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The North China Grid has the highest proportion of fossil fuel-based electricity generation in China and also suffers from severe water scarcity issues. This study uses a multi-objective optimization model to explore future configurations of generating and cooling technologies of the electric power sector in the North China Grid subject to constraints imposed by existing policies on water conservation and carbon reduction in 2030. Our findings highlight that the current carbon reduction commitments of China do not have significant impacts on the North China Grid's electric power sector development while policies in the water sector generate much larger impacts. Imposing water constraint according to the 'Three Red Line' Policy requires increasing utilization of wind power and air cooling systems, which simultaneously increases economic cost and carbon emissions compared to the business as usual scenario. Imposing enhanced carbon emission and water consumption constraints reap the co-benefits of carbon reduction and water conservation by increasing the proportion of solar PV generation to 8.21%, which increases the unit electricity cost from RMB 0.82 per kWh to RMB 1.37 per kWh. In 2030, electricity generation in the North China Grid generates 1599.88 to 1690.89 million tons (Mt) of carbon emissions under different scenarios whereas imposing water constraint reduces water consumption from 3.34 billion m 3 to 1.94 billion m 3 ., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Urbanization is accompanied by growing household consumption and changing consumption patterns, with both having impacts on the life-cycle water pollution generated. This study uses the indicator of grey water footprint (GWF) within an Input-Output framework to examine the decadal change from 2002 to 2017 of the life-cycle water pollution change for household consumption in China, where rapid urbanization has particularly posed looming environmental challenges. Against the background of enlarging inequality, the results also shed light on the impacts of households within different income groups. From 2002 to 2017, GWF required by urban household consumption has increased significantly from 1586 to 2195 km 3 while that for rural households have decreased slightly from 1139 to 964 km 3 during the same period. Total Nitrogen required the largest GWF throughout the whole period and throughout all different income groups. Food consumption dominated the GWF for household consumption. However, the share of GWF for food consumption decreases with income increases, from 83% for extremely poor rural households to 71% for very rich urban households in 2012. Urbanites on average require higher GWF for their consumption than their rural counterparts. An average person from the highest income rural households required 2033 m 3 GWF for household consumption, which is higher than a person from a very poor urban household (1685 m 3 ) but lower than that of a person from poor urban household (2149 m 3 ). While household consumption volume increase has been the primary driver for GWF increase, pollution intensity reduction has offset such impacts. Household consumption pattern change's impacts differ by household income and by pollutant considered., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Substantial amounts of greenhouse gas (GHG) emissions generated at urban wastewater treatment plants (WWTP) are gaining increasing appreciation. Improving upon the commonly used Process-Based Life-Cycle Analysis (PLCA) and Environmentally-Extended Life-Cycle Analysis (EIO-LCA) models, we construct a Hybrid Life Cycle Analysis (HLCA) model and quantify both direct and indirect GHG emissions at the operational stage of WWTPs in Shenzhen, one of the fastest urbanizing cities in the world. Data are collected from 26 wastewater treatment plants in Shenzhen, out of all 32, covering 5 commonly used wastewater treatment technologies in China, i.e. Sequencing Batch Reactor, Oxidation Ditch, Biological Filter, AAO-MBR and AAO. The results show that WWTPs using AAO-MBR technology have the highest GHG emission intensity, averaging 0.79 tons per m 3 , primarily due to its large electricity intensity required. WWTPs using other technologies emit 0.27 to 0.39 tons of GHGs per m 3 of wastewater treated. GHG emissions associated with electricity use occupy the largest share, ranging from 65 to 75%. Therefore, transforming the energy structure of the electric power sector to low-carbon sources can reduce WWTPs operational GHG emissions. In total, GHG emissions from Shenzhen's urban wastewater sector have increased from below 0.5 million tons in 2012 to over 0.6 million tons in 2017. Inter-model comparison shows that EIO-LCA substantially underestimates the urban wastewater sector's GHG emissions using the water sector's average parameters while PLCA also results in minor underestimations due the omission of indirect emissions in the production stage of chemicals and other material inputs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)