Comparative study of thermophilic and mesophilic anaerobic treatment of purified terephthalic acid (PTA) wastewater

The paper provides a critical comparison between mesophilic and thermophilic anaerobic treatment of PTA wastewater through diagnosis of a case study. Aspects covered are bioavailability, biodegradability, microbial population, thermodynamics, kinetics involved and bio-reactor design for PTA wastewater treatment. The results of the case study suggests that one- stage thermophilic anaerobic reactor coupled with coagulation-flocculation pre-treatment unit and an aerobic post treatment unit could be techno-economically viable for PTA wastewater treatment to ensure that the final effluent quality conforms to the international standard. The in-formation emanated from this study could be useful and thought provoking to the professionals and academia in the area of PTA wastewater treatment and can serve as impetus toward the development of research lines in similar problems like the treatment of other petrochemical wastewater such as phenol-con- taining wastewater, benzene/benzoic acid-con- taining wastewater or wastewater from other similar industrial settings.

中国白酒企业酿酒废水处理现状与展望

酿酒废水产生量大、成分复杂且处理难度高,是极具中国特色的高浓度有机废水。本文详细介绍了中国白酒企业的酿酒废水处理现状,从工艺流程、技术特点以及适用范围等方面进行深度剖析总结,发现我国形成了以厌氧微生物处理工艺为主,预处理、好氧微生物工艺为辅的成熟工艺,不仅实现了酿酒废水的达标处理,而且所产甲烷成为企业热能和电力的重要补充。另外,在国家水资源循环利用政策的推动下,针对酿酒废水水质特点开展的资源化利用研究也在如火如荼的进行中,其中包括回锅重蒸、高附加值成分的提取以及微生物碳源制备等新技术,为酿酒废水处理提供了新的可能,助推白酒企业绿色低碳发展。

涉铅洗浴洗衣污水处理研究

经长期跟踪采样分析,明确了铅酸蓄电池生产中涉铅洗浴洗衣污水总铅含量在0.14~0.53 mg/L之间,经厌氧/好氧生化处理后可以达到《电池工业污染物排放标准》(GB 30484-2013)中规定的排放要求。

化机浆废水厌氧和好氧处理的关键技术

化机浆在生产过程中产生的废水组分复杂,污染物处理困难。本文探讨了采取厌氧和好氧工艺时,如何把控重度污染物废水处理的关键技术,使污水处理系统达到稳定、持续、有效运行。

污水处理厂中“AAO+深度处理”工艺减污降碳研究

针对当前污水处理过程中的碳排放问题,设计“AAO(厌氧—缺氧—好氧)+深度处理”的污水处理工艺,并以某污水处理厂为例,将“AAO+深度处理”工艺应用其中,对污水处理效果进行分析,并对该项工艺的降碳和经济性进行探究。

Petro-chemical wastewater treatment by biological process

In order to study the feasibility of treating petro chemical wastewater by the combination of anaerobic and aerobic biological process, a research of treating wastewater in UASB reactor and aeration basin has been conducted. The test results shows that under moderate temperature, with 5\^2 kgCOD/(m\+3·d) volumetric load of COD Cr in the UASB reactor and 24h of HRT, 85% removal rate of BOD 5 and 83% of COD \{Cr\} and 1\^34 m\+3/(m\+3·d) volumetric gas production rate can be obtained respectively. The aerobic bio degradability can be increased by 20%—30% after the petro chemical wastewater has been treated by anaerobic process. As Ns=0\^45 kgCOD/(kgMLSS·d), HRT=4h in the aeration tank, 94% removal rate of BOD 5, 93% of COD \{Cr\}, 98\^8% total removal rate of COD \{Cr\} and 99% removal rate of BOD 5 can be reached.

Elucidating the removal mechanism of N,N-dimethyldithiocarbamate in an anaerobic-anoxic-oxic activated sludge system

N,N-Dimethyldithiocarbamate （DMDTC） is a typical precursor of N-nitrosodimethylamine （NDMA）. Based on separate hydrolysis, sorption and biodegradation studies of DMDTC, a laboratory-scale anaerobic-anoxic-oxic （AAO） system was established to investigate the removal mechanism of DMDTC in this nutrient removal biological treatment system. DMDTC hydrolyzed easily in water solution under either acidic conditions or strong alkaline conditions, and dimethylamine （DMA） was the main hydrolysate. Under anaerobic, anoxic or oxic conditions, DMDTC was biodegraded and completely mineralized. Furthermore, DMA was the main intermediate in DMDTC biodegradation. In the AAO system, the optimal conditions for both nutrient and DMDTC removal were hydraulic retention time 8 hr, sludge retention time 20 day, mixed-liquor return ratio 3：1 and sludge return ratio 1：1. Under these conditions, the removal efficiency of DMDTC reached 99.5%; the removal efficiencies of chemical organic demand, ammonium nitrogen, total nitrogen and total phosphorus were 90%, 98%, 81% and 93%, respectively. Biodegradation is the dominant mechanism for DMDTC removal in the AAO system, which was elucidated as consisting of two steps： first, DMDTC is transformed to DMA in the anaerobic and anoxic units, and then DMA is mineralized to CO2 and NH3 in the anoxic and oxic units. The mineralization of DMDTC in the biological treatment system can effectively avoid the formation of NDMA during subsequent disinfection processes.

