Papers by Ihsanullah Sohoo
Membranes
Solar-activated water treatment has become an emerging research field due to its eco-friendly nat... more Solar-activated water treatment has become an emerging research field due to its eco-friendly nature and the economic feasibility of green photocatalysis. Herein, we synthesized promising, cost-effective, and ultralong-semiconductor TiO2 nanowires (NW), with the aim to degrade toxic azo dyes. The band gap of TiO2 NW was tuned through transition metals, i.e., chromium (Cr) and manganese (Mn), and narrowed by conjugation with high surface area graphene oxide (GO) sheets. Cr–Mn-doped TiO2 NWs were chemically grafted onto GO nanosheets and polymerized with sodium alginate to form a mesh network with an excellent band gap (2.6 eV), making it most suitable to act as a solar photocatalytic membrane. Cr–Mn-doped TiO2 NW @GO aerogels possess high purity and crystallinity confirmed by Energy Dispersive X-ray spectroscopy and X-ray diffraction pattern. A Cr–Mn-doped TiO2 NW @GO aerogels membrane was tested for the photodegradation of Acid Black 1 (AB 1) dye. The synthesized photocatalytic memb...
Open Research Europe
Background: The acceptance of compostable plastic packaging in industrial composting plants is no... more Background: The acceptance of compostable plastic packaging in industrial composting plants is not universal despite available certification for compostability due to the persistence of compostable plastic residues reported by some industrial plants. This study aims to better understand this discrepancy by comparing the disintegration rate of two compostable plastic blends designed for rigid packaging (polylactic acid based) and soft packaging (polybutylene succinate based) between a controlled lab-scale test and an on-field test in an industrial composting plant. Methods: The thermophilic lab-scale disintegration test was conducted according to ISO 20200 in triplicates for 4, 8 and 12 weeks while the on-field test was conducted by exposing duplicate test material in the compost pile of an industrial composting plant in northern Germany, for three weeks. The mass change of the remaining test material >2mm was used as an indicator of disintegration. Results: The rigid packaging bl...
Water
In a water-scarce country such as Pakistan, rainfall is the third-largest source of freshwater. I... more In a water-scarce country such as Pakistan, rainfall is the third-largest source of freshwater. In most of the urban cities of the country, rainwater is mixed with sewerage and is rendered useless for managed aquifer recharge purposes. Therefore, this study investigates the rainfall potential for managed aquifer recharge in Lahore (Pakistan). The present research was designed and conducted by the Irrigation Research Institute (IRI). Three different sites were selected for rainwater sample collection across the study area (Lahore), ranging from urban to rural areas. The rainwater samples were collected and divided into three categories (direct capture, rooftop runoff, street runoff). For longer rainfall events, the effect of time on the quality of the collected rainwater samples was also studied. Spatiotemporal trends of turbidity, pH, electrical conductivity, total dissolved solids, carbonates, bicarbonates, chloride, calcium, magnesium, and hardness in the collected rainwater sampl...
Water
Owing to environmental pollution and increasingly strict regulations, heavy metals have attracted... more Owing to environmental pollution and increasingly strict regulations, heavy metals have attracted the attention of many researchers in various disciplines. Alginate and chitosan derivatives have gained popularity as biosorbents for water treatment. An increase in the number of publications on modified biosorbents for the biosorption of toxic compounds reveals widespread interest in examining the requirements and positive contribution of each modification type. This paper reviews the advantages and disadvantages of using alginate and chitosan for adsorption. Well-known modifications based on chitosan and alginate, namely, grafting, functionalization, copolymerization and cross-linking, as well as applications in the field of adsorption processes, especially amino acid functionalization, are reviewed. The selection criteria for the best biosorbents and their effectiveness and proposed mechanism of adsorption are discussed critically. In the conclusion, the question of why these adsorb...
