The use of metallic iron (Fe0 ) for environmental remediation is applied industrially with a great degree of empiricism. Rules of thumb seem to be the only guide followed by the greater part of the Fe0 remediation community. The present communication demonstrates the validity of such a harsh statement and hopes that the research community will now follow the 10-year-old path concealing Fe0 remediation and mainstream science. A promising application is safe drinking water provision on a decentralized manner.

Silicon nitride (Si3 N4) SNA, SNB, SNC and SND were synthesized by hydrothermal process at temperature of 100o C, 150o C, 200o C and 300o C using Rice Husk Ash (RHA) and Sugarcane Bagasse Ash (SBA) respectively. The percentage of silica ranges from 90.10 to 94.19 with minute impurities.Based on their infrared spectra, for SNA absorption band at 470.6 cm-1 is attributed to Si-N (stretching), which were also observed with SNB, SNC and SND, a weak band at 671.2 cm-1 which is characteristic of a silicon nitride Si-N-Si stretching vibration was observed, for SNC, peak at 574 cm-1 attribute to a-silicon nitride, as temperature increases the spectrum becomes sharper. X-ray diffraction pattern indicates that SNA material contained 64.6% a-phase and 27.8% ß-phase silicon nitride. Therefore, rice husks and sugarcane bagasse have great potential as a raw material for producing Si3 N4 , by the hydrothermal method

Waste water is a potentially rich source of valuable materials including nutrients, such as phosphates. Recovering these compounds is difficult because of their relatively dilute concentrations and complex chemistry of the wastewater itself. The purpose of this study was to synthesize super-paramagnetic nanoparticles (maghemite, ?-Fe2O3 ) for recovering phosphate from simple and complex electrolyte solutions. The ?-Fe2O3 nanoparticles were coated with dimercaptosuccinic acid (DMSA) onto which a tetraethylenepentamine (TEPA) coating was attached using two different methods. The unmodified and modified nanoparticles were characterized with regards to their size/size distribution, surface charge (zeta potential), surface functionality, and specific surface area, using dynamic light scattering, transmission electron microscopy, laser Doppler velocimetry, Fourier transform infrared spectroscopy, X-ray fluorescence, and BET surface area analysis. The TEPA-functionalized nanoparticles, irrespective of the synthesis method used, achieved phosphate adsorption capacities between 11 to 16 mg PO4/g adsorbent. Adsorption increased with increasing solution ionic strength up to 100mM NaCl, and decreased with increasing solution pH. Both relationships were attributed to ionic interactions between the phosphate anion and the negatively charged adsorbent surface. The presence of competing anions, nitrate and sulfate, did not significantly affect phosphate adsorption by the TEPA functionalized ?-Fe2O3 nanoparticles.

Rising costs of power generation as a result of increased condenser tube scaling and corrosion have become critical areas that need intervention at Eskom’s power stations in South Africa. In the past few years, the quality of cooling and raw water has deteriorated with increased concentrations of scale formation metals such as calcium (Ca) and magnesium (Mg) as well as Natural Organic Matter (NOM). The Dissolved Organic Matter (DOC) fraction of NOM in the water forms complexes with metals Ca and Mg under various conditions. In this study, the Cooling Water (CW) and Raw Water (RW) at Lethabo and Duvha power stations were sampled and were analyzed for metals as well as organics and the data obtained was fitted into a Visual MINTEQ chemical model and Langelier Saturation Index (SI) calculations coupled with calcium carbonate precipitation potential models. The data obtained indicated that as the DOC concentration increased, the SI values decreased which may be attributed to the to complexation of Ca and Mg (the scaling metals) bound to DOC, leaving relatively lower concentrations of the free Ca and Mg ions until the reactive sites of DOC were saturated. The seasonal changes affect pH, DOC and concentrations of other metals present in the water that influenced complex formation and scaling.

The objective of this research is focus on pollutants evaluation and remediation of Tannery effluent discharged from Nigerian Institute of Leather and Science Technology (NILEST) Zaria, Nigeria using activated Carbons as adsorbents. The received, spent and Reborn Adsorbents (RGAC) were characterized using both classical (bulk density, ash content and iodine number) and instrumental (AAS, SEM, FTIR and UV-Vis Spectrophotometer) techniques. The role of different operating parameters on Cr uptake was investigated from a batch adsorption mode. Data generated where fitted into four isotherm models viz; Langmuir, Freundlich, Temkin and Dubinin-Radushkevich. The earlier estimated chromium level in the tannery effluent which was above WHO and NESREA permissible limits was considerably reduced via adsorption. On the general, results show good significance in the adsorption behavior of the regenerated adsorbent compared to the commercial sample.