Influence of clinoptilolite rock on chemical speciation of selected heavy metals in sewage sludge

Estimation and Bio-Availability of Toxic Metals between Soils and Plants

“…The average concentrations of plants from (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) are, respectively: 0.012±0.01, 0.0006±0.003, 0.015±0.003, and 2.7±0.001 for Pb, Cd, As, and Hg.…”

“…The risk of transference of heavy metals from soil to plants and from plants to humans should be a matter of great concern [16]. Absorption of heavy metals by plant roots from soil (one of the major routes for the entrance of heavy metals into the food chain) and the following accumulation along the food chain is a potential threat to animal and human health, particularly crops [17].…”

Zeolites versus Lead Toxicity

“…In order to meet increasingly stringent Environmental Quality Criteria (EQC) clinoptilolites are widely applied for heavy metals removing from polluted streams and wastewater [4,19,[32][33][34][35][36][37] and for the elimination of gas pollutants in confinement facilities [7,10]. Besides, this mineral has widespread applications in agriculture [1,2].…”

Effects of Natural Zeolites on Bioavailability and Leachability of Heavy Metals in the Composting Process of Biodegradable Wastes

“…Zorpas et al [38] concluded that the addition of 25% (w/w) zeolite in compost is adequate to eliminate around 12-60% of the heavy metals during sewage sludge composting. Sprynskyy et al [14] reported that the addition of 9.09% clinoptilolite to the sludge reduced the total concentration of metals to around 11-51%. The increases in the concentration of heavy metals in the composting process were mainly because of the losses of mass [37].…”

“…The Na + , K + , and Ca 2+ are exchangeable for balancing the net negative charge and are commonly exchanged with particular cations (cations of Pb, Th, Cd, Zn, Mn, and NH 4 ) in aqueous solutions [1,13]. Natural zeolite has been applied broadly for decreasing the mobility and bioavailability of heavy metals in water hyacinth and sewage sludge composting because of its sorption and exchangeable properties for heavy metals [13,14]. It can uptake heavy metals that are present in the composting mass in easily available fractions, and exchange with Na and K [15].…”