Optimization and validation of enhanced biological reduction of 1,2,3‐trichloropropane in groundwater

Laboratory and field demonstration studies were conducted to assess the efficacy of enhanced biological reduction of 1,2,3‐trichloropropane (TCP) in groundwater. Laboratory studies evaluated the effects of pH and initial TCP concentrations on TCP reduction and the activity of a microbial inoculum containing Dehalogenimonas (Dhg). Laboratory results showed successful reduction at a pH of 5 to 9 with optimal reduction at 7 to 9 and at initial TCP concentrations ranging from 10 to over 10,000 micrograms per liter (μg/L). Based on findings from the laboratory study, the effects of TCP concentration, geochemical conditions, and amendment concentration on bioremediation efficacy were investigated during a field demonstration at a site with relatively low initial concentrations of TCP (< 2 μg/L). The field demonstration included injection of emulsified vegetable oil (EVO) and lactate as a carbon substrate for biostimulation, followed by bioaugmentation using the microbial inoculum containing Dhg. Post‐injection performance monitoring demonstrated reduction of TCP to below laboratory detection limits (< 0.005 μg/L) after an initial lag period of approximately six months following injections. TCP reduction was accompanied by generation of the degradation byproduct propene. A marginal increase in TCP concentrations, potentially due to an influx of upgradient aerobic groundwater containing TCP, was observed eight months after injections thereby demonstrating the sensitivity of this bioaugmentation application to changes in geochemical parameters. Despite this marginal increase, performance monitoring results indicate continued TCP biodegradation 15 months after implementation of the injection program. This demonstration suggests that enhanced biodegradation of TCP by combining biostimulation and bioaugmentation may be a promising solution to the challenges associated with remediation of TCP, even when present at low part per billion concentrations in groundwater.     

Pilot Scale Demonstration of the Electrochemical Peroxidation Process at a Petroleum Spill Site

In a pilot test experiment involving approximately 200,000 gallons of groundwater, Electrochemical Peroxidation (ECP) was used to degrade aqueous phase volatile organic compounds (VOCs) including benzene, toluene, ethylbenzene, and xylene (BTEX) compounds and methyl tertbutyl ether (MTBE) from a petroleum spill. ECP involves a form of the Fenton's Reagent reaction, which uses electrochemically generated iron and dilute hydrogen peroxide (<30 mg/L) to break down organic molecules through oxidation to carbon dioxide and water. This article discusses a pilot scale demonstration of the ECP technology and its application to aqueous phase organic contaminants. The remedial approach used at the pilot test site involves three phases: (1) ex‐situ chemical oxidation, (2) in‐situ oxidation by reinjection of treated effluent near the plume origin, and (3) reestablishment of aerobic biodegradation as the residual hydrogen peroxide discharged to a series of upgradient wells degrades to oxygen. Analytical results of the pilot demonstration indicate that the ex‐situ chemical oxidation reduced total BTEX concentrations in groundwater from over 1,000 ppb to undetectable concentrations (<1 ppb). © 2000 John Wiley & Sons, Inc.     

Fenton氧化工艺在某化工园区集中式污水处理厂升级改造工程中的应用

针对江苏省某化工园区集中式污水处理厂出水COD和TP高于DB32/939—2006《江苏省化学工业主要水污染物排放标准》规定的排放限值的情况,采用Fenton氧化工艺对该污水处理厂装置进行升级改造。小试最佳工艺条件为:初始污水pH 3.0~3.5,H_2O_2(质量分数30%)加入量0.8 m L/L,FeSO_4·H_2O加入量0.8 g/L,反应时间120min,Fenton氧化反应结束后中和反应的适宜pH约为7.0。升级改造工程包括2套并联运行的处理能力各为10 km~3/d的Fenton氧化系统,装置稳定运行后最终控制H_2O_2加入量为150 L/h,FeSO_4·7H_2O溶液加入量为700 L/h,相应的处理后出水COD和TP分别稳定在60 mg/L和0.4 mg/L以下,可达标排放。每吨污水的处理药剂成本约为0.9元。     

