Textile industry in Pakistan is a major economic contributor but also a significant source of environmental pollution. It discharges substantial portion of untreated wastewater containing hazardous organic and inorganic pollutants and synthetic dyes into natural water bodies. Conventional biological treatment methods used in Pakistan have proven inadequate in complete removal of these complex and toxic chemical effluents. Therefore, this study explored the application of molecular distortion techniques (MDTs) for effective treatment of textile wastewater at molecular level. In this study MDTs, refer to the utilization of some physical energy via extreme localized conditions like high temperature, applying electric filed, radiations and high pressure and sometimes produced free radical to break and alter molecular structure of pollutant for easy removal. Such techniques include processes like ultrasonic irradiation, photocatalysis, microwave-assisted oxidation, Fenton’s oxidation, photolysis, ozonation, and plasma treatment, etc. These methods have shown a great potential in degrading recalcitrant organic compounds, reducing toxicity, and improving the overall quality of treated water. Literature survey revealed that the MDTs are effective in breaking down pollutants at the molecular level, offering a more comprehensive solution than conventional methods. However, challenges such as requirements of specialized equipment, high operational costs, energy requirements, and the limit these large-scale applications. Despite these challenges, the integration of MDTs into Pakistan's wastewater treatment infrastructure could significantly reduce the impact of the textile industry on environment. Present study emphasized the need for further research to optimize these techniques for cost-effectiveness and scalability.

Access to clean and safe drinking water is a significant challenge for individuals residing in suburban and remote regions of Pakistan. This study aimed to design, fabricate, and test a multi-effect solar still with four U-shaped condensing stages as a low-cost solution to this problem. The solar still was evaluated for its efficacy in removing common pollutants found in contaminated water sources. The results revealed an impressive 99% efficacy in eliminating various water pollutants, including conductivity, total hardness, pH, fluoride, and nitrate using the solar still. Water quality tests conducted for conductivity, total hardness, pH, fluoride, and nitrate revealed complete elimination of these parameters in most samples. Microbiological pollutants were also assessed through the presence/absence tests for fecal coliform and Escherichia coli, showing no presence in the distillate. In addition, the solar still effectively removed organic parameters, including alachlor, lindane, and endrin, within acceptable international standards. Thus, the proposed solar still has the potential to serve as an alternate method for producing safe drinking water in areas where access to clean potable water is limited. The findings of this study provide valuable insights for policymakers and researchers interested in addressing water scarcity in remote and suburban areas of Pakistan.

The issue of water depletion emerged as a life-threatening problem for the world due to urbanization, groundwater over-extraction, industrialization, and global warming. Current study aimed to address this issue by proposing a solution to distill wastewater using a multi-effect solar still. The study optimizes two condensation tray shapes, U and V, based on the yield produced and the temperatures achieved. Two solar still units with four stages of U and V-shaped trays were connected to a parabolic solar collector. To determine the optimal tray shapes, a rigorous optimization process was carried out using SolidWorks 2020. The optimization process yielded optimum heat flux values of 3.04e01 and 2.84e01 W/m2 for U and V-shaped trays, respectively. Higher the value of heat flux suggested more energy available for condensation. Which was corroborated by physical findings that the U-shaped condensation tray was more efficient, producing an average per day yield of 2.519 L/m2 h compared to the V-shaped tray's yield of 2.041 L/m2 h. The findings provide strong evidence that the U-shape is a better tray shape for condensation purposes. Maximum yield for both units was observed during the peak temperature time between (13:00-15:00 h), indicating a direct correlation between yield and atmospheric temperature.

In recent decades, the fortunes of energy economies have been closely linked in Pakistan. A major energy inefficiency issue was found in Pakistan due to the mismatch between horsepower (HP) requirements and bore depth. Keeping this in view, a total of 194 tubewells were chosen for an energy audit in the Multan region, Pakistan. The Terrameter SAS 4000 was used to measure the accurate demand of the head during the resistivity surveys at all of the selected locations. The results showed that the tubewell sets were installed arbitrarily at high power, irrespective of the provided flow and head, and these pumps used more energy for their flow. The results revealed that the efficiency of the tubewell sets increased from 35 to 54%, from 55 to 80%, from 49 to 80%, and from 48 to 75% for centrifugal pumps with electric motors and diesel engines and for turbines with electric motors and diesel engines, respectively. A weighted overlay analysis indicated that the efficiency of tubewells covering 838.12, 1131.8, and 2077.1 km2 for centrifugal pumps with electric motors, diesel engines, and turbines, respectively, was enhanced for the study area. Similarly, the energy saved for the study area covered 1423.8, 1161.1, and 1131.1 km2, as shown by the overlay analysis. The results revealed that the annual energy saving was found of 3486 kw for 194 tubewells, resulted in the saving of USD 0.204 million in operational costs over one year. The overall results indicate the strong need to adopt proper investigations of the head and power requirements before installing a system in the study area.

