深层搅拌桩在污水净化处理厂中的应用

介绍了肇庆市污水净化处理厂的工程概况和地质情况，针对基坑开挖中的问题，提出了施工设计方案并对水泥土桩样的稳定性进行了详细验算，得出了深层搅拌桩止水帷幕用在该工程中是成功的结论。     

The use of bromophenol blue as a tracer in sewage works

A reliable method for the quantitative assessment of water mixing in sewage works is presented. Using a rapid visible-spectroscopic technique to assay Bromophenol Blue, both laboratory and in situ adsorption/degradation studies are presented which confirm that this dye may be used quantitatively in tracer experiments.     

The growth of cladophora glomerata in a river receiving sewage effluent

A considerable improvement in the natural flora of the River Great Stour has occurred since the mid-1960s when dense growths of Cladophora glomerata dominated sections of the river with the disappearance of some rooted macrophytes. Cladophora growths in the river in response to changing river conditions and sewage treatment operations during a thirty year period are reviewed. A vegetation mapping programme undertaken from 1978 to 1982 to assess the influence of a sewage treatment works discharge on the growth of the filamentous alga has shown that previous recommendations to reduce dissolved phosphorus concentrations in the final effluent need not be implemented.     

The effect of pretreatment to ultrafiltration of biologically treated sewage effluent: a detailed effluent organic matter (EfOM) characterization

Ultrafiltration alone can remove only a portion of the effluent organic matter (EfOM) from biologically treated sewage effluent (BTSE). Use of pretreatment not only improves the EfOM removal but also reduces the membrane fouling. In this research, NTR 7410 ultrafiltration membrane was employed to remove EfOM from BTSE. Different pretreatments namely FeCl(3) flocculation and powder activated carbon adsorption were evaluated. The highest removal of organic matter was observed when flocculation followed by adsorption was used as pretreatment. The flocculation and adsorption removed 68.5% and 71.4% of hydrophobic organics, respectively. The molecular weight (MW) of the EfOM in BTSE ranged from 300 to about 400000 Da. After the flocculation pretreatment, the majority of large MW organic matter was removed. The pretreatment of the flocculation followed by adsorption led to very high removal of both small and large organic matter. Further, this pretreatment led to practically no filtration flux decline.     

The scope for potential energy savings in the flocculation process

Water treatment plants traditionally use coagulation/flocculation process to remove organics and turbidity particles in drinking water. As a result of the chemical optimisation of the coagulation process having such a strong influence, it is believed that the current hydraulic conditions for flocculation cited under best practice could be out of date. A 450 Mld plant treating upland water was chemically optimised, and it was observed that the total mixing energy input could be reduced by 66% without any detrimental impact upon the clarified water being observed. Under the new mixing regime, energy costs could be reduced by £37 300 pa equating to approximately a 280 t reduction in CO ₂.     

Assessment of the UV/chlorine process as an advanced oxidation process

Several organic compounds were used as radical scavengers/reagents to investigate the possibility of the UV/chlorine process being used as an advanced oxidation process (AOP) in the treatment of drinking water and wastewater. The UV/H₂O₂ process was selected as a reference, so that the results from the UV/chlorine process could be compared with those of the UV/H₂O₂ process. Methanol was added to active chlorine solutions at both pH 5 and 10 and into hydrogen peroxide samples. The photodegradation quantum yields and the OH radical production yield factors, which are significant in evaluating AOPs, were calculated for both the UV/chlorine and the UV/H₂O₂ processes. The yield factor for the UV/chlorine process at pH 5 was 0.46 ± 0.09, which is much lower than that of the UV/H₂O₂ process, which reached 0.85 ± 0.04. In addition to methanol, para-chlorobenzoic acid (pCBA) and cyclohexanoic acid (CHA) were added to active chlorine solutions and to H₂O₂ solutions, to evaluate the efficiencies of oxidizing these organic compounds. The specific first-order reaction rate constants for the oxidation of pCBA and CHA, using the UV/chlorine process, were lower than those found using the UV/H₂O₂ process.     

