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This paper presents the effect of microwave and ultrasound irradiation on the enzymatic hydrolysis of water hyacinth biomass in the presence of surfactants. Prior to hydrolyzing, the water hyacinth was treated utilizing alkali with and without microwave assistance. It was revealed that the microwave improved the removal of lignin and hemicellulose. The treated water hyacinth biomass was also characterized using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), and Fourier-Transform Infrared (FT-IR) Spectroscopy. The effect of surfactant and the assistance of microwave and ultrasound were comprehensively studied. Some parameters varied, including stirring speed, surfactant type, concentration, and reaction time. The results indicated that microwave and ultrasound could enhance the reaction rate. Tween 80 here could improve conventional, microwave-assisted, and ultrasound-assisted hydrolysis of water hyacinth biomass. It was found that the ultrasound-assisted hydrolysis was better than that of others. The results of this research can be used as the groundwork for further developing the lignocellulosic biomass hydrolysis process, especially in an advanced enzymatic hydrolysis process.

Noise may cause serious health problems, including physiological responses, specifically in the cardiovascular system. This study aims to assess occupational noise exposure and analyze the correlation between occupational noise and blood pressure in cabin and station personnel. The participants were 30 cabin personnel (train drivers) and 30 station personnel. The cabin had a Leq of 90.3 dBA while the noise level at Poncol Station was still below the threshold limit value (TLV), i.e., 75.8 dBA. The noise exposure assessment also included noise exposure profiling. The Chi-square test showed that noise influenced systolic and diastolic blood pressure changes. Furthermore, for train drivers, the t-test showed a difference in systolic and diastolic between before and after the activity. As for station personnel, there was a difference in systolic, but contrarily it was not the case in diastolic. According to the noise profile, the train whistle had the most significant noise level at 120 dBA. Moreover, the use of a train whistle regularly may raise the noise level exposure to cabin staff and even station workers. This study contributes to scientific evidence that occupational noise might affect blood pressure

Heavy metal contamination in the urban river has become the most severe problem in the urban environment, especially the zinc (Zn) compound is harmful to the environment at current levels of exposure. This study aims to assess the impact of urbanization and industrialization on Zn pollution in surface sediment at the Umeda River. Triplicate surface sediment samples were collected at nine sample points. An atomic absorption spectrophotometer was used for analyzing the Zn and Fe concentrations. The surface sediments in the Umeda River contained 48–159 mg/kg of Zn. The results indicated that Zn concentrations were abundant in the ascending order of 600–1,000 μm, 300–600 μm, and smaller than 300 μm. The higher the grain size, the higher the particulate organic carbon which might contribute to the higher Zn and Fe concentrations. In addition, the sediment quality guidelines indicated that the Zn levels in the study area did not constitute a major threat to biota. Normalization with Fe showed that the Zn pollution in surface sediment had been influenced by anthropogenic activities such as industrialization and urbanization. HIGHLIGHTS Unusual condition of Zn contents in the surface sediment compared with other studies.; Represents the zinc studies in urban areas with some type of land use in the watershed.; The first heavy metals research in the Umeda River, Aichi, Japan.;

ABSTRAK Kegiatan daur ulang sampah di Kota Semarang dapat dilakukan dengan cukup baik berkat campur tangan dari sektor informal. Sayangnya, kegiatan pengelolaan sampah formal tidak mempertimbangkan nilai pemulihan sampah. Penelitian ini bertujuan untuk mengidentifikasi aliran sampah plastik di sektor informal di Kota Semarang. Peneliti menggunakan wawancara mendalam untuk mengumpulkan data. Ada 46 agen daur ulang, termasuk lima (5) pemulung, 17 pengepul 20 perusahaan skala kecil, tiga (3) perusahaan skala besar, dan 1 perantara (pabrik penggilingan plastik) yang telah diwawancarai. Data dari Badan Lingkungan Hidup Kota Semarang digunakan sebagai data sekunder. Hasil penelitian menunjukkan bahwa jumlah sampah plastik yang dihasilkan oleh masing-masing agen daur ulang diperkirakan 23,98 kg/ hari di tingkat pemulung, 54,74 kg/ hari di tingkat pengepul, 347,48 kg / hari di tingkat perusahaan skala kecil, 1.735,3 kg / hari di tingkat perusahaan skala besar, dan 2.160 kg / hari di tingkat perantara. Produsen bijih plastik daur ulang berlokasi di luar Kota Semarang, sedangkan bank sampah berbasis masyarakat adalah bagian dari pengelolaan sampah berbasis masyarakat yang tidak mencari keuntungan. Oleh karena itu, tidak dibahas secara mendalam di penelitian ini. Kata kunci: sampah plastik, aliran sampah, agen daur ulang ABSTRACT Waste recycling activities in Semarang City can be conducted quite well due to the interference of the informal sector. Unfortunately, the formal waste management activities do not consider the utilization of waste recovery value. This study aims to identify the flow of plastic waste in the informal sector in Semarang City. We used in-depth interviews to collect data. There are 46 recycling agents, including five (5) scavengers, 17 scrap dealers, 20 small scale enterprises, three (3) large scale enterprises, and 1 intermediate (plastic grinding mill) that has been interviewed. Data from The Environment Agency of Semarang City obtained as secondary data. The results showed that the amount of plastic waste generated by each recycling agent was estimated at 23.98 kg/day at the scavenger level, 54.74 kg/day at the scrap dealer level, 347.48 kg/day at the small scale enterprise level, 1,735.3 kg / day days at large scale enterprise level, and 2,160 kg/day at the level of plastic waste intermediates. Recycled plastic ore producers are located outside Semarang City, whereas the community-based waste bank is part of community based solid waste management that is not looking for profit. Hence, it is not discussed in depth in this study. Keywords: plastic waste, waste flow, recycling agent

