铝盐-淀粉复合絮凝剂污水处理效果研究

以模拟废水、生活污水、市政污水和制浆造纸废水为实验对象,检验了一种新合成铝盐一淀粉复合絮凝剂中试产品(CAS)的污水处理效果．结果表明,与聚合氯化铝(PAC)相比较,CAS处理不同浓度(100、400和2000mg·L^-1)高岭土模拟废水时最佳投加量分别为3．0、2．0和2．0mg·L^-1,为PAC最佳投加量的60％、50％和50％;同时CAS对该废水、生活污水、市政污水的浊度去除效果略优于PAC,但COD去除率明显高于相同剂量的PAC;处理高浓度制浆造纸污水时,CAS投加量相当于PAC用量的70％。COD处理率提高10％,污泥量减少40％.     

红假单胞菌去除养鱼废水三态氮及COD的研究

利用红假单胞菌(Rhodopseudomonas sp.)wps对鲫鱼养殖废水三态氮及COD进行处理.菌株wps对水体亚硝氮的去除率随菌浓的降低而降低,当添加菌液量降到0.4 mL(终浓度约为5×10⁴cell·mL^-1)时,其对亚硝氮的去除效果已不明显,但同时投加400μg碳源明显提高其亚硝氮去除率,高出对照20.06%;菌株wps对氨氮也有一定去除效果,但碳源的添加对氨氮的去除影响更大;同时施加0.4 mL wps菌液和40μg碳源对硝氮和COD的去除率分别比对照提高20.51%和22.03%.光照与否对其处理养鱼废水的效果影响不大.PCR-DGGE结果分析显示,菌株wps在与土著光合细菌的竞争中处于劣势.     

复合固定化光合细菌及其处理养鱼水的效果

利用海藻酸钠和沸石,将含有球形红假单胞菌、荚膜红假单胞菌、沼泽红假单胞菌、万尼氏红微菌等菌体的复合光合细菌固定化,研究其对养鱼水的氮磷去除效果.比较了两种不同包埋材料固定化光合细菌处理养鱼废水的效果,对固定化光合细菌去除废水中氮磷的工艺条件进行了优化、并通过生物反应器连续处理养鱼水分析了处理后水质的效果.通过2 种固定化工艺的比较,确定了2 %沸石+2 %海藻酸钠(CA )的凝胶剂组合作为固定材料,其颗粒内生物活性最高.复合固定化光合细菌处理养鱼水的最佳条件为:厌氧光照条件下,颗粒粒径3 mm ,包埋比1 :5 ,颗粒投加量5 mg·L-1 ,4d 后养鱼水中NH4+-N 、PO43-和CODMn 的去除率分别为74.4%、84.26%、78.92%.此外,通过连续试验可以看出,固定化光合细菌具有明显的去除氨氮、磷酸盐的作用,其在净化养鱼水质方面具有非常明显的优越性.     

几种混凝剂用于处理制浆造纸综合废水的性能试验

利用烧杯混凝试验,通过改变pH值、药剂投加量等方法开展了一系列混凝试验,比较了一种新型聚合混凝剂硫酸铝聚合氯化铝对以木浆为主的制浆造纸厂的综合废水的处理效果.结果表明,在最佳pH值和投药量条件下,新型聚合混凝剂的处理效果最好.当pH为8.29,药剂投加量为175mg·L^-1时,即使不投加CPAM,处理后的废水COD_Cr去除率为87.4%,浊度去除率为96.4%,色度去除率为89.5%;出水COD_Cr和色度分别为90mg·L^-1左右和约32倍,均达到了广东省《水污染物排放限值》(DB4426-2001)第二时段的一级标准.     

