https://www.selleckchem.com/products/ab928.html 482 to 8.099 and from 2437 to 4136 μmol kg-1, respectively, over the annual cycle. pCO2(water) showed significant positive correlation with turbidity and negative correlation with electrical conductivity and gross primary productivity (GPP). High water discharge could have facilitated high turbidity, especially during the monsoon season, which led to depletion in GPP and enhancement in pCO2(water) which in turn led to very high CO2 effluxes. The CO2 efflux rate in this urbanized riverine stretch was substantially higher than that observed in previous studies carried out in the less urbanized estuarine stretch of Hooghly. This indicates that the presence of highly urbanized and polluted metropolis potentially enhanced the pCO2(water) and CO2 effluxes of this river. Similar observations were made recently in some Asian and Australian urban rivers.Industries continuously emit xenobiotics into the environment, which increases risks of exposing humans and other biota to xenobiotics. Though various conventional and modern environmental remediation technologies are being employed, some of them are ineffective in removing xenobiotics, while others are costly and not feasible for large-scale utilization. Maize stover (MS) and rice husks (RH) are produced in abundance globally, which make them ideal and cost-effective feedstocks for large-scale biochar production for environmental remediation. Since either type of pristine MS and RH biochar may not be effective in removing some xenobiotics, the incorporation of modifiers into MS/RH biochars can help to form composite MS/RH biochar which in turn can better decontaminate water and soil. Thus, this review paper provides a comprehensive overview of the preparation, characterization, and environmental remediation using pristine and composite MS/RH biochar. Possible areas for composite MS/RH biochar applications and future perspectives of the technology in reducing xenobiotics are als