Growth of blue-green algae in the Manukau (New Zealand) oxidation ponds—I. Growth potential of oxidation pond water and comparative optima for blue-green and green algal growth

Water sampled from the Manukau oxidation ponds between 6 December 1973 and 12 July 1974 was tested for its ability to support blue-green algal growth. A local blue-green algal isolate of Anabaena grew well on membrane filtered pond water throughout the year, however the unfiltered water sustained Anabaena only when the resident green algal populations, in particular Chlorella, were low.Temperature and pH optima for growth of Anabaena and the Manukau pond algal dominant, Chlorella, were found to be significantly different: 28–35°C and pH 9–10 and 23–28°C and pH 7–8 respectively. The ambient conditions of the ponds favoured growth of Chlorella over blue-green algae during the period of study.     

Microbial reactions in facultative oxidation ponds—II. Biochemical activity of facultative oxidation pond sediments

Studies of biochemical reactions involved in the decomposition of organic matter in sediments of a facultative oxidations pond have shown that the reactions most sensitive to anaerobic conditions increased in activity with increasing pond depth. Other reactions less affected by anaerobic conditions showed little or no change. Use of these parameters in the examination of malfunctioning ponds is also indicated.     

Equilibrium and kinetic modelling of Cd(II) biosorption by algae Gelidium and agar extraction algal waste

In this study an industrial algal waste from agar extraction has been used as an inexpensive and effective biosorbent for cadmium (II) removal from aqueous solutions. This biosorbent was compared with the algae Gelidium itself, which is the raw material for agar extraction. Equilibrium data follow both Langmuir and Redlich-Peterson models. The parameters of Langmuir equilibrium model are q(max)=18.0 mgg(-1), b=0.19 mgl(-1) and q(max)=9.7 mgg(-1), b=0.16 mgl(-1), respectively for Gelidium and the algal waste. Kinetic experiments were conducted at initial Cd(II) concentrations in the range 6-91 mgl(-1). Data were fitted to pseudo-first- and second-order Lagergren models. For an initial Cd(II) concentration of 91 mgl(-1) the parameters of the pseudo-first-order Lagergren model are k(1,ads)=0.17 and 0.87 min(-1); q(eq)=16.3 and 8.7 mgg(-1), respectively, for Gelidium and algal waste. Kinetic constants vary with the initial metal concentration. The adsorptive behaviour of biosorbent particles was modelled using a batch reactor mass transfer kinetic model. The model successfully predicts Cd(II) concentration profiles and provides significant insights on the biosorbents performance. The homogeneous diffusivity, D(h), is in the range 0.5-2.2 x10(-8) and 2.1-10.4 x10(-8)cm(2)s(-1), respectively, for Gelidium and algal waste.     

Impact of western coal mining—II. Microbiological studies

The occurrence and activity of certain groups of sulfur cycle bacteria associated with waters, sediments, and the coal bearing strata of a coal strip mine at Decker, Montana, were studied. Mining areas in northeastern Wyoming were also examined.Thiobacillus ferooxidans, one of the major contributors to acid mine drainage, was consistently detected in the mining environment. Physiological studies of T. ferrooxidans isolates indicated that these acidophilic iron and sulfur oxidizing organisms were typical of the species in their preference for low pH and ability to oxidize pyrite. Since (i) acidic conditions were not observed at Decker, (ii) the organisms did not multiply in mine water environments and (iii) no acid could be formed from coal samples inoculated with a T. ferrooxidans isolate, it was thought that their activity was limited to microzones in the coal bearing strata where they oxidized sulfuritic material. Any acid formed was quickly neutralized by mineral carbonates associated with the groundwaters and overburden.Sulfate reducing bacteria also were common in the mine waters and sediments. These organisms were particularly active in the sedimentation pond sediments as was evidenced by the rapid rate of conversion of radio-labeled sulfate to sulfide. The hydrogen sulfide produced by these organisms contributed to heavy metal precipitation in the sedimentation pond.     

Binding of Cu(II) to algae in a metal buffer

The interactions of Cu(II) with algal surfaces and exudates were studied in metal-NTA buffers by a combination of several analytical techniques. Suspensions of living algae in the presence of NTA were titrated at constant pH with Cu(II). The various Cu species were determined as follows: a copper ion selective electrode was used reliably in the pCu range 9–12; differential pulse polarography was used to measure separately Cu(II)-NTA complexes and labile Cu(II) species and to evaluate the complexation of copper by ligands in solution; copper bound to the algal surfaces was extracted by acid treatment and measured by AAS. Thus, we determined both the binding of Cu to the algal surfaces and to exudates excreted by the algae. The results were interpreted in terms of conditional equilibrium constants valid at a given pH; the conditional constants, both for the binding to the surfaces and with the exudates increase in the pH range 5.0–6.5. Simple equilibrium models using the experimentally determined binding capacities and equilibrium constants were able to simulate the results and to evaluate the speciation of copper. Under the experimental conditions used, the binding of Cu(II) to algal exudates has a more significant effect on copper speciation than the binding to the algal surfaces. These extracellular ligands may play an important role in decreasing the concentration of free copper ion and thus mitigating the potential toxic effects in organisms.     