Human interventions and rapid changes in land use adversely affect the adequate distribution of water resources. A research study was conducted to quantify the gap between demand and supply for irrigation water in Multan, Pakistan, which may lead to sustainable water management. Two remotely sensed images (Landsat 8 OLI and Landsat 5 TM) were downloaded for the years 2010 and 2020, and supervised classification method was performed for the selected land use land cover (LULC) classes and basic framework. During the evaluation, the kappa coefficient was found in the ranges of 0.83-0.85, and overall accuracy was found to be more than 80% which indicated a substantial agreement between the classified maps and the ground truth data for both years and seasons. The LULC maps showed that urbanization has increased by 49% during the last decade (2010-2020). Reduction in planting areas for wheat (9%), cotton (24%), and orchards (46%) was observed. An increase in planting areas for rice (92%) and sugarcane (63%) was observed. The changing LULC pattern may be related to variation in water demand and supply for irrigation. The irrigation water demand has decreased by 370.2 Mm3 from 2010 to 2020, due to the reduction in agricultural land and an increase in urbanization. Available irrigation water supply (canals/rainfall) was estimated as 2432 Mm3 for the year 2020 which was 26% less than that of total irrigation water demand (3281 Mm3). The findings also provide the database for sustainable water management and equitable distribution of water in the region.

Cascade aerating trickling filters (CATF) with two indigenous and novel support media [date palm fiber, (DPF) and maize cob (MC)] were operated to treat domestic wastewater. The biomass, nitrification rate (NR), oxygen uptake rate (OUR) and cultural characteristics of biofilms were measured to investigate microorganism activity and biodiversity. However, the attached biomass on MC (4760 gVSS/m3) was obviously found more than the DPF (1460 gVSS/m3). Huge biomass may decrease the activity of biofilm in CATF. It was also observed that the nitrifying bacteria grow easily on MC surface due to its lower NR (4.2 mg N gVSS/m3) than DPF (5.3 mg N gVSS/ m3). Similarly, the OUR of MC media was found higher than DPF media that indicated the improved metabolic activities and microbial growth in the biofilm. At filtration velocities of 4, 8, and 12 m/hr, the biofilm biomass increased with increasing filtration velocity, reaching 2105, 4817, and 6247 mgVSS/m2 respectively. At a filtration velocity of 12 m/hr, the highest biofilm density was 39 mg/cm3. Biomass and thickness of Biofilm were lowest at the filtration velocity of 8 m/hr due to the low influent loading rate. Both the CATFs showed good capability of COD removal, nitrification and denitrification.

The precise monitoring of nitrogen (N) is an effective strategy for enhancing the crop yield per unit of land, but it involves field-level soil and crop data. The two years of experimental study were conducted during the cotton growing seasons of 2018 and 2019 at the Agriculture Research Farm of the Department of Agricultural Engineering, Bahauddin Zakariya University, Multan. The Nitrogen Fertilizer Optimization Algorithm (NFOA) was formulated based on the observed data for cotton lint yield (CLY) and GreenSeeker Normalized Difference Vegetation Index (GSNDVI) during the growing stages of cotton. The precision nitrogen application rate-based green seeker (PNAR) G.S for cotton was identified as 150-165 kg/ha. A linear relationship was observed between CLY (R2 = 0.80) for cotton with the GSNDVI. The average nitrogen requirement (Nreq) using (PNAR) G.S was determined through the nitrogen fertilizer optimization algorithm (NFOA). The Nreq was found to be 0.013 kg/kg for cotton. Precision N management originating from handheld crop sensors (GreenSeeker) may be helpful in decision-making for site-specific in-season N fertilizer management to enhance crop yield.

