Biosorption as a Perfect Technique for Purification of Wastewater Contaminated with Ammonia.

Eichhornia crassipes root powder (ECRP) has been used to remove ammonia from aqueous solutions. The biosorption factors such as biosorbent dosage, pH, initial ammonia concentration, and contact time have been considered in batch conditions. The optimal conditions, at pH (6), sorbent dose 5 g/l, time (30 min) ammonia concentration (10 mg/l). Langmuir is better suited than Freundlich isotherm. The kinetic models Thomas, Yoon-Nelson, and Bohart-Adams were applied. These models showed that the adsorption capacity decreased with flow rate increases as follows: 32.57, 31.82, 31.25, and 30.17 mg/g, respectively, at a flow rate 10, 15, 20, and 25 ml/min. The root powder of Eichhornia crassipes was used to treat specific drainage wastewater obtained from the Sabal drain at Menoufia, Egypt. The average efficiency of ammonia removal was 87% per batch adsorption method at pH value = 7.5, sorbent dose 5 g/l, uptake period (30 min), and primary load 7.1 mg/l; however, ammonia removal by column continuous adsorption method exceeded 94%. In addition, ECRP is efficient in removing arsenic, sulfate, nitrates, nitrite, silica, iron, manganese, copper, zinc, aluminum, and lead from actual sewage wastewater, in addition to removing more than 75% COD.

Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of N'-(furan-3-ylmethylene)-2-(4-methoxyphenylamino)acetohydrazide.

Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of furan-2-carbaldehyde 4-methoxy-N-anilinoacetohydrazone were synthesized and characterized by elemental and thermal (TG and DTA) analyses, IR, UV-vis and (1)H NMR spectra as well as magnetic moment and molar conductivity. Mononuclear complexes are obtained with 1:1 molar ratio except complexes 3 and 9 which are obtained with 1:2 molar ratios. The IR spectra of ligand and metal complexes reveal various modes of chelation. The ligand behaves as a neutral bidentate one and coordination occurs via the carbonyl oxygen atom and azomethine nitrogen atom. The ligand behaves also as a monobasic tridentate one and coordination occurs through the enolic oxygen atom, azomethine nitrogen atom and the oxygen atom of furan ring. Moreover, the ligand behaves as a neutral tridentate and coordination occurs via the carbonyl oxygen, azomethine nitrogen and furan oxygen atoms as well as a monobasic bidentate and coordination occurs via the enolic oxygen atom and azomethine nitrogen atom. The electronic spectra and magnetic moment measurements reveal that all complexes possess octahedral geometry except the copper complex 10 possesses a square planar geometry. The thermal studies showed the type of water molecules involved in metal complexes as well as the thermal decomposition of some metal complexes.

First raw transition metal complexes of salicylidene and 2-hydroxy-1-naphthylidene-N-cyanoacetohydrazone.

Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of salicylidene-N-cyano-acetohydrazone H2L1 and 2-hydroxy-l-naphthylidene-N-cyanoacetohydrazone H2L2 have been prepared in ethanolic solution and characterized by analytical, spectral, magnetic susceptibility, molar conductivity and TGA measurements. The analytical data show that all the complexes derived from H2L1 and H2L2 are formed in molar ratios 1M:2L, except the complexes of Mn(II), Co(II) and Cu(II) acetates of H2L2 and the complexes of Mn(II), Co(II) and Ni(II) acetates and CuCl2 of H2L1 are formed in 1:1 molar ratios. The conductance data show that all metal complexes are non-electrolytes. Electronic absorption spectra and magnetic susceptibility measurements proved that the prepared complexes have octahedral configuration except [Co(HL2)OAc] which has tetrahedral structure. The ligand field parameters were calculated for the Co(II) and Ni(II) complexes and the data show that the covalent character of the metal ligand sigma-bond is low. The ESR parameters of the Cu(II) complexes at room temperature were calculated. Thermal TGA for some solid complexes are reported.