氯苯对EGSB反应器内颗粒污泥性质影响的研究*

采用EGSB反应器处理含氯苯有机废水 ,主要研究了氯苯对颗粒污泥性质的影响。结果表明 :氯苯对处理葡萄糖自配水的EGSB反应器内颗粒污泥中的细菌有较强毒害作用 ,连续投加低浓度氯苯 72d后 ,扫描电镜观察可发现颗粒污泥表面和内部细菌均明显受到损害 ,停止投加氯苯恢复运行 30d和 5 0d后 ,仍可观察到颗粒污泥内部细菌受损害的现象 ,且部分颗粒污泥内部存在着明显的空洞 ;随着运行时间的延长 ,反应器内颗粒污泥的粒径有较大程度的增大 ;但长期接触氯苯导致部分颗粒污泥解体 ,使得小粒径污泥增多 ,而大粒径     

一种微生物菌剂处理垃圾渗滤液

利用BM 复合微生物在非曝气和曝气两种条件下, 添加不同量的菌剂去除垃圾渗滤液中的COD、氨氮和总磷,考察处理效果。结果表明: (1)在曝气条件下, 菌剂投加量为0.5%和1%的实验组COD 去除效果最好, 与对照组相比去除率各提高了13.46%和10.14%; (2)在曝气条件下, 氨氮的去除率随着菌剂投加浓度的增加而升高, 在2%投加量作用下氨氮去除率相对于对照组增幅达到了29.94%; (3)在曝气条件下, 菌剂投加量为0.5%和1%的实验组总磷去除效果最好, 去除率比对照组提高了6.23%和8.44%。     

氯苯对EGSB反应器内颗粒污泥性质影响的研究

采用ECSB反应器处理含氯苯有机废水,主要研究了氮苯对颗粒污泥性质的影响。结果表明：氮苯对处理葡萄糖自配水的EGSB反应器内颗粒污泥中的细菌有较强毒害作用,连续投加低浓度氮苯72d后,扫描电镜观察可发现颗粒污泥表面和内部细菌均明显受到损害,停止投加氮苯恢复运行30d和50d后,仍可观察到颗粒污泥内部细菌受损害的现象,且部分颗粒污泥内部存在着明显的空洞;随着运行时间的延长,反应器内颗粒污泥的粒径有较大程度的增大;但长期接触氯苯导致部分颗粒污泥解体,使得小粒径污泥增多,而大粒径污泥相应减少;氮苯对颗粒污泥的损害还表现在使大粒径颗粒的沉速减小,甚至导致部分颗粒污泥内部形成空洞而上浮。     

两种植物条件下土壤中矿物油和多环芳烃（PAHs）的生物修复研究

选择苜蓿草和水稻为供试植物,以污染物水平、有机以、专性细菌和真菌为调控因子,进行土壤中矿物油和PAHs的生物修复研究,结果表明,投肥对苜蓿草土壤中矿物油降解有促进作用,但对水稻土壤中矿物油降解无明显作用,投肥均使苜蓿草和水稻土壤中多环芒烃总量（11种列于美国EPA黑名单上的多环芳烃）降解率提高,这一降解促进效果在水稻土壤中好于苜蓿草土壤,有机肥量与苜蓿草根际土著真菌、细菌数量明显呈正相关,但仅与水稻根际土著细菌数量呈明显正相关,两种土壤中实测真菌和细菌总数均与试验投加专性真菌和细菌量无关,水稻土和苜蓿草土壤中3环多环芳烃的降解随投肥量增大而降解率提高,其在水稻土蓑中的效果好于苜蓿草土壤,投肥怪4环多环芳烃的降解并未产生有效作用。     

RISA法对生物强化处理油脂废水的效应评估

目的:建立对投菌生物强化处理废水的效应评估方法。方法:在流化床生物反应器系统处理油脂废水过程中,投加高效油脂降解菌进行强化处理,采用RISA法对生物强化处理油脂废水的效应进行了评估。结果:投加强化菌后,载体表面的球形菌明显增加,丝状菌减少;油脂去除率提高了15%~21%,CODCr去除率提高了20%~23.5%;RISA分析表明,投加的强化菌5d后在系统中还能被检测到,但在第8d时,强化菌的特征谱带已检测不到。结论:投加的强化菌对系统原有菌群结构产生的影响很小;本实验数据可为生物强化技术应用于实际污水处理提供参考。     

