Distribusi dan Degradasi Sampah Plastik pada Air, Sedimen, dan Biota di Kali Surabaya

Lestari, Prieskarinda (2021) Distribusi dan Degradasi Sampah Plastik pada Air, Sedimen, dan Biota di Kali Surabaya. Doctoral thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Kondisi cakupan pengelolaan sampah di Indonesia yang mengandung 14% komposisi plastik baru mencapai 47,35%. Hal tersebut menyebabkan Indonesia diduga sebagai negara penyumbang sampah plastik ke lautan terbesar kedua di dunia (0,48 - 1,29 juta metrik ton/tahun). Sungai Brantas (± 320 km), penyedia utama air bersih dan irigasi di Provinsi Jawa Timur, diestimasikan berkontribusi 3,89 x 104 ton sampah plastik/tahun ke lautan. Aliran hilir Sungai Brantas, Kali Surabaya (± 42,3 km), juga berperan penting sebagai sumber utama air baku Kota Surabaya dan habitat biota akuatik. Namun, Kali Surabaya mengalami penurunan kualitas air akibat masuknya 215 saluran limbah rumah tangga dan 10 saluran limbah industri. Sebanyak 32,5% penduduk yang bermukim ± 500 m dari Kali Surabaya diestimasikan membuang limbah domestiknya ke sungai. Kondisi tersebut dapat menyebabkan pencemaran sampah plastik di Kali Surabaya. Berbagai mekanisme degradasi kompleks di lingkungan dapat membentuk makro- (>2,5 cm), meso- (5 mm – 2,5 cm), dan mikroplastik (<5 mm). Kondisi tersebut dapat berdampak terhadap penurunan kualitas air, terlepasnya bahan aditif plastik berbahaya ke lingkungan, ancaman biodiversitas biota akuatik, hingga risiko kesehatan manusia. Di sisi lain, perkembangan penelitian pencemaran sampah plastik di Indonesia masih berfokus pada laut (68 studi) dibandingkan di sungai (10 studi) hingga tahun 2020. Penelitian ini bertujuan untuk:1) mengkaji kelimpahan, karakteristik, distribusi sampah plastik (makro-, meso-, mikroplastik) pada air dan sedimen di Kali Surabaya, 2) mengkaji kelimpahan, karakteristik, distribusi mikroplastik pada biota akuatik ikan dan Bivalvia di Kali Surabaya, 3) mengkaji pengaruh radiasi ultraviolet (UV) dan kecepatan aliran air terhadap degradasi sampah plastik di lingkungan akuatik yang disimulasikan.
Pengambilan sampel air dan sedimen dilakukan di delapan lokasi sampling aliran Mlirip dan Kali Surabaya dengan dua pengulangan. Pengambilan sampel sampah plastik per lokasi dilakukan pada tiga kedalaman (permukaan, tengah, dasar), tiga posisi horizontal (kanan, tengah, kiri) berlawanan arah aliran sungai, dan sedimen. Pengambilan sampel biota akuatik dilakukan secara manual random sampling. Sampling, ekstraksi, dan analisis sampel sampah plastik di air, sedimen, biota akuatik dilakukan berdasarkan modifikasi metode National Oceanic and Atmospheric Administration Technical Memorandum NOS-OR & R-48. Kajian pengaruh radiasi UV dan kecepatan aliran air terhadap degradasi sampah plastik dilakukan dengan simulasi laboratorium selama 60 hari dan waktu paparan 8 jam/hari. Lima reaktor diatur berdasarkan data sekunder kondisi existing intensitas UV (0,92 – 2,54 W/m2) dan variasi kecepatan aliran air di musim hujan (0,3 – 0,6 m/detik) dan kemarau (0,1 – 0,3 m/detik) di Kali Surabaya. Analisis degradasi dilakukan berdasarkan perubahan kehilangan massa (weight loss), morfologi permukaan material uji hasil scanning electron microscope (SEM), dan spektrum fourier transform infrared (FTIR) secara berkala (hari ke 0, 30, 60).
Aliran air Mlirip dan Kali Surabaya telah tercemar makro-, meso-, dan mikroplastik dengan kelimpahan rata-rata tertinggi masing-masing didapatkan 0,174; 2,37; 21,16 partikel/m3. Kelimpahan meso- dan mikroplastik di sedimen didapatkan masing-masing berkisar 1,75 – 18,45 dan 124,06 – 1154,00 partikel/kg berat kering. Karakteristik makroplastik didominasi oleh komposisi bekas kantong plastik, bungkus makanan, sedotan, dan wadah makanan berbahan styrofoam berukuran kelas 1 (2-4 cm), 3 (8–16 cm), dan 5 (> 21 cm). Karakteristik meso- mikroplastik di kolom air dan sedimen didominasi oleh partikel berbentuk film, berwarna transparan, dan berukuran besar (LMP) (1-5 cm). Empat jenis polimer yang dominan ditemukan pada makro-, meso-, mikroplastik di aliran air dan sedimen yaitu low-density polyethylene (LDPE), polypropylene (PP), polyethylene (PE) dan high-density polyethylene (HDPE). Distribusi sampah plastik di kolom air hingga sedimen dapat dipengaruhi oleh faktor lingkungan (kecepatan aliran, kecepatan angin, aliran anak sungai, keberadaan dam, aktivitas domestik dan industri) dan karakteristik partikel (bentuk, ukuran, warna, jenis polimer dan nilai densitasnya).