Threshing of wheat is a fundamental post-harvest operation to isolate grains from straw, leading to further processing and storage. This study introduces a promising and power-efficient technology named as “Compression–Oscillation” threshing, which relies on cyclic frictional squeezing rather than beating as in conventional threshers. Discrete element method simulation was used to model the physical characteristics of wheat spikes and grains as well as interaction properties such as bonding, coefficient of restitution, static and rolling friction. Concave clearance and rotor drum speed sensitivity were studied in terms of compressive force and threshing performance in the system. The achieved threshing efficiency is 98.0

Climate change has significant impacts over the worldwide groundwater resources and is generally dependent over location and topography of the region. This study investigates the climate explained variability of groundwater level (CEVGWL) in selected areas of Indus Basin of Pakistan. The sensitivity of groundwater level to climatic factors were investigated using the data for the period of 2003 to 2018 at 482 points. Variability in groundwater level was explained by temperature and precipitation as individual or collectively at various locations across the study zone. The outcomes of trend examination revealed that temperature and precipitation are negatively correlated to each other in the study area. The trend in mean annual temperature over the region varied from negative trend of -0.018 o C/year in Bahawalnagar region to a warming trend of 0.026 o C/year in Rahim Yar Khan region. Similarly, highest positive trend in rainfall of 3.885mm/year was observed at Rahim Yar Khan region. Moreover, the mean values of CEVGWL was examined as 18.56 and 31.98% in pre-monsoon and post-monsoon seasons, respectively. Spatial analysis also indicated that the groundwater level showed positive sensitivity in 50% wells (south-east part) with rise in temperature during pre-monsoon and post-monsoon. It was also noted that precipitation and temperature collectively affect the groundwater level in the study area during both the pre-monsoon and post-monsoon seasons.

Groundwater quality risk assessment is vital to protect this precious resource, because increasing anthropogenic and agricultural activities combined with limited precipitation deteriorate the groundwater quality particularly in the arid regions. Therefore, the assessment of groundwater quality using hydro-chemical and spatial analysis can provide the guidelines for efficient management of groundwater resources. In present study, a total of 87 samples were collected from various pumping wells in district Multan, Pakistan. These samples were analysed for groundwater quality parameters like electrical conductivity (EC), total dissolve solids (TDS), pH, Na+, Ca2+ + Mg2+, Cl−, CO32−, HCO3−, sodium adsorption ratio (SAR), sodium percentage (Na

Irrigated agriculture is highly dependent on groundwater resources in Pakistan. Due to the fiber and food requirements, the reliance on groundwater has been increasing during the past two decades. This research work was conducted at the canal command area of the Dera Ghazi Khan (D.G Khan) canal for years 2017–2019. There were two products of the satellite i.e., AQUA (EOS PM) and TERRA (EOS AM), which were used in this research for determining groundwater demand in the area. For Rabi seasons 2017–2018 and 2018–2019, cropping areas of the major crops i.e., wheat and sugarcane, were 98,712.5 and 131,856.2 ha, and 100,568.7 and 132,743.7 ha, respectively. For the Kharif seasons of 2018 and 2019, cropping areas of major crops i.e., rice, cotton, and sugarcane, were 82,093.7, 74,150, and 98,712.5 ha, and 75,687.5, 79,275, and 132,743.7 ha, respectively.

To enhance the combustion efficiency of high moist coal, it is important to reduce its moisture contents. For reduction of moisture contents, the selection of efficient and low-cost drying technique based on the coal characteristics is helpful to convert the high moist coal to good quality fuel. A total of 18 Thar coal (Pakistan) samples were crushed and sieved at following size fractions (355, 500, 710 mu m). These samples were dried using different techniques, namely, solar-drying, hot air-drying, oven-drying, microwave oven-drying, and flue gases drying. The morphological, physical, and chemical changes were investigated for the effectiveness of different techniques to make the Thar coal as a value-added fuel. The applied drying techniques showed a significant reduction in moisture contents from the Thar coal samples (38.11 to 7.78%). However, the flue gases drying and air-drying techniques showed highest reduction in moisture content (29-31%). Similarly, 35% increase in heating value (HV) J/kg was observed in case of flue gases drying technique. These results indicated that the flue gases and air-drying techniques may be used to reduce the moisture contents and enhance the HV of high moist Thar coal that can be used as value-added fuel in the country.

