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The methods of microbial cells preservation were already known by liquid drying, freeze-drying, and freezing. Those methods could preserve bacteria cells in a long period of time but its survivability was relatively low and used relatively high energy during preservation. Immobilization was known as entrapping, attaching or encapsulating bacterial cells in a suitable matrix. This research was conducted to know the suitability of zeolite as immobilization carrier and also as preservation matrix of two halophilic archaea Haloferax chudinovii and Haloferax lucentense. Variable of this research was the type of the carrier which was raw zeolite, 110oC and 300oC heat-activated zeolite carrier, parameters measured in this study was physical and chemical of zeolite such as chemical content, Si/Al ratio, surface area and pore volume, and biochemical assay, bacterial cells numbers after immobilization and bacterial cells after preservation as bacterial response to the immobilization and preservation. Heat activation was significantly affecting the chemical composition, carrier surface area, and pore volume. Highest surface area, pore volume, and Si/Al ratio were obtained in 110oC pretreated zeolite followed by 300oC pretreated zeolite. The bacterial cells obtained after immobilization process was 1,8x107 cfu/g, 3,0 x 107 cfu/g, and 2,1x107 for raw zeolite, 110oC pretreated zeolite and 300oC zeolite respectively. After 4 months preservation, the slight reduction of the bacterial cells was observed. Immobilization halophilic archaeae using zeolite as carrier was proven as low cost and effective preservation method due to relatively simple process and unspecific preservation temperature requirements.

Exposure to volatile organic compounds (VOCs), such as toluene and BTEX gas, may cause severe impacts on the environment and long-term health problems for the workers. Industry must place this issue as a priority in supporting occupational health and efforts to minimize the environmental effects. However, many industries still have not paid more attention to degrading their industrial waste containing these compounds. Several studies on VOCs degradation in liquid and aerial media were developed in line with the rapid progress of nanomaterial technology. In this work, we have successfully synthesized TiO2/Ti Net nanotubes thin film resulted from anodization of Ti plate at 25 V vs Ag pseudo-reference electrode for eight hours and physically characterized by SEM/EDX and XRD. The activity test of photocatalysis was performed to determine the TiO2/Ti Net Nanotube's performance to degrade toluene steam and BTEX standard gas. Under the optimum experimental condition, the results showed that approximately 70% of toluene and 60% of BTEX standard gas were degraded in 120 min under the optimum experimental condition. The gas reactor generated approximately 400 ppm CO2 as a byproduct.

Pumice is known as a low-cost material with a porous structure, has the potential as an adsorbent to remove various kinds of pollutant compounds. The abundance of pumice is found in Sungai Pasak area and it never been utilized. This study was performed to see the ability of Sungai Pasak pumice as an adsorbent for ammonium removal in water along with its ability to be regenerated. The study was carried out triplo in batches to obtain optimum adsorption conditions which were then used in desorption experiments using HCl 0.1 M agent for regeneration process. The optimum conditions obtained: adsorbate pH 6, adsorbent dose 0.3 g/l, contact time 30 minutes, adsorbent diameter 63 µm and adsorbate concentration 4 mg/l. The results showed that pumice has ability to remove ammonium with adsorption capacity at optimum conditions were 47.06% and 6.27 mg/g with Freundlich's isotherm equation (R2=0.997). Acid agents are able to adsorb ammonium from pumice with an average desorption percentage 88.89% after 2 times of reuse, proving that acidic agents are able to regenerate pumice adsorbents so they can be reused. The potential for adsorption and regeneration of the Sungai Pasak pumice can be utilized to treat water with ammonium such as groundwater and waste water.

Jewelry industry wastewater contains heavy metals, organic chemicals, suspended solids, and anions which tend to be toxic to humans and aquatic biota. This study has shown that the integration of chemical, physical, and biological treatment is suitable for these characteristics, with its adaptivity to land limitations and easy operation. The electrocoagulation unit had a capacity of 1.5 m3 and a filtration unit of 250 L for chemical and physical processes, while the constructed wetland (14 m3) was for biological one. The equalization unit collected wastewater from the mold-making process (3 m3/day), chrome plating (8 m3/day), gemstone washing (1 m3/day), gold laundry (0.25 m3/day), silver laundry (0.3 m3/day), and refining silver/gold (0.005 m3/day). The wastewater was then neutralized into pH range 6–8, pumped into the electrocoagulation unit, filtered by a silica–carbon filter, and treated in the wetland before being discharged into the environment. This technology was able to reduce TSS (71%), COD (91%), Cu (95%), CN (96%), and oil & grease (71%). The quality of treated wastewater has met the local water quality standards, thus obtaining a wastewater treatment permit (IPLC) from the local government. This technology was cheaper and convenient because the electrocoagulation process time was short (60 min).

A rapid catalytic process with low energy requirements gives catalytic ozone the potential to treat industrial textile wastewater in a full-scale application. However, until today, this catalytic ozone technology remains energy-consuming and, as a consequence, expensive. Thus, to overcome the bottleneck related to energy needs, this research aims to design a continuous mode reactor design to treat industrial textile wastewater through catalytic ozone, which integrated solar power plants (PLTS). In this work, a constant mode reactor design combined with an integrated sensor is investigated for industrial textile wastewater. Combining the autonomous and continuous removal of the impurities makes this continuous mode reactor excellent for the treated wastewater on the industrial textile scale.

Penelitian ini bertujuan untuk menganalisis kemampuan regenerasi batu apung Sungai Pasak Pariaman sebagai adsorben untuk menyisihkan amonium dalam air tanah. Regenerasi dilakukan dengan proses desorpsi menggunakan agen desorpsi asam, netral dan basa berupa HCl 0,1M, akuades dan NaOH 0,1M. Hasil penelitian menggunakan larutan artifisial dengan konsentrasi amonium 4 mg/l menunjukkan bahwa HCl 0,1M adalah agen desorpsi terbaik dengan efisiensi penyisihan dan kapasitas adsorpsi tertinggi, yaitu reuse I 47,515% dan 6,335 mg/g serta reuse II 45,133% dan 6,018 mg/g. Agen HCl 0,1M juga memberikan % desorpsi tertinggi pada proses desorpsi I dan II, yaitu 89,734% dan 88,048%. Penerapan agen HCl 0,1M sebagai agen desorpsi pada sampel air tanah dengan konsentrasi amonium 1,655 mg/l pada pH optimum dengan efisiensi penyisihan saat reuse I dan II adalah 34,243% dan 33,441% serta kapasitas adsorpsi saat reuse I dan II adalah 1,889 mg/g dan 1,845 mg/g, sementara pada pH sampel diperoleh efisiensi penyisihan saat reuse I dan II adalah 23,784% dan 23,351% serta kapasitas adsorpsi saat reuse I dan II adalah 1,312 mg/g dan 1,288 mg/g. Dari hasil penelitian didapatkan bahwa batu apung Sungai Pasak Pariaman dapat diregenerasi hingga 2x reuse, dimana diperoleh nilai efisiensi penyisihan dan kapasitas adsorpsi masih dalam rentang nilai adsorpsi awal. Kata kunci: adsorpsi, agen desorpsi, amonium, batu apung, desorpsi, regenerasi