Berdasarkan satuan per organ spesifik, kelimpahan mikroplastik pada ikan tinggi didapatkan pada ikan nila (303,59 partikel/g jaringan lunak insang) dan wader (358,75 partikel/g jaringan lunak gastrointestinal). Berdasarkan satuan per individu, kelimpahan mikroplastik tertinggi didapatkan pada ikan mujair (220,50 partikel/individu). Kelimpahan mikroplastik di Bivalvia tertinggi didapatkan pada spesies Rectidens sumatrensis (189,00 partikel/individu). Karakteristik mikroplastik yang ditemukan di ikan dan Bivalvia didominasi oleh partikel berbentuk fiber, berwarna hitam dan transparan, berukuran LMP, jenis polimer cellophane dan PE. Kelimpahan mikroplastik pada insang dan gastrointestinal berkorelasi positif terhadap karakteristik fisik ikan (panjang dan lebar). Kelimpahan mikroplastik pada Bivalvia berkorelasi positif terhadap panjang cangkang. Kontaminasi mikroplastik pada biota akuatik dapat dipengaruhi oleh kondisi pencemaran di habitatnya, pola konsumsi, pergerakan, perilaku hidup, dan karakteristik fisiknya. Secara umum, keterkaitan distribusi karakteristik mikroplastik di kolom air dan sedimen terhadap biota akuatik masih belum dapat dijelaskan, dimana kesamaan karakteristik hanya ditemukan pada warna, ukuran, dan jenis polimer PE yang dominan.
Dominansi jenis polimer LDPE dan PP di lokasi studi menjadi dasar penetapan material uji simulasi degradasi. Hasil uji simulasi degradasi dengan total waktu paparan 480 jam menunjukkan bahwa radiasi UV dan variasi kecepatan aliran air berpengaruh terhadap inisiasi degradasi plastik LDPE dan PP. Plastik LDPE mengalami weight loss sebesar 3,07% pada kondisi pengaruh radiasi UV dengan kecepatan aliran air tinggi atau musim hujan. Plastik PP mengalami weight loss terbesar sebesar 2,37% pada kondisi pengaruh kecepatan aliran air tinggi tanpa radiasi UV. Berdasarkan hasil analisis SEM, perubahan morfologi material uji menunjukkan permukaan yang tidak rata, tekstur tidak seragam, dan telah terbentuk retakan, patahan, serpihan, dan lubang. Perubahan intensitas transmitan ditemukan pada ikatan C-H stretch, CH2 dan CH3 bend, serta CH2 rock berdasarkan hasil perbandingan spektrum FTIR. Kondisi tersebut menunjukkan bahwa material uji telah mengalami inisiasi degradasi yang dipengaruhi oleh fotodegradasi, degradasi mekanis, dan hidrolisis.

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Solid waste management coverage condition in Indonesia with 14% of plastic composition is still reached up to 47.35%. Furthermore, Indonesia is suspected to be the second largest contributor of plastic waste to the world's ocean (0.48 - 1.29 million metric tons/year). Brantas River (± 320 km), the main source of clean water and irrigation for East Java Province, is estimated to contribute 3.89 x 104 tons of plastic waste/year to the ocean. One of its main downstream of the Brantas, namely Surabaya River (± 42.3 km), also plays an essential role as the main raw water source for water supply for Surabaya City and habitat for aquatic biota organisms. However, the Surabaya River’s water quality has suffered from the presence of 215 household sewage and 10 industrial sewage channels that enter along the river flow. About 32.5% of the population who lived in ± 500 m distance from the river, disposed of their domestic waste into the river. This condition could potentially lead to plastic pollution in the Surabaya River. Various complex degradation mechanisms could form macro- (> 2.5 cm), meso- (5 mm - 2.5 cm), and microplastic (<5 mm). This condition could give several disadvantages, such as water quality deterioration, release of harmful plastic additive substances to the environment, threat to aquatic biota biodiversity, even risks to human health. On the other hand, the development of plastic pollution research in Indonesia is still focused on marine areas (68 studies) compared to the rivers (10 studies) until 2020. Therefore, the objectives of this study were: 1) to investigate the abundance, characteristics, distribution of plastic waste (macro-, meso-, microplastics) in water and sediment in the Surabaya River, 2) to investigate the abundance, characteristics, distribution of microplastics in fish and bivalves in Surabaya River, 3) to examine the effect of ultraviolet (UV) radiation and water velocity on plastic degradation in a simulated aquatic environment.
