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1.
In this study acrylic water base color was removed from synthetic wastewater using coagulation process. Experiments were conducted on the sample containing 100 mg/L and 400 mg/L of acrylic water base color. Destruction of color by means of coagulation/flocculation techniques using ferrous sulfate, alum, lime and polyelectrolyte (cationic, anionic and non ionic). The study was performed in a systematic approach searching optimum values of alum and FeSO4 concentration, pH and temperature. All the experiments were run in a laboratory scale.The obtained results show that treatment with alum and ferrous sulfate alone proved to be very effective in removing the color (> 99 %) and part of COD (60–70 %) from aqueous solution. Lime alone did not significant change on COD and color removal.  相似文献   

2.
Jar-test experiments were conducted to study enhanced coagulation effectiveness in removal of disinfection by products (DBPs) from Zayandehrud River at Isfahan Province-the center part of Iran-in 2004. In this study, the removal of suspended and colloidal particles and natural organic matter (NOM) at various coagulant doses and coagulation pHs was assessed through raw and treated water measurements of turbidity, UV254 absorbance, TOC, and dissolved organic carbon (DOC). The trihalomethane formation potential (THMFP) was also determined by a mathematical relationship with TOC. Results indicated that NOM removal was a function of coagulant type, coagulant dose, and pH of coagulation. In general, TOC, DOC, and UV254 absorbance removal enhanced with increasing coagulant dose. However, further increases in coagulant dosage had little effect on disinfection by-products precursors removal. Ferric chloride was consistently more effective than alum in removing NOM. Coagulation pH was appeared to be a determining factor for maximum NOM removal and the removal of DBPs precursors by enhanced coagulation was significantly enhanced at pH 5.5 in comparison with initial pH of water. Furthermore, it is specified that preadjustment of pH with sulfuric acid reduced the coagulant dosage and thus, production of sludge. The reduction in THMFP was consistent with the trends observed for DBPs precursors removal data (i.e. UV254 and TOC data).  相似文献   

3.
炉渣处理含磷废水的实验研究   总被引：9，自引：0，他引：9       下载免费PDF全文
以炉渣作为吸附剂，用静态吸附实验方法研究了炉渣对模拟含磷废水脱磷的一般规律，结果表明，炉渣是一种有效的吸附剂，对废水中的磷有较强的吸附去除性能。影响炉渣除磷的主要因素有吸附时间、炉渣用量、pH值和原水含磷浓度。在含磷浓度2～13mg／L、炉渣用量5g／L、中性、吸附时间为2h的实验条件下，磷的去除率可高达99％以上。  相似文献   

4.
药剂与粉煤灰联合处理再生造纸废水的实验研究   总被引：2，自引：1，他引：1  
通过混凝实验探讨了用PAC处理再生造纸废水的最佳混凝条件.在此基础上,选用PAM为助凝剂,通过正交实验,获得了较佳的水平条件:先加PAM,质量浓度为3 mg/L,后加PAC,质量浓度为0.2 g/L,反应9 min;处理后的出水经粉煤灰过滤,ρ(COD)可降至37.383 mg/L,ρ(BOD)为20.7 mg/L,浊度为0,pH为11.12,在空气中放置24 h后pH变为8.02.  相似文献   

5.
高氟地下水混凝沉淀降氟试验研究   总被引：5，自引：0，他引：5  
本文开展了山西运城地区高氟地下水的降氟试验，对聚铁、硫酸铝和明矾等不同混凝剂降氟效果进行对比，探讨了地下水硬度对混凝沉淀除氟效果的影响。实验结果表明：明矾混凝沉降效果优于其它混凝剂，0．3g／L的明矾溶液可使含氟浓度4．0mg／L的地下水降低到浓度1．0mg／L以下；地下水的硬度对明矾混凝降氟效果没有明显影响。  相似文献   

