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The fibrous shape of catalysts offers a higher surface area and more accessible active sites than the extrudate and granules counterparts. While entanglement of the fibrous structure may form a self-standing material, its low mass density and brittle nature of catalysts hinder it from practical application, hence, sturdy support is required. This study aims to fabricate a fibrous silica-bound titanium dioxide photocatalyst on top of a fiberglass surface mat (FSM) support using a blow-spinning (BS) technique. The spinning volume varied between 1 and 5 mL while maintaining the Ti/Si mass ratio at 40 and 60%. The BS produced long and continuous fiber of polyvinylpyrrolidone (PVP)-silica-titania composite on top of the FSM for both 40% and 60% composites. Calcination of the composite fiber at 450 °C/2h burnt off the PVP leaving behind the silica-titania composite. After calcination, the two samples displayed different morphology. The silica-titania composite in the 40% Ti/Si sample was found to be deeply penetrated the FSM support and formed a rigid composite. The fibrous structure of the silica-titania, however, collapsed. On the other hand, the silica-titania composite in the 60% Ti/Si sample sits on top of the FSM and partially retained the fibrous shape. Despite the fiber structural collapse and variation in the silica-titania location in the composite, it retained a high photocatalytic activity against methyl orange, methylene blue, and a combination of both dyes. The FSM had a high affinity to adsorb MB and MB removal is due to a combination of adsorption and photodegradation. MO removal, on the other hand mainly due to photodegradation. Higher TiO2 content and spinning volume are beneficial for MO removal but not for MB removal. [ABSTRACT FROM AUTHOR]

Mocaf (modified cassava flour) is flour made from cassava through a microbial fermentation process. Mocaf wastewater has high pollutants, so it needs to be processed before being discharged into the environment. This study aims to treat wastewater of mocaf using a hybrid method: electrocoagulation combined with adsorption. The electrocoagulation process used solar cell electric current. The electrode used aluminium with a distance of 3 cm. The time process of electrocoagulation is 30 minutes. The adsorption process used activated carbon commercials. The concentration of the adsorbent is 3, 5, and 10 g/L. The time process of adsorption is 9 hours with sampling times of 1, 3, 6, and 9 hours. The analysis carried are COD, TDS, TSS, pH. The hybrid method of electrocoagulation and adsorption using activated carbon commercial adsorbent had an efficiency of COD removal up to 47,27% (3863 mg/L), optimum pH of wastewater mocaf 8,295; TDS 846 mg/L; TSS 500 mg/L on concentration adsorbent ten g/L and 6 hours adsorption time. The hybrid method of electrocoagulation and adsorption could reduce pollutants in mocaf wastewater and the result under the quality standard of pH, TDS, and TSS. [ABSTRACT FROM AUTHOR]

TiO2−coated glass has been successfully prepared for practical water treatment application under UV-light irradiation. This work demonstrated the immobilized TiO2 powder on glass support using the dip-and spray coating method. The number of coating processes was varied to studies their effect on photocatalytic efficiency. The annealed process at high temperature was conducted to improve the adhesion of TiO2 powder to the glass substrates. Surface observation of the coating TiO2 showed that the dip-coating method has a better result than the spray coating method. All the glass surfaces can be covered by TiO2 perfectly, and this process did not affect the photocatalytic activity. Almost 100% of 4 ppm Rhodamine B could be decomposed by immobilized TiO2. The current research is potentially used as a standard method to immobilize TiO2 on the glass substrate on a larger scale in the future. Accordingly, separating the process between TiO2 and liquid-based solution after the photocatalytic process is more straightforward. [ABSTRACT FROM AUTHOR]

The cadmium discharge is one of the most watched issues in an environment and its removal either in waste-stream or environment requires high cost and energy consumption. The adsorption is an applicable process mostly used in any waste-water treatment process to date. The natural biomass offers a candidacy to be converted as environmentally friendly bio-sorbent for cadmium and lead however the study on marine algal biomass modification as biosorbent to remove heavy metals is limited. This study was aimed to synthesize and characterize biosorbent derived from marine algal biomass, Chlorella vulgaris-supported Zero Valent Iron (ZVI). This study was applying a sequence of modification, i.e.: alkali activation using NaOH followed by wet reduction to generate biomass-supported ZVI. Thus, three types of biosorbents were characterized and evaluated to remove Cd and Pb. The characterization of biosorbent was carried out using FTIR and the measurement for both Cd and Pb was conducted using FAAS. The investigation on biosorbent using FTIR exhibited several functional group consisted of mainly hydroxyl, carbonyl and amino. The Chlorella vulgaris-supported ZVI was able to remove 96% of Cd and 97% of Pb, more effective compared to NaOH activation and non-modified biomass. [ABSTRACT FROM AUTHOR]

In order to investigate the performance and cost analysis of electrocoagulation process, various electrolytes are picked out to remove Fe, color, and turbidity in peat water through batch and continuous reactors. Peat water has brownish red color, acidity, high turbidity, and a large concentration of Fe which exceed the water standard quality. Electrocoagulation is an electrochemical method for water treatment that along the anode where active coagulant as aluminum ions is released into the solution. Several kinds of electrolytes are applied, such as 0.01M NaCl p.a., 0.01M NaCl technical grade, 0.01M NH4Cl p.a., and 0.01M K2SO4 p.a. with process time up to 120 minutes. The results show that the electrocoagulation in a batch process using NH4Cl for 120 minutes obtains the highest of removal percentage of Fe, color, and turbidity, which are 90.92%, 84.93%, and 99.94%, respectively. However, according to scoring evaluation, commercial NaCl using through continuous reactor generates the outputs have fulfilled the water standard quality as well as batch condition with low-cost production about Rp 23.21/Liter, about 64.18% cheaper than without electrolytes addition, and 82.93% more inexpensive than generally chemical treatment. [ABSTRACT FROM AUTHOR]