Release of nitrogen and trace metal species from field stacked biosolids

Concerns over elevated nitrate (NO3-) levels found in groundwater near former biosolid stockpiling locations resulted in the Maine Department of Environmental Protection (MDEP) imposing stricter regulations governing the stockpiling of biosolids in October 2002. The goals of this study were to measure the amount and speciation of nitrogen (N) and trace metals leaving stockpiled biosolids and travelling through the soil column. The biosolids were placed on plastic-lined cells to collect all leachate. Ammonium (NH4+), ranging from 2000 to 4900 mg L(-1), was the dominant N species (90% of total N) in the leachate from the Class B lime-stabilized biosolids in the lined cell experiment. Nitrate (NO3-) and nitrite (NO2-) concentrations were negligible, remaining below 0.25 and 0.1 mg L(-1), respectively. Dissolved organic carbon (DOC) concentrations as high as 8900 mg L(-1) and chemical oxygen demand (COD) as high as 37 000 mg L(-1) were measured in the leachate leaving the lined cell. Fifteen zero-tension pan lysimeters (ZTP-lysimeter) were installed in a 90 m2 plot at depth intervals of 30, 60, and 100 cm. Leachate passing through the soil column underlying the biosolids stockpile was collected in the ZTP-lysimeters. The average ZTP-lysimeter NH4+ concentrations ranged from 1400 mg L(-1) at 60 cm depth to 145 mg L(-1) at 90 cm depth. The average ZTP-lysimeter DOC concentrations ranged from 2000 mg L(-1) at 60 cm to 525 mg L(-1) at 90 cm. Trace metal determinations of the leachate collected from the lined cell and ZTP-lysimeters showed arsenic loading rates exceeded the state limits of 0.5 kg ha(-1) year(-1) by an order of magnitude. Arsenic concentrations were in excess of several thousand milligrams per litre in the lined-cell leachate and several hundred milligrams per litre in the ZTP-lysimeters as deep as 90 cm under the biosolid stockpile. Phosphorus, iron and manganese in excess of several thousand milligrams per litre were observed in both the lined-cell leachate and ZTP-lysimeters. Significant concentrations of other trace metals were found at depth in the zero-tension ZTP-lysimeter plot. Trace metals were largely mobilized by the DOC from the biosolids and due to the presence of anaerobic environment, especially in the underlying soil.     

酞菁蓝颜料生产废水处理试验研究

采用初沉-电凝聚-加碱沉淀-生化工艺处理酞菁蓝颜料生产废水,试验表明,COD可从1190mg／L降至95．9mg／L,Cu^(2 )质量浓度可从163．5mg／L降至0．7mg／L,色度可从210倍降至43．3倍,出水COD、色度达到GB8978—1996《污水综合排放标准》一级排放标准,Cu达到二级排放标准。     

Successful full‐scale enhanced anaerobic dechlorination at a NAPL strength 1,1,1‐TCA source area

Bioremediation of 1,1,1‐trichloroethane (TCA) is more challenging than bioremediation of other chlorinated solvents, such as tetrachloroethene (PCE) and trichloroethene (TCE). TCA transformation often occurs under methanogenic and sulfate‐reducing conditions and is mediated by Dehalobacter. The source area at the project site contains moderately permeable medium sand with a low hydraulic gradient and is approximately 0.5 acre. TCA contamination generally extended to 35 feet, with the highest concentrations at approximately 20 feet. The concentrations then decreased with depth; several wells contained 300 to 600 mg/L of TCA prior to bioremediation. The area of treatment also contained 2 to 30 mg/L of TCE from an upgradient source. Initial site groundwater conditions indicated minimal biotic dechlorination and the presence of up to 20 mg/L of nitrate and 90 mg/L of sulfate. Microcosm testing indicated that TCA dechlorination was inhibited by the site's relatively low pH (5 to 5.5) and high TCA concentration. After the pH was adjusted and TCA concentrations were reduced to less than 35 mg/L (by dilution with site water), dechlorination proceeded rapidly using whey (or slower with sodium lactate) as an electron donor. Throughout the remediation program, increased resistance to TCA inhibition (from 35 to 200 mg/L) was observed as the microbes adapted to the elevated TCA concentrations. The article presents the results of a full‐scale enhanced anaerobic dechlorination recirculation system and the successful efforts to eliminate TCA‐ and pH‐related inhibition. © 2012 Wiley Periodicals, Inc.     

