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Sewage treatment plants (STPs) as a carrier of microplastics (MPs) have received considerable attention worldwide recently. In India, the majority of studies on MPs have been conducted in sediments, riverine, and marine systems, while knowledge on MPs occurrence in STPs is scarce. Henceforth, this work evaluated the presence of MPs in sewage and sludge in a hybrid growth, secondary treatment-based STP system. Optical microscopy, scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy methods were used to examine the abundance of MPs in raw sewage, effluent from different treatment units of the STP, and sludge samples. A total number of MPs of 201 ± 19 (2021) and 197 ± 22 (2022) were detected in the studied STP system. Results showed that MPs ranged between 64.3 ± 4.89–47.66 ± 4.71 n/L (sewage) and 1.14 ± 0.30–1.38 ± 0.65 n/g (sludge) with the overall removal efficacy of the studied STP estimated to be around 80%. Fragments and fibers were predominant among all shapes and particles mostly belonged to sizes <50 μm and <50 μm–250 μm in sewage and sludge, respectively. In total, seven polymers were identified of which low-density polyethylene (LDPE) constituted the highest proportion in sewage (26%–31%) and polyvinyl chloride (PVC) contributed the highest in the sludge (22%–27%). Moreover, MPs control measures have been discussed based on the findings of this study to restrict MPs re-entry into the environment via treated effluent and sludge. [Display omitted] • First study on MPs occurrence and removal in a hybrid growth MBBR-based STP. • Around 80% MPs were removed via the primary and secondary treatment stages in the STP. • LDPE (in sewage) and PVC (in sludge) were the most prevalent polymers. • Small-sized MPs (<250 μm) like fragments and fibers were predominant shapes. • Advanced treatment options for MPs removal from secondary-treated effluent discussed. [ABSTRACT FROM AUTHOR]

Sewage sludge, generated post wastewater treatment, constitutes only a small percentage of the total amount of sewage treated, however, its sustainable management is inevitable. In this study, the energy recovery potential of sewage sludge by incineration and anaerobic digestion is investigated for India. The dewatered sludge has total solid content of 25–45% whereas, the primary characteristics of sewage sludge showed significant organic content of about ∼23–40% (dry basis). The calorific value was found to be 8–21 MJ/kg for sludge dry matter. The energy recovery potential of sewage sludge was 555–1068 kWh/tonne on sludge dry matter basis for incineration and 315–608 kWh/tonne for anaerobic digestion. Additionally, the energy recovery potential of current sewage treatment in India was found to be ∼15.3 × 105 or 8.6 × 105 MWh, annually for incineration and anaerobic digestion, respectively. The study had provided in depth view of sludge to be considered as energetic material and its energy recovery potential countrywide, which would not only help for give a proper direction for recovering energy but also helpful to deal with the issue of sludge management in India. Image 1 • Sludge generated from sewage treatment plants was explored for energy alternatives. • The sewage sludge contains high heating value, organic matter and volatile matter etc. • Energy recovery potential of sewage sludge produced in India was estimated. • The energy recovery from sewage sludge could reduce energy demands and reduce land requirement for its disposal as well. [ABSTRACT FROM AUTHOR]

Abstract: Sludge Hygienisation Research Irradiator (SHRI) Facility at Vadodara (India) has been disinfecting liquid sewage sludge with 60Co gamma rays since 1992. At some point, the radiation process was modified from its originally designed closed-loop system to an open-loop system. Dosimetry experiments were performed to estimate absorbed doses to the sludge for different periods of irradiation of a 15m3 batch in an open-loop irradiation process. The paper reports the dosimetry results and evaluated operational parameters of the irradiator, namely, effective dose rate in the open-loop system, irradiation efficiency, and throughput. Also, the open-loop system and the closed-loop system are compared in terms of the effective dose rate. [ABSTRACT FROM AUTHOR]

The notion of the infrastructure gap is widely articulated in development studies to denote lacunae and areas of need in infrastructure functioning and connectivity across regions and nations. Sanitation infrastructure is one of the clearest areas in which to examine this gap. To close the gap, government and multilateral agencies are espousing citywide inclusive sanitation. This means comprehensive sanitation services for all through a combination of centralized and decentralized projects and a variety of techniques and services. However, this diversity of projects, techniques, and services will create additional challenges for infrastructure connectivity and functionality that need to be addressed through empirical research. We explore the gaps in wastewater and fecal sludge management infrastructure in India by approaching the problem from the activities and perspectives of three nonstate leaders and their associates. We argue that the notion of infrastructure disarray is an appropriate orienting idea as it points to an emerging field of experimentation and innovative activity while also showing how conditions of dysfunction and disconnection are sustained and reproduced. Taking disarray as a condition of infrastructure confusion among overlapping and disconnected segments of the sewage services chain, the cases show how nonstate actors and their communities are confronting disarray, reproducing these conditions of disarray, or grappling with ways to overcome this disarray. This article is categorized under:Engineering Water > Sustainable Engineering of WaterEngineering Water > Planning WaterHuman Water > Water Governance The Nagwa drain in Varanasi where Dr. Mishra carried out his flow measurements.This paper argues that infrastructure disarray rather than infrastructure gap is a more useful notion for framing the challenges and conditions of wastewater management in India today. Taking disarray as a condition of infrastructure confusion among overlapping and disconnected segments of the sewage services chain, the cases show how nonstate actors and their communities are confronting disarray, reproducing these conditions of disarray, or grappling with ways to overcome this disarray. [ABSTRACT FROM AUTHOR]