Sustainability, 2022
Finding a sustainable approach for municipal solid waste (MSW) management is becoming paramount. ... more Finding a sustainable approach for municipal solid waste (MSW) management is becoming paramount. However, as with many urban areas in developing countries, the approach applied to MSW management in Karachi is neither environmentally sustainable nor suitable for public health. Due to adoption of an inefficient waste management system, society is paying intangible costs such as damage to public health and environment quality. In order to minimize the environmental impacts and health issues associated with waste management practices, a sustainable waste management and disposal strategy is required. The aim of this paper is to present a concept for the development of new bioreactor landfills for sustainable waste management in Karachi. Furthermore, this paper contributes to estimation of methane (CH4) emissions from waste disposal sites by employing the First Order Decay (FOD) Tier 2 model of the Intergovernmental Panel on Climate Change (IPCC) and determining of the biodegradation rate...
International Journal of Environmental Research and Public Health, 2022
Open disposal is the most common technique used for municipal solid waste (MSW) management due to... more Open disposal is the most common technique used for municipal solid waste (MSW) management due to the absence of sanitary landfills in Pakistan. The major cities and small towns in Pakistan have become a showcase of negligence and mismanagement of MSW, which results in deterioration of the environmental and social-life quality. Moreover, research has proved that inefficient handling (disposal) of MSW results in uncontrolled emissions of greenhouse gases (GHGs), mainly methane, and adds a significant share in global climate change. This study aims to estimate methane emissions from MSW disposed of at dumpsites and compare the GHG mitigation potential of different landfill strategies in specific climate and waste compositions in Karachi. The GHG estimations are based on lab-scale investigations conducted by simulating landfill conditions through the landfill simulation reactor (LSR) experiment. The synthetic MSW sample representing the composition of MSW generated in Karachi was used ...
RSC Advances, 2016
APTES functionalized montmorillonite has potential applications in the removal of Sr(ii) from was... more APTES functionalized montmorillonite has potential applications in the removal of Sr(ii) from wastewater by coordination–adsorption.
Chemical Engineering Journal, 2016
Abstract Precious metal Palladium (Pd) is a scarce natural resource with increasing industrial de... more Abstract Precious metal Palladium (Pd) is a scarce natural resource with increasing industrial demand. The use of microorganisms for biorecovery of Pd is a promising approach because it mimics natural biogeochemical cycles. In this study, we investigated the biorecovery of Pd 0 nanoparticles (Pd 0 -NPs) by Enterococcus faecalis ( E. faecalis ) with sodium formate as electron donor. X-ray diffraction analyses exhibited that the process could successfully reduce Pd 2+ and generate Pd 0 -NPs. Transmission electron microscope observation showed that the Pd 0 -NPs were associated at the membrane and inside of the cell. Under the optimum conditions of temperature (40 °C), sodium formate concentration (25 mM), biomass (1.2 g L −1 ), and 210 mg L −1 Pd 2+ (pH 3.0–3.5) were completely reduced within 48 h. The percentage of the Pd 0 -NPs with an average size lower than 10 nm increased from 91.5% to 99.6% as the biomass increased from 1.2 to 3.6 g L −1 , respectively. The catalytic property of the Pd 0 -NPs treated by ultrasonication was higher than chemically prepared Pd 0 . It showed that 6.3 mg Pd 0 -NPs could catalyze the complete reduction of 5.0 μmol Cr 6+ in 12 h. All of these findings suggest that it is potentially feasible to recover Pd 0 -NPs with catalytic activity from industrial wastes using E. faecalis .
Sustainability
Food security and energy transition are among the current major global environmental challenges. ... more Food security and energy transition are among the current major global environmental challenges. Although these issues individually are significant in their own right, they are connected to each other in a nexus with different interrelationships and dependencies. In the quest for non-fossil alternatives for energy, cultivation of bioenergy crops has become an important part of the energy policy in many countries. In this regard, the use of fertile agricultural land for growing crops for energy production rather than for food supply affects the global food security. Recent conflicts and the geopolitical crisis in Europe, leading to increased food, fuel, and fertiliser prices, the existing climate crisis, and the crisis caused due to the COVID-19 pandemic, have further reinforced the understanding of this nexus, with certain countries mulling limiting biofuel production from agricultural land and others banning food grain exports to safeguard food supply. The idea of growing non-food ...
