The effect of drinking water sources due to Cyclone Aila at Shyamnagar, Sathkhira district, Bangladesh

Bangladesh is the most vulnerable country to disaster and its impact. Coastal Bangladesh along with the Bay of Bengal is the most important and suffered group of cyclone impacts. Cyclone Aila hit the southwestern coast of Bangladesh on 25 May 2009. About two million people were affected and washed away a huge number of households, lives, livestock, crops, and all other resources of the affected area. Water resources in the coastal area are always a term of crisis and even the aila mostly damaged all the resources including surface or groundwater sources. This study focuses on the recovery status of the affected area with considering the drinking water sources. About 36 water samples had been collected for the experiment including rainwater harvesting (6), pond sand filters (6), protected pond (6), and hand tube well (6) from specific six unions of Shyamnagar Upazilla under Sathkhira District in between the time of August to October 2016. A questionnaire field survey was conducted in the most affected coastal area in Bangladesh where about 103 households (309 respondents) participated in their willingness and the study considering their frequency of loss. The results showed a huge dimension of the water crisis and its mitigation. Protected pond and tube well water exceeded the DoE standard for almost all chemical parameters except potassium (3.28 mg/L and 3.75 mg/L), sulfate (377.19 mg/L and 225.66 mg/L), chloride (365.05 mg/L and 349.10 mg/L) and arsenic (1.76±0.25 mg/L and 3.78±1.43). Pond sand filter (PSF) and rainwater harvesting (RWH) had shown the lowest amount of all chemical concentrations compared with another two sources. The respondents face the problem of the distance from the household and the yearly availability of drinking water. They demand monitoring and source management system improvement along with community-based resource management. From the aila event, a huge recovery application is implemented here but these are not sufficient. Respondents gave some opinions to solve this crisis. Considering all aspects, they need a low-cost and more efficient drinking water source to survive their situation

Determination of water quality and efficient removal of arsenic and iron from groundwater using mahogany fruit husk and banana peduncle charcoals

The groundwater (GW) of Bangladesh is predominantly contaminated with arsenic (As) and iron (Fe) which has a bad impact on human health. We tried to remove these elements with easily available mahogany-fruit (Swietenia mahagoni) husk charcoal (MHC) and banana (Musa acuminata) peduncle charcoal (BPC). The trial was implemented with 3 replications throughout the research. The sampled GW contained 0.06 mg As L−1 and 4.83 mg Fe L−1. Firstly, the pH was 3, 5, 7, and 9 with a 250 mg L−1 dose. The MHC removed almost 91.05 % of As at pH 5.0, and BPC removed almost 86.67 % of As at pH 9. However, in the case of Fe, the MHC removed almost 100 % at pH 7 and 9; and BPC removed the same quantity at pH 5, 7, and 9. Secondly, the contact times were 0, 5, 10, 20, and 40 min with a 250 mg L−1 dose at pH 7.0. The maximum removal of As and Fe was 100 % with MHC and BPC at 5 min. The pseudo-first-order kinetic, pseudo-second-order kinetic, and intra-particle diffusion models were considered. The result showed that the rate of adsorption followed the pseudo-second-order kinetic model. Lastly, the adsorbent doses were 0, 50, 150, 250, and 350 mg L−1. At pH 7, the highest removal of As was 79.47 % and Fe removal was 100 % at 350 mg L−1 dose for MHC. Similarly, the values were 79.29 % and 100 % for the same at 350 mg L−1 dose of BPC, indicating these charcoal are good for heavy metals removal

Arsenic-phosphorus interactions in the soil-plant-microbe system: dynamics of uptake, suppression and toxicity to plants

High arsenic (As) concentrations in the soil, water and plant systems can pose a direct health risk to humans and ecosystems. Phosphate (Pi) ions strongly influence As availability in soil, its uptake and toxicity to plants. Better understanding of As(V)-Pi interactions in soils and plants will facilitate a potential remediation strategy for As contaminated soils, reducing As uptake by crop plants and toxicity to human populations via manipulation of soil Pi content. However, the As(V)-Pi interactions in soil-plant systems are complex, leading to contradictory findings among different studies. Therefore, this review investigates the role of soil type, soil properties, minerals, Pi levels in soil and plant, Pi transporters, mycorrhizal association and microbial activities on As-Pi interactions in soils and hydroponics, and uptake by plants, elucidate the key mechanisms, identify key knowledge gaps and recommend new research directions. Although Pi suppresses As uptake by plants in hydroponic systems, in soils it could either increase or decrease As availability and toxicity to plants depending on the soil types, properties and charge characteristics. In soil, As(V) availability is typically increased by the addition of Pi. At the root surface, the Pi transport system has high affinity for Pi over As(V). However, Pi concentration in plant influences the As transport from roots to shoots. Mycorrhizal association may reduce As uptake via a physiological shift to the mycorrhizal uptake pathway, which has a greater affinity for Pi over As(V) than the root epidermal uptake pathway

The role of plant growth promoting bacteria on arsenic removal: a review of existing perspectives

Phytobial remediation is an innovative tool that uses plants and microbes to mitigate Arsenic (As) contamination of the environment. Recently, plant growth-promoting bacteria (PGPB) that assists phytoremediation has been highly touted for both improving plant metal tolerance and promoting plant growth while achieving the goal of large-scale removal of As. This review focuses on the PGPB characteristics influencing plants and the mechanisms in which they function to overcome/lessen As-induced adversities. Several recent examples of mechanisms responsible for increasing the availability of As to plants and coping with As stresses facilitated by PGPB will be reviewed. Although drawbacks to phytoremediation have been reported, encouraging results have been developed with regular monitoring. Introducing PGPB-assisted phytoremediation of As in a field requires an assessment of the environmental effects of PGPB, especially with respect to the impacts on indigenous bacteria

Physiology of iron in rice and barley grown under arsenic toxic condition

岩手大学博士（農学）doctoral thesi

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