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In the industry of textile, dyes can cause major environmental problems due to azo compounds contained as difficultly degraded material. To remove the synthetic dyes it is used Photodegradation method because of cheap and environmentally friendly. This research purposed to determine the influence of orange peel (OrPl) and OrPl - Cetyltrimethylammonium Bromide (CTAB) addition on photocatalyst semiconductor properties of ZnO and to degrade the Methylene Blue (MB). ZnO, ZnO/ OrPl, and ZnO/ OrPl -CTAB materials were characterized using FTIR, XRD, BET, SEM EDX and DR-UV. Based on FTIR results ZnO peaks were formed directly during the decomposition of zinc acetate. In addition, the absence of typical CTAB absorption indicates a complete calcination process. The characterization using XRD showed that there was no damage caused by the addition of OrPl -CTAB to ZnO. ZnO/ OrPl and ZnO/ OrPl -CTAB crystal structure formed was wurtzite with a hexagonal shape. The characterization using BET showed that OrPl -CTAB addition caused a largest surface area and pore size compared to ZnO and ZnO-OrPl. The results of characterization using DR-UV showed that the narrowest band gap energy was ZnO/ OrPl -CTAB 1:25 is 3.153 eV showing smaller band gap energy than ZnO. Characterization of DR-UV revealed that the smallest energy gap of the band was ZnO/OrPl -CTAB 1:25 at 3.153 eV, indicating a smaller band gap energy than ZnO. The characterization results showed that the material with the best character was ZnO/ OrPl -CTAB with the addition of 25 mL(1:25) Zn Acetate. In addition, ZnO/ OrPl -CTAB material was better than ZnO and ZnO/ OrPl in degrading MB. In the without UV irradiation method, the optimum conditions were obtained at 110th minutes for ZnO/ OrPl -CTAB to degrade MB by 78%, while ZnO/ OrPl and ZnO were only able to degrade by 71% and 46%, respectively at 100th minutes. Meanwhile, under UV irradiation method, the optimum condition were obtained for ZnO/ OrPl -CTAB to degrade MB at 110 minutes by 94% while ZnO/ OrPl was only 88% and ZnO 83% at 100 minutes. [ABSTRACT FROM AUTHOR]

Superabsorbent polymers, a three-dimensional cross-linked polymer, show excellent properties in retaining a large amount of water and have been widely applied in various fields. This report studied the synthesis of chitosan-strach superabsorbent by chemical crosslinking. The polymers were prepared by using 1:1 ratio of chitosan and starch in a concentration of 2% w/v with 2-25% v/v of glutaraldehyde as cross-linker. The characterization of chitosan-starch polymers was performed by using analytical tools, such as FTIR and SEM. Water absorption capacity was evaluated by swelling ability followed by the batch sorption of different 0.9% w/v salt solutions of NaCl, MgCl2, FeCl3 and synthetic urine composed of urea, NaCl, KCl, and Na3PO4. The biodegradation was evaluated by the difference mass of polymers before and after plantation in soil. The optimum polymers were obtained by using 5% of glutaraldehyde with water sorption capacity of 349.68%. The water absorbency capacity of different salts was 121.37%, 138.59%, and 165.20% for NaCl, MgCl2, FeCl3, respectively. The absorption capacity of SAP in synthetic urine, 1% w/v NaCl, 0.64% w/v Na3PO4, 0.6% w/v KCl, and 2.43% w/v urea solutions was 87.83%, 117.72%, 103,39%, 99.28%, and 91.08%, respectively. The degradation study indicated that the polymers were completely degraded in 14 days. [ABSTRACT FROM AUTHOR]

Methyl Orange (MO) is one of the dyestuffs that are often used in the textile industry. MO itself has non-biodegradable anionic properties and has the potential to cause hypersensitivity allergies, thus it potentially been dangerous, especially for aquatic environment. One of the methods which often used is photodegradation method. Photodegradation was a method that was easy to implement and relatively affordable. Additionally, dyes could be more easily decomposed into simpler components with the intention that being safer for the environment. This research aimed to degrade MO using ZnO composited with orange peel (OP) which had been modified with cetyltrimethylammonium bromide (CTAB) addition. CTAB itself served as template to increase surface area of the ZnO material, thereby increasing their photocatalytic activities. ZnO, ZnO/OP, and ZnO/OP-CTAB were characterized using FTIR, XRD, SEM-EDX, BET and DR-UV. The results showed that ZnO/OP-CTAB degraded MO more than both ZnO/OP and ZnO. It was achieved optimum condition for without UV irradiation method in 40 minutes treatment, where ZnO/OP-CTAB was able to degrade MO by 48% whereas ZnO/OP and ZnO were only by 40% and 28%, respectively. In with UV irradiation method the optimum condition was achieved for 50 minutes, which ZnO/OP-CTAB succeeded in degrading MO by 78% while ZnO/OP was 74%. This treatment gave different results for ZnO, which ZnO gave optimum performance with %removal of 40% for 40 minutes treatment. Based on the reaction kinetics, it was known that the photodegradation reaction of MO by ZnO, ZnO/OP, and ZnO/OP-CTAB followed the pseudo-second-order reaction kinetics model. [ABSTRACT FROM AUTHOR]