phenolic compound and antioxidant activity.The phenolic compound was determined using the Folin-Ciocalteau method, antioxidant activity was determined by the DPPH (1-diphenyl-2-picrylhydrazyl) method expressed in IC50. Potential level was calculated by comparing the value of total phenolic compound and antioxidant activity. The results showed that red ginger ( Zingiber officinale var Rubrum) had the highest a phenolic and flavonoid content. Therefore that red ginger, Zingiber officinale var Rubrum is the most potential level as an antioxidant followed by Curcuma longa, Curcuma zedoaria, Curcuma zanthorrhiza, and Curcuma aeruginosa Roxb.</jats:p

Start-up strategy of a thermophilic upflow anaerobic filter for treating palm oil mill effluent

A thermophilic upflow anaerobic filter treating palm oil mill effluent was started up in a dm3 laboratory-scale reactor. The reactor was operated continuously at a thermophilic temperature 55°C for over 10 weeks with increased loadings of chemical oxygen demand (COD) of 0.1-0.5 kg COD m-3 day-1. The start-up strategy was accomplished over sequential increase of temperature of 0.5-1°C per day in which the mesophilic bacterial seed was gradually acclimatized to the thermophilic conditions. At these conditions, the reactor showed satisfactory results in organic removal efficiency (up to 97 and 94% for biological oxygen demand (BOD) and COD, respectively) and biogas production rates of 26.8-116.1 m-3 day-1 for organic loading rates varied from an initial value of 5.8 to 10.9 kg COD m-3 day-1. The thermophilic anaerobic filter was stable in terms of acidity and alkalinity. In this study, the start-up process of the thermophilic reactor was accomplished in a relatively short time and was stable under mesophilic conditions

Bioenergy II: Production of Biodegradable Lubricant from Jatropha curcas and Trimethylolpropane

Jatropha oil has good potential as the renewable energy as well as lubricant feedstock. Production of Jatropha oil based lubricant was performed via a two-step process; (i) the transesterification of Jatropha oil to produce Jatropha Methyl Ester (JME) and, (ii) transesterification of JME with trimethylolpropane (TMP) under the presence of alkaline based catalyst. Transesterification of Jatropha oil was carried out at 65°C for 1 hour by using 1-2% NaOH as catalyst. While, the transesterification of JME was carried out at 150°C with pressure kept at 10mbar. The conversion of JME to jatropha biolubricant was found to be more than 80%. However, to maintain forward reaction, the amount of JME was maintained at about 4:1 ratios to TMP. The basic properties of jatropha biolubricant are found comparable to other plant based biolubricant.</jats:p

Effects of SRT and HRT on Treatment Performance of MBR and Membrane Fouling

40L of hollow fiber membrane bioreactor with solids retention times (SRT) of 30, 15 and 4 days were setup for treating synthetic wastewater at hydraulic retention times (HRT) of 12, 8 and 4 hours. The objectives of the study were to investigate the effects of SRT and HRT on membrane fouling. A comparative analysis was carried out for physiochemical quality parameters (turbidity, suspended solids, COD, NH3-N and PO43-). Scanning electron microscopy (SEM), energy diffusive X-ray (EDX) analyzer and particle size distribution (PSD) were used to characterize the membrane fouling properties. The influence of SRT on the quality of effluent, activated sludge quality, and membrane fouling were also correlated. Lower membrane fouling and slower rise in trans-membrane pressure (TMP) were noticed at the longest SRT and HRT of 30d and 12h, respectively. Increasing SRT results in noticeable reduction of dissolved organic matters. The best removal efficiencies of COD, TSS, NH3-N and PO43- were 93%, 98%, 80% and 30% respectively. The high HRT with shorter SRT induced faster fouling rate. The main fouling resistance was cake layer. The most severe membrane fouling was observed at SRT and HRT of 4 and 12, respectively with thickness cake layer of 17mm as reflected by higher TMP, lower effluent removal and thick sludge cake layer