6.
In this study, the treatability of marble processing wastewater by electrocoagulation using aluminum and iron electrodes was investigated. The sample used was from the marble-processing plant in Sivas and its turbidity, suspended solids, chemical oxygen demand and total solids concentrations were about 1,914?NTU, 2,904, 150 and 4,750?mg/L, respectively. The effects of various operating parameters such as initial pH, current density and electrolysis time on turbidity, suspended solids, chemical oxygen demand and total solids removal efficiencies were investigated. The settling characteristics of waste sludge produced and energy and electrode consumption were also determined. The optimum values of initial pH, current density and electrolysis time in electrocoagulation studies carried out using aluminum electrode were found to be 7.8, 30?A/m2 and 5?min, respectively. Under these conditions, the removal efficiencies obtained for turbidity, suspended solids, chemical oxygen demand and total solids were 98.5, 99.2, 55.2 and 92.4?%, respectively. Corresponding energy and electrode consumptions were 0.143?kWh/kg SS and 0.010?kg Al/kg SS. For iron electrode, the optimum parameter values were found to be 7.8 pH, 20?A/m2 and 5?min, respectively. Under these conditions, removal efficiencies for turbidity, suspended solids, chemical oxygen demand and total solids were determined as 94.3, 99.1, 54.2, and 96.1?%, respectively. Energy and electrode consumptions were 0.0571?kWh/kg SS and 0.0206?kg Fe/kg SS, respectively. Settling characteristics of sludge produced during experiments carried out using both aluminum and iron electrodes were fairly good. The results showed that electrocoagulation method can be used efficiently for the treatment of marble processing wastewater under proper operating conditions.  相似文献   

7.
采用PAC(聚合氯化铝)与PFS(聚合硫酸铁)混凝剂处理污水，并进行了对比实验。结果表明。在污水COD浓度为920mg／L，PFS折算为Fe2O3的投加量为300mg／L，pH为9．0时，出水COD为406mg／L，COD去除率为55．8％，而PAC折算为Al2O3的投加量为120mg／L时，出水COD为369．8mg／L，COD去除率为59．8％。PAC较PFS对COD的去除率高约4％。  相似文献   

8.
Hybrid anaerobic baffled reactor for treatment of desizing wastewater   总被引：3，自引：3，他引：0  
Polyvinyl alcohol-containing desizing wastewater discharged within final textile wastewater has a great impact to the environment due to its poor biodegradability. An improved lab-scale hybrid anaerobic baffled reactor was developed to treat desizing wastewater. The modification was achieved by increasing the height of hybrid anaerobic baffled reactor and application of proper effluent recycle enabled to increase the ability of entrapping microbe-rich small particles in the reactor and prompted the formation of granules. The significant difficulty in hybrid anaerobic baffled reactor operation is the slow start-up procedure, which is crucial to the overall polyvinyl alcohol-containing desizing wastewater treatment. Therefore, the ability of a hybrid anaerobic baffled reactor, treating desizing wastewater, to achieve a prompt start-up was studied at lab-scale. Results showed that inoculated with anaerobic granular sludge and adoption of effluent recycle during start-up, the system demonstrated a good performance of polyvinyl alcohol removal efficiency (above 17.2 %) and satisfactory stability of pH and alkalinity in effluent (range around 7.4–8.0 and 700–920 mg/L, respectively) and the sludge appeared obviously granulation. Thus, the prompt start-up was achieved after 60 days. The start-up strategy used for this process has achieved its goals by creating an active microbial population. The improved lab-scale hybrid anaerobic baffled reactor proved to be an efficient reactor configuration for the treatment of desizing wastewater, which favored the prompt start-up of hybrid anaerobic baffled reactor. The results also provide evidence to modify the design of anaerobic baffled reactor to improve reactor performance.  相似文献   

