Improvement of wastewater quality of Dhaleswari river, Bangladesh using submerged macrophyte Egeria densa

Clean water is one of the significant goals among the 17 Sustainable Development Goals (SDGs), which will be achieved by at least 2030. It includes six outcome-oriented targets- improve water quality, wastewater treatment, ensure freshwater supplies are three of them. In Bangladesh, Freshwater ecosystem is continuously degraded due to rapid industrialization, which occurred along the riverside areas. In this context, laboratory-based work has been conducted to analyze the water quality of Dhaleshwari River, Bangladesh, which has already been polluted by industrial waste. The collected water samples were treated by submerged macrophyte Egeria densa to observe the changing water quality parameters. The growth of plants and roots were assessed after 10 days of exposure to three categories of water treatment. Initial and final water quality parameters were observed by the analysis of pH, EC, TDS, TSS, Acidity, Alkalinity, Total Hardness, Ca Hardness, COD, Sulphate (SO42-), Phosphate (PO43) Total Chlorine (Cl-) and Copper (Cu2+). The result showed that almost all the toxic parameters of water were reduced significantly at the end of the experiment. The present study hypothesized that submerged macrophyte E. densa can be used as a potential tool to upgrade the water quality of polluted rivers.Keyword: Clean water, Submerged macrophyte, SDG 6, Dhaleswari River, Freshwater ecosyste

Municipal wastewater can result in a dramatic decline in freshwater fishes: a lesson from a developing country

Impacts of ineffective wastewater management on the biodiversity of receiving waters in developing countries are poorly documented. Using a before-after-control-impact methodology, we measured the effects of untreated wastewater release on the fish community in the Barnoi River, Bangladesh. In 2006, prior to untreated wastewater discharge, fish abundance, species richness and water quality were similar across sampling sites. In 2016, after 8 years of wastewater release to the downstream reach, fish abundance and species richness were reduced by >47% and >35% respectively at downstream sites compared to unaffected upstream sites and >51% and >41% lower respectively compared to the pre-wastewater discharge period. The wastewater impact was particularly severe during months of low discharge (October–December). Water transparency, dissolved oxygen and pH were lower (P < 0.001) at impacted downstream sites compared to upstream sites. Nineteen species (41.3% of all species we recorded) are threatened in Bangladesh and the abundance of these species, except one, decreased significantly (P < 0.05) at the impacted sites. We recommend improved wastewater management by applying primary treatment facilities and incorporating reedbed filtration as a mean of biological treatment, into the canals carrying wastewaters. The success of such measures should be tested with fish species that were most responsive to wastewater, using the indicator species concept

Municipal wastewater can result in a dramatic decline in freshwater fishes: a lesson from a developing country

Impacts of ineffective wastewater management on the biodiversity of receiving waters in developing countries are poorly documented. Using a before-after-control-impact methodology, we measured the effects of untreated wastewater release on the fish community in the Barnoi River, Bangladesh. In 2006, prior to untreated wastewater discharge, fish abundance, species richness and water quality were similar across sampling sites. In 2016, after 8 years of wastewater release to the downstream reach, fish abundance and species richness were reduced by >47% and >35% respectively at downstream sites compared to unaffected upstream sites and >51% and >41% lower respectively compared to the pre-wastewater discharge period. The wastewater impact was particularly severe during months of low discharge (October–December). Water transparency, dissolved oxygen and pH were lower (P < 0.001) at impacted downstream sites compared to upstream sites. Nineteen species (41.3% of all species we recorded) are threatened in Bangladesh and the abundance of these species, except one, decreased significantly (P < 0.05) at the impacted sites. We recommend improved wastewater management by applying primary treatment facilities and incorporating reedbed filtration as a mean of biological treatment, into the canals carrying wastewaters. The success of such measures should be tested with fish species that were most responsive to wastewater, using the indicator species concept

Governance based on partnership with NGOs: Implications for development and empowerment in rural Bangladesh

10.1177/0020852304044255International Review of Administrative Sciences702271-29