Removal of Chromium from Synthetic Effluent using Nymphaea rubra

Equilibrium Uptake and Bioaccumulation of Basic Violet 14 Using Submerged Macrophyte Hydrilla verticillataThe percentage removal and uptake capacity of Basic Violet 14 using Hydrilla verticillata with living biomass was studied under batch conditions. The survival of H. verticillata was studied using the chlorophyll content in the living biomass. Bioaccumulation of Basic Violet 14 using H. verticillata was tested by varying the wet sorbent dosage (0.5-2.5 g), initial pH (3-8), and initial dye concentrations (5-25 mg L À1 ). The results show that the plant was effectively accumulating the Basic Violet 14 dye. The uptake capacity of Basic Violet 14 dye was observed as 5.9 and 21.3 mg g À1 at the initial dye concentration of 5 and 25 mg L À1 , respectively, for a biomass of 5 g L À1 (wet weight) at pH 7.0 for 144 h. In general, the plant growth was found to be normal at lower concentrations and showed higher removal efficiency. It was also observed that removal efficiency of H. verticillata was found to decrease with increase in initial dye concentration. The biomass sample surface was analyzed using SEM imaging and functional groups present in the biomass were analyzed using FTIR. The equilibrium uptake capacity was analyzed by Langmuir and Freundlich isotherms. The equilibrium data was found to be fit well to both Langmuir and Freundlich isotherm models with higher coefficient of determination. In the last decades, the use of phyto-technologies has become an effective alternative method for the remediation of contaminated water systems [5]. Phytoremediation is defined as the use of plants, both terrestrial and aquatic; to absorb, concentrate, and precipitate contaminants from polluted aqueous sources with low contaminant concentration in their roots [6]. The U.S. Environmental Protection Agency (EPA) seeks to protect human health, environment associated with hazardous waste sites, and encourages the development of innovative technologies such as phytoremediation to clean up hazardous sites [7].Most of the work has been already established on the accumulation of heavy metal using plant such as Hydrilla verticillata for cadmium accumulation [8], Pistia stratiotes for arsenate uptake [9], Wolffia globosa for an indicator of metal pollution in the water bodies [10], P. stratiotes for lead uptake [11]. Only limited work has been established for the removal of textile dyes using living aquatic plant. In this present study, H. verticillata was used as living biomass for the accumulation of basic dye from synthetic dye solution.Basic dyes are salts of the colored organic bases containing amino and imino groups and also combined with a colorless acid, such as hydrochloric or sulfuric acid. They are brilliant and most fluorescent among all synthetic dyes. Basic Violet 14 was selected as a model compound to estimate the accumulation capacity of H. verticillata. It is a submerged plant, and it has been observed to grow luxuriantly in various contaminated water bodies of India [12]. H. verticillata has attracted the attention ...

Section: Equilibrium Modelingmentioning

confidence: 99%

Equilibrium Uptake and Bioaccumulation of Basic Violet 14 Using Submerged Macrophyte Hydrilla verticillata

Gopalakrishnan

Saravanan

Dharmendirakumar

et al. 2011

“…The sorption of Cr 3þ onto the cell surface of Pseudomonas aeruginosa was described well by the Langmuir isotherm while Cr 6þ appeared to fit to the Freundlich model [35]. In another study, the removal of chromate from synthetic effluent using Nymphaea rubra was better fitted to the Freundlich isotherm model with the equilibrium data when compared to the Langmuir isotherm model [36]. In the present investigations, higher Q max and K f values were found for the living biomasses compared to the dried biomasses for Cr 6þ .…”

Section: Discussionmentioning

confidence: 92%

Chromium Removal through Biosorption and Bioaccumulation by Bacteria from Tannery Effluents Contaminated Soil

Alam¹,

Ahmad²

2011

Four bacterial isolates (two resistant and two sensitive to chromium) were isolated from soil contaminated with tannery effluents at Jajmau (Kanpur), India, and were identified by 16S rDNA gene sequencing as Stenotrophomonas maltophilia, Exiguobacterium sp., Pantoea sp., and Aeromonas sp. Biosorption of chromium by dried and living biomasses was determined in the resistant and sensitive isolates. The effect of pH, initial metal concentration, and contact time on biosorption was studied. At pH 2.5 the living biomass of chromium resistant isolate Exiguobacterium sp. ZM-2 biosorbed maximum amount of Cr 6þ (29.8 mg/g) whereas the dried biomass of this isolate biosorbed 20.1 mg/g at an initial concentration of 100 mg/L. In case of chromate sensitive isolates, much difference was not observed in biosorption capacities between their dried and living biomasses. The maximum biosorption of Cr 3þ was observed at pH 4.5. However, biosorption was identical in resistant and sensitive isolates. The data on chromium biosorption were analyzed using Langmuir and Freundlich isotherm model. The biosorption data of Cr 6þ and Cr 3þ from aqueous solution were better fitted in Langmuir isotherm model compared to Freundlich isotherm model. Metal recovery through desorption was observed better with dried biomasses compared to the living biomasses for both types of chromium ions. Bioaccumulation of chromate was found higher in chromate resistant isolates compared to the chromate sensitive isolates. Transmission electron microscopy confirmed the accumulation of chromium in cytoplasm in the resistant isolates.

“…Clearly, adsorption at pH < 5 is obtained: with a percentage removal of nearly 50%. Although recent studies reported adsorption of Cr(VI) at low pH values [19,20], previous investigators indicated no adsorption of Cr(III) below pH 5 [5].…”

Section: Effect Of Phmentioning

confidence: 98%

“…It is well known that adsorption of chromium on surfaces is pH dependent [5,19,22]. The pH of our system was dependent on the amount of added solid particles due to partial solubility of calcium carbonate from limestone.…”

Section: Effect Of Phmentioning

confidence: 99%

“…Some of the previous studies focused on the adsorption of Cr(VI) [7,10,15], while others on the adsorption of Cr(III) [9,11,16,17]. Recent publications focused on the removal of Cr(VI) using various biomass sorbents [18][19][20][21][22][23][24], including, e.g., Nymphaea rubra [19], Pseudomonas aeruginosa, and Bacillus subtilis [20], dried roots of water hyacinth [21], and Mucor racemosus [22]. Investigated parameters in these studies included pH, dosage of biomass, contact time, and initial concentration of chromium.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Treating Leather Tanning Wastewater with Stone Cutting Solid Waste

Al-Jabari

Abualfailat

Shaheen

2011

This paper presents a new environmental approach for reducing environmental impacts of two local Palestinian industries: It implements the principle of ''treating waste by waste.'' The technical feasibility of chromium removal from wastewater in leather making by its treatment with solid waste from stone cutting industry is demonstrated experimentally, and found to be an efficient approach. Nearly full removal of chromium is obtained at optimum operating conditions using sufficient mass of solid waste (limestone) and allowing enough contact time between the two wastes. This study investigated effects of various parameters on the percentage relative decrease in concentration by using ultra violet (UV)/Vis spectrophotometry. Kinetic curves showed that percentage relative decrease in concentration increased with time until approaching a plateau (adsorption capacity). The adsorption capacity increased with increasing limestone to liquid ratio (solid content), until nearly full removal of chromium was obtained when the solid content was 5 g/100 mL or higher. This was accomplished within few days when the particles were settled. The adsorption capacity was pH dependent; adsorption at pH < 5 was obtained, as a finding which was not reported by previous investigators for Cr(III) adsorption using other particles. The percentage removal was nearly doubled at higher pH values (>5). Further research work is proposed to distinguish between the contributions of the two removal mechanisms of precipitation and adsorption.