The reclaimed water of domestic sewage reused in recycling cooling system has been widely spread and applied. Chemical scale inhibitors are the most economic and effective measures to prevent condensers and circulating pipes from scaling currently. Green scale inhibitor are highly regarded for their non-toxicity, phosphate-free, reproducibility and biodegradability. The paper selects two kinds of new green scale inhibitors used in the recycling cooling water of Beijing Thermoelectric Plant. By the measuring the scale inhibition rate, scaling amount, turbidity and SEM, it shows that Polyepoxysuccinic acid (PESA) is worth spreading and applying in the industrial recycling cooling system with reclaimed wastewater, for its high scale inhibition rate, good dispersion, low consumption, high economy and practicability.

Monodisperse hollow silica nanospheres were prepared using functionalized polystyrene (PS) as a template and characterized by transmission electron microscopy (TEM), nitrogen adsorption and thermo gravimetry (TG) techniques. The effect of ammonia amount on hollow silica spheres was explored. It is found that the ammonia amount is important to the fabrication of hollow silica nanospheres. The roughness and thickness of the silica shell increased with the increase of ammonia amount. When ammonia amount reached 20 ml, the product hadn’t been hollow structural. The TGA curves and the BET results of the samples supplied a proof for the formation mechanism of the hollow silica spheres.

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In recycling cooling system used reclaimed water, the main ions of the reclaimed water must form chemical scales with the increase of temperature and concentrate ratio , In order to control the formation of scale, we must control the fouling ion in the reclaimed water.In this paper the influence laws of Ca2+, Mg2+, HCO3- , SO42-, PO43-, NH4+ , NO2- , NO3- in reclaimed water on the scale inhibition are researched . The experimental results show that Ca2+, HCO3- , PO43- in reclaimed water have negative impact on scale and antiscale ;Mg2+ and NH4+ have positive effect on scale and antiscale;and SO42-, NO2- , NO3- hardly affected on scale and antiscale.

The main risk of reclaimed water reused in industry is to control fouling. The main ingredients in reclaimed water form the chemical scale which is one of the main components of the fouling in the recycling cooling system. The main chemical scale of reclaimed water is carbonate scale (calcite). In this paper, by using the actual reclaimed water which reused as make-up water in Beijing Thermal Power Plant to simulate the 4 times concentrate ratio recycling water to study the influence of main ingredients of reclaimed water such as pH，soluble silica, the most content of anions and cations on carbonate scale. The experimental results show that pH, soluble silica, calcium ion and alkalinity have greater influence on scale inhibition, but magnesium ion, chloride ion and sulfate ion have smaller influence on scale inhibition.