Effect of wastewater composition on archaeal population diversity

Distribution and occurrence of Archaea and methanogenic activity in a laboratory scale, completely mixed anaerobic reactor treating pharmaceutical wastewaters were investigated and associated with reactor performance. The reactor was initially seeded with anaerobic digester sludge from an alcohol distillery wastewater treatment plant and was subjected to a three step feeding strategy. The feeding procedure involved gradual transition from a glucose containing feed to a solvent stripped pharmaceutical wastewater and then raw pharmaceutical wastewater. During the start-up period, over 90% COD removal efficiency at an organic loading rate (OLR) of 6 kg COD m(-3)d(-1) was achieved with glucose feeding, and acetoclastic methanogenic activity was 336 ml CH4 gTVS(-1)d(-1). At the end of the primary loading, when the feed contained solvent stripped pharmaceutical wastewater at full composition, 71% soluble COD removal efficiency was obtained and acetoclastic methanogenic activity decreased to half of the rate under glucose feed (166 ml CH4 gTVS(-1)d(-1)). At the end of secondary loading with 60% (w/v) raw pharmaceutical wastewater, COD removal dropped to zero and acetoclastic methanogenic activity fell to less than 10 ml CH4 gTVS(-1)d(-1). Throughout the course of the experiment, microbial community structure was monitored by DGGE analysis of 16S rRNA gene fragments. Five different archaeal taxa were identified and the predominant archaeal sequences belonged to methanogenic Archaea. Two of these showed greatest sequence identity with Methanobacterium formicicum and Methanosaeta concilii. The types of Archaea present changed little in response to changing feed composition but the relative contribution of different organisms identified in the archaeal DGGE profiles did change.     

The impact of wastewater irrigation on the chemical quality of groundwater

The purpose of this investigation was to assess the groundwater impact of irrigation with industrial wastewater (baker's yeast wastewater, BYW) and to determine if agricultural reuse can be considered as an efficient wastewater treatment method. The impact of the irrigation and the status of the groundwater quality were determined using chemical parameters that are typical contaminants of BYW and characterise the content of total suspended solids (TSSs), organic matter (biochemical and chemical oxygen demands), nutrients (N_org, N‐NH₄, N‐NO₃, N_total, P_total and K), salts (Cl, SO₄ and Na) and pH. The study revealed that BYW irrigation did not cause a significant increase in the content of these parameters in groundwater at a low water table region (WTR). However, at a high WTR, the irrigation had an extremely significant (P < 0.001) impact on the chemical status of groundwater that has been demonstrated by substantially high values of COD, N‐NH₄, Cl, SO₄ and Na.     

谈园林喷灌优势及旧有公园绿地喷灌安装改造

根据目前园林喷灌的应用情况,归纳了园林喷灌的优点,分析了公园绿地建设时未能同时建设安装喷灌的原因,并较详细的总结了旧有公园绿地喷灌安装改造的经验,为公园绿化养护提供了指导。     

Greywater reuse for irrigation: Effect on soil properties

A controlled study of the effect of greywater (GW) irrigation on soil properties was conducted. Containers of sand, loam and loess soils were planted with lettuce, and irrigated with fresh water, raw artificial GW or treated artificial GW. Greywater was treated using a recirculating vertical-flow constructed wetland. Soil samples were collected every 10 days for the 40-day duration of the study, and plant growth was measured. Soils were analysed for physicochemical and biological parameters to determine changes caused by the different treatments. It was demonstrated that raw artificial GW significantly increased the development of hydrophobicity in the sand and loam soils, as determined by water droplet penetration time. No significant changes were observed for the loess soil under all treatments. Observed hydrophobicity was correlated with increased oil and grease and surfactant concentrations in the soil. Zeta (ζ) potential of the soils was measured to determine changes in the soil particle surface properties as a result of GW irrigation. A significant change in ζ-potential (less negative) was observed in the raw artificial GW-irrigated sand, whereas no difference was observed in the loam or loess. Soils irrigated with fresh water or treated GW exhibited no increase in hydrophobicity. Fecal coliform bacteria were absent or < 10 CFU g^− 1 in soils irrigated with fresh water or treated GW, but at least 1 order of magnitude higher in raw artificial GW irrigated soils. Only in the last sampling event and only for the loess soil was plant growth significantly higher for fresh water irrigated vs. raw or treated GW irrigated soils. This study demonstrates that treated GW can be effectively irrigated without detrimental effects on soil or plant growth; however, raw GW may significantly change soil properties that can impact the movement of water in soil and the transport of contaminants in the vadose zone.     

