Assessment of bioavailability and leachability of heavy metals during rotary drum composting of green waste (Water hyacinth)

Reduction of bioavailability of heavy metals during vermicomposting of phumdi biomass of Loktak Lake (India) using Eisenia fetida

“…The supplemented number of micro flora present in the gut of earthworms might have played an important role in this process and increased the nutrients' concentration in the vermicompost (Khwairakpam and Bhargava, 2009;Hait and Tare, 2012). Furthermore, nutrients were increased during the process which might be due to net loss of dry mass (Amir et al, 2005;Singh and Kalamdhad, 2013a). Heavy metals are important ingredient for plants, animals and humans, but their higher content is known to have toxic effects.…”

“…The flame photometer (Systronic 128) was used for analysis of Na, K and Ca concentration and atomic absorption spectrometer (AAS) (Varian Spectra 55B) was used to quantify the Mg, Zn, Cu, Mn, Fe, Ni, Pb, Cd and Cr concentrations after the digestion of 0.2 g sample with 10 mL of H 2 SO 4 and HClO 4 (5:1) mixture in block digestion system (Pelican Equipments Chennai, India) for 2 h at 300 o C. Watersoluble heavy metals were determined after extraction of 2.5 g sample with 50 mL of distilled water (sample: solution ratio = 1:20) at room temperature for 2 h in a shaker at 100 rpm (Singh and Kalamdhad, 2013a). DTPA extractable metals were obtained by mechanically shaking 4 g ground sample (screened through 0.22 mm sieve) with 40 mL of 0.005 M DTPA, 0.01M CaCl 2 and 0.1 M (triethanolamine) buffered to pH 7.3 at 100 rpm (Guan et al, 2011).…”

“…Heavy metal uptake by plants the resulting accumulation in human tissues through the food chain causes both health and environment concerns (Wong and Selavam, 2006). The bioavailability and related eco-toxicity of heavy metals to the plants depend on their specific chemical forms or ways of binding rather than the total metal concentration obtained after strong acid digestion (Singh and Kalamdhad, 2013a). The bioavailability of metals in vermicompost amended soil is a self-motivated process that depends on unambiguous combination of biochemical and environmental parameters.…”

“…The final product formed after composting is rich in important plant nutrients such as nitrogen, phosphorous, potassium, calcium, trace elements, and it can be used as a soil conditioner in agricultural applications (Gabhane et al, 2012). Composting and vermicomposting of different aquatic weed have been performed by many researchers (Gabhane et al, 2012;Singh and Kalamdhad, 2012a, 2013aand 2013bGajalakshmi et al, 2002).…”

Enhanced clean-up of lead-contaminated alluvial soil through Chrysanthemum indicum L.

“…However, organic inputs are always preferred on account of greener, economic and more eco-friendly view. Composting can enhance organic matter degradation and humification process, and consequently, it can reduce the toxicity of metals (Singh and Kalamdhad 2013).…”