Water and sediment samples were collected from eight sampling locations in Mlirip and the Surabaya Rivers with two repetitions. Sampling of plastic waste (macro-, meso-, microplastics) was carried out at three stratified water depths (surface, middle, bottom) and three horizontal positions (right, center, left) based on the opposite direction to the river flow. Aquatic biota samples were collected by manual random sampling. Sampling, extraction, and analysis of plastic waste were done based on the modified method of the National Oceanic and Atmospheric Administration Technical Memorandum NOS-OR & R-48. The study of UV radiation and water flow velocity effect on plastic waste degradation was done by laboratory simulation for 60 days with exposure time of 8 hours/day. Five simulated reactors in the laboratory have been arranged based on the existing condition approach from secondary data of UV intensity (0.92 - 2.54 W/m2) and water velocity in the rainy (0.3 - 0.6 m/s) and dry (0.1 - 0.3 m/s) seasons in the Surabaya River. Plastic degradation analysis was carried out based on changes in weight loss percentage, surface morphology of the material based on the results of scanning electron microscope (SEM), and comparison of the Fourier Transform Infrared (FTIR) spectrum of the polymers periodically (day 0, 30, and 60).
The Mlirip and the Surabaya Rivers have been polluted by macro-, meso-, and microplastics with the highest average abundance values 0.17; 2.37; 21.16 particles/m3, respectively. The abundance of meso– and microplastics in the sediment ranged from 1.75 to 18.45 and from 124.06 to 1154.00 particles/kg d.w., respectively. Macroplastic characteristics were dominated by the composition of used plastic bags, food wrappers, straws, and food containers made from styrofoam in sized of class 1 (2-4 cm), 3 (8–16 cm), and 5 (> 21 cm). Meso- and microplastic characteristics in the water column and sediment were dominated by film in shape, transparent in color, and large size particles/LMP (1-5 mm). Four main polymer types of plastic waste in the water column and sediment were identified as low-density polyethylene (LDPE), polypropylene (PP), polyethylene (PE), and high-density polyethylene (HDPE). The distribution of plastic waste in the water column and the sediment along the river could be influenced by some environmental factors (flow velocity, wind speed, tributary flow, presence of dams, domestic and industrial activities) and particle characteristics itself (shape, size, color, polymer type, density value).
Based on units per specific organ, the highest microplastic abundance in fish was found in Oreochromis niloticus (303.59 particles/g soft tissue of gill) and Rasbora argyrotaenia (385.75 particles/g soft tissue of gastrointestinal). Based on individual unit, the highest microplastic abundance was found in Oreochromis mossambicus (220.50 particles/individual). The highest microplastics abundance in the bivalves was found in Rectidens sumatrensis (189.00 particles/individual).The microplastic characteristics in the fish and bivalves were dominated by fiber shaped particles, black and transparent in color, LMP in size, and polymer types of cellophane and PE. The microplastic abundance in the gill and gastrointestinal tract were positively correlated with the physical characteristics of the fishes (length and width). The microplastic abundance in the bivalves was positively correlated with the length of the shell. Microplastic contamination in the aquatic biota could be influenced by pollution levels in their surrounding habitat, consumption and movement patterns, life behavior, and physical characteristics. In general, the relationship between microplastic distribution in the water column, sediment, and aquatic biota has remained unclear, in which similar characteristics were only found in the dominant color, size, and polymer type of PE.
Polymer types of LDPE and PP were dominantly found in the study location. Thus, these situation became the basis for determining the polymer types of test material in the simulated degradation. The results of the simulated degradation with a total exposure time of 480 hours showed that UV radiation and water velocity variations have initiated the degradation of LDPE and PP. The LDPE experienced the highest weight loss of 3.07% under the condition of UV radiation with high water velocity or rainy season. Meanwhile, PP experienced the highest weight loss of 2.37% under the condition of high water velocity without UV radiation. Based on the results of SEM, changes in morphology of the test material were found in the form of uneven and inhomogeneous surface texture, in which cracks, flakes, grooves, and deep pits were formed. Changes in transmittance intensities were found in the C - H stretch, CH2 and CH3 bend, and CH2 rocking bonds based on the results of FTIR spectrum comparison. These conditions could indicate that the test material has undergone the degradation initiation, which was influenced by photodegradation, mechanical, and hydrolysis mechanisms.

Item Type:	Thesis (Doctoral)
Uncontrolled Keywords:	distribusi, degradasi, sampah plastik, pencemaran, sungai, distribution, degradation, plastic waste, pollution, river
Subjects:	T Technology > TD Environmental technology. Sanitary engineering > TD194.6 Environmental impact analysis T Technology > TD Environmental technology. Sanitary engineering > TD420 Water pollution
Divisions:	Faculty of Civil, Planning, and Geo Engineering (CIVPLAN) > Environmental Engineering > 25001-(S3) PhD Thesis
Depositing User:	Prieskarinda Lestari
Date Deposited:	02 Sep 2021 03:17
Last Modified:	02 Sep 2021 03:17
URI:	http://repository.its.ac.id/id/eprint/91623

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