9.
In this research, physical, chemical and biological treatability of Tehran solid waste leachate was studied. Results indicate that the amount of COD for the fresh raw leachate of Tehran is equal to 66,608 mg/l. The leachate is transferred to an equalization tank for storage and pH control process. After neutralization, leachate is introduced to an up flow and down flow anaerobic reactor. The effluent of anaerobic reactor is conducted to a sequencing batch reactor. Sequence batch reactor (SBR) effluent was pumped in to sand and activated carbon filters, after chemical coagulation and clarification. Results showed that anaerobic reactor with detention time of 3 days had a 35% COD removal and increasing the detention time to 4.5 days would improve the COD removal to 45%. Nutrient adjustment with phosphorus and nitrogen increased the initial 23% efficiency of sequence batch reactor to 44%. The effluent COD of SBR reactor was 21,309 mg/l. Recycling of aerobic reactor effluent with incoming feed to anaerobic reactor reduced the anaerobic reactor influent COD to 20,000 mg/l and this caused 53% and 57% COD removal in the anaerobic and aerobic effluent, respectively. The total systems COD performance increased to 80% and SBR effluent COD eventually reduced to 4,000 mg/l. Coagulation, flocculation and sedimentation processes were practiced to make the 4,000 mg/l effluent COD comply with environmental standards of Iran. The optimum coagulant found to be ferric chloride with the dosage of 50 mg/l at pH of 12, which reduced 10% of COD to an amount of 3,676 mg/l. The effluent was stored in a tank and then pumped in to pressure sand filter and afterwards to activated carbon filter. The COD removal was three and 90% for sand and activated carbon filters, respectively. The total process reduced the remaining COD to 36 mg/l, which is in compliance with environmental standards of Iran.  相似文献   

10.
A comparative study was performed between cactus (Opuntia spp.) and alum as coagulants. Monthly samples of raw water, delivered from (Al-Mashroo Canal), were studied and analyzed for turbidity removal during the period from August 29, 2014, to July 23, 2015. The analysis was conducted to decide the optimum dose, optimum velocity gradient, and optimum flocculation time for both coagulants. The results of the study indicate the efficiency of alum over cactus and that the optimum dose of alum was larger than that of cactus. The pH level of raw water was in the range of 7.734–8.203, while the temperature of raw water was in the range of 13–35 °C during the period of the study. The reliable velocity gradient for both coagulants was 25 1/s, and the reliable flocculation time for both coagulants was 20 min. The residual turbidity for cactus was in the range of 0.0–296 NTU, while that of alum was in the range of 0.0–5.81 NTU.  相似文献   

11.
Application of advanced oxidation process for wastewater treatment has gained more attention recently. In this study, the efficiency of coagulation–flocculation pretreatment coupled with sulfate radical-based advanced oxidation process (SR-AOP) in the removal and mineralization of organic matter of sugarcane vinasse was evaluated. For coagulation–flocculation, jar-test experiment was carried out with ferric chloride as coagulant and the removal of TOC, color and UV254 was determined. The results revealed that by using 15 g/L of coagulant, 70 % of TOC removal and nearly 100 % of UV254 and color removal were achieved. The pretreated vinasse was then subjected to SR-AOP. In this study, sulfate radical was generated using persulfate (PS) and peroxymonosulfate (PMS) activated by Fe(II). The effect of reaction time, oxidants to Fe(II) ratio and pH on the TOC removal efficiency were investigated. For the effect of reaction time, the TOC removal was found to increase significantly for the first 5 min. TOC removal was found to increase with increasing concentration of Fe(II) for PMS. However, for Fe(II)/PS, the TOC removal efficiency was decreased with increasing Fe(II) concentration. Both Fe(II)/PMS and Fe(II)/PS showed the highest TOC removal efficiency when the oxidation was carried out at pH 7. By using the selected optimum condition, nearly 70 and 49 % of TOC removal were achieved for PMS/Fe(II) and PS/Fe(II), respectively. Therefore, it can be concluded that SR-AOP can be a promising alternative method for TOC removal from sugarcane vinasse.  相似文献   

12.
A large portion of water is consumed during various textile operations thereby discharging wastewaters with pollutants of huge environmental concern. The treatment of such wastewaters has promising impact in the field of environmental engineering. In this work, Fenton oxidation treatment was engaged to treat simulated textile wastewater. Box–Behnken design and response surface methodology were employed to optimize the efficiency of Fenton process. Iron dose, peroxide dose and pH were considered as input variables while the responses were taken as chemical oxygen demand and color removal. A total of 17 experiments were conducted and analyzed using second-order quadratic model. The quadratic models generated for chemical oxygen demand and color removal efficiencies were validated using analysis of variances, and it was found that the experimental data fitted the second-order model quite effectively. Analysis of variances demonstrated high values of coefficient of determination (R 2) for chemical oxygen demand and color removal efficiencies with values of 0.9904 and 0.9963 showing high conformation of predicted values to the experimental ones. Perturbation plots suggested that the iron dosage produced the maximum effect on both chemical oxygen demand and color removal efficiencies. The optimum parameters were determined as Fe2+ dose—550 mg/L, H2O2 dose—5538 mg/L, pH—3.3 with corresponding chemical oxygen demand and color removal efficiencies of 73.86 and 81.35%. Fenton process was found efficient in treatment of simulated textile wastewater, and optimization using response surface methodology was found satisfactory as well as relevant. From the present study, it can also be concluded that if this method is used as pretreatment integrated with biological treatment, it can lead to eco-friendly solution for treatment of textile wastewaters.  相似文献   