Energies
This work aimed to estimate the annual methane production from the municipal solid waste disposal... more This work aimed to estimate the annual methane production from the municipal solid waste disposal sites in Pakistan. In this study, the Intergovernmental Panel on Climate Change (IPCC) default methodology was used to estimate theoretical methane formation potential of the waste disposal sites in major cities of Pakistan. The estimates of this study are based on the last population census conducted in the year 2017 and latest available data regarding the waste generation and management practices in the cities considered in the study. Results showed that 31.18 million tonnes of municipal solid waste (MSW) is generated annually. The top 10 major populated cities in Pakistan (with 20% share in country’s population) contributing 31% share in the total quantity of MSW generated in overall country. On average 50–60% of the MSW generated is collected and openly dumped at the designated waste disposal sites. After analyzing the data, we estimate that annually 12.8 MtCO2-eq of methane is emit...
Sustainability
Pakistan is facing a severe energy crisis due to its heavy dependency on the import of costly fos... more Pakistan is facing a severe energy crisis due to its heavy dependency on the import of costly fossil fuels, which ultimately leads to expansive electricity generation, a low power supply, and interruptive load shedding. In this regard, the utilization of available renewable energy resources within the country for production of electricity can lessen this energy crisis. Livestock waste/manure is considered the most renewable and abundant material for biogas generation. Pakistan is primarily an agricultural country, and livestock is widely kept by the farming community, in order to meet their needs. According to the 2016–2018 data on the livestock population, poultry held the largest share at 45.8%, followed by buffaloes (20.6%), cattle (12.7%), goats (10.8%), sheep (8.4%), asses (1.3%), camels (0.25%), horses (0.1%), and mules (0.05%). Different animals produce different amounts of manure, based upon their size, weight, age, feed, and type. The most manure is produced by cattle (10–2...
Sustainability
Sustainable management of municipal solid waste is one of the major challenges for authorities in... more Sustainable management of municipal solid waste is one of the major challenges for authorities in developing countries. Current waste disposal methods in Pakistan and other developing countries are not meeting standards of any proper waste management system opted for in the developed world. This mismanagement of waste is leading to serious environmental problems at local as well as global levels. This study aims to investigate the methane emissions from waste dumpsites in the city of Karachi, Pakistan, and to propose an effective approach to enhance their environmental sustainability. The methane emissions from waste disposal sites were assessed by simulating four different landfill situations during the landfill simulation reactor experiment. The residual methane reduction potential of each waste disposal approach was assessed by a biochemical methane test of waste after the experiment. It is estimated that in the present situation, about 11,500 tons of CO2-eq methane is released a...
Science of The Total Environment
It is the first effort to recover Pd 0-NPs by E. faecalis with sodium formate. Pd 0-NPs were reco... more It is the first effort to recover Pd 0-NPs by E. faecalis with sodium formate. Pd 0-NPs were recovered at the membrane and intracellular of E. faecalis cells. The time for the Pd 2+ bioreduction was shortened by controlling of temperature. The size of Pd 0-NPs (<10 nm) were mainly adjusted by biomass, pH, and temperature. A novel method to retrieve Pd 0-NPs from bio-Pd 0-NPs by ultrasonication was proposed. g r a p h i c a l a b s t r a c t a b s t r a c t Precious metal Palladium (Pd) is a scarce natural resource with increasing industrial demand. The use of microorganisms for biorecovery of Pd is a promising approach because it mimics natural biogeochemical cycles. In this study, we investigated the biorecovery of Pd 0 nanoparticles (Pd 0-NPs) by Enterococcus fae-calis (E. faecalis) with sodium formate as electron donor. X-ray diffraction analyses exhibited that the process could successfully reduce Pd 2+ and generate Pd 0-NPs. Transmission electron microscope observation showe...