Pretreatment of hypersaline mustard wastewater with integrated bioreactor

A full-scale experimental study of treating mustard wastewater by the integrated bioreactor with designed scale of 1 000 m3/d is conducted combined with a demonstration project.The systematical researches on the efficiency of combined operation conditions of anaerobic-aerobic and anaerobic-aerobic-flocculation as well as chemical phosphorus removal of hypersaline mustard wastewater are conducted.The optimal operation condition and parameters in pretreatment of mustard wastewater in winter(the water temperature ranges 8-15 ℃) are determined:the anaerobic load is 3.0 kg(COD)/(m3·d),the average COD and phosphate concentration of the inflow are respectively 3 883 mg/L and 35.53 mg/L and the dosage of flocculent(PAC) is 400 mg/L.The anaerobic-aerobic-flocculation combined operation condition and postpositive phosphorous removal with ferrous sulfate are employed.After treatment,the COD of the effluent is 470 mg/L and the average phosphate concentration is 5.09 mg/L.The effluent could achieve the third-level of Integrated Wastewater Discharge Standard(GB 8978-1996).

Effects of anaerobic digestion and aerobic treatment on the reduction of gaseous emissions from dairy manure storages

Effects of anaerobic digestion and aerobic treatment on the reduction of gaseous emissions from dairy manure storages were evaluated in this study.Screened dairy manure containing 3.5%volatile solids(VS)was either anaerobically digested or aerobically treated prior to storage in air-tight vessels.Anaerobic digestion was carried out using a mesophilic anaerobic sequencing batch reactor operated at a hydraulic retention time of 20 days and an organic loading rate(OLR)of 1 gVS/L/day.Aerobic treatment was achieved using an aerobic reactor operated at a hydraulic retention time(HRT)of 10 days and an OLR of 2 gVS/(L·d).The treated manure was put into the storage on a daily basis for a period of 180 days.All the gases produced during this period were captured and analyzed for methane,carbon dioxide and volatile organic compounds(VOCs).Untreated manure was stored and analyzed in the same way as the treated manure and used as a control for comparison.The results show that low amounts of gases were produced during the first 84 days of storage in both treated and untreated manure,but increased significantly after this time point.The generally expected positive impacts of anaerobic and aerobic treatment on the reductions of methane and VOCs were confirmed in this study.However,the effects of anaerobic and aerobic treatment varied over the time of storage,especially for VOCs.The results of this study indicate that to achieve significant reductions in VOC emission the storage time of anaerobic digester or aerobic reactor effluent should be limited to no more than 100 days.

我国污泥处理处置技术研究进展

污泥是污水处理的副产物,具有污染和资源的双重性,长期以来的重水轻泥思想致使污泥的安全处理处置成为了我国污水处理事业发展的短板。对我国污泥处理处置相关政策进行了解读,详细介绍了厌氧消化、好氧堆肥、干化焚烧和深度脱水等4条主流污泥处理处置技术路线及其应用情况,分析了干式炭化(热解炭化)、湿式炭化(水热炭化)、碳排放、区域污泥处理处置路线等研究热点。“双碳”目标的提出推动了污泥处理处置行业的高质量发展,未来应通过碳排放指标对污泥处理处置技术路线的碳排放水平进行量化评估,以推动污泥处理处置朝着绿色、低碳、可持续的方向发展。各地区应根据自身发展需求和污水污泥成分,综合考虑匹配、衔接、成本等因素,选择合适的污泥处置处理方法。

厌氧+好氧工艺在抗生素污水处理工程中的应用

本文主要以某生物制药厂排放的抗生素污水为例,对“厌氧+好氧”工艺在抗生素污水处理方面的应用展开相关讨论,分析处理结果,并总结经验教训。

厌氧塔同步处理污水及好氧剩余污泥的应用研究

文中介绍厌氧塔同步处理污水及部分好氧剩余污泥时,在调试期及运营期的运行情况,结果表明,厌氧塔引入好氧剩余污泥后,综合COD容积负荷Nv总为6.5~7.5 kg/(m^(3)·d),COD去除率在90%以上且运行稳定,厌氧塔可同步处理污水及部分好氧剩余污泥。

抗生素工业废水生物处理技术的现状与展望

分析了各类抗生素工业废水的水质特征和主要污染因子，综述了目前应用的好氧和厌氧生物处理工艺，在此基础上提出了前处理－厌氧－好氧生物处理的组合工艺路线，并对各工艺的作用和可能采用的技术进行了比较分析，最后指出应重点研究高效低耗复合反应器、除硫脱氮工艺和厌氧毒性试验方法．

