Life cycle environmental sustainability and cumulative energy assessment of biomass pellets biofuel derived from agroforest residues.

This study was carried out to produce low-emitting biomass pellets biofuel from selected forest trees such as (Cedrus deodara and Pinus wallichiana) and agricultural crop residues such as (Zea mays and Triticum aestivum) in Gilgit-Baltistan, Pakistan using indigenously developed technology called pelletizer machine. Characterization, environmental life cycle impact assessment, and cumulative energy demand of biomass pellets biofuel produced from selected agriculture crops and forest tree residues were conducted. The primary data for biomass pellets production was collected by visiting various wood processing factories, sawmills, and agricultural crop fields in the study area. Biomass pellets are a type of biofuel that is often made by compressing sawdust and crushing biomass material into a powdery form. The particles are agglomerated as the raw material is extensively compressed and pelletized. Biomass pellets have lower moisture content, often less than 12%. Physically, the produced pellets were characterized to determine moisture content, pellet dimensions, bulk density, higher heating value, ash content, lower heating value, and element analysis. A functional unit of one kilogram (kg) biomass pellets production was followed in this study.The life cycle impact assessment of one kg biomass pellets biofuel produced from selected agro-forest species revealed environmental impact categories such as acidification (0.006 kg SO2 eq/kg pellets), abiotic depletion (0.018 kg Sb eq/kg pellets), marine aquatic ecotoxicity (417.803 kg 1,4-DB eq/kg pellets), human toxicity (1.107 kg 1,4-DB eq/kg pellets), freshwater aquatic ecotoxicity (0.191 kg 1,4-DB eq/kg pellets), eutrophication (0.001 kg PO4 eq/kg pellets), global warming (0.802 kg CO2 eq/kg pellets), and terrestrial ecotoxicity (0.008 kg 1,4-DB eq/kg pellets). Fossil fuel consumption was the hotspot source to all environmental impacts investigated. To measure the cumulative energy demand of biomass pellets made from different agroforestry species leftovers showed that the maximum cumulative energy was from wheat straw pellets (13.737 MJ), followed by corncob pellets (11.754 MJ), deodar sawdust pellets (10.905 MJ) and blue pine sawdust pellets (10.877 MJ). Among the various production activities, collection and transportation of primary raw material, crushing, screening, adding adhesives, pelletizing, cooling, final screening, and packing have the maximum contribution to the water scarcity index, followed by lubricating oil (0.00147m3). In contrast, the minimum contribution to water footprint was from electricity (0.00008m3) and wheat starch (0.00005m3). The highest contribution to the ecological footprint impact categories such as carbon dioxide, nuclear, and land occupation was lubricating oil and less contribution of wheat starch and electricity for manufacturing one kg pellets biofuel. It is concluded that physico-mechanical and combustion properties of the biomass pellets biofuel developed in the present study were following the Italian recommended standards. Therefore, it is strongly recommended that the Government of Pakistan should introduce the renewable biomass pellets industry in the country to reduce dependency on fossil fuels for cooking and heating purposes.

Environmental sustainability assessment of biodiesel production from Jatropha curcas L. seeds oil in Pakistan.

According to IPCC Annual Report (AR-5), environmental impact assessment of any product prototype is recommended before its large-scale commercialization; however, no environmental profile analysis of any biodiesel prototype has been conducted in Pakistan. Therefore, objective of this study was to conduct a comprehensive life cycle assessment (LCA), water footprint and cumulative energy demand (CED) of biodiesel production from Jatropha curcas L. (JC) seeds oil in Pakistan. A cradle-to-gate LCA approach was applied for 400 liter (L) JC biodiesel produced in Pakistan. JC biodiesel production chain was divided into three stages i.e., 1). cultivation of JC crop 2). crude oil extraction from JC seeds and 3). crude oil conversion to biodiesel. Primary data for all the stages were acquired through questionnaire surveys, field visits and measurements in the field. Potential environmental impacts were calculated in SimaPro v.9.2 software using Eco-indicator 99 methodology. Results showed that crude oil extraction stage accounted for highest emissions (77%) to the overall environmental impact categories evaluated, followed by oil conversion stage (21%) and JC cultivation stage (02%), respectively. The three stages of JC biodiesel production chain are major contributor to ecotoxicity with a contribution of 57% to this impact category. Higher contribution to ecotoxicity was due to agrochemicals used in the JC cultivation. Similarly, fossil fuels impact category was responsible for 38% of overall environmental impacts. In addition, water footprint of JC biodiesel production chain was 2632.54 m3/reference unit. Cumulative energy required for 400L JC biodiesel production chain was 46745.70 MJ in Pakistan. Fossil diesel consumption, synthetic fertilizers use and purchased electricity were major hotspot sources to environmental burdens caused by JC biodiesel production in Pakistan. By performing sensitivity analysis at 20% reduction of the baseline values of fossil diesel used, synthetic fertilizers and purchased electricity, a marked decrease in environmental footprint was observed. It is highly recommended that use of renewable energy instead of fossil energy would provide environmental benefits such as lower greenhouse gases and other toxic emissions as compared to conventional petroleum fuels. It is also recommended that JC as a biofuel plant, has been reported to have many desired characteristics such as quick growth, easy cultivation, drought resistance, pest and insect resistance, and mainly great oil content in JC seeds (27-40%). Therefore, JC plant is highly recommended to Billion Tree Afforestation Project (BTAP) for plantation on wasteland because it has multipurpose benefits.

