Removal of Pb by EDTA-washing in the presence of hydrophobic organic contaminants or anionic surfactant

Citric acid and ethylene diamine tetra-acetic acid as effective washing agents to treat sewage sludge for agricultural reuse

“…Nutrients are essential for plant growth (Hanay et al, 2009;Singh and Sinha, 2004;Zhang et al, 2008), and the use of sewage sludge in agriculture to ameliorate the physicochemical deficiencies of degraded soil is a practice that is growing worldwide (Gupta and Sinha, 2006;Singh and Agrawal, 2007). Moreover, land application is considered one of the most economic and effective ways to dispose of sludge and supply plants with nutrients (Zhu et al, 2013).…”

“…Moreover, EDTA has been reported to have low aquatic toxicity and it is does not bioaccumulate in living organisms throughout the food chain. However, its application may lead to nutrient deficiencies in the re-claimed sewage (Zhang et al, 2008). There are also other problems associated with the use of EDTA in remediation.…”

Copper and zinc removal from contaminated soils through soil washing process using ethylenediaminedisuccinic acid as a chelating agent: A modeling investigation

“…Moreover, [S,S]-EDDS can be also produced by some fungi and bacteria [17,18]. Soil washing processes have been investigated for the effect of metal speciation and concentration [19][20][21][22]: the effect of soil characteristics, such as particle distribution size, pH, organic matter content, and cation exchange capacity [23][24][25][26][27], and appropriate washing operating conditions, including the EDDS-to-metal ratio, and the solid-toliquid ratio [10, 19,[27][28][29][30]. The nature of the interaction and the structure of complexes formed between EDDS and HMs has also been studied [21,30].…”

Conceptual model and sensitivity analysis for simulating the extraction kinetics of soil washing

“…Nevertheless, sensitivity analysis of the model is needed for evaluating the relative significance of parameter values and establishing the model robustness for field use. This is because the independently determined parameter values may be varied to some extent due to solution pH (Vandevivere et al 2001;Tandy et al 2004;Polettini et al 2007), contamination age and chemical speciation (Kirpichtchikova et al 2006;Tsang et al 2007b;Jalali and Khanlari 2008), metal redistribution due to adsorption and/or metal exchange (Tsang et al 2009;Zhang et al 2010), influence of organic matter and iron oxide dissolution on solution speciation (Tandy et al 2006;Koopmans et al 2008;Yip et al 2010a), and interactions with coexisting organic contaminants, dissolved organic matter, and other chemical reagents (Zhang et al 2007;Zhang et al 2008;Zou et al 2009;Yip et al 2010b).…”

“…Moreover, by increasing the k i ″ above 1, the readsorption of Zn in the latter extraction stage was signified. These results suggest that even if we can economically manipulate the operational conditions (e.g., mixing regime, temperature, and ultrasonic agitation) (Vandevivere et al 2001;Zou et al 2009) or add supplementary chemical additives (e.g., reducing/oxidizing agents, surfactants) (Peters 1999;Vandevivere et al 2001;Dermont et al 2008;Zhang et al 2008) to promote the fraction of fast extraction and the extraction rates, chelantenhanced soil washing is unlikely to be a feasible option in the cases that require stringent metal removal (e.g., above 70%) and high readsorption rate. On the other hand, Cu extraction (see Fig.…”