Reduction of cadmium contaminated groundwater pollution by using mineral adsorbents and industrial sorbents

<p>    Iron nanoparticles are capable of removing heavy metals due to their significant specific surface relative to their weight. Iron nano powders with an average particle size of 50 nm and very high reactivity are suitable for groundwater purification and industrial wastewater treatment. In fact, the very high ability of iron nanoparticles of zero valences in its reduction and high reactivity makes this material a good choice in achieving the above goals. Due to its small size, after injection, these particles can be spaced and transferred easily. On the other hand, natural zeolites are important aluminosilicates in adsorption processes due to their low cost. In this research activity, a comparison was made between the adsorption percentage of zero iron nanoparticles as an industrial adsorbent with the minerals, calcite, and zeolite. By adding 1 gram of adsorbent powder to a solution of 10 ppm cadmium, decreased cadmium concentrations at different time intervals in three experiments with two replications was measured by an atomic absorption spectrometer. The results showed that 38.4% of cadmium was adsorbed by nanoparticles after 3 hours, which was 8.53% and 5.5%, respectively for the usage of calcite and zeolite mineral adsorbents. This indicates an increase of 29.86 and 32.9% in adsorption of nanoparticle adsorbent compared to calcite and zeolite. To investigate the effect of adsorption percentage in a saturated porous medium, 100 ml of 10 ppm cadmium solution in the presence of 50 g of soil with an average diameter of 1.11 mm saturated with 50 ml of cadmium solution with the same concentration in reaction with 1 g of adsorbent powder was used 22 hours after the start of the experiment, 51.55% of the total cadmium was removed from the environment by soil and industrial adsorbent, and the adsorption percentages for calcite and zeolite in the porous medium were 17.5% and 7.75%, respectively.</p><p>Keywords: Cadmium, Zero iron nanoparticles, Calcite, Zeolite.</p>

Antimicrobial activities of different agents including pyrophyllite against foodborne pathogens: A brief review

There has been worldwide an increasing interest and more strict criteria for food/feed safety including absence or reduction of the total number of microorganisms (bacteria, moulds and yeasts). Besides heavy metals, materials of biological origin (plant extracts, bio waste, chitosan etc.), some mineral adsorbents also have antimicrobial properties. There is much information about the antibacterial activity of the modified bentonite, montmoriollonite, smectute, zeolites and antifungal activity of various metal ion-exchanged zeolites and natural mineral clay, but there is almost no information about the antimicrobial properties of pyrophyllite, a monoclinic mineral from the group of phyllosilicates. This work summarizes the recent developments of antimicrobial agents and their application, current research, and trends in the area, highlighting pyrophyllite and its potential applications. Pyrophyllite, an unexploited mineral, possesses antimicrobial properties such as antibacterial and antifungal activities against foodborne pathogens which contributes to the protection of consumer?s health and preservation of the environment. Results from preliminary investigations indicate that pyrophyllite showed antibacterial properties against Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, and antifungal properties against fungal pathogens (Fusarium oxysporum, Phoma glomerata and Rhizoctonia solani). This mineral can also be used for biological control of F. oxysporum in the soil for growing potato.

Sterile phosphate as a novel calcic adsorbent for phosphorus removal from wastewater

Sterile phosphate (SP) was investigated for phosphorus removal from wastewater using batch adsorption experiments. The novel adsorbent is a mining by-product obtained from the phosphate mining plants having a strong affinity with phosphorus ions present in wastewater. The results of the batch adsorption experiments indicated that 30 min of contact time between the adsorbent and wastewater was sufficient for attaining equilibrium. The phosphorus removal from wastewater increased with increasing initial phosphorus concentration, adsorbent dose and temperature, while it decreased with increasing initial pH values. The maximum phosphorus removal efficiency was noted to be 94.4%. It was achieved in slightly acidic conditions (pH = 4), with an adsorbent dose and initial phosphorus concentration of 3 g L−1 and 20 mg L−1, respectively, and at room temperature. Kinetic analysis showed that phosphorus adsorption onto sterile phosphate was best fitted with the pseudo-second order kinetic model. The adsorption equilibrium data fitted well to the Langmuir model equation, indicating monolayer coverage of the adsorbent. The adsorption capacity calculated from the Langmuir model equation was found to be 7.962 mg g−1. Comparing with some industrial products and natural mineral adsorbents, sterile phosphate was found to be the most efficient adsorbent for phosphorus removal from wastewater.