Ankur Rajpal

• Doctor of Philosophy
• Project Scientist-II at Indian Institute of Technology Roorkee

This work investigated the microbial community dynamics in ten full-scale cyclic technology-based sequencing batch reactors (SBR) based municipal wastewater treatment plants. In all the plants, pre-anoxic selectors are integrated with the main SBR aeration tanks, and the operation is controlled with dissolved oxygen (DO) conditions and oxygen uptak...

The present study assessed a mechanical biological treatment (MBT) based solid waste treatment and disposal (SWTD) facility of an Indian Municipality. The non-biodegradable and the biodegradable fractions are separated from the mixed waste by trommel screens. The biodegradable fraction is used to make compost. The nonbiodegradable fraction is recov...

Landfill leachate is a complex mix of organics, inorganics and heavy metals produced from conventional and engineering landfilling practices. The adverse effects of landfill leachate on human and environmental health have forced the relevant authorities to stipulate stringent disposal requirements, producing the need for ground-breaking technologic...

Dewatered sludges from twenty-two sewage treatment facilities were characterized to develop the quality control indices in India. This study used fertilizer index (FI) and clean index (CI) as a tool for categorizing sludge utilization into different classes (A, B, C and limited use classes LU-1, LU-2, LU-3) by their fertilizing potential, toxicity...

A novel pilot scale post-anoxic integrated biofilm activated sludge system of capacity 50 m³/d, was used to treat municipal wastewater. Treatment process comprised of three biological reactors which includes aerobic tank with PVA-gel beads followed by anoxic tank and aerobic tank. The plant was operated at HRT of 6 h, with an average SRT of 10 days...

Slaughterhouse plants, especially meat and poultry products (MPPs), generate significant quantities of wastewater during the slaughtering process and the cleaning of machinery. The handling and final disposal of wastewater from the slaughterhouse is a public and environmental health issue due to its pollution potential. The monitoring of three full...

This study aims to enhance nutrient removal efficiency and functional microorganisms’ role in governing simultaneous nitrification and denitrification (SND) using the well-designed compartmented selectors with the SBR aeration tanks. Simultaneous nitrification and denitrification were observed in ten wastewater treatment plants of India; they are b...

In addition to many other well-documented factors, local conditions are rudimentary conditions of sharp change observed in wastewater characteristics from place to place. The monitoring of 3 million liters per day-capacity full-scale Sequencing Batch Reactor (SBR) at Roorkee (India) drew attention to the processes involving simultaneous nitrificati...

Anaerobic treatment of wastewater is a well-established process, with a history of more than 100 years. It not only decreases the amount of waste byproducts (sludge), but the process also produces surplus energy, through release of biogas. Earlier, low-rate anaerobic continuous stirred tank reactors were employed but they did not have sufficient ca...

Cyclic technology–based sequencing batch reactors (SBR) treating municipal wastewater were audited for their performance under full hydraulic load design conditions. The performance data showed that the WWTPs produced an effluent having a very low concentration of chemical oxygen demand (COD, 10 mg/L), biochemical oxygen demand (BOD, <10 mg/L), and...

Incomplete removal of organic matter and nutrients in the effluent is the major problem in the wastewater treatment system. In developing countries like India, different treatment technologies are widely used, and moving bed biofilm reactor (MBBR) has shown greater efficiency and stability compared to the conventional process. The majority utilize...

The study investigates the fate of 20 contaminants of emerging concern (CECs) in two full-scale wastewater treatment plants (WWTPs) based on the Biodenipho™ (WWTP 1) and anaerobic-anoxic-oxic (WWTP 2) processes. Samples of both the dissolved and solid phases (particulate and sludge) from all the wastewater and sludge processing-related units were s...

Sludge production in wastewater treatment is one of the main offsets in the operation and maintenance of a biological wastewater treatment plant (WWTP). One of the primary management strategies can be curtailing the production in a liquid treatment stream. A polyvinyl alcohol (PVA) gel-based oxic-anoxic-oxic process was investigated for the wastewa...

The present study investigated the detection of severe acute respiratory syndrome–coronavirus 2 (SARS-CoV-2) genomes at each treatment stage of 14 aerobic wastewater treatment plants (WWTPs) serving the major municipalities in two states of Rajasthan and Uttarakhand in Northern India. The untreated, primary, secondary and tertiary treated wastewate...

Two full-scale pre-anoxic selector-equipped SBR based wastewater treatment systems were analyzed in this study to determine the role of storage products in simultaneous nutrient removal (TN and TP) via simultaneous nitrification and denitrification (SND) and enhanced biological phosphorus removal (EBPR) mechanisms, respectively. For nutrient remova...

