Papers by Keyword: Phosphorus Removal

Abstract: Phosphorus is a non-renewable source and due to its high levels of phosphorus in water body may lead to eutrophication problems. It may come from many sources such as industry, agriculture and also from wastewater treatment plant. Large excessive of phosphorus may increase the purification cost and serious water quality problem because of the effect of algae toxin in water. Conventional wastewater treatment plant (WWTP) requires lot of cost such as labour, capital and maintenance costs. Therefore, the lab-scale aerated steel slag filter (ASSF) emerged as an alternative method to remove phosphorus from water due to its simple and also low cost technology has been developed to overcome this problem. This lab-scale filter has been conducted by using synthetic wastewater for an eight weeks starting from 19 March until 4^th May 2014. This study is to investigate the effect of pH range from 4.5 to 7.5 and temperature for phosphorus removal mechanism. From this study, result shows that lab-scale ASSF achieve about 90% of phosphorus removal at pH 5.0. Based on X-ray fluorescence (XRF) analysis, the steel slag is rich in Ca, Al and Fe which is enhance the P removal with the influence of pH for precipitation mechanism process in this experiment.

Abstract: Fe-containing compound clinoptilolite media (Fe-M), prepared with natural clinoptilolite, was applied to be the filter media of BAF, and then the treating performance of sewage by BAFs with Fe-M and ceramsite were investigated. Because Fe-M had relatively larger surface area, better pore connectivity, higher biofilm microbial biomass, and the ion-exchanging and adsorption effect, a higher ammonia nitrogen removal efficiency was obtained in BAF with Fe-M than ceramsite; and higher phosphorus removal in BAF with Fe-M was also realized by the adsorption and precipitation effect of the leaching ferric ions. Fe-M is more suitable to be used as the filter of BAF to treat sewage wastewater than ceramsite, which has a high value of broad application prospects and engineering popularization value.

Abstract: The graduation design topic for a sewage treatment plant processesdesign - inverted AAO process in durian. Main task is tantamount to designaccording to the requirement of the nature of the city sewage, sewage, scalepreliminary design to complete sewage treatment plant and single processing structure design.

Abstract: In order to study combination effect of aquatic plants for the purification of eutrophic wastewater, research was carried out in greenhouse with water hyacinth (Eichhornia crassipes), hornwort (Ceratophyllum demersum L) an water milfoil (Myriophyllum verticillatum L). In the treatment of water hyacinth + water milfoil , the removal efficiency of ammonium nitrogen (NH₄⁺-N), nitrite nitrogen (NO₃^--N) , total nitrogen (TN), total phosphorus (TP) and COD was 74.7%, 61.7%, 65.6%, 73.8% and 50.8% respectively. And that of water hyacinth + hornwort was 79.0%, 52.6%, 67.5%, 46.2% and 56.9%. The combination of different aquatic plants have better removal efficiency than single species. Water milfoil showed good removal ability for the eutrophication pollutants, such as nitrogen and phosphorus, while hornwort was good at the purification of COD.

Abstract: The treatment performance and biofilm development of the start-up stage in an up-flow Biological Aerated Filter (BAF) with composite steel slag media is investigated, while the operating conditions is HRT 2h, temperature 23-27°C, DO 3-5mg/L. The results showed that the composite steel slag media BAF could be secussfuly operated in a short time, while the phosphorus could be removed 90% in 8 days as well as the ammonia nitrogen and COD could be removed 80% in 25 days after the beginning of reactor start-up. At the same time, the biofilm on the carrier could be observed and a lot of protozoa population, such as Rotifera, Vorticellidae and Parameciidae, could be characteristiced with optical microscope in the BAF system. It is conclued that the operation of the composite steel slag media BAF for nitrogen and phosphorus removal could be carried out quickly and conveniently, and provided a unique advantage for the future application.

Abstract: In order to improve the biological oxidation and phosphorous removal in BAF, compound inoculation method was introduced to start two stage biological filters by alternative aeration. The two stage biological filters were connected by serial way, and three phases "batch aeration phase, the phase of small flow water for gradually increasing in the load, the alternative aeration phase" were adopted as the start up procedure. The experimental results showed that: COD removal rate was 83.3% after the former two stages; Ammonia nitrogen removal rate was stable at 81.5% while the TP removal efficiency was 68.9% and COD removal rate reached above 80% at the end of the third phase. Totally, 25 days were necessary for the biofilm formation in two stages BAF.

Abstract: In this study, different acid modification methods were used to prepare two types of inorganic flocculation compounds. First, under simulated wastewater conditions, the optimal input quantity for phosphorus elimination of flocculant #1 was 0.5 g/L, and the optimal agitation conditions were rapid agitation at 300 rpm for 60 s followed by slow agitation at 20 rpm for 15 min. The optimal input amount of flocculant #2 was 0.8 g/L, and the optimal agitation conditions were rapid agitation at 300 rpm for 30 s followed by slow agitation at 100 rpm for 10 min. Then they were used to treat water from the East Lake. The removal rates of TP, ammonia nitrogen, COD, and turbidity by flocculant #1 were 91.45%, 60.90%, 80.71%, and 93.05%, respectively; the corresponding removal rates by flocculant #2 were 92.74%, 58.49%, 76.92%, and 84.66%, respectively. The discharged water for both flocculants had TP and COD concentrations that met the type III standards in GB3838-2002.

Abstract: MBR technology for sewage treatment has the advantages of high volumetric load, good treatment performance and so on. But the MBR technology also has the shortage of membrane fouling. So this study selected the control method of fixing combination packing added in the MBR reactor, so as to reduce the membrane pollution, at the same time in the reactor to create the environment of coexistence of anaerobic and aerobic for biological denitrification. Through the research of the pollutants removal efficiency and the membrane pollution, it was founded that this method can remove 85-95% of COD and ammonia nitrogen. Effluent COD concentration generally is about 25mg/L, and the minimum of it is less than 10 mg/L. Effluent ammonia nitrogen is generally less than 10 mg/L. The minimum effluent concentration of ammonia nitrogen was less than 1 mg/L. The removal rate of total phosphorus was between 30-45%.

Abstract: This research adopts the important iron electrolysis, removal of the wastewater of high COD, SS, phosphorus pretreatment experiment. Discusses the different iron dosing quantity, iron carbon ratio, and pH value, reaction time on the COD and turbidity, the influence of the phosphorus removal effect. Studies show that iron important electrochemical test in brewery wastewater treatment static optimal processing conditions for: water pH value is 4, 5% dosage of iron filings, 60 min temperature response, COD removal rate was 52.31%. When the iron carbon ratio of 2:1, removing effect is good, can reach 54.53%.

Abstract: Phosphorus contamination in aquatic system was a widespread problem in Zhejiang province due to the excess use of detergent, agrochemicals and other organic phosphorus chemicals. Volcanic rock, an adsorbent with porous structure and large surface area, was applied for phosphorus removal in wastewater. The results showed that the phosphorus removal rate and equilibrium time had positive correlation with the initial phosphorus concentration, while the volcanic rock particle size could also affect the adsorption performance as volcanic rock with smaller particle size used to have a larger cation exchange capacity and higher surface area. Both Langmuir adsorption and the Freundlich adsorption happened throughout phosphorus removal process, showing the strong capacity and capability of volcanic rock as absorbent for phosphorus wastewater. It is promising to use volcanic rock in phosphorus water/wastewater purification systems due its large quantities and accessibility in nature.