Pollution studies of River Khan (INDORE) India—I. Biological assessment of pollution

Pollution studies of the River Khan, Indore (India) have been made, with an emphasis on the biological assessment of water quality. The study covers a critical analysis and testing of various European methods for the biological monitoring of water pollution, under the Indian conditions in the River Khan. The river has been divided into different zones of pollution. The biological data have been correlated with the chemical data, and the practical implications of the European saprobity system, under the Indian conditions have been discussed. The importance of benthic macro-invertebrates in the assessment of water quality in the river has also been discussed.     

Biodegradation of nitrilotriacetate (NTA) by bacteria—II. Cultivation of an NTA-degrading bacterium in anaerobic medium

Bacterial strains with the ability to utilize nitrilotriacetate (NTA) under aerobic and anaerobic conditions have been isolated from natural waters exposed to NTA. One of these strains (NTA-A2) is a facultative anaerobe which grows under anaerobic conditions on NTA if nitrate is available in the medium. (Under aerobic conditions this strain can utilize acetate, glucose and some other sugars as well as NTA but not EDTA (ethylenediaminotetraacetate) or lactose as the sole carbon source.) The properties and characteristics of the strain NTA-A2 are described.     

The biological treatment of carbonization effluents—III New advances in the biochemical oxidation of liquid wastes

Biological treatment systems operating the continuous, completely mixed activated-sludge process have been employed to study the effect of the addition of certain biochemical factors such as p-aminobenzoic acid (PAB). This substance was found to act as an accelerating agent or growth factor on the nitrogenous constituents of certain wastes, when added to the influent at a concentration of only a few milligrams per litre. By using a solution of ammonium thiocyanate as the standard substrate, a number of such substances have been found, which can be classified into various groups and which have a significant effect on the rate of removal of constituents of coke-oven wastes such as thiocyanate and cyanide, which are normally the rate-limiting factors in coke-oven waste treatment. The results of the investigation illustrate a method of improving some biological oxidation processes, which may be adapted to full-scale treatment. It is believed that pyruvic acid plays a key role in the mechanism of the improved treatment process and experimental evidence has been found to support the hypothesis that an organic substance will behave as a growth factor if its aerobic degradation results in the formation of pyruvic acid, or some compound closely related to pyruvic acid in the biochemical sense. An example of the latter type of compound is glucose, the application of which to spent liquor treatment is economically attractive.     

Experimental study on the wind-induced vibration of a dry inclined cable—Part II: Proposed mechanisms

The possibility of dry inclined cable galloping is of concern in the design of bridge stay cables. Although the phenomenon has only been observed in a few experimental studies, the fact that the mechanism of excitation is not fully understood makes it difficult to develop solutions with confidence. To clarify its physical nature, a series of dynamic and static model wind tunnel tests have been carried out in the current study. The present paper will focus on exploring the applicability of Den Hartog criterion and on an explanation of its driving mechanism. The spatial structure of the flow field surrounding an inclined cable will be examined to assist in better understanding of the phenomenon. Results show that the critical onset condition of the divergent motion predicted by the Den Hartog criterion (as applied to an inclined circular cylinder) agrees well with the experimental observation. However, satisfaction of the criterion only occurs within a critical range of Reynolds number. Further, within the critical ranges of wind speed and cable orientation, flow around the cable is found to be better organized. The resultant fluid forces acting at different longitudinal locations of the cable tend to point toward the same direction which generates greater cross-flow excitation force, and the axis-wise lift correlation is enhanced.     

Dynamics of the ozonation of phenol—I. Experimental observations

This first paper presents the results of an experimental investigation of the ozonation of phenol in a semi-batch reactor, in which mass-transfer kinetics of ozone into solution and the kinetics of the reaction between molecular ozone and phenol are considered separately. Attention has been given to distinguishing between direct and indirect reaction pathways involving ozone. Intermediates and final products of the reaction have been measured as a function of time using high pressure liquid chromatography.     

Sorption of hydrophobic compounds by sediments, soils and suspended solids—II. Sorbent evaluation studies

Concepts underlying the sorption of hydrophobic compounds and models for representation of observed equilibrium relationships were presented in Part I of this series. The earlier paper also summarized and evaluated major factors which affect the sorption of pollutants in natural environmental systems. This second part of the series presents a detailed summary and evaluation of the sorption of a particular class of hydrophobic pollutants, polychlorinated biphenyls (PCB), on a variety of different types of sediments, soils, suspended solids, and microorganisms. Equilibrium models described in Part I are used here to describe and analyze the PCB sorption data.     