用熄焦粉处理焦化废水的试验研究

用焦化厂自产的熄焦粉对生化后的废水进行吸附处理，出水COD从233mg／L降至50mg／L，达到GB8978--1996一级排放标准；用熄焦粉与微生物联合曝气处理焦化废水，出水COD从1086mg／L降至119mg／L。     

In Situ treatment of PFAS‐impacted groundwater using colloidal activated Carbon

Poly‐ and perfluoroalkyl substances (PFASs) have been identified by many regulatory agencies as contaminants of concern within the environment. In recent years, regulatory authorities have established a number of health‐based regulatory and evaluation criteria with groundwater PFAS concentrations typically being less than 50 nanograms per liter (ng/L). Subsurface studies suggest that PFAS compounds are recalcitrant and widespread in the environment. Traditionally, impacted groundwater is extracted and treated on the surface using media such as activated carbon and exchange resins. These treatment technologies are generally expensive, inefficient, and can take decades to reach treatment objectives. The application of in situ remedial technologies is common for a wide variety of contaminants of concern such as petroleum hydrocarbons and volatile organic compounds; however, for PFASs, the technology is currently emerging. This study involved the application of colloidal activated carbon at a site in Canada where the PFASs perfluorooctanoate (PFOA) and perfluorooctane sulfonic acid (PFOS) were detected in groundwater at concentrations up to 3,260 ng/L and 1,450 ng/L, respectively. The shallow silty‐sand aquifer was anaerobic with an average linear groundwater velocity of approximately 2.6 meters per day. The colloidal activated carbon was applied using direct‐push technology and PFOA and PFOS concentrations below 30 ng/L were subsequently measured in groundwater samples over an 18‐month period. With the exception of perfluoroundecanoic acid, which was detected at 20 ng/L and perfluorooctanesulfonate which was detected at 40 ng/L after 18 months, all PFASs were below their respective method detection limits in all postinjection samples. Colloidal activated carbon was successfully distributed within the target zone of the impacted aquifer with the activated carbon being measured in cores up to 5 meters from the injection point. This case study suggests that colloidal activated carbon can be successfully applied to address low to moderate concentrations of PFASs within similar shallow anaerobic aquifers.     

UASB-SBR-絮凝工艺处理地沟油制生物柴油废水

采用UASB-SBR-絮凝工艺处理地沟油制生物柴油废水，考察了各个阶段的废水处理效果。实验结果表明：UASB稳定运行阶段进水COD约为15000mg/L时，COD去除率约为87%，出水COD在2500mg/L以下，出水挥发性脂肪酸（VFA）浓度为4~6mmol/L，最佳容积负荷为15.0kg/（m3·d）；采用SBR处理UASB出水，当容积负荷为1.5kg/（m3·d）时，出水COD在200mg/L以下，COD去除率在83%以上，ρ（NH₃-N）在5mg/L以下，TP约为25mg/L。向SBR出水中加入质量分数为5%的聚合氯化铝进行化学除磷，加入量为5mL/L，处理后废水TP为4~6mg/L。处理后废水的COD，ρ（NH₃-N），TP均达到CJ343-2010《污水排入城市下水道水质标准》的A类要求。     

高浓度酚醛树脂生产废水的预处理

采用二次缩合反应预处理高浓度酚醛树脂生产废水。一次反应的最佳工艺条件为：甲醛加入量0.010 0 mL/mL，Ba（OH）2加入量0.005 g/mL，反应时间3 h，反应温度85 ℃。最佳工艺条件下的一次反应COD去除率为 52.9%。二次反应中，当反应温度为80 ℃、反应时间为3 h、尿素加入量为3 g/L时，二次反应COD去除率最高，为31.5%。COD=85 000 mg/L、ρ（挥发酚）= 12 000 mg/L、ρ（甲醛）=6 740 mg/L的废水经两次缩合反应处理后，出水中COD=27 400 mg/L，COD的总去除率为67.8%;ρ（挥发酚）=2 400 mg/L，挥发酚的总去除率达80.0%;ρ（甲醛）= 980 mg/L，甲醛的总去除率达84.9%。处理1 t废水还可回收酚醛树脂6.75 kg。     

