Extraction of Amino-J Acid from Waste-water by Emulsion Liquid Membrane

The emulsion liquid membrane technique was used to extract amino-J acid from industrial dye waste-water.The effects of stirring speed,ratio of the emulsion to water(Rew),ratio of the oil to internal phase(Roi)and membrane phase components on the extraction rate were investigated and optimized.The results showed that the extraction rate of amino-J acid approached 97% when the stirring speed was 300 r/min,Rew 1:6,Roi 1:1,trioctylamine(TOA)3 mL/100 mL kerosene,and methyl?didecyle?alcohol?acrylate(LMA-2)3 g/100 mL kerosene,respectively.The extraction rate had not changed with the oil phase reused for times.

Coagulation behaviors and in-situ flocs characteristics of composite coagulants in cyanide-containing wastewater:Role of cationic polyelectrolyte

In this paper, composite coagulants （PFS, PFSC05, PFSC1 and PFSC5）, prepared by mixing polyferric sulfate （PFS） and cationic polyelectrolyte （CP） coagulants with different weight percent （Wv） of CP （Wp = 0%, 0.5%, 1% and 5%, respectively）, were adopted to treat cyanide-containing wastewater. PFSC5 exhibited superior coagulation performances at optimal conditions： the removal of total cyanide （TCN） and chemical oxygen demand （COD） was 95%-97% and 50%-55%, respectively. The effects of CP on the properties and structure of flocs were investigated by laser diffraction instrument and small-angle laser light scattering （SALLS）, respectively. The results show that the flocs of PFSC5 have higher growth rate, higher strength factor and lower recovery factor than other flocs. They are also much denser and more uniform owing to the higher fractal dimension （DO and less microflocs （10-100μm）. Furthermore, the dense structure of the PFSC5 flocs can be restored after shear and is more resistant to hydraulic conditions. Particularly, detailed morphology evolution of the flocs was in-situ detected by on-line particle imaging. Due to strong ionic strength in wastewater, the CP in PFSC5 plays a significant role of adsorption, while the main mechanism of CP is electrostatic patch aggregation during the PFSC05 systems.

New Design &Build Biological System through the Use of Microalgae Addressed to Sustainable Development

Current trends in energy consumption and biofuel manufacturing are neither secure nor sustainable, because they are not provided by necessary cost effective technologies. Further reductions of cost and technological development will be needed for biofuels to be able to compete effectively without subsidy. With the debate raging about raw material of biofuel, microalgae may offer a solution to this conundrum;creating enormous reserves of biofuels and boosting feed production. In this goal Center suggest projects, which incorporate water recourse management and restoration of lakes, freshwater conservation and cleanup through cost effective biodiesel manufacturing as well as pharmaceuticals destruction through the use of microalgae Chlorella and wastewaters aimed to replace the burning technology includes also supplying biofuel profitably and developed pilot bussiness plan based on the cost effective technology through applying new innovative approaches in various stages of microalgae production. The benefits of microalgae are so overwhelming that this, combined with the prospect of the improvement in nature protection, makes it imperative for the world to devise an international response and a plan of action. Incentives will be needed for the development of industry-led platforms such as the World Microalgae Technology Platform and its international financial fund. Microalgae must be the key tool for the new design and building sustainable development and environment management.

Re-evaluation of several heavy metals removal by natural limestones

Different treatment technologies have been efficiently applied to remove heavy metals from waste- water. Efforts have been made to find out the most economic water treatment technology by using low cost and easily accessible natural materials. On the other hand, heavy metals are the most threatening groundwater contaminants because of their toxicity and harmful effects on human and biota. This review discusses the use of natural geological materials for heavy metal removal in aqueous systems. Special attention has been devoted to natural limestone through a systematic inventory of relevant published reports. The removal of toxic metals may include different mechanisms （e.g., physisorption, chemisorptions, precipitation, etc.）, depending on the physico-chemical properties of the material and the removed metal. Sorption of toxic metals （e.g., Pb, Cu, Cd, Zn, Cr, Hg, etc.） onto natural limestone involved precipitation of metal carbonate as a predominant removal process, but often subordinated by adsorption and ion exchange, depending on the physico-chemical properties of the studied limestone.

Coextraction of vanadium and manganese from highmanganese containing vanadium wastewater by a solvent extraction-precipitation process

High-manganese containing vanadium waste-water(HMVW)is commonly produced during the vanadium extraction process from vanadium titano-magnetite.HMVW cannot be reused and discharged directly,and is harmful to the environment and affect product quality due to heavy metals in the wastewater.The wastewater is usually treated by lime neutralization,but valuable metals(especially V and Mn)cannot be recovered.In this study,an efficient and environmentally friendly method was developed to recover valuable metals by using a solvent extraction-precipitation process.In the solvent extraction process,98.15%of vanadium was recovered,and the V2Os product,with a purity of 98.60%,was obtained under optimal conditions.For the precipitation process,91.05%of manganese was recovered as MnCO3 which meets the III grade standard of HG/T 2836-2011.Thermodynamic simulation analysis indicated that MnCO3 was selectively precipitated at pH 6.5 while Mg and Ca could hardly be precipitated.The results of X-ray diffraction and scanning electron microscopy demonstrated that the obtained V2Os and MnCO3 displayed a good degree of crystallinity.The treated wastewater can be returned for leaching,and resources(V and Mn)in the wastewater were utilized efficiently in an environmentally friendly way.Therefore,this study provides a novel method for the coextraction of V and Mn from HMVW.

Species distribution of arsenic in sediments after an unexpected emergent discharge of high-arsenic wastewater into a river

The unexpected emergent discharge of high- arsenic wastewater into water environments results in significantly increased levels of arsenic in water; however, the species distribution of arsenic in sediments has never been reported before for such cases. This study focuses on an As pollution accident in the Dasha River, and uses sequential extraction procedures with deionized water, l mol-L-1 MgC12 at pH = 8, 1 mol.L-1 NaH2PO4 at pH = 5, and 1 mol. L-1 HC1 to investigate four binding phases of arsenic （i.e., water soluble, ion-exchangeable, strongly- bound, and precipitates） in sediments at different layers in different cross-sections along the fiver. The average ratio of arsenite （As（III）） to arsenate （As（V）） was found to decrease from 0.74：1 in fiver water to 0.48：1 in sediment, owing to its higher affinity toward As（V） than As（III）. The content of arsenic in the sediments was relatively low and the maximum content was observed to be 36.3 mg-kg1 for As（IID and 97.5 mg.kg1 for As（V）. As（III） and As（V） showed different binding phases in sediments, and the average fractions of these four species were determined to be 0.09, 0.11, 0.17, and 0.63 for As（III） and 0.03, 0.14, 0.63, and 0.20 for As（V）, respectively. For all the sediment samples, the content of arsenic showed no relationship with the characteristics of the sediments such as the particle diameter, the content of organic carbon, Fe, and Mn, although a negative correlation with particle diameter was observed for the sediments in the uppermost 2-cm layer. The unexpected emergent As incident results in the high content of total arsenic in the surface sediment, which may be potential secondary source to the elevated As levels in surface water.