Low BOD Research Articles

Anthropometric somatotype of Bod girls: A comparison of high and low altitude populations.

The high altitude environment is known to influence the morphophysiology of man in a variety of ways. Its possible impact on somatotype of adolescent girls has not been investigated so far. For this purpose 348 female Bods, from 10 to 18 years old, have been somatotyped from high altitude (n = 176) of Ladakh (3,534 m) and low altitude (n = 172) of Kullu Valley (1,500-2,200 m). The results of the study reveal greater mesomorphy and ectomorphy in the high altitude Bod girls than in ethnically similar low altitude Bod girls of comparable age. The study has accorded the differences in the somatotypes to the high altitude stresses. Striking similarities in boys and girls in terms of higher mesomorphy and ectomorphy in the highlander Bods than the coeval lowlanders confirm the hypothesis that the high altitude environment influences the somatotype components.

Packed-Cage RBC with Combined Cultivation of Suspended and Fixed-Film Biomass

The situation in the treatment of wastewaters from small sources in Czechoslovakia has been discussed and two types of manufactured rotating biological contactors have been described. The evaluation of RBCs' operation showed the main disadvantages of the contactors with conventional discs, viz. the low 0C and low mixing effect. In a newly designed RBC, the discs or packets of discs were replaced by a cage packed with a random medium. The cage was equipped with tubular aeration and mixing elements. The long-term tests with a pilot-plant and a full-scale unit using synthetic as well as municipal wastewaters proved the ability of the packed-cage RBC to achieve a low effluent BOD with such organic loadings when the effluent from the conventional RBCs already deteriorated. Besides the BOD removal the 0C of the packed-cage RBCs was tested to verify the possibility of the combined cultivation of suspended and fixed-film biomass. On the basis of results presented here, a new package wastewater treatment plant for about 500 PE will be designed.

A comparative study of the air and oxygen activated sludge systems

Abstract A comparative study of air and pure oxygen activated sludge systems, with respect to energy requirements and performance characteristics, was conducted. It was shown that despite the higher efficiency of absorption the oxygen system is in most practical cases more energy demanding than the air system. Treatment efficiencies and sludge production rates were found to be similar in both cases. However, the oxygen system produced a sludge with better settling characteristics, particularly when operated at low BOD loadings.

Treatment of sanitary landfill leachate: Biological treatment

In most cases leachates from sanitary landfills are highly polluted (COD, BOD 5, ammonium) and must be treated before discharge. Treatment experiments with aerated lagoons, activated sludge plants and rotating biological contactors in laboratory and technical scale are described. Treatment with full degradation of organics and oxydation of ammonium (nitrification) are possible with attention to some special problems of leaching treatment such as high ammonium concentrations, the BOD 5 N-ratio , precipitation of inorganics, cooling, foaming etc. From aerated lagoons BOD 5-effluents ⩽ 50 mg l −1 could be obtained at volumetric loadings ⩽ 20 g BOD 5 m −3 day −1. Shorter retention times in activated sludge plants result in lower BOD levels (⩽ 25 mg l −1) at loading rates between 0.02 and 0.05 kg BOD 5 kg MLSS −1 day −1 provided that the BOD 5 N-ratio > 1 . In all other cases the dimension parameter for activated sludge plants is ammonium load ⩽ 0.03 kg N kg MLSS −1 day −1. Similar results are obtained with rotating biological contactors also with ammonium as the critical loading value, here as an area loading ⩽2 g N m −2 day −1. In all cases ammonium is the dominate parameter and careful operation is necessary because nitrification is a very sensitive process. Operation problems could result in serious water pollution problems with discharges of high concentrations of ammonium or nitrite.

Treatment of Sanitary Landfill Leachate : Biological Treatment

In most cases leachates from sanitary landfills are highly polluted (COD, BOD5, ammonium) and must be treated before discharge. Treatment experiments with aerated lagoons, activated sludge plants and rotating biological contactors in laboratory and technical scale are described. Treatment with full degradation of organics and oxydation of ammonium (nitrification) are possible with attention to some special problems of leaching treatment such as high ammonium concentrations, the BOD5/N-ratio, precipitation of inorganics, cooling, foaming etc. From aerated lagoons BOD5-effluents ≤ 50 mg l-1 could be obtained at volumetric loadings ≤ 20 g BOD5 m -3 day-1. Shorter retention times in activated sludge plants result in lower BOD levels (≤ 25 mg l-1) at loading rates between 0.02 and 0.05 kg BOD5 kg MLSS- 1 day-1 provided that the BOD5/N-ratio > 1. In all other cases the dimension parameter for activated sludge plants is ammonium load ≤ 0.03 kg N kg MLSS-1 day- 1. Similar results are obtained with rotating biological contactors also with ammonium as the critical loading value, here as an area loading ≤2 g N m-2 day-1. In all cases ammonium is the dominate parameter and careful operation is necessary because nitrification is a very sensitive process. Operation problems could result in serious water pollution problems with discharges of high concentrations of ammonium or nitrite.