Persistence of some phenylamide pesticides in the aquatic environment—II. Adsorption on clay minerals

Adsorption of IPC, CIPC, Linuron, Neburon and Vitavax on bentonite clays (H-, Fe- and Ca-forms) was investigated. Adsorption was found to conform with Freundlich's equation and to depend on the nature of saturating cation as well as the chemical structure of phenylamides. Considerable amounts of bentonite are needed to bring about effective removal of these pesticides from polluted water. The role of suspended clay minerals in the decontamination of surface waters will be rather limited.     

Heat loss to the ground from a building—II. Slab on the ground

The heat flow to the ground from a rectangular slab with an even thermal insulation is analysed. The steady-state heat loss factor is given in complete diagrams for any ratio between length and width of the slab and for any constant insulation of slab and ground surface. A two-dimensional edge approximation for time-dependent heat loss at the perimeter of the slab is introduced. New analytical solutions for the edge heat loss due to periodically variable outdoor temperature or a step change in the outdoor temperature are presented. The effect on the heat loss due to different variations of the outdoor temperature is easily analyzed with these solutions. For example, daily periodic variations can certainly be neglected. Based on this, simple design rules for the heat loss during a heating season and the peak effect are given.     

Effects of inorganic metal toxicity on bod—I methods for the estimation of bod parameters—II

Metal toxicity: In this study, the effects of HgCl₂, HgSO₄, K₂Cr₂O₇, CuSO₄, ZnSO₄ and Al₂(SO₄)₃ on BOD were investigated using a respirometer. When these inorganic metal compounds were added to a synthetic medium, respirometric BOD values and bacterial growth in an aeration system were affected. Parameter estimation: Some new solutions of the first order equation are time saving alternatives to the existing ones. Ultimate BOD values obtained from the second order equation are significantly higher than those produced from the first order equation. There is linear relationship between first and second order BOD parameters using crude sewage samples, but not when synthetic medium is used.     

水厂除藻除嗅试验研究

针对高藻期水库水采用高锰酸盐复合药荆(PPC)、高锰酸钾(KMnO4)和氯进行了化学预氧化强化水厂除藻除嗅性能的试验研究,并与单独使用混凝剂时的处理效果进行了对比.结果表明,PPC对水库高藻水具有较好的除浊和除有机物效果,且高于KMnO4;PPC预氧化对藻类和臭味的去除效果高于KMnO4预氧化.     

Removal of phenylamide pesticides from drinking waters—II. Adsorption on powdered carbon

Chemical coagulation with aluminium or ferric sulphates is not an effective mean for the removal of phenylamide pesticides from drinking water. The effects of chlorine, u.v.-catalyzed chlorination and chlorine dioxide on phenylamides were investigated. Several aniline derivatives and intermediate products having the amide linkage intact were detected in the treated solutions. The presence of such degradation products may exert the same undesirable effects on water quality as the parent compounds. Chlorine dioxide tends to be the oxidant of choice for the removal of phenylamides from polluted waters.     

Construction of the Seikan undersea tunnel—II. execution of the most difficult sections

This paper describes the three main problems associated with the difficult sections of the work which were encountered and for which solutions were found during construction of the Seikan Tunnel: (1) the excavation of squeezing ground; (2) water inflow accidents; and (3) the excavations of unconsolidated zones. Squeezing ground, which appeared in the F-10 fault with an earth pressure as high as 2 MPa, was excavated employing spring line drifts and the short bench method with steel pipe supports filled with reinforcing hoop-shaped steel bars and grouted with a high-strenth mortar. The most serious water inflow incident (maximum rate of 70 m³/min.) occurred in the service tunnel on the Hokkaido side in May 1976, causing inundation of 3 km of the service tunnel and 1.5 km of the main tunnel. By correctly judging the situation and making strenuous efforts over the next 5.4 months, the remedial work—which included water drainage—was safely completed. There were no fatalities or serious injuries resulting from the accident. The unconsolidated soft sand layer of the Kuromatsunai Formation, which existed in the middle of the Tsugaru Straits, was excavated without any water inflow accidents. This was accomplished with the aide of water-seal grouting and by carrying out construction procedures with care. Although different measures were required for each problem, the difficulties were overcome by careful investigation and construction management.     

Effect of pulpmill effluent on dissolved oxygen in a stratified estuary—II. Numerical model

A numerical model is presented which simulates the biological and physical processes of oxygen supply in a stratified inlet. The results of the model show that the introduction of pulpmill effluent into the upper layer of the inlet causes a decrease in the dissolved oxygen concentration of the water due to blockage of photosynthesis in the stratum of water immediately below the halocline. Removal of the biochemical oxygen demand from the effluent has very little effect on the oxygen concentration in the upper layer since the supply of oxygen from the lower layer is blocked by the stain. Removal of 90 per cent of the stain from the effluent restores the oxygen concentrations to near normal.