This preprint is almost the same as the published version, barring a few modifications. However, readers are encouraged to read the published version here: https://doi.org/10.1016/j.wasman.2021.01.032

Management of agro-waste is a major challenge globally due to inefficient disposal techniques, which concominantly leads pollution and loss of renewable bioenergy. Anaerobic digestion of agro-waste is one of the ways to tackle this problem but hindered by the recalcitrant nature of agro-waste. This study investigated the effect of granular activate...

In addition to many other well-documented factors, local conditions are rudimentary conditions of sharp change observed in wastewater characteristics from place to place. An optimized and flexible treatment strategy is required to handle these fluctuations and variations in quality. Pre-anoxic selector-equipped sequencing batch reactors (SBR) perfo...

Anaerobic digestion (AD), a series of biochemical processes, is accomplished by the group of anaerobes, functioning collectively to transform organic mass into biogas and nutrient-rich digestate. Each microbial group has its unique qualities (growth rate, , susceptibility and, diversity and density) as a response to variable operating conditions. T...

In the recent decades, the role of wastewater treatment plants has been entrenched for the dissemination of antibiotic resistant bacteria into the environment. The present study explores the dynamics of earthworms- microorganisms interactions involved in the high treatment efficacy of vermifiltration technology along with reduction of antibiotic re...

The thrust of this study was to assess the upgradation of an existing 3.5 million liters per day (MLD) full-scale conventional MBBR-based sewage treatment plant (STP) into Aerobic/Anoxic/Aerobic configuration. Initially, the plant was designed and constructed for achieving BOD and TSS to <30 mg/L and <50 mg/L, respectively. Recently, due to the adv...

In this study, a novel integrated system (MBBR, anoxic and oxic) was developed to enhance carbon and nitrogen removal for treating raw municipal wastewater. Poly Vinyl Alcohol (PVA) gel beads were used as a biomass carrier in MBBR. The system was operated for more than a year at seasonally varied temperatures (10 ºC to 30 ºC) at HRT of 6, 5 and 4.4...

The solid waste found in rural areas can be used as a soil conditioner providing essential nutrients to crops and enhancing agricultural productivity. It is an eco-friendly and economic preference for Municipal Solid Waste Management (MSW). This study investigates the solid waste management scenario in rural areas along the river Ganga and proposes...

The wastewater treatment plants effluent has been implicated in the spread of antibiotic resistant bacteria (ARB) as these environment contains multiple selective pressures that may increase mutation rates, pathogen survivability, and induce gene transfer between bacteria. In lieu of this, the present study explored the dynamics of earthworm-microo...

We investigated the presence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) RNA at different treatment stages of 15 wastewater treatment plants (WWTPs) in two North Indian states of Rajasthan and Uttarakhand. Untreated (influent), biologically treated, and disinfected wastewater samples were collected from May to August 2020. The q...

An environmental monitoring plan (EMP) has been formulated to examine the effects of the Nizamuddin bridge project during construction and operation phases, operated in Delhi, India, and efficacy of implementation of mitigation measures. The environmental monitoring components include ambient air quality monitoring, water quality monitoring of Yamu...

This research presents a comparative performance evaluation of five HYBAS (MBBR+ASP) based STPs in India, 3.5 MLD Srinagar Pauri Garhwal, 5 MLD Munni Ki Reti Tehri Garhwal, 2 MLD Gyansu Uttarakashi, 50 KLD Kirtinagar Tehri Garhwal and 10 KLD Kirtinagar Tehri Garhwal. The specific objectives of the study were as follows: The first objective was comp...

Stormwater runoffs are one of the primary causes for deteriorating water quality in the Nainital Lake, India – a prominent tourist attraction and the sole drinking water source for the habitants of Nainital City. Treatment of fluctuating runoffs and contaminant influxes before mixing with the lake’s water by conventional methods would require a lar...

Moving bed biofilm reactor based sewage treatment plants (STPs) have been installed in northern India over the last decade. As such, there are no performance evaluation studies of this technology in the region. Evaluation of four such STPs was carried out in terms of removal efficiency of physicochemical parameters, microbiological parameters and h...

Contamination level of four phthalates in untreated and treated wastewater of fifteen wastewater treatment plants (WWTP) and their fate in a full scale sequencing batch reactor (SBR) based WWTP was evaluated in this study. The four phthalates were Diethyl phthalate (DEP), Dibutyl phthalate (DBP), Benzylbutyl phthalate (BBP) and Diethylhexyl phthala...