The mutagenic activity in a section of the sheep river, Alberta receiving a chlorinated sewage effluent

Base line mutagenic activity in a section of the Sheep River, Alberta, was investigated using the Ames' Salmonella/mammalian microsomal assay system. Low levels of mutagenic activity were observed in water and benthic macroinvertebrate samples, especially from the site at which the chlorinated sewage effluent was discharged. These results are discussed with respect to the potential harmful effects of sewage effluent chlorination.     

The physicochemical speciation of Cd, Pb, Cu, Fe and Mn in the final effluent of a sewage treatment works and its impact on speciation in the receiving river

A scheme for the speciation of metals in freshwaters has been applied to the analysis of the final effluent from a sewage treatment plant and to the receiving river upstream and downstream of the effluent outfall. The treatment plant was selected because of the high influent and effluent concentrations of Cd. The metal speciation patterns in the effluent are interpreted primarily in terms of organic interactions, which appear to be exerting a solubilizing effect on Cd and Cu, but not on the Pb and Fe which are principally associated with the particulate size fraction (> 12 μm). The influx of metals with the sewage effluent alters the speciation pattern in the river. A large part of the Cd is added to the smallest size fraction (< 0.015 μm). However, the major part of each metal, with the exception of Mn, is associated with the colloidal and particulate size fractions, thus minimising the immediate toxic significance to aquatic life.     

The effect of sewage and industrial waste discharges on the primary production of a shallow turbulent river

Sewage and industrial waste discharges have been found to have a deleterious effect on the primary productivity of the shallow turbulent tropical river Khan (Indore) India. Even though net primary production rates have exceeded the respiration rates in the early recovery zone, the industrial wastes and sewage discharges have been found to decrease the overall productivity of the river. The above studies have been compared with other investigations in the temperate regions of the world, which generally refer to the effects of organic pollution on the primary productivity of the running waters. The present investigations lead to a generalized observation that in tropical running waters, toxic industrial wastes and sewage discharges have a depressing effect on the overall production rates. However, comparable studies in the temperate regions are nonexistent, as the studies in the temperate regions mainly refer to organic pollution and do not take into account the effects of toxic industrial waste and sewage discharges.     

The behaviour of polychlorinated biphenyls in the primary sedimentation process of sewage treatment: A pilot plant study

The behaviour of polychlorinated biphenyls (PCB) in the primary sedimentation stage of sewage treatment has been studied using a pilot scale primary sedimentation plant. The plant was operated at different hydraulic loadings, selected to cover the range expected during normal operation of a sewage treatment works. Concentrations of PCB in raw sewage were found to be in the low ng l^?1 range and in the high ng l^?1 range in primary sludges. A relationship between raw sewage PCB concentrations and variations in the raw sewage flow to the full-scale sewage treatment works was evident. Removal efficiencies of PCB were found to be highest at dry weather flow and lowest at three times dry weather flow, their removals being comparable to those of suspended solids. Mass balances of PCB and suspended solids in the treatment process have been calculated and the possible sources of error considered. Comparisons of the results have been made with those of previous studies. The implications of the presence of PCB in waste waters and sewage sludges for water re-use and sewage sludge disposal are discussed.     

A model for the movement of sewage effluent, according to sea state, in a bay situation

A model system to describe the movement of sewage effluent according to sea state within a bay situation is described. The postulates were tested following dye movement under simulated conditions on a scale model of St Andrews Bay down to the 25 fathom level and by following float movements in the bay under different sea state conditions. Bacterial counts for both coliforms and Group D streptococci further substantiate the postulates and show that the lowest counts are obtained alongshore under calm conditions and the highest counts under storm conditions. This is noteworthy since maximum recreational use is made of the water under calm sea conditions.     

