Application Of Biological Aerated Filter Based On Sludge Ceramsite To Treat Water-jet Weaving Wastewater

Water jet loom is an important weaving machine in the textile industry.It consumes water resources and generates a large amount of waste water during the production process,which causes a series of problems.On the one hand,large-scale water-jet weaving wastewater is urgently needed for treatment and reuse,and on the other hand,a large amount of sludge generated during water treatment is also urgently needed for disposal.In response to increasingly stringent environmental protection policy requirements,it is imminent to treat the water-jet weaving wastewater in the textile industry,and carry out resource-based sludge disposal.Biological aerated filter?BAF?combines traditional biological membrane method and filtration technology,and is widely used in various wastewater treatment because of its high biological retention and good effluent quality.At present,ceramics technology that follows the"four modernizations"principle of sludge disposal has become a research hotspot,and has attracted much attention because it can be used in the field of water treatment and realize the dual benefits of"treating waste with waste."Therefore,actively exploring the combined application of sludge ceramics technology and biological aerated filter to strengthen wastewater treatment is of great significance for the sustainable development of the water jet loom industry.This paper focuses on the pollution reduction of the water jet loom industry in the textile industry in Changxing area,combines the two aspects of sludge ceramics resource recycling technology and wastewater bio-enhancement.Based on the self-made sludge ceramsite,biological aerated filters are constructed,and compares the commercially available ceramsite in the market.Then carries out the research on reduction of pollutants from water-jet weaving wastewater by self-made sludge filter biological aerated filter,and explores the action mechanism from three aspects:pollutant removal characteristics,microbial characteristics,and filter water treatment characteristics.The main achievements are as follows:1. Investigation on the current status of water reuse stations in water jet loom.8water-jet weaving wastewater treatment stations have been built in Jiapu Town,Changxing County.The core processes are all air-floating-sedimentation,and the sludge produced is transported to the cement plant after dehydration.The average concentrations of COD and oil in the effluent from the typical water jet loom processing station?are 522.95 mg·L^-1and 9.09 mg·L^-1,respectively,which can not reach the first-class standard of"Integrated Wastewater Discharge Standard"?GB8978-1996?,and standards need to be mainly controlled.The annual output of sludge from water station?is about 7000 t?water content 80%?,the p H is 6.67?6.91.The main components include Si O₂,Al₂O₃,etc.,and the metal element content does not exceed the limit value in"Sludge mud of Urban sewage treatment plant"?GB/T 24188-2009?.It is less harmful,so the comprehensive treatment technology of sludge recycling can be further explored.2. Research and development of sludge-based ceramsite and performance test analysis. It was determined that the sludge ceramsite was prepared with sludge,bottom mud,and fly ash ratio of 5:3:2,firing temperature of 1130?,and holding time of 20 min.The damage rate,mud content,hydrochloric acid solubility,void ratio and specific surface areas are 4.97%,0.73%,1.56%,45.65%,1.7215 m²·g^-1,respectively,which meets the limits specified in"Ceramic ceramsite filter for Water treatment"?CJ/T 299-2008?.The characterization shows that the composition of sludge ceramsite is similar to the commercially available ceramsite,with C,O,Si and Al as main elements,including oxides such as quartz,calcium feldspar and other oxides.The sludge ceramsite is coarse and porous,with an internal porosity and pore volume of 36.5%and 0.2432 cm³·g^-1,respectively,which are suitable for the adsorption and fixation of microorganisms.The metal content in the sludge ceramsite leaching solution did not exceed the"Dangerous Waste Identification Standard Leaching Toxicity Identification"?GB5085.3-2007?,which is a kind of environmentally-friendly resource-based water treatment filter.3. Study on performance of sludge ceramsite BAF system for water-jet weaving wastewater Treatment.A sludge ceramsite-based aerated biofilter?SSC-BAF?and a commercially available ceramsite-based aerated biofilter?CTC-BAF?were constructed.In the start-up phase,SSC-BAF completed the film hanging after 7 days and completed the domestication of microorganisms after 59 days.Compared with 12and 65 days of CTC-BAF,the SSC-BAF startup cycle was shorter and more impact resistant.Considering reuse standards,to determine the optimal gas-water ratio system of 5:1,HRT of 6 h,at this time SSC-BAF removal of COD,oils,turbidity were 86.7%,89.6%,97.7%,respectively,which is slightly better than that of CTC-BAF for 85.3%,87.0%and 96.1%.SSC-BAF's ability to remove COD is restored after 6 hours of backwashing,and the backwash cycle is 8-9 days,while the backwash cycle of CTC-BAF is 6-7 days.Under the same conditions,the overall performance of SSC-BAF is better than that of CTC-BAF.It is proved that the ceramsite prepared by using sludge and other raw materials has the value of water treatment application and can realize"treat waste with waste".4. Study on the mechanism of sludge ceramsite BAF system for water-jet weaving wastewater treatment.The water-jet weaving wastewater contains a large amount of benzene,protein polysaccharides,amides,phenols,esters and so on.Contaminant removal characteristics show that the SSC-BAF system can efficiently degrade phenols,esters,and aromatic proteins in wastewater.The dominant bacteria that degrade weaving wastewater are Novosphingobium spp.,Sphingobium spp.,Piscinibacter spp.,Halomonas spp.,etc.In addition,SSC-BAF biomass and community diversity are much higher than CTC-BAF.The sludge filter material is better enriched with functional genus such as Novosphingobium spp.,Sphingobium spp.,Haliangium spp.,which proves that SSC-BAF has better water treatment efficiency.The self-made sludge ceramsite has a larger water holding rate,a lower absolute value of Zeta potential,and a more suitable p H value,which promotes the adhesion of microorganisms in it,enabling the system to start up quickly and efficiently degrade pollutants.5. Engineering applications.Construction of sludge resource disposal project with a designed daily capacity of 200 tons?water content 80?.The main processes are sludge preheating,plate and frame pressure filtration,drying ceramics,etc.The total cost of per ton ceramsite using sludge pottery technology is 257.2 yuan;The water-jet weaving wastewater pollution reduction project is adapted to local conditions to design a biological aerated filter of 10,000 m³·d^-1,and use sludge ceramsite as a filter material to comprehensively achieve pollution reduction in the water jet loom industry.