The effects of unbalanced ammonia and BOD concentrations on oxidation ponds

The performance of oxidation ponds and the quality of their effluents is usually defined and evaluated in terms of high or low BOD. The work described here shows that this does not always give a complete picture, because high ammonia concentrations might lead to anoxic conditions in the pond inspite of low BOD of the water.

Characteristic evaluation of trickling filter process

Making rational assumptions concerning the biochemical reactions on the microbiological film attached to filter media, a method to predict the fraction of BOD removed of the wastewater is proposed. Effective first-order rate constants, multiplied by the active fraction of the biofilm surface on filter media, are correlated with liquid flow rate, specific surface area of the media, initial BOD in liquid and temperature by analyzing previously reported data Using the correlation obtained, the operating characteristics of both standard and high-rate trickling filters are quantitatively evaluated under various operating conditions and discussed. The application of trickling filter is best limited to rather low BOD loading conditions, because of its low BOD removal rate per unit power consumption at high BOD loading.

The Effect of Metallic and Ionic Species on the Performance of a Biological Effluent Treatment System

Abstract Review of the available results appearing in the recent literature is presented focusing particularly upon the effects of metallic ions such as Cr, Cu, Zn, Cd, Hg, V, Zn, Ni and Co. Some original data involving the effects of Na are presented and discussed. Development of parameters used in evaluating the influence of toxic or inhibitory species on the mixed microbial population of an activated sludge system is of crucial importance and different techniques employed such as BOD-COD-TOC-removal rates, Oxygen Uptake Rate, and others are discussed, showing relative inadequacy of currently applied assays. From the data available, certain trends can be discerned. There is a definite threshold concentration for each metallic ion, depending on the organic load of the feed. In the order of increasing toxicity to activated sludge systems reflected in lower BOD removals the following metals have been listed as inhibiting factors at concentrations starting from 1 ppm applied on a continuous basis: hexavalent chromium, cobalt, zinc, cadmium, trivalent chromium, copper and nickel. Metals in combination have not been reported to exhibit any significantly different effects as compared to those observed with individually introduced metallic ions. Tolerance of some activated sludge systems to shock loadings by various inorganic ions and metals is reviewed. The conclusions are of particular importance for estimating the performance of biox systems handling industrial effluents which are likely to contain toxic components of inorganic or metallic nature.

REDUCTION OF LIQUID WASTE LOADS IN SWEET CORN PROCESSING BY CHANGING SEQUENCE OF UNIT OPERATIONS

ABSTRACTMore than 70% of the BOD generated in liquid waste during sweet corn processing reportedly comes from the cutting, washing and blanching operations. The effects of manipulating these operations on BOD and COD were evaluated. Three different sequences were used in combination with both water and steam blanching techniques under pilot plant conditions. Three replications were performed in 1973 and six replications in 1974. The average BOD/COD ratio was 0.56. Steam blanching yielded significantly lower BOD and COD than did water blanching. When corn was first blanched on the cob and then cut and washed, COD was reduced by approximately 50% from the standard cut/wash/blanch sequence. Succulometer values and soluble solids levels in the product were not significantly affected by type of blanch. However, volumes of expressed liquid from succulometer tests were significantly lower for the blanch/cut/wash sequence than for the other two sequences. Blanching on the cob was probably causing gelation of the starches, thus binding water in the kernels.

Long term BOD determinations on biologically treated and untreated kraft mill effluent discharged to Lake Saimaa, Finland

Long-term BOD determinations have been carried out on kraft pulp mill effluent over a period of more than 200 days using the conventional dilution method and utilizing a special bottle sealing technique. Determinations were made at the temperatures 2, 5, 10 and 20°C on untreated effluent and on effluent treated by an experimental biological extended aeration treatment plant which treated effluent discharged to Lake Saimaa in eastern Finland. BOD curves have been constructed for up to a period of 200 days and the results indicate that untreated effluent exerts a two-stage BOD on receiving waters, the second stage commencing after approx. 28 days. Treated effluent was found to have a low BOD and showed no second stage of oxygen uptake.

Aerobic Treatment of Fruit Cannery Waste Water with Added Nitrogen

Increased land disposal costs and more stringent legislation implies more sophisticated treatment methods for food processing plant wastes. Fruit cannery wastes, characterized by high BOD values and very low N & P levels, present problems for biological oxidation systems.A pilot plant aeration system with sludge recirculation was used to determine the most suitable form of N for use as a nutrient supplement. It was possible, using a three compartment system, to achieve up to 99+ percent BOD removal with an average retention time of about 2.5 days. The final effluent was clear and was free of nitrate, nitrite and ammonia N. Use of a single aeration chamber with sludge recirculation (average retention time 30hours) gave up to 98+ percent BOD removal.Sodium nitrate at 56ppm added N was the only effective nitrogenous additive. Others tested (urea, ammonium phosphate, ammonium nitrate, sodium nitrite and ammonia) gave poor floe characteristics and much lower BOD removal.

