Jurnal Riset Teknologi Pencegahan Pencemaran Industri

The effect of Inoculum to Substrate and Carbon to Nitrogen Ratios on the Biogas Quantity and Quality from Anaerobic Digestion of Salvinia molesta: Experimental and Kinetic Studies

Mon, 27 Jun 2022 00:00:00 +0700

The purpose of this study was to investigate the effect of inoculum to substrate (I/S) and carbon to nitrogen (C/N) ratios on the biogas quantity and quality from anaerobic digestion of Salvinia molesta (SM). The I/S was adjusted to become 1.5, 2, 2.5 and the C/N was to become 21.5, 25, 30. Anaerobic digestion (AD) was operated during 30 days under the room pressure and temperature. The results showed that increase in I/S from 1.5 to 2.5 increased the biogas yield from 19.01 to 33.84 mL/g VS. Besides that, it increased the methane content from 52.54 to 69.01%. Furthermore, increase in C/N to 21.5 to 30 decreased the biogas yield from 33.84 to 30.85 mL/g VS and then decreased the methane content from 69.01 to 6.99%. Hence, the best condition was in the substrate with I/S of 2.5 and C/N of 21.5. The measured data was successfully predicted through the modified Gompertz and the first order kinetic models with R² of 0.9905 and 0.9476 respectively.

Soaking up the Sun: Solar Energy Optimization during Pandemic, Study Case at Micro, Small and Medium Enterprises (MSME) Rattan Crafts Center in Trangsan Village, Sukoharjo, Central Java

Sujarwanto Dwiatmoko, Archibald Nagel, Jaka Windarta — Mon, 27 Jun 2022 00:00:00 +0700

The National Energy General Plan has set a target of achieving the Renewable Energy mix by 23% by 2030, to achieve this the transition of energy to RE must be done immediately. Solar energy is one of the opportunities of renewable energy that is very abundant in Indonesia. Along with the issuance of the Minister of Energy and Mineral Resources Regulation number 49 of 2018 concerning the Use of Rooftop Solar Power System by Consumers of PT Perusahaan Listrik Negara (Persero) which provides opportunities for the utilization of PV Rooftop for household and commercial sector. In view of this, the Central Java Government plans to install Rooftop Power Plant in the Micro, Small and Medium Enterprises (MSME) Sector to develop the utilization of RE in the productive sector while improving the economic recovery of the Covid-19 pandemic. The use of renewable energy (EBT) is expected to save electricity costs in MSMEs. The results of planning using Helioscope software showed that in the three MSMEs with different PLTS capacities, namely 1 Kwp, 2.04 KWp and 4 KWp can produce annual energy production of 1,191 MWh, 2,433 MWh and 5,352 MWh respectively. After the installation of the PLTS, it was proven that in the first two months after installation energy consumption can decrease to minimum usage.

Decision Making for Biological Tofu Wastewater Treatment to Improve Quality Wastewater Treatment Plant (WWTP) Using Analytical Hierarcy Process (AHP)

Mon, 27 Jun 2022 00:00:00 +0700

This research aims to build a support system for tofu wastewater treatment using the Analytical Hierarchy Process (AHP) method. This research was conducted in one of the household tofu industries in Jakarta. AHP method was used to choose/decide the most effective combination of technologies to treat tofu wastewater. Based on the literature study and inlet characterization, Three alternatives were proposed. Alternative 1 consists of a Collecting tank, Neutralization Tank, Preliminary Sedimentation, Anaerobic Digester, Aeration Tank, and Final Settlement Body. While alternative 2 consists of a Collecting tank, Neutralization Tank, Preliminary Sedimentation, Anaerobic Biofilter, Aeration Tank, and Final Settlement Tank. Alternative 3 consists of a Collecting tank, Neutralization Tank, ABR, Aeration Tank, and Final Sedimentation Tank. The decision criteria used for AHP were effluent quality, land requirement, construction cost and easy maintenance. The primary data used were wastewater flow and outlet concentration. While data of area use , maintenance cost and construction cost were extracted from literature study. The result shows that alternative 3 was the most effective sequence of technology. Eigen Vector Analysis Recapitulation showed that alternative 1 has an overal value of 0.31, alternative 2 has value of 0.2 and alternative 3 has value of 0.5. Using alternative 3, BOD5 can be removed up to 95%, COD can be removed by maximum of 95% by ABR, TSS can be removed by 80% which met the quality standard.

