The excessive amount of global plastic produced over the past century, together with poor waste management, has raised concerns about environmental sustainability. Plastic recycling has become a practical approach for diminishing plastic waste and maintaining sustainability among plastic waste management methods. Chemical and mechanical recycling are the typical approaches to recycling plastic waste, with a simple process, low cost, environmentally friendly process, and potential profitability. Several plastic materials, such as polypropylene, polystyrene, polyvinyl chloride, high-density polyethylene, low-density polyethylene, and polyurethanes, can be recycled with chemical and mechanical recycling approaches. Nevertheless, due to plastic waste’s varying physical and chemical properties, plastic waste separation becomes a challenge. Hence, a reliable and effective plastic waste separation technology is critical for increasing plastic waste’s value and recycling rate. Integrating recycling and plastic waste separation technologies would be an efficient method for reducing the accumulation of environmental contaminants produced by plastic waste, especially in industrial uses. This review addresses recent advances in plastic waste recycling technology, mainly with chemical recycling. The article also discusses the current recycling technology for various plastic materials.

The rapid accumulation of plastic and textile waste, particularly polyethylene terephthalate (PET), has emerged as a global challenge for sustainable resource management. Conventional recycling methods, including mechanical and chemical routes, recover limited value and often degrade material quality while consuming substantial energy. Biocatalytic recycling, by contrast, offers a resource-efficient alternative that transforms post-consumer PET into high-purity monomers under mild and environmentally benign conditions. This review examines advances in enzymatic PET depolymerization, focusing on hydrolases such as cutinases, PETases, MHETases, and lipases. The discussion highlights enzyme engineering, reactor design, and process integration that improve kinetics, thermostability, and yield. From a resource perspective, biocatalytic recycling redefines PET waste as a renewable carbon feedstock capable of re-entering industrial cycles, thereby reducing reliance on virgin petrochemicals and mitigating greenhouse gas emissions. Ultimately, this review positions biocatalytic PET recycling as a cornerstone technology for achieving circularity and advancing global resource sustainability.

Abstrak Produksi biogas dari limbah cair singkong menawarkan sumber energi yang berkelanjutan, meskipun efisiensinya masih menjadi tantangan. Penggunaan zeolit alami sebagai media untuk mengimobilisasi bakteri anaerob menunjukkan potensi, namun efisiensi proses ini dapat lebih ditingkatkan dengan aktivasi zeolit. Namun, pengetahuan tentang bagaimana zeolit yang diaktifkan secara basa (NaOH) mempengaruhi aktivitas mikroba dan hasil biogas masih terbatas. Dalam penelitian ini, kami menunjukkan bahwa zeolit alam Lampung yang diaktifkan secara basa signifikan meningkatkan produksi biogas dengan menyediakan media imobilisasi yang lebih efektif bagi bakteri anaerob. Analisis Fourier transform infrared spectroscopy (FTIR) mengungkapkan perubahan struktural, dengan pergeseran gelombang Si-O dan Al-O, yang menunjukkan interaksi kimia yang lebih baik setelah aktivasi. Scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDX) mengonfirmasi peningkatan kandungan Al dan Na; Al meningkat secara signifikan dari 5,62% menjadi 7,48%, yang menunjukkan peningkatan kandungan Al dalam struktur zeolit setelah aktivasi. Sementara itu, analisis xray diffraction (XRD) mengungkapkan kristalinitas 21% pada zeolit yang diaktifasi, yang menunjukkanpermukaan mendukung untuk perlekatan mikroba. Analisis Brunauer-Emmett-Teller (BET) menunjukkan struktur mesopori (34,335 Å) yang meningkatkan kontak bakteri dengan substrat. Reaktor dengan zeolit yang diaktifkan mencapai puncak produksi biogas sebesar 620 mL, melebihi kontrol karena peningkatan stabilitas mikroba dan pengurangan akumulasi asam lemak volatil (VFA). Hasil ini menunjukkan bahwa zeolit yang diaktivasi secara basa dapat secara signifikan meningkatkan efisiensi sistem produksi biogas dengan meningkatkan imobilisasi mikroba dan stabilitas proses Abstract Biogas production from cassava wastewater offers a sustainable energy source, though efficiency remains challenging. Natural zeolite is a promising material for anaerobic bacteria immobilization media. However, there is limited knowledge of how alkaline-activated (NaOH) zeolite affects microbial activity and biogas yield. Here, we show that alkaline-activated Lampung natural zeolite significantly enhances biogas production by providing a more effective immobilization medium for anaerobic bacteria. Fourier transform infrared spectroscopy (FTIR) analysis reveals structural changes, with a shift in Si-O and Al-O vibrations, indicating improved chemical interaction post-activation. Scanning electron microscope-energy dispersive x-ray spectroscopy (SEM-EDX) confirms increased Aland Na content; the Al increased significantly from 5.62% to 7.48%, which may indicate an increase in Al content within the zeolite structure after activation. Meanwhile, the x-ray diffraction (XRD) analysis revealed a 21% crystallinity in the activated zeolite, suggesting a favorable surface for microbial attachment. Brunauer-Emmett-Teller (BET) analysis shows a mesoporous structure (34.335 Å) that improves bacterial contact with the substrate. The reactor with activated zeolite achieved peak biogas production of 620 mL, outperforming the control due to enhanced microbial stability and reduced volatile fatty acid (VFA) accumulation. These results sugest that alkaline-activated zeolite can significantly boost the efficiency of biogas production systems by improving microbial immobilization and process stability

Tarahan Village is one of the larger villages in Katibung District, South Lampung. Despite not being classified as an agricultural region, Tarahan Village exhibits remarkable productivity in cultivating vegetables and fruits. So far, organic waste from fruits and vegetables has been discarded and burned or used only for animal feed. The large volume of unprocessed fruit and vegetable waste causes various problems for village residents, both directly and indirectly. Besides that, the village's intensive horticultural farming activities have encouraged the increased use of inorganic fertilizers. This pollutes the environment and harms the soil, organisms that live in the soil, and humans who consume these horticultural products. The application of liquid organic fertilizer, specifically POC, is deemed necessary to effectively address the issue of fruit and vegetable waste management while ensuring the quality of organic horticultural products. A composter is a suitable technology employed for the production of liquid fertilizer. Since oxygen is crucial for microorganisms in decomposing organic matter, the POC produced through the aerobic composting process will mature more quickly and not produce offensive odors. The goal of implementing this technology is to spread the word that garbage can be turned into something valuable if managed properly, leading to a cleaner community and more economic opportunities. The rotary POC technology scheme consists of a plastic drum that is supported by an iron structure. The drum is furnished with a rotating lever designed for the purpose of stirring, thereby facilitating the uniform mixing of organic material upon the addition of the bioactivator. The agitation of the solution facilitates the efficient execution of the aeration process. The equipment scheme has been developed with the aim of enhancing the effectiveness and efficiency of composting with regard to both time management and the quality of the final outcomes. This technology has the potential to be an alternative solution for dealing with household waste, and the product in the form of POC has the potential to reduce the use of inorganic fertilizers.

Pengelolaan Sampah Plastik Menjadi Paving Block Sebagai Prospek Bisnis Masyarakat Desa Kota Agung, Pesawaran