Health risk assessment of heavy metals via consumption of dietary vegetables using wastewater for irrigation in Swabi, Khyber Pakhtunkhwa, Pakistan.

Health assumptions to the population due to the utilization of contaminated vegetables have been a great concern all over the world. In this study, an investigation has been conducted to ascertain metal concentrations in the wastewater, soil and commonly consumed vegetables from the vicinity of Gadoon Industrial Estate Swabi, Khyber Pakhtunkhwa Pakistan. Physicochemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS) and total solids (TS) and heavy metals such as Pb, Cr, Cd, Ni, Zn, Cu, Fe, Mn were determined using Atomic Absorption Spectrophotometer (AAS). Moreover, possible health risks due to the consumption of vegetables have also been estimated. pH and TSS in wastewater were found to be higher than the permissible limit set by WHO (1996). These results revealed that Cr concentration in the wastewater was above the permissible limits of United States Environmental Protection Agency (USEPA) which may lead to a detrimental effect on soil quality deterioration, ultimately leading to food contamination. ANOVA analysis demonstrated a significant difference in soil samples for Pb, Cr, Cd, Ni, Zn and Cu at p ≤ 0.001, for Mn at p ≤ 0.05 while no significant difference was observed for Fe respectively. ANOVA analysis also exhibited the highest mean value for Pb, Cr, Cd and Zn in vegetables. A substantial positive correlation was found among the soil and vegetable contamination. The transfer factor for Cr, Pb, Zn, Mn, Ni, Cd and Cu was greater than 0.5 due to contamination caused by domestic discharges and industrial effluents. Health assessment via consumption of dietary vegetables revealed a higher level than the permissible limit (HRI > 1) for Pb and Cd in children and adults. Enrichment factor (EF) due to consumption of vegetables was found higher for Pb and Cr respectively. Based on the findings of this study, there would be a significant risk to the consumers associated with consumptions of vegetables being cultivated in Gadoon Industrial Estate area of district Swabi. Therefore, strict regulatory control measures are highly recommended for the safety of vegetables originated from the study area.

Predictions of inter- and intra-lobar deposition patterns of inhaled particles in a five-lobe lung model.

OBJECTIVE: To develop a stochastic five-lobe lung model and to compute particle deposition fractions in the five lobes, considering anatomical as well as ventilatory asymmetry. MATERIALS AND METHODS: The stochastic five-lobe lung model was derived from an existing stochastic model for the whole lung, which implicitly contains information on the lobar airway structure. Differences in lobar ventilation and sequential filling of individual lobes were simulated by a stochastic lobar ventilation model. Deposition fractions of inhaled unit density particles in the five lobes were calculated by an updated version of the Monte Carlo deposition code Inhalation, Deposition, and Exhalation of Aerosols in the Lung (IDEAL). RESULTS: Simulations for defined exposure and breathing conditions revealed that the two lower lobes receive higher deposition and the two upper lobes lower deposition, compared to the average deposition for the whole lung. The resulting inter-lobar distribution of deposition fractions indicated that the non-uniform lung morphometry is the dominating effect, while non-uniform ventilation only slightly enhances the lobar differences. The relation between average lobe-specific deposition fractions and corresponding average values for the whole lung allowed the calculation of lobe-specific deposition weighting factors. DISCUSSION: Comparison with limited deposition measurements for upper vs. lower (U/L) and left vs. right (L/R) lobes revealed overall agreement between experimental and theoretical data. Calculations of the L/R deposition ratio for inhaled aerosol boli confirmed the hypothesis of Möller et al. that the right lung is less able to expand at the end of a breath because of the restrictive position of the liver.

