Study on Application of Novel Flocculating Agent in Treating Refinery Wastewater with High Concentration of Pollutants

After conducting a lot of screening experiments the appropriate flocculating formulations for treating high-concentration wastewater discharged from a certain refinery were selected. The oil removal rate and COD removal achieved by these flocculating formulations were better than that achieved by the conventional compound formulation consisting of polyaluminium chloride(PAC) and polyacrylamide(PAA) . Addition of an oil/water separating agent to the formulation could improve its oil removal performance to facilitate the oil/water separation of the oil-in-water emulsion in the high-concentration wastewater along with improved adaptability of the formulation to the wastewater containing high concentration of pollutants. This flocculating agent has promising prospects for commercial application.

Experimental Study on Application of A Charging Flocculation Agent for Treatment of Turbidity and Suspended Solid in Catfish Farming Water in Vinh Long Province

The electrically charged flocculation agent Kiyomaru was made on the basis of activating surface sand, clay, volcanic ash and then combined with strong electrical charge on the surface. Thus, it is the flocculant with natural and inorganic origin including 24.7% Na, 11.5% Al, 19.6% Si, 22.5% S, 1.8% K, 19.0% Ca and 0.9% Fe. The experimental results showed that the Kiyomaru is a flocculation agent with ability to treat the turbidity and suspended solid in the catfish farming waters with very high sedimentation rate and removal efficiency. The efficiency of turbidity removal is from 98.7% to 99.1%, while that for TSS removal is from 93.5% to 95.2% using 0.2 mg/L of the flocculation agent. Beside those, the agent can remove the organic matters （BOD, COD） from 21.4% to 26.7%, Total N from 32.4% to 33.9% and Total P from 85.4% to 89.3%. When the concentration of this flocculate agent is 0.2 g/L, turbidity treatment efficiency can range from 98.7% to 99.1%; TSS treatment efficiency can range from 93.5% to 95.2%. Besides, this flocculation agent is also capable of reducing 21.4%-26.7% of the organic matter, 32.4% to 33.9% of Total N and 85.4% to 89.3% of Total P.

Ammonium Metavanadate Fabricated by Selective Precipitation of Impurity Chemicals on Inorganic Flocculants

High purity ammonium metavanadate(NH_(4)VO_(3))is the most vital chemical to produce V2O5,VO2,VN alloy,VFe alloy and VOSO4,which have some prospective applications for high strength steel,smart window,infrared detector and imaging,large scale energy storage system.NH_(4)VO_(3)is usually produced by spontaneous crystallization from the aqueous solution due to its sharp dependence of solubility on the temperature.However,hazardous chemicals in industrial effluent,include phosphorate,silicate and arsenate,causing severe damage to the environment.In this work,these impurities are selectively precipitated onto inorganic flocculants,while the vanadate dissolved in an aqueous solution keeps almost undisturbed.Therefore,high purity NH_(4)VO_(3)is produced by the crystallization from the purified solution.By screening various flocculants and precipitating parameters,polyaluminum sulfate with an optimal amount of 50 g/L,is demonstrated to selectively remove phosphorate,silicate and arsenate,corresponding to the removing efficiency of 93.39%,97.11%and 88.31%,respectively.NH_(4)VO_(3)from the purified solution holds a purity of 99.21%,in comparison with 98.33%in the product from the crude solution.This purifying technology cannot only produce NH_(4)VO_(3)with high added value,but also reduce the environmental pollution of waste liquid.

Cemented backfilling technology with unclassified tailings based on vertical sand silo

A new technology characterized by rapidly non-mechanical settlement of unclassified tailings was developed based on a large number of tests, and dynamic settlement and continual slurry preparation without hardening in vertical sand silo were eventually realized by the addition of an effective flocculating agent (NPA). The results show that the sedimentation velocity of interface between unclassified tailings and water after the addition of NPA increases by 10-20 times, the sedimentation mass fraction of unclassified tailings at the bottom of vertical sand silo is up to 64%, the solid particle content of waste water meets the national standard, and the side influences of NPA can be removed by the addition of fly ash. The industrial test result shows that the system, the addition manner and the equipments are rational, and the vertical sand silo is used efficiently. This developed system is simple with large throughput, and the processing cost is 2.2 yuan(RMB)/m3, only 10%-20% of that by mechanical settlement.

RESEARCH ON CATIONIC POLYMER WATER BASE DRILLING FLUIDS

Cationic polymer drilling fluid (CPDF) is a new water base drilling fluid in which high molecular weight (HMW) cationic polymer (CPAM) is an encapsulating and flocculating agent and organic quaternary ammonium compound (NW-1) acts as shale inhibitor. This paper describes the experimental results of cuttings recovery, particle size distribution layer spacing and Zeta potential, and discusses the inhibition of CPDF system and its major additives. The advantages of CPDF will be proved by its application in well LX-2.