The use of fortified soil-clay as on-site system for domestic wastewater purification

The quest for simple, low-cost and high-performance decentralized wastewater treatment system for domestic application in developing nations necessitated this study. Clay samples collected from different deposits in Nigeria were characterized by studying the mineralogical and geochemical composition using X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS), respectively. Three major clay minerals of kaolinite, illite and smectite were identified. The geochemical studies showed the abundance of SiO2, Al2O3 and H2O+ in each of the clay samples. Performance efficiency studies were conducted to determine the best combination ratio of pebbles/soil-clay. Soil-clay fortified by pebbles in combination ratios of 1:3 (i.e. pebbles:soil-clay = 1:3 (w/w) showed the optimum water purification, while the combination 3:1 gave the least. The flow rate studies showed that the wastewater had a longer residence time in non-fortified soil-clay than in fortified soil-clay. Two modes of treatment methods were employed-single and double column treatment methods (SCT and DCT). The two methods gave effluents of good quality characteristics, but those from the DCT were of better quality. The quality of effluents also varies from one clay type to another. The quality of effluents from media containing smectite clay mineral was better than those from other columns. Repeated usage of the fortified clay column showed a decrease of pH, TS and DO, and an increase of COD when monitored over a period of 10 days.     

一体式A/O-MBR工艺在煤矿生活污水处理中的应用

采用一体式厌氧/好氧膜生物反应器(A/O-MBR)工艺对某150 m3/d煤矿生活污水处理工程进行了改造,介绍了改造的设计参数与方法,指出投产后整个系统运行稳定,出水CODCr、氨氮平均为22.85 mg/L和3.38 mg/L,其去除率分别为88.39%和89.59%,满足回用水质要求。     

The efficacy of inclined tube and plate modules in a high lime clarification process

The introduction of inclined tube and plate modules into the upper section of a high lime clarifier effected a decided improvement in the quality of the overflow. The performance of these modules, within defined limits, was relatively insensitive to pH, hydraulic loading and temperature. However, flocculant dosage and clarifier turbidity strongly influenced module performance. The modules became particularly useful at clarifier turbidities in excess of three Jackson turbidity units, effecting reductions in the carry-over of suspended material of more than 50%. In a high lime process, these modules would require at least a three-monthly hosing and brushing down. Annual acid washes would most probably be required to ensure satisfactory continuous operation.     

Application of bacteria involved in the biological sulfur cycle for paper mill effluent purification

In anaerobic wastewater treatment, the occurrence of biological sulfate reduction results in the formation of unwanted hydrogen sulfide, which is odorous, corrosive and toxic. In this paper, the role and application of bacteria in anaerobic and aerobic sulfur transformations are described and exemplified for the treatment of a paper mill wastewater. The sulfate containing wastewater first passes an anaerobic UASB reactor for bulk COD removal which is accompanied by the formation of biogas and hydrogen sulfide. In an aeration pond, the residual COD_organic and the formed dissolved hydrogen sulfide are removed. The biogas, consisting of CH₄ (80-90 vol.%), CO₂ (10-20 vol.%) and H₂S (0.8-1.2 vol.%), is desulfurised prior to its combustion in a power generator thereby using a new biological process for H₂S removal. This process will be described in more detail in this paper. Biomass from the anaerobic bioreactor has a compact granular structure and contains a diverse microbial community. Therefore, other anaerobic bioreactors throughout the world are inoculated with biomass from this UASB reactor. The sludge was also successfully used in investigation on sulfate reduction with carbon monoxide as the electron donor and the conversion of methanethiol. This shows the biotechnological potential of this complex reactor biomass.     

MBBR工艺应用于某污水处理厂的升级改造

针对某污水处理厂的升级改造中MBBR工艺的应用情况进行分析,目的就是提高污水处理效果,实现对污水的合理处理,确保经过处理后的污水能够达到排放标准,保证经过升级改造后的污水厂运行稳定.     