Cd、Pb投加浓度对其在黑土中化学形态分布及油菜生长和吸收Cd、Pb的影响

采用室内模拟实验和连续形态分级方法研究了Cd、Pb投加浓度对其在黑土中化学形态分布及油菜生长和吸收Cd、Pb量的影响.结果表明:随Cd、Pb投加量的增加,土壤中Cd交换态含量增幅较大,Pb碳酸盐结合态、Fe-Mn氧化物结合态含量增幅较大;外源Cd在土壤中的存在形态以交换态和残留态为主,Pb的交换态比例相对较低,其存在形态主要为残留态;土壤Cd、Pb投加浓度较低时,促进了油菜的生长,投加浓度较高时,对油菜生长的抑制作用较为明显;地下部分Cd、Pb含量远高于地上部分,与Cd相比,Pb向地上部的迁移率相对较小;土壤中Cd、Pb各形态含量与油菜地下、地上部分吸收的Cd、Pb量均呈显著正相关,与干质量呈负相关;交换态Cd、Pb对油菜干质量影响最大,碳酸盐结合态对油菜吸收Cd、Pb的贡献最大.     

Temporal and spatial variations of chemical oxygen demand in Lake Taihu,China, from 2005 to 2009

We undertook a study in Lake Taihu, China, from 2005 to 2009 including a total of 639 samples to determine: (i) the seasonal dynamics and spatial distribution of the chemical oxygen demand (COD) and (ii) the relationships between the COD concentration and the biochemical oxygen demand (BOD), phytoplankton pigment, total dissolved nitrogen (TDN), and total dissolved phosphorus (TDP) concentrations, as well as the chromophoric dissolved organic matter (CDOM) absorption coefficient. There were significant spatial differences in the COD concentration, which gradually decreased from Zhushan Bay in the northwest, to the north, the lake center, and the southeast of the lake. The COD concentration was significantly higher at near-shore sites than that at open water sites. The mean COD concentrations were significantly higher in the spring and summer than in the winter and autumn. The lowest annual mean COD concentration appeared in 2009, which could be attributed to improvements in water quality management and high rainfall. The COD concentrations in all four seasons were strongly correlated with phytoplankton pigment, suggesting that extracellular release of COD from phytoplankton was an important COD source. The correlation coefficients between the COD and phytoplankton pigment concentrations were higher in the spring, summer, and autumn than in the winter, showing a more important contribution of phytoplankton degradation to COD in the algal bloom season than in the non-algal bloom season. These new data on the temporal and spatial characteristics of the COD in Lake Taihu will be crucial for developing future strategies for water quality management.     

Aerobic biodegradation of potato slops under moderate thermophilic conditions: effect of pollution load

The effect of the pollutant load on the efficiency of aerobic biodegradation of potato slops with a mixed population of thermo- and mesophilic bacteria of the genus Bacillus was examined. Batch biodegradation processes were carried out at 45 degrees C, using slops with the initial chemical oxygen demand (COD) totalling 11.3, 18.0, 42.6, 58.0 and 74.0 g O2/l. The extent of COD removal ranged from 80.4% (with COD of 11.3 g O2/l) to 88.7% (with COD of 58.0 g O2/l). With potato slops of higher initial COD levels (58.0 and 74.0 g O2/l), the first 24h of growth were characterised by a deficiency of oxygen and a considerable rise in the content of acetic acid, which was then removed. In the first 48 h of the process, irrespective of the initial COD level, the biodegradation of the pollutants removed in the course of the entire process exceeded 91%. The rate of COD removal calculated for that period was a linearly increasing function of the initial pollution load.     

Use of protozoa and metazoa for decreasing sludge production in aerobic wastewater treatment

Summary A new approach to decreasing sludge production in aerobic biological wastewater treatment involving use of protozoa and metazoa was tested. The dissolved organics in the two synthetic wastewaters (based on acetic acid and methanol, respectively) tested were decomposed to >90% and the biomass production was decreased by 60–80%. The total sludge yield, expressed as total suspended solids per gram chemical oxygen demand removed, was 0.17 g TSS/g COD in the system fed acetic acid, whereas it was 0.05 g TSS/g COD in the system fed methanol. The explanation for this difference was that in the system fed methanol, dispersed bacteria were obtained that were easily grazed by the protozoa and metazoa in the predator stage. In the system fed acetic acid, the bacteria formed zoogloeal flocs, which protected them from grazing in the predator stage. With both carbon sources a significant release of nitrate (> 7 mg N/l) and of phosphate (> 2.5 mg P/l) was observed in the effluent.     