Utilization of Peroxide Bleached Sugar Palm (Arenga pinnata) Fibre Waste into Cellulose Nano Crystal

Mon, 27 Jun 2022 00:00:00 +0700

Sugar palm (Arenga pinnata) fibre (SPF) waste is a side product of sugar palm starch production and needs to be processed to avoid environmental pollution. Since the SPF has high cellulose content, it can be beneficial if it is valorized into high-value products such as cellulose nanocrystal (CNC). The CNC production from SPF was initiated by cellulose production by using an environmentally friendly peroxide bleaching as elementary chlorine free bleaching method. The CNC production was conducted via sulfuric acid hydrolysis at a temperature of 40°C, solid/liquid ratio of 1:10, and hydrolysis time of 45, 60, 75, and 90 minutes. The same functional groups were observed in all CNC samples, including the appearance of the ester sulfate group. The decrease in yield and crystallinity index (CrI) as the hydrolysis time was observed. These phenomena were caused by the degradation of the crystalline structure of cellulose and the formation of the ester sulfate group. The measurement of CNC diameter size was carried out by using the scanning electron microscopy (SEM) technique. The CNC diameter was below 100 nm which indicated the nanoparticle formation was observed at CNC produced at hydrolysis times of 75 and 90 minutes. In conclusion, CNC production was successfully produced from peroxide bleached SPF which is more environmentally friendly than the conventional method using chlorite bleached cellulose. Furthermore, it is needed to optimize the production of SPF CNC in further research.

Rooftop PV Plant Development Planning at the Central Java Provincial DPRD Secretariat Office

Andrian Mayka Ariawan, Jaka Windarta, Sujarwanto Dwiatmoko — Mon, 27 Jun 2022 00:00:00 +0700

Central Java Province targets the achievement of the new and renewable energy (EBT) portion in the energy mix by 2030 at 22.55%. In order to achieve this target, the Central Java Provincial Government has consistently developed the use of EBT, one of which is through the construction of rooftop solar power plants (Rooftop PV Plant) in government buildings. In addition to requiring a fairly high initial investment cost, the construction of a Rooftop PV plant connected to the PT. PLN (Persero) requires a fairly complicated process, so proper planning must obtain optimal results. This paper will discuss an example of a Rooftop PV Plant development plan at the Secretariat Office of the Central Java Provincial DPRD, including the use of electrical energy prior to the installation of a Rooftop PV Plant; an analysis of the condition and availability of the location; the design and system of a Rooftop PV Plant; an estimate of the total potential energy that can generate; the investment costs of a Rooftop PV Plant; as well as evaluating the results of using Rooftop PV Plant. The electricity bill at the Central Java Provincial DPRD Secretariat Office prior to installing Rooftop PV Plant is Rp. 91.308.323,- per month. The recommended PV design, built on an area of 197 m2, is a rooftop on-grid PV Plant system with 6 PV arrays, each of which PV arrays are installed with as many as 20 solar modules arranged in series. The total number of solar modules installed is 120 solar modules with a total capacity equivalent to 30 kWp. Based on the simulation results using the PVSyst 6.4.3 software, the Rooftop PV Plant system can generate electrical energy of up to 43,420kWh per year or equivalent to 118.9kWh per day with a performance ratio of 79.4%. The potential for saving electricity costs from the simulation results can reach Rp. 4,034,441.- per month. The results of the evaluation of the utilization of the Rooftop PV Plant through the recording of the inverter monitoring system within 1 (one) year after installation shows the amount of electrical energy produced is 40,558 kWh, so that the manager of the Secretariat of the DPRD Central Java Province office can save a budget of Rp. 3,768,514.- per month from the use of the Rooftop PV Plant. This figure is not much different from the simulation results at planning. There is a difference in the cost savings of electricity payments at the Central Java Provincial DPRD Secretariat Office during 2020 of Rp. 4,493,300,- excluding savings due to the use of Rooftop PV Plant due to implementing the work from home (WFH) system during the COVID-19 pandemic, which resulted in a significant reduction in the use of electrical energy.