厌氧/好氧/生物脱氨工艺处理煤化工废水

采用厌氧/好氧/生物脱氨/混凝沉淀工艺处理煤化工废水,设计总处理量为360m3/h。4个多月的调试运行结果表明,该工艺运行稳定,耐冲击负荷能力强,当进水平均COD为2 141 mg/L、总酚为391 mg/L、氨氮为92 mg/L时,处理后出水COD<100 mg/L、总酚<10 mg/L、氨氮<15 mg/L,出水水质达到《污水综合排放标准》(GB 8978—1996)的一级标准。

厌-好氧交替工艺处理辽河油田废水的试验

采用厌－好氧交替（ＡＡＡ）工艺处理适当稀释或原浓度的油田废水，进水ＣＯＤ３６０—９５０ｍｇ／Ｌ，ＣＯＤ去除率均保持在６０％左右．经过厌氧ＵＡＳＢ反应器处理后的废水，再经ＡＡＡ工艺进行处理，在ＨＲＴ８—１２ｈ的条件下，其ＣＯＤ浓度能够从３５０ｍｇ／Ｌ降到１６０—２４０ｍｇ／Ｌ，ＣＯＤ去除率３１％—４８．５％．对于ＣＯＤ浓度为１６０—１８０ｍｇ／Ｌ的废水，采用好氧接触氧化法作为好氧二级处理，其出水ＣＯＤ去除率在５０％—６０％，出水ＣＯＤ浓度一般接近８０ｍｇ／Ｌ左右．

缩短厌氧消化时间改善猪场废水厌氧消化液好氧后处理性能的可行性

采用批式厌氧消化以及间歇曝气的摇瓶试验进行猪场废水厌氧-好氧处理,研究了猪场废水厌氧消化对好氧后处理的影响,以及控制厌氧消化进程改善猪场废水厌氧消化液好氧后处理性能的可行性.对猪场废水原水(厌氧消化0d)直接进行好氧处理,COD和NH4+-N去除率分别可达到95%和98%以上,出水COD低于300mg.L-1,NH4+-N低于10mg.L-1.对厌氧消化液进行好氧后处理,出水COD和NH4+-N浓度随好氧处理时间的增长逐渐升高,厌氧消化前处理时间越长,升高时间越早,幅度越大.实验结束时,出水COD基本在500～600mg.L-1之间;厌氧消化3、6、9、12d的消化液好氧后处理出水的NH4+-N分别达到22.2、105.4、147.6、171.4mg.L-1.尽管厌氧消化3d时,COD去除率只有47.5%,但消化液好氧后处理的效能仍然没有提高,只是系统恶化的时间略迟于厌氧消化6、9、12d的消化液.厌氧消化液好氧后处理效果差的原因主要是:在厌氧消化过程中,各污染物降解的差异导致了厌氧消化液可生化性降低以及碳、氮、磷比例失调,影响了好氧后处理过程微生物的生长;厌氧消化液中缺乏易降解有机物,导致反硝化效果差,产生的碱度不能弥补硝化过程消耗的碱度,引起pH下降,进而影响了微生物活性.因此,通过缩短厌氧消化时间的方式来改善消化液好氧后处理的性能是不可行的.

生活污水分散处理技术的应用现状

从预处理系统、二级处理系统、自然就地净化系统、集成化污水净化槽等几方面对国内外小量生活污水分散式处理技术的发展和实践作了较为全面的综述,并提出了我国在该领域的研究和发展方向。

规模化养牛场粪便处理生命周期评价

以某规模化养牛场为例,应用生命周期评价方法,对畜禽粪便两种不同处理方式进行生命周期污染物排放清单分析,在此基础上进行了生命周期环境影响评价。结果表明,畜禽粪便处理过程中主要的环境影响类型是全球变暖,其次是环境酸化和富营养化。其中好氧堆肥工艺的环境酸化和富营养化潜力大于厌氧发酵处理工艺,厌氧发酵工艺全球变暖潜力大于好氧堆肥。综合比较,厌氧发酵的环境影响优于好氧堆肥,其环境影响综合指数分别为0.011 2、0.024 3,该养殖场宜采用厌氧发酵工艺处理畜禽粪便。

稻秸好氧厌氧两相发酵工艺与产气特性研究

木质纤维素水解困难是制约秸秆沼气生产效率提高的主要因素,针对秸秆的木质纤维素难降解问题,提出湿法好氧厌氧两相发酵工艺。在中温37℃的条件下,水解产酸发酵容器不密封,采用搅拌供气、不供气的好氧水解方式,进行两相发酵实验。结果表明,好氧厌氧两相发酵工艺能够显著破坏稻秸的木质素结构,提高木质素降解率,其搅拌供气组的木质素降解率可达4.57%,而单相厌氧发酵结束时的木质素降解率仅为0.13%,两相发酵工艺的TS产气率可达到411.19 m L/g,较单相厌氧发酵高30%左右。表明好氧厌氧两相发酵工艺可有效降解木质素并提高产气率。