Effect of molybdate on methanogenic and sulfidogenic activity of biomass

The effect of molybdate, a sulfate analog, on the total methanogenic activity (TMA) and total sulfidogenic activity (TSA) of biomass metabolizing synthetic sucrose based substrate containing sulfate was investigated in batch assays. In Phase I of the study, TMA and TSA were assessed twice for four feed changes at a chemical oxygen demand to sulfate (COD/SO(4)(2-)) ratio of 3.5. In Phase II, long-term experiments were conducted for 10-13 feed changes with varying chemical oxygen demand (COD) concentration, sulfate concentration, COD/SO(4)(2-) ratio, molybdate dose and biomass with different growth histories. Assays with 3mM molybdate showed TSA inhibition over 85%. Dose dependency was observed for sulfate concentration, COD/SO(4)(2-) ratio, and biomass history. The minimum concentration that gave over 93% TSA inhibition was 0.25 mM. However, intermediate concentrations of molybdate inhibited methane producing bacteria (MPB) activity. TMA stimulation was observed at 0.75-2.0 mM molybdate.     

Biodegradation and detoxification of phenolic compounds by pure and mixed indigenous cultures in aerobic reactors

Degradation and detoxification of a mixture of persistent compounds (2-chlorophenol, phenol and m-cresol) were studied by using pure and mixed indigenous cultures in aerobic reactors. Biodegradation assays were performed in batch and continuous flow reactors. Biodegradation was evaluated by determining total phenols, ultraviolet spectrophotometry and chemical oxygen demand (COD). Microbial growth was measured by the plate count method. Scanning electronic microscopy was employed to observe the microbial community in the reactor. Detoxification was evaluated by using Daphnia magna toxicity tests. Individual compounds were degraded by pure bacteria cultures within 27 h. The mixture of 2-clorophenol (100 mgl⁻¹), phenol (50 mgl⁻¹) and m-cresol (50 mgl⁻¹) was degraded by mixed bacteria cultures under batch conditions within 36 h: 99.8% of total phenols and 92.5% of COD were removed; under continuous flow conditions 99.8% of total phenols and 94.9% of COD were removed. Mineralization of phenolic compounds was assessed by gas chromatography performed at the end of the batch assays and in the effluent of the continuous-flow reactor. Toxicity was not detected in the effluent of the continuous-flow reactor.     

Impact of fly ash pretreatment on aerobic treatment of thermomechanical pulping spent liquor

This study investigated the impact of biomass‐based fly ash (FA) pretreatment on the biodegradability of a thermomechanical pulping spent liquor (TMPL) in an aerobic system. In this study, FA was mixed with TMPL under the conditions of 6 wt.% based on TMPL, 25°C and 10 h, which removed a part of recalcitrant organic materials and resulted in 68.0, 40.0, 60.1, 81.2 and 48.3% reductions in chemical oxygen demand (COD), biochemical oxygen demand (BOD), total organic carbon (TOC), lignin and sugar, respectively. FA‐pretreated TMPL pressate (FA‐TMPL) was biologically treated in an aerobic system of sequencing batch reactor (SBR). The performance of the biological treatment with and without FA pretreatment was studied in two parallel SBRs over three months. The combination of FA and biological treatments removed 97.3% of COD, 98.3% of BOD, 96.3% of lignin, 99.5% of sugar, and 98.1% of TOC. Without FA pretreatment, the biological system removed 87.3% of COD, 89% of BOD, 81.6% of lignin, 98.6% of sugars, and 90.5% of TOC. The results also confirmed that the settling ability of sludge, which was indicated as a sludge volume index, was reduced from 109.3 mL/g to 53.5 mL/g. In addition, the advantages of using FA pretreatment in aerobic systems were discussed in detail. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:370–378, 2018     

Relationship between phytoplankton and environmental factors in landscape water supplemented with reclaimed water

