Hazardous oily sludge management remains a major challenge in the petroleum industry, motivating the development of efficient waste-to-fuel conversion processes. In this study, catalytic pyrolysis of oily sludge was investigated in a semi-continuous rotary kiln reactor using γ-Al₂O₃, with emphasis on reactor-dependent behavior under realistic conditions, including heat transfer, mixing, and product distribution. A Central Composite Design (CCD) within Response Surface Methodology (RSM) was applied to model the process, evaluate variable effects, and analyze interactions. Results showed predominantly monotonic behavior within the studied range, with no internal stationary point detected. The model demonstrated strong predictive capability (R² = 0.9781), confirming its adequacy. The highest liquid yield (86.7 wt
Polycarbonate is widely used in electrical/electronic, automotive, optical, and medical applications because of its transparency, heat resistance, and impact strength. Recycling waste bisphenol A-based polycarbonate (BPA-PC) is complicated by resin blends, additives, contamination, and potential release of bisphenol A (BPA), which increase separation difficulty and reduce recyclate quality. This review summarizes mechanical recycling, selective chemical depolymerization, thermochemical conversion, and enzymatic/microbial degradation of BPA-PC. The routes are compared using feedstock adaptability, reaction severity, product selectivity/recovery, separation burden, carbonate-carbon fate, technology maturity, and closed-loop potential. Selective depolymerization is particularly attractive for recovering BPA and useful carbonate-derived coproducts, whereas future development should emphasize realistic post-consumer feedstocks, recyclable catalysts, continuous operation, and techno-economic and life-cycle evaluation.
Valorizing wheat straw as a renewable resource remains challenging due to its recalcitrant lignocellulosic structure. Integrating photocatalytic materials with aerobic composting is a promising strategy to enhance organic matter transformation. While UV-B-shielded benefits composting, TiO2’s role in lignocellulosic degradation remains unclear. This study investigates the effects of TiO2 amendment on wheat straw composting under UV-B-shielded conditions, and focuses on overall compost performance rather than exclusive photocatalytic mechanism exploration, exploring TiO2 impacts under UV-B-shielded conditions with four dosages (0, 1, 3, and 5 wt
The rapid deployment of photovoltaic (PV) technologies is expected to generate substantial end-of-life (EOL) module waste, creating a need for efficient recovery of valuable materials and environmentally responsible recycling routes. This review critically examines recycling strategies for end-of-life crystalline-silicon PV modules, covering mechanical, thermal, chemical, and emerging environmentally preferable approaches. Mechanical processes are effective for bulk material separation and pretreatment but generally provide limited recovery of high-value components at high purity. Thermal methods enable effective polymer decomposition and delamination but may involve substantial energy consumption and gaseous emissions, whereas chemical processes can achieve selective and high-purity recovery of silicon and metals at the expense of reagent consumption, wastewater generation, and occupational and environmental risks. Emerging approaches based on lower-hazard solvents, deep eutectic solvents, and recyclable chemical systems offer potential improvements but remain insufficiently validated at module and industrial scales. Across the reviewed technologies, the major barriers are process integration, energy and chemical demand, waste and emission management, economic viability, product purity, and large-scale continuous operation. Future researches should therefore focus on integrated hybrid processes that combine efficient pretreatment with selective material recovery, closed-loop solvent and reagent management, and reduced environmental burdens.
In the technology of preparing α-hemihydrate gypsum by the atmospheric pressure salt solution method, the application and cyclic utilization of chlorine-free salt solutions are current urgent problems to be solved. This paper systematically investigated the process and results of phosphogypsum converting to α-hemihydrate gypsum in the chlorine-free salt solution system, and analyzed the performance of the recovery solution. The composite salt solution of NaNO3-Na2SO4 (0.95 : 0.05) was found to resolve the problems of high salt concentration and short induction period in pure salt solution of NaNO3. In a 20
