Heavy metals in chrome-tanned shaving of the tannery industry are a potential hazard to the environment of Bangladesh

During the tannery production process, huge quantities of waste especially chrome shaving are produced and are being discharged directly into the environment of Bangladesh. To know the concentration of some heavy metals in chrome shaving, the samples were collected, digested, and analyzed. Among the determined metals e.g. zinc (Zn), lead (Pb), and chromium (Cr), the Cr concentration was very high. The average concentration of Cr was 13,832.70 mg Kg−1 dry weight which was equivalent to almost 1.383%. Chromium in leather shavings poses a critical problem for disposal or management. Recovery of Cr and management of chrome shaving are strongly suggested

Conversion of waste plastic (low density polyethylene) to alternative resources

Plastic pollution has become one of the top issues at present throughout the world. In Asian continent plastic pollution is found at the highest rate and Bangladesh is ranking as the 10th number of plastic wastes producer. To minimize the plastic pollution its management is necessary. To do that we tried to convert the plastic wastes as alternative resources for example plastic tiles or plastic tobs. The study was conducted at Jashore University of Science and Technology campus where polyethylene plastic wastes are found available. Molten LDPE were mixed with varying proportion of sand to conduct two experiments. First one is the preparation of plastic tiles and the second one is the making of tobs. Both of the two experiments kept in incubation under water for 7 and 14 days and experimental characterization such as water absorption variation, compressive strength, SEM, FTIR and EDX were done using standard procedures. Density and water absorption changes with the increase in plastic percentage in both the two experiments. In the 1st experiment, compressive strength was done and showed that at the increase of plastic % up to 45% tiles could bear maximum load above 3000 psi that match the standard concrete tiles strength. In the case of EDX analysis, C, O and Hg showed at the highest peak than other elements in both the two experiments. In the surface internal structure of the 1st experiment, some structural deformation was noticed but in the 2nd experiments some cracks and cavities formation found on the naked eye. In the chemical structure of the 1st experiment showed C-O stretching, C=C stretching, O=C=O stretching whereas in the 2nd experiment, most of the tob samples showed C-O stretching, O-H stretching, C=C stretching and N-H stretching. The plastic tiles could be used in rare or rural area and plastic tobs could be used as decorative purposes. From the results, we found the satisfactory output of the product and could be used as alternative resources

Water quality index and health risk assessment for heavy metals in groundwater of Kashiani and Kotalipara upazila, Gopalganj, Bangladesh

Abstract The groundwater quality of the Gopalganj district in Bangladesh was not well documented. Therefore, this research was done to determine the groundwater quality in the study area. The water quality index and the human health risk for heavy metal ingestion were used to describe the water quality. The water quality was performed through the estimation of turbidity, pH, electrical conductivity, total dissolved solids, and concentration of sodium, potassium, ammonium, nitrate, iron, manganese, zinc, copper, and arsenic. The mean turbidity, pH, and total dissolved solids in the two upazila were within the permissible limit. However, the electrical conductivity in both the upazila was higher than the WHO-prescribed value in which the higher concentration was in Kotalipara. Excess concentrations of iron and arsenic were found in the Kashiani upazila, but these were below the detection limit in Kotalipara upazila. The water quality index revealed that roughly 61.0% of samples of Kashiani upazila were of poor quality. However, about 96.0% of samples of Kotalipara upazila were of excellent quality. Chronic health risks due to the revelation of drinking have also been determined by assessing the hazard quotient and hazard index. In Kashiani, almost 85.0% of samples were elevated chronic risks for adults and 100.0% of the samples were very high chronic risks for children. In Kotalipara, all the samples (almost 100%) were suggested to have a lower chronic risk for adults and children. The results suggested that the carcinogenic risk of arsenic via oral exposure was very high for both adults and children in Kashiani upazila

Comparison of digesting capacity of nitric acid and nitric acid-perchloric acid mixture and the effect of lanthanum chloride on potassium measurement

Abstract: Nitric acid-perchloric acid mixture is the renowned digesting reagent in the scientific world of plant nutrition. Beside this, some other inorganic acids can be used as the digester of plant samples. Therefore, this experiment was conducted to find out if there is any difference between the digesting capacity of nitric acid (HNO 3 ) and nitric acid-perchloric acid mixture (HNO 3 -HClO 4 ) or not. The hydroponic experiments were conducted with barley (Hordeum vulgare L. cv. Minorimugi) and rice (Oryza sativa L. cv. Akihikari) seedlings. At suitable stage, the plant samples were collected, washed with deionized water, separated into shoot and root, dried, grinded and then divided into two groups for shoot and root individually for two types of seedlings. One group was for only HNO 3 acid and the other group was for HNO 3 -HClO 4 acid mixture. Phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) were measured after digesting the samples. There was no significant difference between the digesting capacity of HNO 3 acid and HNO 3 -HClO 4 acid mixture. Potassium was measured by diluting the samples (200-600 times) containing lanthanum chloride (LaCl 3 ) or withou