The present study brings insight to the antimicrobial activity of isolated bacterial species in a vermifilter (VF) during the combined treatment of domestic wastewater and organic fraction of municipal solid waste (OFMSW). The study showed that vermifilter resulted in an effluent with biochemical oxygen demand (BOD) <20 mg/L and coliforms<103 MPN/1...

A comparative study was performed to treat the domestic wastewater through two different epigeic earthworms (Eisenia fetida and Eudrilus eugeniae) based vermifiltration unit (VF1 and VF2). Results revealed a significant removal of biochemical oxygen demand (88%), total suspended solids (78%), and total dissolved solids (75%) in the treated wastewat...

two kinds of composting systems viz., Rotary drum composting and windrow composting system. Physico-chemical parameters, enzymatic activity and germination index test were analyzed. A statistical correlation values were relatively higher in case of rotary drum composting system as compared to windrow pile, having highly with higher degradation rate...

Performance evaluation of vermireactors (Trials T1, T2, T3) for co-treatment of organic fractions of municipal solid waste (OFMSW) and sewage was conducted on three different earthworm species such as Eisenia fetida, Perionyx excavatus, and Perionyx sansibaricus. The results were compared with control reactor (T4) (without earthworms) for 120 days....

The present study focuses on the effect of filter media (riverbed gravel, mud balls, coal and glass balls) for the removal of pathogens during vermifiltration of domestic wastewater. This novel study was conducted for the first time on different vermifilters (VFs) with different media and pathogen removal was extensively investigated for a period o...

The study was designed to determine the effect of earthworms and the mechanism behind removal of pathogens during wastewater treatment by vermifiltration. The experimental phase continued for 10 weeks, starting after the initial stabilization phase of one week. Significant organic matter degradation and coliform removal were observed during vermifi...

The effects of alkali-enhanced microwave (MW; 50–175 °C) and ultrasonic (US) (0.75 W/mL, 15–60 min) pretreatments, on solubilisation and subsequent anaerobic digestion efficiency of pulp and paper mill waste-activated sludge, were investigated. Improvements in total chemical oxygen demand and volatile suspended solids (VSS) solubilisation were limi...

One of the most versatile and remunerative techniques for handling biodegradable solid wastes is composting. Composting refers to aerobic degradation of organic material and is one of the main waste treatment methods used for treating separated organic waste. Microbes play a key role as degraders during the composting-process and microbiology of co...

ABSTRACT Waste production has increased in recent years due to increasing population, industrialization and urbanization. Waste processing is a critical issue in modern society. Vermifiltration can be an efficient and promising technology in decentralized wastewater treatment. Digestion of organic matter by earthworms and the earthworm–microorganis...

In the present study a low-cost, sustainable and eco-friendly technology has been applied to treat domestic wastewater utilizing earthworms. The symbiotic and synergistic interaction of earthworms with microorganisms is responsible for the treatment of wastewater as it passes through the gut and intestine of earthworms. A pilot scale vermifilter (V...

The aim of the study was to examine safe reuse and recycling of organic waste digestate obtained from a biogas plant (5 % total solid) with enhanced nutrient value through vermitechnology. Two indigenous epigeic earth-worm species Perionyx excavates and Perionyx sansi-baricus were tried individually for this purpose. The results clearly show a sign...

Abstract: Better efficiency of composting process for domestic solid waste was calculated after monitoring two kinds of composting systems viz., Rotary drum composting and windrow composting system. Physico-chemical parameters, enzymatic activity and germination index test were analyzed. A statistical correlation was adopted between germination ind...

In India the exotic epigeic species, Eisenia fetida is mostly used for vermicomposting. The introduction of exotic species into local bio system may affect the indigenous earthworm species population. A comparative study between exotic species (Eisenia fetida) and indigenous species Perionyx sansibaricus and Perionyx excavates was performed to dete...

Abstract: In this study, efficiency of vermitechnology in stabilizing sludge without pre-treatment was studied. The sludge was directly introduced in the vermicomposting reactors after their withdrawal from the bio-methanation reactor installed for experimentation on domestic waste. One Liter (5% TS) sludge was loaded after every fourth day and it...

In India the exotic epigeic species, Eisenia fetida is mostly used for vermicomposting. The introduction of exotic species into local bio system may affect the indigenous earthworm species population. A comparative study between exotic species (Eisenia fetida) and indigenous species Perionyx sansibaricus and Perionyx excavates was performed to dete...