The occurrence of sewage fungus in rivers in the United Kingdom

Sewage-fungus outbreaks are associated with the presence of biodegradable organic matter in water and thus in turn with effluents which discharge such materials. Outbreaks in the United Kingdom are mostly of limited extent except where a river has received a succession of polluting effluents. Of the sanitary measurements at present in use BOD and soluble organic carbon provide the most reliable guide to the slime-promoting properties of a water, but they are hot infallible since heavy slime outbreaks can be associated with low BOD values and vice versa. Possible reasons for this would include the differing rates at which various biodegradable substances can be utilized and the presence or absence of inhibitors and poisons. Where slime outbreaks are associated with waters of low BOD or organic carbon content the presence of rapidly biodegradable materials hot normally present in a good quality sewage effluent (e.g. sugars) has often been noted ( Amberg and Cormack, 1960; Phaup and Gannon, 1967). Adequate secondary biological treatment of an effluent seems in most cases to provide a reliable safeguard against slime outbreaks, but where this is insufficient such treatment followed by a tertiary “polishing” process is likely to be effective. Although the results of the present survey and the 1960 WPRL Questionnaire cannot be directly compared it seems likely that the sewage-fungus situation in rivers in the United Kingdom bas hot deteriorated in the last decade.

Effects of Paint Industry Effluent on Soil Productivity

The impact of various dilutions (2.5, 5, 10, 25 and 50%) of paint industry effluent on physico-chemical properties of soil and the germination, growth and dry matter productions of corn (Zea mays L.) and rice (Oryza sativa L.) have been studied. The effluent was acidic and had low BOD and COD values because of its low content of suspended solid. It contained high concentration of calcium, medium concentrations of nitrogen, sodium, potassium, sulphate, chloride and low concentrations of phosphorus, magnesium and bicarbonate. The trace element like Mn, Ni, Cu, Zn and Pb were measured in the μg L-1 level. On irrigation of soil with the effluent an increase in the water soluble salts, pH, electrical conductivity, cation exchange capacity, nitrogen, phosphorus potassium, sodium, calcium, magnesium and iron contents of the soil for effluent concentrations of 2.5, 5 and 10% were observed but all these parameters were found to decrease on treatment of the soil with the effluent concentration of 25% and above. The effluent of the lower concentrations (2.5, 5 and 10%) enhanced the growth of both crops. However, negative effects on seed germination, dry matter production and the yield of both crops were found for the effluent concentration of 25% and above. doi: 10.3329/jbas.v32i1.2441 Journal of Bangladesh Academy of Sciences, Vol. 32, No. 1, 41-53, 2008

Composition of planktonic organisms and its associated physico-chemical parameters in two ponds at African regional aquaculture centre (ARAC) Aluu, Port Harcourt

Composition of plankton communities in two ponds at African Regional Agriculture Centre (ARAC) Aluu, Port Harcourt was undertaken between May and June 2004, to assess the composition, relative abundance and distribution of plankton. The diversity of plankton was poor. Twenty-eight taxa representing four (4) families were recorded for phytoplankton while seventeen taxa representing four families were identified for zooplankton. Chlorophyta and Cladocera were the most dominant classes in phytoplankton and zooplankton in terms of abundance, constitute 13.0% and 17.1% respectively. The water quality of the ponds is evident by high temperature (28.80C), depth (57.5cm), transparency (42), dissolved oxygen (4.9mg/l) and low BOD of (1.4mg/l). The lower density of organisms could be partly attributed due to heavy rainfall which destabilize the surface water and substrate. Hence, extensive studies of the ponds where aquatic organisms are kept should be carried out to maintain proper utilization of ponds.KEYWORDS: Plankton, composition, communities richness, abundance.

PENURUNAN BOD, COD, DAN ZAT WARNA LIMBAH PENCELUPAN DENGAN FITOEKSTRAKSI MENGGUNAKAN KIAMBANG (Salvinia natans)

This research was conducted to study the potential of the plants ‘useless’ as kiambang(Salvinia natans) which are easy to find, and not as valuable as textile dyeing waste handlingmedia. Treatment technique used is to replace the growth medium with the waste in questionin this case of waste taken in the dyeing industry. The concentration of methylene blueinwaste of dye, and congo red, before and after treatment, determined by spectrophotometry.Fluid absorbance was measured at a wavelength of 664 nm for methylene blue and 496 nmfor congo red. Long time treatment used is 6, 12, 18, 24, 30, 36, and 48 hours. These resultsindicate that kiambang (Salvinia natans) is useful to lower BOD and COD of waste dyeing,although its ability to reduce the content of the dye congo red and blue methyl insignificant.This may be caused by too concentrated the dyeing waste.

Treatment of Textile Waste Liquors

The character of textile waste liquors and methods that can be employed for their purification are discussed. Although the examples are based largely on cotton processing, the methods are applicable generally. The need for mixing and balancing waste liquors is emphasised. Methods of biochemical treatment are described with some indication of relative costs. The method usually used to remove suspended solids is described briefly, and the effects of oxidising and reducing substances on the biochemical treatment are discussed. The ease of treatment of effluents containing surface‐active agents depends on whether the agent is ‘hard’ or ‘soft’, i.e. whether the agent has a low or high BOD. If the waste is discharged to a sewer, the treatment costs depend on the size of the community in which the works is situated. The re‐use of part of the effluent from textile processes and the analytical tests made on the effluent are discussed briefly.