The water quality of Feng-qing Lake, which is a landscape lake supplemented with reclaimed water, was surveyed to investigate the relationship between phytoplankton and environmental variables. A total of 29 water samples were collected to analyze temporal variations of phytoplankton and environmental factors from July 2013 to June 2014. Six phyla and 39 genera of phytoplankton were identified when the lake was supplied with reclaimed water. Among these, Cyanophyta and Chlorophyta account for 38.46% and 30.77% of phytoplankton, respectively. The dominant species in the lake are Pseudanabaena limnetica and Chlorella vulgaris, which are present the entire year. Other leading species include Cosmarium sp. and Raphidiopsis curvata. Principal component analysis (PCA) was conducted to analyze the relationship among environmental factors. Canonical correspondence analysis (CCA) was performed to investigate the relationship between environment factors and dominant species. The PCA result showed that temperature (T), total phosphorus (TP), total nitrogen (TN), transparency, and dissolved oxygen are the main factors that affect the eutrophication level of the lake. The CCA result revealed that TN, PO₄³⁻–P, chemical oxygen demand (COD), T, and chlorophyll a exhibit a close relation with dominant species. In particular, TN, salinity, and COD influence the growth of P. limnetica; T and COD influence the growth of R. curvata; and T, PO₄³⁻–P, NH₃–N, and pH influence the growth of C. vulgaris and Cosmarium sp.     

Mesophilic anaerobic digestion in a fluidised-bed reactor of wastewater from the production of protein isolates from chickpea flour

A study of the anaerobic digestion of wastewater derived from the production of protein isolates from chickpea flour was carried out in a laboratory-scale, mesophilic (35 °C) fluidised-bed reactor with saponite as bacterial support. Soluble chemical oxygen demand (SCOD) removal efficiencies in the range of 96.8–85.2% were achieved in the reactor at organic loading rates (OLR) of between 0.58 and 2.10 g chemical oxygen demand (COD)/l per day, hydraulic retention times (HRT) of between 14.9 and 4.5 days and average feed COD concentration of 9.1 g/l. Eighty-five percent of feed COD could be removed up to OLR of 2.1 g COD/l per day. The yield coefficient of methane production was 0.34 l of methane (at STP) per gram COD removed and was virtually independent of the OLR applied. Because the buffering capacity of the experimental system was maintained at favourable levels with excess total alkalinity present at all loadings, the rate of methanogenesis was not affected by loading. Experimental data indicated that a total alkalinity in the range of 1090–2130 mg/l as CaCO₃ was sufficient to prevent the pH from decreasing to below 7.2 for OLR of up to 2.7 g COD/l per day. The volatile fatty acid (VFA) levels and the VFA/alkalinity ratio were lower than the suggested limits for digester failure (0.3–0.4) for OLR and HRT up to 2.7 g COD/l per day and 3.5 days, respectively. For a HRT of 2.8 days (OLR of 3.00 g COD/l per day) the start of acidification was observed in the reactor.     

Anaerobic treatment of wastewater with high suspended solids from a bulk drug industry using fixed film reactor (AFFR)

Studies were carried out on the treatment of wastewater from a bulk drug industry using an anaerobic fixed film reactor (AFFR) designed and fabricated in the laboratory. The chemical oxygen demand (COD) and total dissolved solids (TDS) of the wastewater were found to be very high with low biochemical oxygen demand (BOD) to COD ratio and high total suspended solid (TSS) concentration. Acclimatization of seed consortia and startup of the reactor was carried out by directly using the wastewater, which resulted in reducing the period of startup to 30 days. The reactor was studied at different organic loading rates (OLR) and it was found that the optimum OLR was 10 kg COD/m(3)/day. The wastewater under investigation, which had a considerable quantity of SS, was treated anaerobically without any pretreatment. COD and BOD of the reactor outlet wastewater were monitored and at steady state and optimum OLR 60-70% of COD and 80-90% of BOD were removed. The reactor was subjected to organic shock loads at two different OLR and the reaction could withstand the shocks and performance could be restored to normalcy at that OLR. The results obtained indicated that AFFR could be used efficiently for the treatment of wastewater from a bulk drug industry having high COD, TDS and TSS.     

Use of Chemical Oxygen Demand Values of Bacterial Cells in Waste-Water Purification

Four methods for determining substrate recoveries in studies concerned with the partition of substrate between sludge synthesis and respiration were investigated. An energy balance comparing chemical oxygen demand (COD) removed with the summation of oxygen uptake and the COD of the cells produced yielded average recoveries closer to 100% than any of the other three methods tested. The standard COD test was shown to yield highly reproducible values when used to determine the COD of activated sludge. Although the protein and carbohydrate content of the cells varied with cell age, a concomitant variation in cell COD was not noted.