Research on leachate recirculation from different types of landfills

Landfills can produce a great amount of leachate containing highly concentrated organic matter. This is especially true for the initial leachate from landfilled municipal solid wastes (MSW) that generally has concentrations of COD(Cr) and BOD(5) up to 80,000 and 50,000mg/L, respectively. The leachate could be disposed by means of recirculating technique, which decomposes the organics through the action of proliferating microorganisms and thereby purifies the leachate, and simultaneously accelerates organic decomposition through water saturation control. Data from experimental results indicated that leachate recirculating could reduce the organic concentration considerably, with a maximum reduction rate of COD(Cr) over 95%; and, using a semi-aerobic process, NH(3)-N concentration of treated leachate could be under 10mg/L. In addition, the organic concentration in MSW decreased greatly.     

催化臭氧氧化法处理抗生素废水生化出水

以负载不同金属的硅胶为催化剂,采用催化臭氧氧化法处理抗生素废水生化出水,并对催化剂投加量、反应时间等反应条件进行了优化。实验结果表明：铁/硅胶催化剂效果最好;在铁/硅胶催化剂投加量为0.33 g/L、反应时间为1 h的条件下处理COD为954.7 mg/L、BOD₅为66.8 mg/L、ρ（氨氮）为98 mg/L的抗生素废水生化出水,COD去除率为54.9%,氨氮去除率为44.4%,BOD₅/COD由0.07提高至0.20。     

两相厌氧+A/O工艺处理腈纶和丙烯酰胺混合废水

采用两相厌氧+A/O工艺处理腈纶和丙烯酰胺混合废水。实验结果表明：在混合进水中V（腈纶废水）∶V（丙烯酰胺废水）=1、产酸反应器HRT为20 h、产甲烷反应器HRT为36 h、A/O池HRT为24 h、DO为4~5 mg/L、混凝池进水COD为（4 000±300） mg/L的条件下，总COD去除率为87%~89%，A/O池出水COD低于500 mg/L，出水达到GB 8978—1996《污水综合排放标准》中的三级标准;在混凝池进水BOD₅/COD为0.20~0.30的条件下，产甲烷反应器出水BOD₅/COD为0.55~0.65，说明两相厌氧可明显提高废水的可生化性。     

水力空化-Fenton氧化联合超声吸附处理煤气化废水

采用水力空化-Fenton氧化联合超声吸附处理煤气化废水,考察了单独Fenton氧化及单独水力空化工艺条件,并对Fenton氧化、水力空化和水力空化-Fenton氧化工艺处理过程进行了动力学初探。实验结果表明:在反应时间60 min、废水pH 3.0、Fe~(2+)加入量900 mg/L、H_2O_2加入量3 600 mg/L、空化压力0.4 MPa的条件下,水力空化-Fenton处理煤气化含酚废水的COD和苯酚去除率分别为93.05%和90.29%;进一步采用超声吸附处理后,出水COD和苯酚质量浓度分别为92.9 mg/L和4.5 mg/L,达到GB 8978—1996《污水综合排放标准》三级指标。     

Fenton氧化-生物接触氧化工艺处理甲醛和乌洛托品废水

采用Fenton氧化一生物接触氧化工艺处理含甲醛和乌洛托品的模拟废水（简称废水），在H2O2（体积分数30％）加入量2．5g／L、H2O2与Fe^2＋质量浓度比3．75、反应时间3h、不调节废水初始pH的Fenton氧化预处理最佳操作条件下，废水COD从1000mg／L左右降至300mg／L，COD去除率达72％。原废水完全无法直接进行生化处理，经Fenton氧化预处理后其BOD，／COD约为0．5，易于生化处理。Fenton氧化一生物接触氧化工艺处理废水，生物接触氧化停留时间为12h时，废水COD去除率高达94％，处理后出水COD小于70mg／L，处理效果很好。     