The application of an upflow reactor in the denitrification step of biological sewage purification

A study is made of the biological purification of sewage by the denitrification process, using an upflow reactor which does not contain any granular material for attached growth. In the experiments nitrate as such was added to the sewage. At a sludge load of about 0.18 g COD/g MLSS day, 70% purification, based on COD, was obtained. The amount of the removed COD oxidized by the nitrate was 63%. At a linear velocity through the upflow reactor of 0.12 m h⁻¹ the sludge mass concentration was about 30g SS 1⁻¹.Based on the results of the experimental work the application of an upflow reactor for denitrification in a new sewage purification system—called the two-sludge system with pre-denitrification—is discussed.     

石灰土施工过程中常见质量问题的预防控制

结合工程实例，对石灰土施工过程中常见质量问题的表现形式及产生原因进行了分析，并对施工工序的质量控制要点进行了探讨，指出施工单位要做好技术交底，对原材料把好关，严格按规范要求的施工工艺施工，以保证工程质量。     

Determination of caffeine as a tracer of sewage effluent in natural waters by on-line solid-phase extraction and liquid chromatography with diode-array detection

A new liquid chromatographic (LC) method with automated on-line solid phase extraction was developed to determine caffeine at sub-microgram per litre concentrations in waters. The filtered sample was pre-concentrated in a pre-column, which was backwashed with acidic water at pH of 2.70. The concentrated caffeine was separated using a C18 column with a gradient of water-acetonitrile and detected by diode array detection (DAD) at 210 nm. Four different pre-columns: C18, PRP-1, PLRP-s and Env were evaluated for the on-line solid phase extraction of caffeine. The PLRP-s pre-column allowed the enrichment of up to 100 mL of environmental water sample with highest recovery. The procedure was validated by recovery experiments in water spiked at 0.5 1.0 and 4.0 microg/L. Average recoveries were between 92.1 +/- 5.2% and 97.8 +/- 2.6%. Detection limits as low as 0.1 microg/L from 50 ml of sample were achieved. The proposed method has the advantages of higher reliability and sensitivity, simpler sample preparation and shorter analysis time in comparison with off-line solid-phase extraction. The utility of the method was demonstrated at two field sites: Bolivar and Halls Head (Australia). At Bolivar, the treatment process included 6-week lagoon storage which is believed to have attenuated caffeine, and thus limited its use as an environmental tracer of reclaimed water. At the Halls Head site, where the storage period is shorter, caffeine was detected in both the treated sewage effluent and in groundwater near ponds where the reclaimed water is at similar concentrations. These results suggest that the environmental conditions under which caffeine is conservative require better definition.     

The use of an upflow fixed bed reactor for treatment of a primary settled domestic sewage

This study presents and demonstrates results obtained from an half full-scale upflow fixed bed reactor (UFBR) treating a primary settled domestic sewage. This study used expanded clay with an effective size of 2.7 mm containing hematite and magnetite as a granular medium.The content of TSS in the effluent treated was always between 10 and 20 mg l⁻¹ for bed depths ranging from 2 to 3 m and filtration rates of 3–6 m³m⁻²h⁻¹.The profiles taken all along the reactor show that the activity of the biomass is constant over the whole height of the reactor. Moreover, an air/water volume ratio of 2:1 is amply sufficient to satisfy the oxygen demand of the biomass. The average removal efficiency based on the soluble COD remains virtually unchanged as a function of the filtration rate at about 70% of the influent. For a final BOD₅ of 30 mg l⁻¹, loadings of 4.5–8 kg BOD₅m⁻³ can be applied. This corresponds to filtration rates of 3–6 m³m⁻²h⁻¹. The removal efficiencies for BOD₅ are then about 80%.After optimization of the backwashing conditions, the consumption of backwash water is about 5% of the volume of filtered water.Sludge measurements carried out during our experiments indicate an excess sludge production of 1 kg kg⁻¹ BOD₅ eliminated. The nature of these sludges is very similar to the biological sludges produced in the high rate activated sludge process.This study has made it possible to establish design parameters of an UFBR and to develop technology for applications. These results are applied to two wastewater treatment plants which began to operate in 1984: these plants serve population equivalents of 40,000 and 11,000.