Study On Treating Pigment Wastewater With Macroporous Adsorption Resins

Pigment production is an important part of fine chemicals. Whether it is organic pigments or inorganic pigments in its manufacturing process has caused serious pollution to ewater environment. Organic pigments have been widely used in inks, paints, rubber products, plastic products, cultural and educational supplies and colorant for building materials, synthetic fibers and fabrics of dyeing. Organic pigments can be divided into azo pigments, phthalocyanine pigments, polycyclic pigments and triphenylmethane pigments and others. Azo pigments is one of the main production in organic pigment, so the research of azo pigment wastewater processing method may solve the contamination of pigment chemical plants.Along with the pigment and the correlation industry development, its production wastewater has become one of the main pollution sources. Pigment wastewater has a large quantity, high COD, deep color and non-biodegradable organics. It will cause serious water pollution if direct discharge without effective treatment.Our work is the research on pigment wastewater treatment by LS-100 macroporous absorption resins, which has not been reported in domestic. Results indicate:the concentration of wastewater is decreased with the decreasing of time; the absorption quantity which COD and aniline of wastewater are adsorbed by resins is increased with the increasing of concentration of wastewater, and basically is linear; COD and aniline are easily absorbed under lower temperature; the absorption quantity of aniline is increased with the increasing of pH. COD and aniline accord with the Langmiur and Freundlich isotherm models under certain concentration and temperature's limits. Furthermore, the concentration and absorption flow rate have effect on absorption; the kind of desorption agent and flow rate have also effect on desorption.The factors affecting adsorption and desorption effects are studied. The process conditions determined by the repeated tests are as follows: adsorption flow rate 3BV/h, pH around 8.0, adsorption temperature 25℃, adsorption quantity for single column 18BV, desorption flow rate is 2BV/h, desorption temperature is 50℃.The desorption agent is the mixture of alkaline ethanol and hydrochloric acid.Fixed bed adsorption-regeneration experiments show that COD and aniline removal achieve 87% and 96%,respectively. The reusing capability of the macroporous adsorption resins is good.