Renewable and Sustainable Energy Reviews
Processes
In the biogas plants, organic material is converted to biogas under anaerobic conditions through ... more In the biogas plants, organic material is converted to biogas under anaerobic conditions through physical and biochemical processes. From supply of the raw material to the arrival of the products to customers, there are serial processes which should be sufficiently monitored for optimizing the efficiency of the whole process. In particular, the anaerobic digestion process, which consists of sequential complex biological reactions, requires improved monitoring to prevent inhibition. Conventional implemented methods at the biogas plants are not adequate for monitoring the operational parameters and finding the correlation between them. As Artificial Intelligence has been integrated in different areas of life, the integration of it into the biogas production process will be inevitable for the future of the biogas plant operation. This review paper first examines the need for monitoring at the biogas plants with giving details about the process and process monitoring as well. In the fol...
Modified calcium saturated montmorillonite (Mt) was prepared at different 3-aminopropyltriethoxys... more Modified calcium saturated montmorillonite (Mt) was prepared at different 3-aminopropyltriethoxysilane (APTES) loadings through grafting. The as-products were characterized by XRD, FTIR and elemental analysis. Surface analysis such as acidity was examined at different H + concentrations, showing that the release of OH À from the modified samples increased in the following order: APTES 4.0CEC -Mt > APTES 3.0CEC -Mt > APTES 2.0CEC -Mt > APTES 1.0CEC -Mt. Batch experiments were conducted and different conditions (pH, temperature and co-existing ions) were used to evaluate the adsorption capacity of the modified samples. The study developed a new way to confirm the mechanism, which indicated that ligand adsorption was the dominant sorption mechanism for Sr(II) uptake onto APTES-Mts. In general, APTES grafted montmorillonite possessed a higher efficiency of Sr(II) uptake and showed great potential for Sr(II)-rich wastewater treatment.
It is the first effort to recover Pd 0-NPs by E. faecalis with sodium formate. Pd 0-NPs were reco... more It is the first effort to recover Pd 0-NPs by E. faecalis with sodium formate. Pd 0-NPs were recovered at the membrane and intracellular of E. faecalis cells. The time for the Pd 2+ bioreduction was shortened by controlling of temperature. The size of Pd 0-NPs (<10 nm) were mainly adjusted by biomass, pH, and temperature. A novel method to retrieve Pd 0-NPs from bio-Pd 0-NPs by ultrasonication was proposed. g r a p h i c a l a b s t r a c t a b s t r a c t Precious metal Palladium (Pd) is a scarce natural resource with increasing industrial demand. The use of microorganisms for biorecovery of Pd is a promising approach because it mimics natural biogeochemical cycles. In this study, we investigated the biorecovery of Pd 0 nanoparticles (Pd 0-NPs) by Enterococcus fae-calis (E. faecalis) with sodium formate as electron donor. X-ray diffraction analyses exhibited that the process could successfully reduce Pd 2+ and generate Pd 0-NPs. Transmission electron microscope observation showed that the Pd 0-NPs were associated at the membrane and inside of the cell. Under the optimum conditions of temperature (40 °C), sodium formate concentration (25 mM), biomass (1.2 g L À1), and 210 mg L À1 Pd 2+ (pH 3.0–3.5) were completely reduced within 48 h. The percentage of the Pd 0-NPs with an average size lower than 10 nm increased from 91.5% to 99.6% as the biomass increased from 1.2 to 3.6 g L À1 , respectively. The catalytic property of the Pd 0-NPs treated by ultrasonication was higher than chemically prepared Pd 0. It showed that 6.3 mg Pd 0-NPs could catalyze the complete reduction of 5.0 lmol Cr 6+ in 12 h. All of these findings suggest that it is potentially feasible to recover Pd 0-NPs with catalytic activity from industrial wastes using E. faecalis.
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Papers by Ihsanullah Sohoo