13.
对人工合成锰钾矿氧化降解高浓度含酚废水的特性进行了研究。结果表明,体系酸度和矿物用量是影响废水处理效果的重要因素。加酸量为0.12 mol/L,矿物用量20 g/L,温度70℃,反应时间3 h时效果最佳,废水总酚含量由1269 mg/L降低至268 mg/L,同时CODCr与TOC去除率为31.2%和70.5%。经GC/MS测定,水中酚类物质为苯酚、甲基苯酚、二甲基苯酚,最佳条件下,酚类物质浓度已低至检测限以下,水中残余吲哚、长链烷烃、喹啉及其衍生物等难降解有机物。  相似文献   

14.
吗啉废水的生化处理工艺   总被引：2，自引：0，他引：2  
以含有吗啉、甲基吗啉的高浓度有机废水为研究对象,提出了曝气吹脱-吸附-生物处理的联合工艺,并在室内进行了小试实验。结果表明：原废水经过2次曝气吹脱后,ρ(NH3-N)从62 500 mg/L降为431 mg/L,ρ(COD)从50 840 mg/L降为26 051 mg/L。通过吸附实验,ρ(COD)从26 051 mg/L降为2 769 mg/L,ρ(NH3-N)从412 mg/L降为134 mg/L。在生物处理室内小试实验中,采用了活性污泥反应器与曝气生物滤池相结合的处理工艺。在活性污泥反应系统中,当废水pH为7.5、ρ(DO)为4.3 mg/L、水力停留时间为30 h时,COD的去除率最高,可以达到83.1%。在曝气生物滤池中,当ρ(DO)为3.3 mg/L时,COD去除率最高,达到55.8%。在生物处理的最佳参数条件下进行连续监测,当进水ρ(COD)为2 769 mg/L、出水ρ(COD)平均值为387 mg/L时,COD去除率可达到85.9%。吗啉废水经过此联合工艺的处理,ρ(COD)从50 840 mg/L降为387 mg/L。  相似文献   

15.
Exposure to high concentration of nitrate through drinking water poses a threat to human health and environment. Electrocoagulation (EC) is an alternative water treatment process that involves electrogeneration of coagulant agents. In the present study, EC was exerted for the nitrate removal in a batch reactor using aluminum and iron anodes simultaneously. The effects of the main parameters including electrical current, initial pH, NaCl dosage, initial nitrate concentration and presence of turbidity on NO3 ? removal were investigated. NO2 ? as a by-product was monitored during electrolysis, and nitrate–nitrite index was calculated. The results indicated that optimum condition was pH of 5, 300 mA electrical current, 100 mg/L NaCl and electrolysis time of 40 min, under which removal efficiency was 81.5 %. Nitrite anion was generated during electrolysis of nitrate solution which increases nitrate–nitrite index at the first reaction time, and it was eliminated after 20-min electrolysis time. Reaction kinetic of nitrate removal in the absence and presence of turbidity was first-order and zero-order, respectively.  相似文献   

16.
正交混凝试验在矿井水处理设计中的应用   总被引：1，自引：0，他引：1       下载免费PDF全文
针对高悬浮物矿井水,设计了5水平6因素的L25(56)正交混凝试验,并通过极差分析确定了混凝的最优化条件,即选择PAC作为混凝剂,pH值调节为9,混凝剂与助凝剂浓度比为20∶1,助凝剂PAM投加滞后30 s,水力条件依次为n=350 r.min-1快速搅拌30 s,n=120 r.min-1中速搅拌4 min,n=60 r.min-1慢速搅拌6 min。通过单因素分析了6种因素对混凝的影响程度,即:PAM投量>混凝剂种类>pH值>混凝剂投量>水力条件>投加时间。依试验结果,对垂向轴式混合反应池进行了参数设计。  相似文献   