分子筛催化剂生产废水的生物处理

采用氨化—硝化—反硝化三段联合生物工艺处理分子筛催化剂生产过程中产生的含有机胺废水。实验结果表明：在氨化过程中，当进水COD稳定为1 200~1 600 mg/L时，出水COD低于300 mg/L，COD去除率稳定在80%左右，当进水ρ（有机氮）为100~160 mg/L时，出水ρ（有机氮）均低于30 mg/L，有机氮去除率大于80%，在整个氨化过程中，出水ρ（氨氮）较进水ρ（氨氮）提高了35~200 mg/L;硝化过程中，当进水ρ（氨氮）小于等于300 mg/L时，出水ρ（氨氮）最终稳定在15 mg/L以内，氨氮去除率大于90%;在反硝化过程中，亚硝酸盐氮去除率基本稳定在98%以上，最终出水COD低于80 mg/L，出水ρ（总氮）低于25 mg/L。     

臭氧氧化—A/O工艺处理PVA废水

采用臭氧氧化—A/O工艺处理聚乙烯醇（PVA）废水,研究了臭氧氧化时间、臭氧流量以及废水pH等因素对臭氧氧化效果的影响。实验结果表明：当气体臭氧质量浓度为30 mg/L、臭氧氧化时间为45 min、臭氧流量为4 L/min、废水pH为8时,PVA质量浓度从进水的93.2 mg/L降至4.5 mg/L;PVA溶液的BOD₅/COD从0.014增加至0.310,可生化性明显改善;臭氧氧化—A/O工艺处理后出水COD降至50 mg/L左右,达到GB 8978—1996《污水综合排放标准》中的一级排放标准;出水PVA质量浓度为1.6 mg/L,明显优于A/O工艺（33.1 mg/L）。     

UASB反应器反硝化处理工业废水

采用絮状污泥成功启动升流式厌氧污泥床(UASB)反应器处理含甲酸、苯胺、环已酮、NO3-等的工业废水。UASB反应器以低负荷启动,10天后逐渐提高进水COD,出水COD保持在710~770 mg/L,COD去除率为40%~60%;出水TOC保持在115~314 mg/L,TOC去除率由60.3%逐渐升高至87.2%,最终维持在81%左右;出水中ρ(NO3-)维持在134~176 mg/L,NO3-去除率为90%左右,系统稳定后NO3-去除率几乎为100%。在进水COD容积负荷不超过5.00 kg/(m3·d)的条件下,实际COD容积负荷稳定在2.00 kg/(m3·d)左右,实际TOC容积负荷稳定在1.00 kg/(m3·d)以上。当进水COD容积负荷不大于4.48 kg/(m3·d)时,COD去除率为55%~74%,TOC去除率为63%~87%,NO3-去除率大于95%。     

铁屑微电解法深度处理油田钻井污水

采用化学混凝-铁屑微电解法深度处理钻井污水。确定了最佳工艺条件：铁屑与活性炭的质量比为0．5，反应时间为2h，污水pH为1．0，温度为常温，反应后用石灰乳调节污水pH至12。处理后钻井污水COD可由原水的8065mg／L降至430mg／L，COD去除率大于94％，色度去除率达100％，达到国家综合污水三级排放标准。     

吸附-Fenton氧化-絮凝法处理对硝基苯胺生产废水

采用吸附-Fenton氧化-絮凝法处理对硝基苯胺生产废水(简称废水),研究了吸附剂、脱附温度、絮凝剂等因素对处理效果的影响.经实验确定的最佳工艺条件为:DM301大孔树脂加入量5.0 g/L,吸附时间20 h,Fenton氧化pH 3.0,H_20_2加入量0.3 moL/L,m(Fe):m(H_20_2)=6,絮凝阴离子型聚丙烯酰胺加入量20 mg/L.在此条件下对COD为2 780 mg/L、色度为185倍和pH为12.2的废水进行处理,出水的COD、色度和pH分别为169 mg/L、10倍和6.5,COD去除率和色度去除率分别达到93.9%和94.5%.DM301树脂在10～25次重复使用后对硝基苯胺的平均总去除率为47.7%,对硝基苯胺的平均回收率为37.9%.