No abstract

This research has been done to study the effect of addition of TiO2 photocatalyst in liquid waste of silver industry in Ungga Village, Kec. Praya Kab. Central Lombok on the effectiveness of photoreduction of Cu (II) ions which are catalyzed by TiO2. The photoreduction process is carried out by irradiating liquid waste containing Cu (II) ions without or with the addition of TiO2 photocatalyst powder in a closed reactor equipped with UV lamps. The photoreduction process conditions are 50 mL of silver waste containing Cu (II) with reaction time for 24 hours and a mass of TiO2 20 mg at each 10 ppm Cu (II) ion concentration. The photoreduction results are determined by the difference in the concentration of the starting Cu (II) ions with the residual Cu (II) ion concentration in the silver craft waste without or with the addition of TiO2 photocatalyst. Furthermore, the data obtained were compared to the results of photoreduction of Cu (II) ions pure TiO2 laboratory scale. The amount of metal in the mixture was determined by Atomic Absorption Spectrophotometric Method (AAS). The results showed that in silver handicraft waste containing Cu (II) ions, the addition of TiO2 can increase the effectiveness of the Cu (II) ion photoreduction from 6.57% to 33.38%, which begins with the adsorption process. The other ions cause inter-reduction competition metals so as to decrease the effectiveness of TiO2 catalysed Ti (II) ionic ferrication in silver handicrafts waste in Ungga Village Kec. Praya Kab.central Lombok

Laundry waste contains detergent which can cause water pollution because itcontains various kinds of substances that can affect various waterparameters, especially such as TDS (total dissolved solids) and TSS (totalsuspended solids). To reduce these parameters is done by the coagulationprocess which is adding moringa seed powder as coagulant. Moringa seedscan work as a coagulant because they contain an active substance, 4-alfa-4-rhamnosyloxy-benzil-isothiocyanate. The coagulation process was carried outby varying several coagulation parameters such as the size of the coagulantpowder (Al (80-100mesh) and A2 (100mesh), stirring speed (slow, medium,and fast), settling time (15, 45 and 75 minutes) and mass ratio to samplevolume (100 mg against 100, 150 and 200 mL) .The samples used in thecoagulation process were taken by grab sampling technique and thedetermination of TDS and TSS levels was carried out by the gravimetricmethod. The data showed the size of moringa seed powder coagulant, stirringspeed, settling time and coagulant mass ratio with sample volume influencethe% decrease in TDS and TSS levels, optimum conditions on coagulantpowder size> 100 mesh, moderate stirring speed, 15 minute deposition timeand coagulant mass ratio to sample volume 1: 1 ( mg / L), where% decreasein TDS is 74.07% from 270000 mg / L to 70000 mg / L and TSS of 82.14%from 56000 mg / L to 10000 mg / L.

In this study a study of the effect of TiO2 photocatalysts and Hg (II) ions in thewastewater of the silver industry in Ungga Village, Kec. PrayaKab. CentralLombok to the effectiveness of Cu (II) photoreduction which is catalyzed byTiO2. The photoreduction process is carried out by irradiating liquid wastecontaining Cu (II) and Hg (II) ions without or by adding TiO2 photocatalystpowder in a closed reactor equipped with UV light. The condition of thephotoreduction process is 50 mL of silver waste containing Cu (II) and Hg (II)with a reaction time of 24 hours and a mass of TiO2 20 mg at 10 ppm Cu (II) ionconcentration. Photoreduction results are determined based on the difference inthe concentration of Cu (II) ions with the concentration of residual Cu (II) ionsin silver waste without the addition of TiO2 photocatalysts. Furthermore, thedata obtained compared to the results of Cu (II) photoreduction catalyzed bypure TiO2 laboratory scale. The amount of metal in the mixture was determinedby the Atomic Absorption Spectrophotometry (AAS) method. The results showedthat in silver handicrafts containing Cu (II) and Hg (II) ions the addition of TiO2can increase the effectiveness of Cu (II) photoreduction from 6.57% to 33.38%,which begins with the adsorption process. Hg (II) in silver handicraft wastecauses inter-metal reduction competition so that it can reduce the effectiveness ofCu (II) ion photoreduction catalyzed by TiO2 by 9.84% when compared to thepercentage of Cu (II) ion Ti2O scale scale laboratory testing.

A study has been carried out on the effect of the addition of TiO2 photocatalysts and oxalic acid sourced from pineapple skin at various pH and concentrations, to the effectiveness of Cu (II) ion photoreduction catalyzed by TiO2. The photoreduction process was carried out by irradiating the mixture consisting of a solution of Cu (II) ion and TiO2 photocatalyst powder without or in the presence of oxalic acid in a closed reactor equipped with a UV lamp with stirring. The photoreduction process conditions are 50 mL of 10 ppm Cu (II) ion solution (0.157 mmol / L) and varying concentrations of oxalic acid, and 20 mg of TiO2, with a 24-hour reaction time. The photoreduction product was determined based on the difference in the initial Cu (II) ion concentration and the remaining Cu (II) ion concentration in the solution after the photoreduction process was determined by the Atomic Absorption Spectrophotometry (AAS) method. The results showed that the addition of TiO2 could increase the effectiveness of Cu (II) ion photoreduction from 9.03% to 43.22%, which was initiated by the adsorption process. The presence of oxalic acid in pineapple skin in a photoreduction reaction system with greater concentration causes a relatively high increase in Cu (II) ion photoreduction because oxalic acid can prevent recombination of electrons with OH radicals, so that the Cu (II) photoreduction process can run optimally due to the amount of relatively large number of available electrons.