17.
In this research, a novel laboratory scale anaerobic/upflow sludge blanket filtration combined bioreactor was designed and operated to improve the efficiency of the upflow sludge blanket filtration process for the simultaneous removal of phosphorus and nitrogen from wastewater. The anaerobic/upflow sludge blanket filtration technique was developed by adding an anaerobic reactor to its influent and operated by varying the main process parameters in order to gain the optimum conditions. The results showed that biological removal efficiency of nitrogen and preservation of sludge blanket strongly depend on wastewater characteristics, hydraulic retention time, sludge age and process controlling parameters. The combined bioreactor performed a total nitrogen removal efficiency of 96.6 % with the sludge age of 25 days, total hydraulic retention time of 24 h and optimum “chemical oxygen demand/nitrogen/phosphorus” ratio of 100/ 5/1. This ratio also improved the compaction quality of sludge blanket in the upflow sludge blanket filtration clarifier. The average specific nitrification and denitrification rates occurred during the process can be expressed as 4.43 mg NOx-N produced/g VSS.d and 5.50 mg NOx-N removed/g VSS.d at the optimum ratio, respectively. To avoid sludge rising due to denitrification process, the optimum total hydraulic retention time of 16 to 24 h was achieved based on the effluent quality. This study suggested that the anaerobic/upflow sludge blanket filtration bioreactor at the optimum operational conditions can be an effective process for removal of nutrients from municipal wastewater.  相似文献   

18.
采用混凝沉淀技术处理钨矿选矿废水,通过试验确定HNJY新型高效复合絮凝剂作为混凝剂最为合适,投加量为120mg/L,经处理后废水出水水质符合国家污水排放标准并能回用,废水SS约11500mg/L,处理后的出水要求为SS<10mg/L。技术经济分析,投资总费用为67.5万元,处理成本为0.60元/m3,设计工艺可靠且经济合理。本工程既防止了废水对环境的潜在污染,又解决了枯水期选矿用水不足的问题。  相似文献   

19.
A novel biosorbent synthesized from Ficus racemosa leaves based on the treatment using NaOH was applied for removal of Acid Blue 25 from aqueous solution. The synthesized biosorbent was characterized using scanning electron microscopy, Fourier transform infrared spectroscopy and Brunauer–Emmett–Teller analysis. NaOH treatment was demonstrated to remove lignin content from the biomass and to induce the development of significant pores. Batch experiments were performed to evaluate the effect of important operating parameters such as pH (range of 2–10), biosorbent dose (range of 1–10 g/L), contact time (range of 0–5 h), initial dye concentration (range of 50–400 mg/L) and temperature (range of 293–323 K) on the extent of removal of Acid Blue 25. The established optimum conditions were pH of 2, biosorbent dose of 4 g/L, contact time of 3 h and temperature of 323 K, yielding maximum removal of dye. Pseudo-second-order model was found to best fit the kinetic data. Langmuir and Temkin isotherm models were found to best fit the equilibrium data. The obtained thermodynamic parameters confirmed endothermic and spontaneous nature of adsorption. The study established the utility of novel biosorbent for removal of Acid Blue 25 with higher adsorption capacities (83.33 mg/g) as compared to the more commonly used adsorbents. Desorption-adsorption  studies conducted for seven cycles indicated potential reusability of synthesized biosorbent for the treatment of dye effluents.  相似文献   

20.
The possibility of using the dolomite geochemical barrier for fine cleaning of alkaline wastewaters against fluorine was substantiated in experiments for coal-burning power plants. It was found that the residual fluorine concentration at pH 10.4–10.6 conformed to the optimum values for potable waters (0.7–0.9 mg/L), whereas the degree of fluorine removal at pH > 12.0 was at a maximum at 99.2% with less than 0.1 mg/L residual fluorine concentration. The optimum residual concentration of fluorine was obtained under the stoichiometric excess of dolomite over reactive CaO in ashes and slag wastes, which allowed calculation of the required capacity of dolomite barriers.  相似文献   

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