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Thermochemical processes utilizing biomass demonstrate promising prospects for the generation of syngas. In this work, a gasification process employing combination of an indigenous low-grade coal with two distinct biomass sources, namely rice husk (RH) and wood sawdust (WS), was explored. The gasification of the selected feedstock was performed using a double-staged multi-opposite burner (MOB) gasifier. A 3D computational fluid dynamics (CFD) model was employed to analyze the effect of kinetic and diffusion rates on the overall gasification performance of an entrained flow biomass gasifier. DPM was employed to track the particles' trajectory, while the gas phase was treated as the continuous phase, and its behavior was predicted using a standard k-epsilon turbulent model. To calculate both the homogeneous and heterogeneous reaction rates, the finite rate/eddy dissipation model was implemented. The findings indicate that the char conversion efficiency exceeded 95% across all instances. Among the different reaction schemes, scheme E (which involved complete volatile and char combustion reactions) produced better results in comparison with published results, with less than 1% error. Hence, scheme E was validated and utilized for the rest of the simulated cases. The feeding rate has an inverse effect on the overall performance of the gasifier. An increase in feed rate decreases the CO and H2 composition in syngas. The maximum CO value was observed to be 57.59% at a 1.0 O/C ratio with a 0.005 kg/s feed rate, and the maximum H2 value was observed to be 16.58% in the same conditions for Lakhra coal samples. In summary, Lakhra coal exhibited better performance than other biomass samples due to its better fixed carbon and volatiles in its composition. [ABSTRACT FROM AUTHOR]

Highly contaminated municipal wastewater is being disposed of into land and rivers without any prior treatment has severe side effects on human and marine animals. This research focused on the treatment of Majeed Keerio village municipal wastewater through horizontal flow constructed wetland system. The experimental study was evaluated and monitored timely over a year. The overall treatment efficiency performance of the wetland system was determined by considering organic pollutants removal efficiency. This study emphasized on the design of horizontal flow constructed wetland for the effective treatment of municipal wastewater of village Majeed Keerio, Sakrand, Sindh. The constructed wetland efficiently reduced COD, BOD5, TSS, turbidity, total phosphate, total nitrogen pollutants of wastewater, which was about 92.3%, 93%, 96%, 96.4% and 74%, respectively. This method reduced all thermotolerant coliforms. Constructed wetland system was found most economical and effective for the treatment of domestic wastewater. The effect of different hydraulic loading rates under varying hydraulic retention times within the constructed wetland was examined. The higher hydraulic retention times resulted in improved pollutants removal efficiency. [ABSTRACT FROM AUTHOR]

Appropriate eco-friendly methods to mitigate the problem of emissions from combustion of fossil fuel are highly demanded. The current study was focused on the effect of using coal & coalbiomass co-combustion on the gaseous emissions. Different biomass' were used along with coal. The coal used was lignite coal and the biomass' were tree waste, cow dung and banana tree leaves. Various ratios of coal and biomass were used to investigate the combustion behavior of coalbiomass blends and their emissions. The study revealed that the ratio of 80:20 of coal (lignite)- cow dung and 100% banana tree leaves emits less emissions of CO, CO2, NOx and SO2 as compared to 100% coal. Maximum amount of CO emissions were 1510.5 ppm for banana tree waste and minimum amount obtained for lakhra coal and cow dung manure (70:30) of 684.667 ppm. Maximum percentage of SO2 (345.33 ppm) was released from blend of lakhra coal and tree leaves (90:10) and minimum amount of SO2 present in samples is in lakhra coal-banana tree waste (80:20). The maximum amount of NO obtained for banana tree waste were 68 ppm whereas maximum amount of NOx was liberated from lakhra coal-tree leaves (60:40) and minimum amount from cow dung manure (30.83 ppm). The study concludes that utilization of biomass with coal could make remedial action against environment pollution. [ABSTRACT FROM AUTHOR]