Heavy Metal Release from Some Industrial Wastes: Influence of Organic and Inorganic Acids, Clay Minerals, and Nanoparticles

Knowledge about heavy metal release from industrial solid wastes(ISWs) is crucial for better management of their environmental risks. This study was conducted to investigate the effect of organic and inorganic acids, clay minerals, and nanoparticles(NPs) on the release of heavy metals from sugar factory waste, ceramic factory waste, leather factory waste, and stone cutting waste. The influence of the extractants on heavy metal release from these ISWs was in the following descending order: citric acid > oxalic acid > nitric acid≥ sulfuric acid > Ca Cl2. Addition of clay minerals and NPs as adsorbents decreased heavy metal release, which was significantly lower in NP-treated wastes than in the clay mineral-treated wastes. On the other hand, the presence of organic and inorganic acids increased heavy metal adsorption by NPs and clay minerals. These results suggest that NPs can be applied successfully in waste remediation,and organic and inorganic acids play an important role in the removal of heavy metals from the studied adsorbents.

Assessment of mobile and potential mobile trace elements extractability in calcareous soils using different extracting agents

Understanding trace elements mobility in soils,extracting agents,and their relationships with soil components,are essential for predicting their movement in soil profile and availability to plants.A laboratory study was conducted to evaluate extractability of cadmium(Cd),cobalt(Co),copper(Cu),nickel(Ni),and zinc(Zn)from calcareous soils utilizing various extracting agents to be specific CaCU,DTPA,EDTA,HNO3,MgCl2,NaN03,NH4NO3,and NH4OAc.Cluster analysis indicated that DTPA and NH4OAc,HN03 and EDTA,and M gCl2 and NH4NO3 extracting agents yielded comparative values,whereas NaN03 and CaCl2 have shown different behavior than other extracting agents for all studied trace elements.The speciationof extracted trace elements in solutions indicated that in the CaCl2,NaN03,NH4NO3,and MgCl2 extracting agents most extracted Cd,Co,Ni,Zn,and part f Cu were as free ions and may be re-adsorbed on soils,leading to lower extractability,whereas,in the caseof HNO3 extracting agent,the likelihoodof re-adsorptionof trace elements may be little.The resultsof speciationof trace elements using NH4OAc DTPA,and EDTA extracting agents showed that Me-(Acetate)3,Me-(Acetate)2(aq),Me(DTPA)3-3-,Me(EDTA)2-.and MeH(EDTA)-complexes dominated in solutions indicating that the extracted trace elements may not be re-adsorbed on soils,leading to higher extractability.The resultsof this study are useful for short and long-term evaluationsof trace elements mobility and further environmental impacts.

CFTR mutations causing congenital unilateral absence of the vas deferens(CUAVD)and congenital absence of the uterus(CAU)in a consanguineous family

Cystic fibrosis(CF)is one of the most common recessive genetic diseases,with a wide spectrum of phenotypes,ranging from infertility to severe pulmonary disease.Mutations in the cystic fibrosis transmembrane conductance regulator(CFTR)gene are considered the main genetic cause for CF.In this study,we recruited a consanguineous Iranian pedigree with four male patients diagnosed with congenital unilateral absence of the vas deferens(CUAVD),and one female patient diagnosed with congenital absence of the uterus(CAU).Testicular biopsy of one patient was performed,and hematoxylin and eosin(H and E)staining of testis sections displayed the presence of germ cell types ranging from spermatogonia to mature spermatids,indicating obstructive azoospermia.To explore the underlying genetic factor in this familial disorder,we therefore performed whole-exome sequencing(WES)on all available family members.WES data filtration and CFTR haplotype analysis identified compound heterozygous mutations in CFTR among four patients(two CUAVD patients carried p.H949Y and p.L997F,and one CUAVD and the female CAU patient carried p.H949Y and p.I148T).All these mutations were predicted to be deleterious by at least half of the prediction software programs and were confirmed by Sanger sequencing.Our study reported that CFTR compound heterozygous mutations in a consanguineous Iranian family cause infertility in both sexes.

Improving TC drill bit's efficiency and resistance to wear by graphene coating

Displaying a two-dimensional pure crystal carbon structure,Graphene is the strongest,yet thinnest substance discovered by scientists.Coating tungsten carbide(TC)drill bits with graphene to evaluate the effect of graphene on the wear,as well as the rate of penetration of the drilling bit was examined in this research.Two evaluation approaches were employed:one with employing ANSYS Software and the second by employing atomic pressure chemical vapor deposition(APCVD synthesis)in the laboratory to produce a monolayer graphene coating.The simultaneous software-based and lab-based testing were performed to increase the credibility of the results and minimize the potential errors.Conducting the simulation using ANSYS,the maximum shear elastic strain,equivalent elastic strain,equivalent(von mises)stress,total deformation and maximum shear stress were investigated prior and after the gra-phene coating was applied on TC simulated bit.Total deformation was only slightly increased,while the maximum shear elastic strain was almost doubled,reflecting that the bit's wear was significantly reduced after the coating.Lab-based APCVD synthesis results showed 34%increase in compressive strength of the coated bit,in comparison to the uncoated one.The failure occurred for uncoated bit at 35 MPa,where the coated bit experienced failure at 46.9 MPa.The Von Mises stress test conducted on the coated and uncoated samples also indicated that this stress was 41%less for the coated bit,in comparison to the uncoated one.Finally,two small-scale drilling operations,one using a 1inch graphene-coated TC bit and the other using a 1inch non-coated TC bit,were performed on a granite block,to evaluate the performance of the graphene-coated bit in practice.In a chosen 120-min time frame,27 consecutive holes could be drilled by the graphene-coated TC bit,while 19 consecutive holes could be drilled by the uncoated TC bit,in identical drilling conditions.This implies a 42%increase in ROP.