Evaluation of the viral population in two wastewater treatment plants: Study of different sampling techniques

A 1-year survey was undertaken on two biological wastewater treatment plants by two different laboratories, in order to gather information on the enteric viral population concentration and on the removal efficiency of the treatment. Different sampling techniques were compared. Results were comparable and showed that enteric viruses were present all year round, their numbers fluctuating randomly within a day. Composite sampling over a period of at least 15 h gave a good representation of the average virus population.     

Effect of PAC addition on sludge properties in an MBR treating high strength wastewater

This paper examines the sludge characteristics in a submerged membrane bioreactor (MBR) operated on a high strength wastewater from an alcohol distillery. Two membrane bioreactors, each with a 30 μm mesh filter, were investigated with and without addition of powdered activated carbon (PAC). Experiments were conducted with varying organic loading rates ranging from 3.4 to 6.9 kgCOD m⁻³ day⁻¹ and the specific oxygen uptake rate (SOUR), sludge volume index (SVI), mixed liquor suspended solids (MLSS), particle size and extracellular polymeric substances (EPS) were monitored over a 180 day period. Respirometric experiments did not show enhancement in microbial activity with PAC supplementation. Addition of PAC decreased the SVI thereby perceptibly improving sludge dewaterability. The sludge particle size, which increased with time, appeared to be independent of PAC addition but was influenced by the aeration intensity. PAC also did not affect the sludge EPS concentration; however, the EPS composition, in terms of protein/carbohydrate (polysaccharide) ratio was altered resulting in a high P/C ratio. FTIR analysis of the sludge samples indicated that the functional groups associated with the sludge polysaccharides appear to be involved in its interaction with PAC.     

Nutrient recovery and crop yield enhancement in irrigation with reclaimed wastewater: a case study

The paper reports results of treated wastewater reuse field experiments carried out in Apulia (Southern Italy). Fennel and lettuce were irrigated with four different water sources: three reclaimed wastewater streams, obtained by applying different treatment schemes to the same municipal wastewater, and a conventional source (well water). Differences between the three effluents were significant in terms of suspended solids and faecal indicators. Both lettuce and fennel yields were enhanced by the high content of nutrients in the effluent of one of the treatment plants, which had been operated for partial nitrogen removal. In particular, fennel productivity was enhanced by replacing chemical fertirrigation with the supply of nutrients contained in the irrigation water.     

Potential for wastewater reuse in irrigation: case study from Aden (Yemen)

Wastewater treatment with waste stabilization ponds (WSP) is a very efficient, low cost and low maintenance operation. The treated wastewater from WSP should be considered as a valuable resource for reuse by water resources managers. Yemen’s water resources are currently experiencing a crisis, because all surface water and groundwater resources are exploited beyond the level of recharge. Promoting water reuse of treated wastewater for irrigation could mitigate this water crisis. This paper assesses the performance of a WSP in the city of Aden by examining the quality of treated sewage predominantly of domestic origin. A comparison with international guidelines reveals that it is possible to use the final effluent to a limited extent in irrigation. This paper includes an outline of the social, religious and political reasons for the water crisis, and explores the idea of reuse of effluent for different irrigation practices.     

含油废水再生利用处理工艺研究

对不同含油废水的常用处理方法作了简单介绍,研究了中国石化山东炼油厂对含油污水的处理工艺,对反渗透后产生的浓水回用作了探讨,并提出了今后对含油废水处理技术的一些建议与展望.     

三维电极法处理染料废水的研究

归纳了染料废水的各类处理方法,从反应器结构、电极板材料、粒子电极、操作条件等方面总结了三维电极法处理染料废水的研究发展方向及存在的问题,并对其未来进行了展望,以推进和发展该方法的应用。     

Development of an electromagnetic hydrocyclone separator for purification of wastewater

A number of various organic and inorganic contaminants are commonly present in the technological fluids hindering production quality. Importantly, waste influents must be purified to meet the appropriate environmental standards for their disposal. This paper deals with the development of a treatment technique for technological and wastewater streams allowing the separation of microscopic droplets of water, sand, oil and other organic and inorganic contaminants. Some existing approaches and processes for treatment of contaminated fluids are briefly reviewed and the design of an electromagnetic hydrocyclone separator is presented in this paper. The effect of the main forces on the separation of small‐sized impurities (<10 μm) is analysed. The experimental tests demonstrated the efficiency of the developed apparatus in purifying the industrial wastewaters of the textile dyeing industry.     