Transportasi laut termasuk penyumbang emisi polutan udara baik dari aktivitas pelayaran di laut maupun aktivitas di pelabuhan.Inventarisasi emisi polutan udara sektor transportasi laut masih sangat jarang.Kajian ini dilakukan untuk mengkuantifikasi dan mengestimasi sebaran emisi dari sektor transportasi laut di pelabuhan.Inventarisasi menggunakan data operasional pelabuhan dan faktor emisi sekunder.Sebaran emisi polutan udara dari aktivitas pelabuhan diperkirakan dengan model AERMOD View. Hasil inventarisasi beban emisi dari aktivitas transportasi laut di pelabuhan didominasi oleh aktivitas pelayaran dalam pelabuhan yaitu pada saat approaching time disusul oleh aktivitas mesin bantu saat bongkar muat (berthing time). Aktivitas bongkar muat di darat hanya berkontribusi 1% dari aktivitas mesin bantu saat berthing time. Sebaran emisi polutan udara aktivitas bongkar muat cenderung mengarah ke Barat Laut-Tenggara, sementara sebaran emisi dari aktivitas pelayaran cenderung merata ke sebagian besar area Semarang kawasan tengah dan Utara.

Industri pengolahan buah umumnya memiliki kadar organik yang tinggi, Salah satunya adalah industri pengolahan nanas. PT Great Giant Pineapple, Lampung, (PT GGP) merupakan produsen nanas kaleng ekspor yang menghasilkan limbah yang berpotensi mencemari lingkungan apabila tidak dikelola dengan baik. Salah satu upaya pengelolaan lingkungan dan perbaikan berkelanjutan, PT GGP berupaya melaksanakan sistem produksi bersih. Produksi bersih merupakan suatu strategi pengelolaan lingkungan yang bersifat preventif dan terpadu yang perlu diterapkan secara terus menerus pada proses produksi dan daur hidup produk dengan tujuan megurangi resiko terhadap manusia dan lingkungan. Tujuan dari penelitian ini adalah untuk menganalisis kesetimbangan energi dan manfaat secara kuantitatif dalam penerapan sistem produksi bersih di sistem pengolahan limbah cair PT GGP. Kesetimbangan energi dianalisis dengan menggunakan indikator NER (Net Energy Ratio) dan NEP (Net Energy Production). Manfaat finansial dari penggunaan kembali sludge juga dievaluasi secara kuantitatif. Dalam produksi biogas jumlah energi input yang dibutuhkan sebesar 1,002 MJ/hari/m3 air limbah, menghasilkan jumlah energi output sebesar 108,587 MJ/hari/m3 air limbah. Sehingga Nilai NER = 108,37 dan NEP = 17,585 MJ/hari/m3 air limbah. Sementara itu, dengan pemanfaatan Sludge atas perusahaan memperoleh keuntungan sebesar Rp 3.326.687.65/hari dan pemanfaatan sludge bawah memperoleh keuntungan sebesar Rp 19.054.592 /hari pada tahun 2015.