The main problem in treating grey water is the large variation in quality observed over short timescales. Different treatment schemes have been used such as physical, chemical and biological processes to treat this effluent. However they have some problems like adjusting shock loading of organic matters and chemicals. Therefore, in the present study chemical coagulation process was tested to treat grey water. Coagulants (alum and ferric chloride) were used in the present work to treat both real and synthetic grey water. The findings showed that at a dose of 30 mg/L of ferric chloride, 90% of the solution's turbidity and 80% of the TDS could consistently be removed. These findings were well matched with biological active filter system that reported 85% of COD removal from grey water. In addition, the effects of pH and alkalinity on the removal performance were also investigated. Overall, the present study showed that both traditional and proposed novel chemical process could treat grey water to the required level which can further be re-used for agricultural activities.

At field level, prediction of crop yield and determination of appropriate fertilizer application rate based on soil and landscape attributes often require for better management practices finally maximizing crop yield. The present study was designed to evaluate the potential of Artificial Neural Networks (ANNs) model to predict wheat grain yield and to determine the urea fertilizer application rate for maximizing wheat grain yield. The urea fertilizer, %sand, %silt, %clay, elevation, soil nitrogen (N), soil electrical conductivity (EC), soil phosphorus (P) and soil pH were used as input parameters and wheat grain yield was used as output. The ANNs model was trained using 124 data sets collected during growing seasons of 2008-09 to 2010-11 and evaluated using randomly selected 20 data sets of 2010-11 and 48 data sets of 2011-12. The results showed that ANNs model has the potential to predict wheat grain yield under semiarid conditions, as the mean absolute error (MAE) of 6.50% was found for training and 9.48% was observed for testing the model. To determine urea fertilizer application rate for maximizing wheat grain yield, the trained model was run for 14 urea fertilizer levels ranging from 0 to 400 kgurea ha(-1). It was examined that 210 kg-urea ha(-1) produced maximum grain wheat yield (4200 kg ha(-1)) and further increase of urea fertilizer rates resulted in decrease of wheat grain yield. These results also showed that ANNs model is a useful tool to estimate the wheat grain yield response to soil and landscape attributes and to determine the optimum urea fertilizer level for maximizing the wheat grain yield in semi-arid conditions of Faisalabad.

A pilot scale trickling filter system was designed, developed, and operated using a constant recirculation method for treatment of municipal wastewater. Maize cob (TF1) and date palm fibre (TF2) were used as biofilm support media in a trickling filter system. Both the TF1 and TF2 were compared based on the removal efficiency of pollution indicators such as biological oxygen demand (BOD), chemical oxygen demand (COD), total dissolved solids (TDS), total suspended solids (TSS), electrical conductivity (EC), total nitrogen (TN), total phosphorus (TP) and sulphates. The hydraulic flow rate and loading were set as 0.432 m3/h and 0.0064 m3/m2.minute, respectively at temperature range of 15–42 °C for 15 operational weeks. Both the TF1 and TF2 showed acceptable removal efficiency (61% to 76.3%) for pathogen indicators such as total count, fecal coliforms and Escherichia coli. However, 8–15% higher removal efficiency was observed for TF1 for all the pollution indicators compared to TF2. The results suggest that both the biofilm support media in trickling filter have potential to treat municipal wastewater in peri-urban small communities to produce environmentally friendly effluent.

For granular materials, discrete element modeling is one of the best computer tools to simulate their behavior and interactions. A field experiment was carried out to evaluate the performance of disc furrow openers in paddy soil. Discrete element simulation was done to develop a 3D DEM model for notched, toothed and double disc furrow openers using EDEM software. Hertz Mindlin contact model with bonding was applied for simulation to fulfill the obligations of the soil moisture and bonding between the cohesive particles. Simulated and field experimental data were compared to determine the applicability in the different working conditions. The results of the simulation validated the applicability of the Hertz-Mindlin contact model with bonding to simulate the no till paddy soil using an extremely narrow tillage tool. The calibrated value of normal and shear stiffness was 5×107 N/m, and the calibrated value of bond normal and shear strength was 3×107 Pa. The relative error (–1.7% to 20.6%) for the double disc furrow opener was lower as compared with that notch typed (29.2% to 44.4%) and toothed type (31.5% to 45.9%) furrow openers. Keywords: soil tillage, discrete element method, discrete element modeling, furrow opener, paddy soil DOI: 10.25165/j.ijabe.20201304.4800 Citation: Ahmad F, Qiu B J, Ding Q S, Ding W M, Khan Z M, Shoaib M, et al. Discrete element method simulation of disc type furrow openers in paddy soil. Int J Agric & Biol Eng, 2020; 13(4): 103–110.