Towards a "crippled-mode" operation of an industrial wastewater treatment plant

In house treatment of metal plating wastewater mainly involves chemical treatments performed in continuous flow stirred tank reactors (CFSTR). The inflow of these tanks is directly produced by the plating shops activity, and the storage capacity never exceeds a few hours of incoming flow. Thus, any fault on one of the CFSTR may impose a complete stop of the whole manufacturing process, which is unacceptable for the manufacturer. Another solution would be having "spare" CFSTRs ready to be used as alternative in case of any CFSTR fault or maintenance. The latter solution however implies additional costs in equipment, storage space and maintenance so as to keep this equipment fit and ready for operation. The paper presents the study of a "crippled-mode" wastewater treatment (WWT) operation which enables a sufficiently efficient working of the WWT plant during maintenance phases and failure repairing on any of the CFSTR, without any extra equipment needed. This survey has been performed on real industrial WWT plants, with a continuous influent and under industrial operation constraints. The performances of the detoxication have been analysed when a CFSTR is short-circuited and the corresponding chemical treatment is shunt in the upstream or downstream CSFTR. This work shows the possibility of satisfying the environmental regulations with a WWT plant functioning under subnormal conditions.     

基于系统优化的湿喷工艺在煤矿中的运用

湿喷工艺是将一定配合比的骨料经过各种湿喷机械搅拌并从喷嘴喷射到受喷体上的方法,能克服干喷混凝土的初期强度低,回弹率较大,现场工作环境粉尘多等技术难题,但我国大多数湿喷采用半机械化作业,人工加料和水等,同时,一套完整连续的湿喷装备也不适合我国煤矿井底狭小的空间使用。针对此问题,通过试验室骨料配合比试验,研究了适合优化系统的湿喷混凝土添加剂;通过湿喷装备优化设计,初步实现了湿喷工艺全程机械化定量优化;最后,经过现场观测和取样分析,结果表明优化湿喷系统的巷道施工快速,湿喷混凝土反弹率低,作业空间粉尘浓度大大降低,同时测试现场湿喷形成的岩块力学性能普遍提升,研究成果可以在类似条件下推广运用。     

浸没式膜—生物反应器处理市政废水试验研究

通过浸没式膜—生物反应器处理市政废水的小试试验,考察了系统的处理效果、污泥特性、膜污染特性及清洗效果,结果表明:SMBR的高效截留作用可弥补生物处理单元的不稳定性,相比CAS工艺对市政废水有更好的处理效果。     

浅析新昌县梅渚-澄潭组团污水的出路

对新昌县梅渚—澄潭组团生活污水水量及其污染负荷方面进行了论述,对污水出路三个方案从环境和经济可行性进行了比较研究,得出了污水处理的最优方案,从而解决了组团污水出路问题。     

嗜盐菌在高盐废水处理中的应用研究

嗜盐菌是一类能在高盐环境下进行正常生长代谢的细菌,同时其具有降解有机物的功能,这使得生物法处理高盐废水成为可能,论述了嗜盐菌的分类、特性及作用机理,并综述了国内外高盐废水生物处理的研究进展,最后展望了其应用前景。     

Effect of Khirbet As-Samra treated effluent on the quality of irrigation water in the Central Jordan Valley

Khirbet As-Samra (KA) treated wastewater is being used in irrigation in the Central Jordan Valley. The treated water is collected in King Talal Dam (KTD) and then mixed with King Abdullah Canal (KAC) water, which is diverted from the Yarmouk River for further use in agriculture. The treated water has adversely affected the water quality of Yarmouk River. Comparison of the results of water quality tests with guidelines for water to be used for irrigation, salt tolerance of agricultural crops and the influence of water quality on the potential clogging of drip irrigation systems reveals that treated effluent from KA can be used for irrigation with restrictions. Moreover, concentrations of all trace elements were found to be low and within guidelines for irrigation water. Clogging of drip emitters is expected due to high calcium and magnesium contents, besides the high bacterial counts and nutrients that promote algal growth.     

浅谈膜生物反应器技术在中水回用中的应用

指出膜生物反应器水处理技术是中水回用技术中的一种生物技术与膜技术相结合的高效水处理技术,重点介绍了膜生物反应器的结构、特点以及该技术的市场前景,对改善环境,缓解水资源短缺起着重要的作用。     

洗车废水的回用实验研究

为了达到节约用水和废水回用的目的,对西安市某洗车行洗车废水回用处理工艺进行了研究,旨在通过试验找到一种经济有效的方法,为小型一体化洗车废水回用设备的研究提供借鉴资料。     

柠檬酸废水处理研究

介绍了柠檬酸的性质和用途，详细地阐述了几种柠檬酸废水的处理工艺，如厌氧生物法、好氧生物法、厌氧-好氧生物组合法、厌氧-兼氧-好氧生物组合法，并对不同方法的原理和工艺流程做了比较，从而促进柠檬酸废水处理的研究。