Limbah elektronik adalah masalah yang muncul di Indonesia karena mengandung bahan yang berpotensi berbahaya. Dalam rangka menciptakan manajemen yang ramah lingkungan dari limbah elektronik, fasilitas yang memadai diperlukan. Tujuan dari penelitian ini adalah untuk memilih lokasi yang optimal untuk mengembangkan fasilitas pengolahan limbah elektronik (FLPE). Pemilihan lokasi yang optimal dilakukan dengan menggunakan metode model ELECTRE III. ELECTRE adalah keluarga metode analisis keputusan multi-kriteria yang berasal di Eropa. Kriteria yang dipilih untuk analisis ini adalah penduduk setempat, penduduk yang dilayani, persentase belanja bulanan, harga rata-rata rumah tangga per unit, populasi pengangguran, status finansial dari penduduk lokal, jarak dari fasilitas yang telah ada, dan jarak dari pelabuhan terdekat. ELECTRE III membutuhkan penentuan tiga ambang batas, yaitu ambang kelalaian (q), ambang batas preferensi (p), dan ambang veto (v) dalam upaya untuk lebih beradaptasi dengan ketidakpastian. Bobot masing-masing kriteria yang ditentukan sesuai dengan kepentingan relatif terhadap kriteria lain. Lokasi optimal untuk FPLE adalah Provinsi Banten berdasarkan model ELECTRE III. Kata Kunci: limbah elektronik, fasilitas, optimasi, ELECTRE Abstract E-waste is an emerging issue in Indonesia due to its potentially hazardous content and some precious metal. In order to create an environmentally sound management of e-waste, a facility is necessary. The objectives of this study are to to select the optimal location of e-waste dismantling and sorting facility (DSF/FLPE). The optimal location selection was conducted using the method of ELECTRE III model. ELECTRE is a family of multi-criteria decision analysis methods that originated in Europe. The criteria chosen for this analysis are local population, population served, the percentage of monthly expenditure, average household price per unit, unemployed population, financial status of the local population, distance from existing facilities, and distance from the nearest port. ELECTRE III requires the determination of three thresholds, namely threshold of negligence (q), threshold of preference (p), and the veto threshold (v) in the effort to better adapt to uncertainties. The weight of each criterion was determined according to its importance relative to other criteria. The optimal location for e-waste DSF is Banten Province based on ELECTRE III model. Keywords: e-waste, facility, optimization, ELECTRE

Limbah cair yang dihasilkan industri tahu sangat merugikan lingkungan jika tidak dilakukan pengolahan terlebih dahulu. Namun, limbah cair tahu dapat diolah secara anaerob sehingga menghasilkan biogas. Maka dari itu, penelitian ini bertujuan untuk mengetahui besarnya potensi biogas yang dapat dihasilkan dari limbah cair tahu sebagai upaya dalam teknologi bersih serta mengetahui kelayakannya dari aspek ekonomi dan lingkungan. Penelitian dilakukan pada industri tahu skala rumah tangga yang berlokasi di Desa Puspiptek, Tangerang Selatan dengan metode digesti anaerobik. Hasil penelitian menunjukkan bahwa selama waktu tinggal 14 hari, limbah tahu menghasilkan biogas sebesar 1.525 liter dengan penurunan kandungan COD sebesar 8,1% dari 748,75 mg/L menjadi 688,125 mg/L, Total Solid sebesar 56,9% dari 16,36 g/L menjadi 7,049 g/L, dan Volatile Solid sebesar 66,3% dari 14,85 g/L menjadi 5,001 g/L. Hasil analisis simulasi kelayakan biogas berdasarkan aspek ekonomi berupa Harga Pokok Penjualan (HPP) Rp7.342 per kg, BEP 109.500 kg/tahun, dan PBP 0,48 dengan pengolahan limbah tahu sebesar 5676 liter per hari, menghasilkan biogas sebanyak 5,174 m3 per hari. Banyak sekali manfaat yang didapat dari pemanfaatan limbah menjadi biogas, baik dari aspek ekonomi, lingkungan, maupun sosial

An environmentally sound management of plastic waste in Semarang City is necessary due to increasing plastic waste generation; limited capacity of Jatibarang Final Disposal; dangers of open burning of plastic waste; pollution of water resources both surface water and sea water; and limited amount of raw materials for the manufacture of plastic resin. This study aims to present the assessment of plastic waste management from collection to final disposal as well as its estimated generation. A field study was conducted to identify the material flow of plastic waste, particularly PET bottles. To estimate the potential generation of plastic waste, a top-down approach was used. The volume of plastic waste in Semarang reached 16.28% of the total municipal waste, in which the highest part of inorganic waste. The total estimated plastic waste generation in Semarang City, particularly from households, was 1012.486 m3/day. There is an urgent need for improving the plastic management in Semarang due to existing low recycling rate.

The Two for One Twister (TFO) machine emits very disturbing noise and the noise exposes the workers while performing their tasks. The noise also lead to works stress. So, it is necessary to determine the relationship between the noise and work stress of TFO machine operators. This study was conducted by measuring the noise of TFO engine with Enviro-meter and then correlating the noise and work stress with SPSS 16 software. Spearman correlation test results showed that a strong correlation between noise with work stress (p value = 0.042). In order to reduce the noise level that will decrease stress for workers, Fault Tree Analysis was conducted to determine the source of the noise. Based on the qualitative analysis of FTA, the causes of the noise were as follows: the lubricating oil was not applied, seal of oil valve leaked, bearing was not replaced (2 years economic life), the traveler was not replaced (10 days economic life), and the Doubling machine was troubled. Based on the quantitative analysis of the probability of job stress of TFO machine operator due to noise TFO machines from a known probability of 0.041, hence, the system was feasible for use.