In order to evaluate the water quality of one of the most polluted urban river in Malaysia, the Penchala River, performance of eight biotic indices, Biomonitoring Working Party (BMWP), BMWPThai, BMWPViet, Average Score Per Taxon (ASPT), ASPTThai, BMWPViet, Family Biotic Index (FBI), and Singapore Biotic Index (SingScore), was compared. The water quality categorization based on these biotic indices was then compared with the categorization of Malaysian Water Quality Index (WQI) derived from measurements of six water physicochemical parameters (pH, BOD, COD, NH3-N, DO, and TSS). The river was divided into four sections: upstream section (recreational area), middle stream 1 (residential area), middle stream 2 (commercial area), and downstream. Abundance and diversity of the macroinvertebrates were the highest in the upstream section (407 individual and H′?=?1.56, respectively), followed by the middle stream 1 (356 individual and H′?=?0.82). The least abundance was recorded in the downstream section (214 individual). Among all biotic indices, BMWP was the most reliable in evaluating the water quality of this urban river as their classifications were comparable to the WQI. BMWPs in this study have strong relationships with dissolved oxygen (DO) content. Our results demonstrated that the biotic indices were more sensitive towards organic pollution than the WQI. BMWP indices especially BMWPViet were the most reliable and could be adopted along with the WQI for assessment of water quality in urban rivers. 相似文献
Journal of Material Cycles and Waste Management - Low-cost and effective activated carbon for copper ion adsorption was prepared from walnut shell by CO2 activation in a fluidized bed. The effects... 相似文献
Environmental Science and Pollution Research - In dengue mosquitoes, successful embryonic development and long lifespan are key determinants for the persistence of both virus and vector. Therefore,... 相似文献
In this study, the effects of pre-oxidants permanganate (PM), persulfate (PS), hydrogen peroxide (PO), and ozone (OZ)) and/or adsorption on pseudoboemite-chitosan shell magnetic nanoparticles (ACMNs) on haloacetonitrile (HAN) and trichloronitromethane (TCNM) formation from aspartic acid (Asp; positive charge) and/or histidine (His; negative charge) were compared. Asp and His apparently do not interact in aqueous solution during chlorination. Asp and/or His can undergo partially oxidation by PM, but are recalcitrant to direct oxidation by PS and PO. Pre-oxidation with OZ decreases the formation of HANs but increases the formation of TCNM. ACMN prefers to adsorb Asp over His in the competitive sorption of coexisting Asp and His because of attractive electrostatic interactions. The rank order for the effect of the pre-oxidants and ACMN adsorption on dichloroacetonitrile and trichloroacetonitrile formation is OZ and ACMN adsorption > PM and ACMN adsorption > PS and ACMN adsorption > PO and ACMN adsorption; that for the effect of the pre-oxidants and ACMN adsorption on TCNM formation is PM and ACMN adsorption > PS and ACMN adsorption > PO and ACMN adsorption > OZ and ACMN adsorption. The favored adsorption of Asp over His by ACMN is weakened by pre-oxidation.
Electrostatic precipitation is considered as an effective technology for fine particle removal. A lab-scale wet electrostatic precipitator (ESP) with wire-to-plate configuration was developed to study particle migration and collection. The performance of the wet ESP was evaluated in terms of the corona discharge characteristics, total removal efficiency and fractional removal efficiency. The corona discharge characteristics and particle removal abilities of the wet ESP were investigated and compared with dry ESP. Particle removal efficiency was influenced by discharge electrode type, SO2 concentration, specific collection area (SCA) and particle/droplet interaction. Results showed that the particle removal efficiency of wet ESP was elevated to 97.86% from 93.75% of dry ESP. Three types of discharge electrodes were investigated. Higher particle removal efficiency and larger migration velocity could be obtained with fishbone electrode. Particle removal efficiency decreased by 2.87% when SO2 concentration increased from 0 ppm to 43 ppm as a result of the suppression of corona discharge and particle charging. The removal efficiency increased with higher SCA, but it changed by only 0.71% with the SCA increasing from 25.0 m2/(m3/s) to 32.5 m2/(m3/s). Meanwhile, the increasing of particle and droplet concentration was favorable to the particle aggregation and improved particle removal efficiency.
Implications: This work tends to study the particle migration and collection under spraying condition. The performance of a wet electrostatic precipitator (ESP) is evaluated in terms of the corona discharge characteristics, total particle removal efficiency, and fractional particle removal efficiency. The effects of water droplets on particle removal, especially on removal of particles with different sizes, is investigated. The optimization work was done to determine appropriate water consumption, discharge electrode type, and specific collection area, which can provide a basis for wet ESP design and application. 相似文献
Several biofuel cropping scenarios were evaluated with an improved version of Soil and Water Assessment Tool (SWAT) as part of the CenUSA Bioenergy consortium for the Boone River Watershed (BRW), which drains about 2,370 km2 in north central Iowa. The adoption of corn stover removal, switchgrass, and/or Miscanthus biofuel cropping systems was simulated to assess the impact of cellulosic biofuel production on pollutant losses. The stover removal results indicate removal of 20 or 50% of corn stover in the BRW would have negligible effects on streamflow and relatively minor or negligible effects on sediment and nutrient losses, even on higher sloped cropland. Complete cropland conversion into switchgrass or Miscanthus, resulted in reductions of streamflow, sediment, nitrate, and other pollutants ranging between 23‐99%. The predicted nitrate reductions due to Miscanthus adoption were over two times greater compared to switchgrass, with the largest impacts occurring for tile‐drained cropland. Targeting of switchgrass or Miscanthus on cropland ≥2% slope or ≥7% slope revealed a disproportionate amount of sediment and sediment‐bound nutrient reductions could be obtained by protecting these relatively small areas of higher sloped cropland. Overall, the results indicate that all biofuel cropping systems could be effectively implemented in the BRW, with the most robust approach being corn stover removal adopted on tile‐drained cropland in combination with a perennial biofuel crop on higher sloped landscapes. Editor's note : This paper is part of the featured series on SWAT Applications for Emerging Hydrologic and Water Quality Challenges. See the February 2017 issue for the introduction and background to the series. 相似文献
Journal of Material Cycles and Waste Management - This paper focuses on the performance of oil palm empty fruit bunch (EFB) gasification using a medium-scale downdraft gasifier for power... 相似文献