Changing dynamics of river ecosystem from aquatic to terrestrial: A case of Bhairab River, Jashore, Bangladesh

The changing dynamics of river ecosystems from aquatic to terrestrial in the Southwestern areas of Bangladesh have been widely observed in recent years. Nevertheless, there has been no consensus on whether the changes are caused by human activities or by natural processes. For a better understanding of the cause, this study was conducted based on a field survey through a pre-tested structured questionnaire measuring the river water quality. The water quality of the river was assessed to know how much the existing river water was affecting its aquatic ecosystem or not. People’s perception was also investigated to assess the factors mostly responsible for changing the river ecosystem. It was found that the most responsible factors are human activities. Among them, the construction of cross embankments over and along the Bhairab River was the most (22%) responsible factor for changing the river ecosystem. The 2nd and 3rd most responsible factors were bridge construction (18%) and illegal encroachment (18%). Other reasons for changing the ecosystem of the river were the diversion (16%), cultivation of the riverside land (12%), the introduction of exotic species (8%), and disposal of wastes and industrial effluents into the river (6%), respectively. Besides, it is also believed that the construction of Farakka Barrage on the River Ganges (the mother of the Bhairab River) is also responsible for changing the aquatic ecosystem into a terrestrial ecosystem

Hydro-chemical characteristics and groundwater quality evaluation in south-western region of Bangladesh: A GIS-based approach and multivariate analyses

The study focuses on the chemistry of groundwater and if it is suitable for drinking and for use in agriculture using water quality indices, GIS mapping, and multivariate analyses in Sharsa Upazila, Jashore district, Bangladesh. In this study, the concentration of NH4+, K+, Ca2+, EC, Turbidity overstep BDWS drinking standards in 69 %, 14 %, 100 %, 40 % (WHO), 73 % of samples respectively. The value of Water Quality Indices (WQI) results inferred that the maximum specimen was held good quality for drinking uses, and the values distributed central eastern part to the south-eastern part were good quality water in the selected studied area. The study area's PH, EC, SAR, Na (%), TH, and NO3− values were mapped using GIS tools to show their spatial distribution. The cluster and correlation matrix analyses are used to validate for Principle Component Analysis (PCA). The five PCA results exhibited that the presence of EC, turbidity, K+, SO42− and NO3− was significant and was caused by both geogenic (rock weathering and cation exchange) and anthropogenic (agrochemicals, animal feedback) factor. According to the hydro-geochemical data, the maximum number of samples is of the Ca–Mg–HCO3–Cl type and is dominated by rocks. The irrigation water indices like MH, KR, SAR, and %Na indicate show high-quality groundwater for irrigation purposes. Most of the samples were satisfactory and compiled with WHO and Bangladeshi criteria for standard drinking water guideline values

Preparation of environmental friendly plastic brick from high-density polyethylene waste

Plastic wastes are growing fast and affecting the environment negatively. Thus, finding different methods of disposing of is becoming a major concern. This research aimed to minimize the plastic by recycling it into construction materials. For this, grinding high-density polyethylene (HDPE) was mixed with cement at different percentages to produce plastic bricks. The compressive strength, density, and water absorption capacity were investigated. The compressive strength was found within the recommended value (2000 psi) up to 35% mixture of HDPE. The addition of HDPE with cement decreased the density, increased the ductility, and improved the workability which led to producing lightweight materials

Enhancing groundwater quality assessment in coastal area: A hybrid modeling approach

Monitoring of groundwater (GW) resources in coastal areas is vital for human needs, agriculture, ecosystems, securing water supply, biodiversity, and environmental sustainability. Although the utilization of water quality index (WQI) models has proven effective in monitoring GW resources, it has faced substantial criticism due to its inconsistent outcomes, prompting the need for more reliable assessment methods. Therefore, this study addressed this concern by employing the data-driven root mean squared (RMS) models to evaluate groundwater quality (GWQ) in the coastal Bhola district near the Bay of Bengal, Bangladesh. To enhance the reliability of the RMS-WQI model, the research incorporated the extreme gradient boosting (XGBoost) machine learning (ML) algorithm. For the assessment of GWQ, the study utilized eleven crucial indicators, including turbidity (TURB), electric conductivity (EC), pH, total dissolved solids (TDS), nitrate (NO3−), ammonium (NH4+), sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), and iron (Fe). In terms of the GW indicators, concentration of K, Ca and Mg exceeded the guideline limit in the collected GW samples. The computed RMS-WQI scores ranged from 54.3 to 72.1, with an average of 65.2, categorizing all sampling sites' GWQ as “fair.” In terms of model reliability, XGBoost demonstrated exceptional sensitivity (R2 = 0.97) in predicting GWQ accurately. Furthermore, the RMS-WQI model exhibited minimal uncertainty (<1 %) in predicting WQI scores. These findings implied the efficacy of the RMS-WQI model in accurately assessing GWQ in coastal areas, that would ultimately assist regional environmental managers and strategic planners for effective monitoring and sustainable management of coastal GW resources