Environmental impact assessment of municipal solid waste management value chain: A case study from Pakistan.

The present study quantified environmental impacts of the Rawalpindi Waste Management Company (RWMC) value chain in Pakistan for three consecutive years (2015-2018) using a cradle-to-grave life cycle assessment (LCA) approach. Energy potential from municipal solid wastes (MSW) was also predicted till the year 2050. Based on a functional unit of 1.0 tonne of MSW, the study analyzed inputs and outputs data through SimaPro v.8.3 applying CML 2000 methodology and cumulative exergy demand indicator (CExD). LCA revealed that operational activities of RWMC mainly contributed to marine aquatic ecotoxicity, i.e. 8962.83 kg1,4-DBeq t-1 MSW, indicating long-range transport of petrogenic hydrocarbons from the company's fleet gasoline combustion. Similarly, human toxicity potential, global warming potential and freshwater aquatic ecotoxicity potential were also found to be significant, i.e. 18.14 kg1,4-DBeq t-1 MSW, 15.79 kgCO2eq t-1 MSW and 6.22 kg1,4-DBeq t-1 MSW, respectively. The CExD showed that company activities consumed 827.14 MJ t-1 MSW exergy from nature, and gasoline used in MSW transport was the most exergy-intensive process, using 634.47 MJ exergy per tonne MSW disposed of. Projections for energy generation potential up to the year 2050 showed that MSW of Rawalpindi city will have the potential to produce 3901 megawatt of energy to fulfill the energy needs of the country. Possible stratagems to reduce environmental impacts from the municipal solid waste management (MSWM) value chain of RWMC include curtailing dependency on petrogenic and fossil fuels in mobile sources, optimization of waste collection methods and dumping routes, inclining attention toward suitable wastes-to-energy conversion technology and opting for a holistic approach of MSWM in Pakistan.

Improvement in overall performance of Catla catla fingerlings fed phytase included low cost plant by products-based diet.

Phytic acid's presence in low-cost Moringa by-products effect the availability of important nutrients, diminishing the fish quality and blood composition in fish. Phytate having chelating effects with nutrients and minerals, can be reduced by the supplementation of phytase enzyme. Without the use of enzyme, plant meal may cause water pollution and decrease the fish health that results in higher culture cost. Therefore, current study was designed to check improvement in overall performance of Catla catla fingerlings fed Moringa by product-based diets supplemented with phytase (0, 300, 600, 900, 1200 and 1500, FTU/kg). All diets were integrated with non-digestible marker (Cr2O3) at the rate of 1%. The fingerlings were fed couple of times a day (4% of live wet weight). Results showed significant (p < 0.05) improvement in nutrient digestibility (i.e. EE, CP and GE), carcass composition and hematological parameters (i.e. RBCs, PLT and Hb) at 900, FTU/kg of phytase in contrast with other treatments. Moreover, phytase addition improves the water quality by reducing the nutrients leaching through feces at low cost. Current results indicated that, using mixture of Moringa seed meal and Moringa leaf meal based diet supplemented with phytase at 900, FTU/kg concentration is the most optimum level to develop a cost-effective as well as eco-friendly fish feed with maximum absorption of important nutrients and minerals in fish body resultantly high higher fish performance.

Modeling intersubject variability of bronchial doses for inhaled radon progeny.

The main sources of intersubject variations considered in the present study were: (1) size and structure of nasal and oral passages, affecting extrathoracic deposition and, in further consequence, the fraction of the inhaled activity reaching the bronchial region; (2) size and asymmetric branching of the human bronchial airway system, leading to variations of diameters, lengths, branching angles, etc.; (3) respiratory parameters, such as tidal volume, and breathing frequency; (4) mucociliary clearance rates; and (5) thickness of the bronchial epithelium and depth of target cells, related to airway diameters. For the calculation of deposition fractions, retained surface activities, and bronchial doses, parameter values were randomly selected from their corresponding probability density functions, derived from experimental data, by applying Monte Carlo methods. Bronchial doses, expressed in mGy WLM-1, were computed for specific mining conditions, i.e., for defined size distributions, unattached fractions, and physical activities. Resulting bronchial dose distributions could be approximated by lognormal distributions. Geometric standard deviations illustrating intersubject variations ranged from about 2 in the trachea to about 7 in peripheral bronchiolar airways. The major sources of the intersubject variability of bronchial doses for inhaled radon progeny are the asymmetry and variability of the linear airway dimensions, the filtering efficiency of the nasal passages, and the thickness of the bronchial epithelium, while fluctuations of the respiratory parameters and mucociliary clearance rates seem to compensate each other.