[Study on dioxin emission for typical non-wood pulp making in China].

Based on the requirement of National Implementation Plan for the Stockholm Convention on Persistent Organic Pollutants (NIP), six industries including pulp and paper industry have been set as the priority key sectors to implement the best available technology and best environmental practice (BAT/BEP) within a specific time for UPOPs reduction. Non-wood pulping has always played important role in virgin pulp production in China, its elemental chlorinated bleaching process has been confirmed as main source of Dioxin emission for the sector. As the signature party of Stockholm Convention and long time existing country of non-wood pulping, identification of Dioxin emission situation is significant importance to China to committee the obligation of Stockholm Convention.

[Recovery of Cd2+ by an electrolytic process from the concentrated solution of micellar enhanced ultrafiltration].

Micellar enhanced ultrafiltration (MEUF) is a new method which is based on the surfactant of the unique characteristic of parental molecular structure that can remove heavy metals in the water. The concentrated solution by dealing with the MEUF contains high concentration of heavy metal ions, so it must be need for further processing. The electrolysis method was employed to recovery Cd2+ from the concentrated solution of micellar enhanced ultrafiltration (MEUF).

Effect of groups difference in surfactant on solubilization of aqueous phenol using MEUF.

Micellar-enhanced ultrafiltration (MEUF) was used to remove phenol from simulant aqueous solutions. The effect of groups difference of cationic surfactant on the solubilization of phenol was investigated through orthogonal experiment, namely, surfactants with the same length of hydrocarbon chain but different hydrophilic head group and vice versa. The effects on the solubilization of phenol of various operating parameters in the practical application of MEUF with OTAB were studied, including surfactant concentration, electrolyte concentration, feed phenol concentration, operating pressure, temperature, respectively.

[Recovery and reuse of SDS by ultrafiltration with acid or chelator].

The retentate stream containing Cd2+ was chosen for the investigation. Effects of acid reagent, chelator, pH and operation mode on separation of Cd2+ and recovery of SDS, as well as efficiency of reclaimed SDS were investigated. The optimum conditions in acidification were obtained: H2SO4 as acid reagent, pH = 1.

Recovery of surfactant SDS and Cd2+ from permeate in MEUF using a continuous foam fractionator.

The purpose of this study was to investigate the use of foam fractionation to recover valuable surfactant (SDS) and metal ion (Cd2+) in the permeate of micellar-enhanced ultrafiltration (MEUF). The effects of operating factors, such as time, air flow rate, feed flow rate, liquid height, foam height, feed surfactant concentration, ethanol concentration and temperature on separation characteristics were studied in the continuous operation. When the concentrations of surfactant (SDS) and metal ion (Cd2+) in the feed solution were 500 mg/L and 10 mg/L, an enrichment ratio of 3.