Bio-based and biodegradable (bio-)plastics are heralded as a key solution to mitigate plastic pollution and reduce CO emissions. Yet, their end-of-life treatments embodies complex energy and material interactions, potentially leading to emissions through incineration or recycling. This study investigates the cradle-to-grave, emphasizing the waste management stage, carbon footprint for several types of bio-plastics, leveraging both GWP100a and CO uptake methods to explore the carbon reduction benefits of recycling over disposal.
View Article and Find Full Text PDFHeat pump can be used to recover abundant thermal energy contained in the discharge of municipal wastewater treatment plants. While there are some design standards for common heat pump systems, the design of a sewage source heat pump (SSHP) system is still often based on a fixed heat load and neglects the interdependencies between the equipment sizing and operating parameters. To address the issue that previous design methods have not balanced investment and operational costs well from a global optimisation perspective, this work formulates the simultaneous optimisation of SSHP design and operation as a non-linear programming problem.
View Article and Find Full Text PDFLow-carbon water production technologies are indispensable for achieving sustainable development goals and mitigating global climate change. However, at present, many advanced water treatment processes lack a systematic assessment of related greenhouse gas (GHG) emissions. Thus, quantifying their life-cycle GHG emissions and proposing strategies toward carbon neutrality is urgently needed.
View Article and Find Full Text PDFHigh operating cost caused by electric energy consumption is a common problem challenging many municipal wastewater treatment plants (WWTPs). Due to the characteristics of intermittent inflow and aeration, WWTPs using sequencing batch reactor technology and its variants can be managed to relieve operating cost through taking advantage of time-of-use electricity pricing. However, little attention has been paid to the scheduling of treatment processes in the context of WWTPs.
View Article and Find Full Text PDFMacrophyte combined with artificial aeration is a promising in situ remediation approach for urban rivers polluted with nutrients and organic matter. However, seasonal variations and aeration effects on phytoremediation performance and root-adhered microbial communities are still unclear. In this study, Pontederia cordata was used to treat polluted urban river water under various aeration intensities.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
September 2012
In order to investigate the spatial distribution pattern and degree of heavy metal pollution in river network sediments of Wenzhou, 29 sediment samples were collected, and using atomic fluorescence spectrometry (AFS) and inductively coupled plasma-optical emission spectrometry (ICP-OES) heavy metal concentration in the samples were analyzed. The Kriging interpolation map reflected the spatial distribution of heavy metal. Comprehensive geo-accumulation index based on the Nemerow index method was established to assess the pollution degree.
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