Microbial degradation of synthetic sperm whale oils

Thirteen synthetic sperm whale oils, including four sulfated and three sulfurized products, were tested for biodegradability using growth ofPseudomonas aeruginosa and BOD₅ as indicators. All of the underivatized oils were found to be easily degraded; the sulfated and sulfurized products were relatively resistant. Four oils showed anti-microbial properties at concentrations of more than 1.0%. All the replacements are capable of causing BOD loading problems.     

Ecofriendly Method for Bioremediation of Chlorpyrifos from Agricultural Soil by Novel Fungus Aspergillus terreus JAS1

The aim of this work was to study the degradation of three azo dyes, Orange II, Methyl red and Biebrich Scarlet by electro-Fenton and the effect of the electrochemical pretreatment on the biodegradability of the solutions. The electrochemical pretreatment showed that an electrochemical reduction on the carbon felt electrode was mainly responsible for the decolorization of the azo dyes. Indeed, the electrochemical behaviour of the azo dyes highlighted their electroactivity; electrolysis with and without ferric ions led to the same decolorization yield, namely 99 % at 15 min for Methyl red, and stable chemical oxygen demand (COD) values were recorded during decolorization. In a second step and owing to the absence of by-product electroactivity in reduction, the formation of hydroxyl radicals by the Fenton reaction led to the oxidation of by-products from the electrochemical reduction. It was illustrated by the decrease recorded for the COD values. The results also showed that the azo bond cleavage occurring during the electrochemical reduction was not sufficient to significantly reduce recalcitrance, as shown from biological oxygen demand (BOD)₅/COD ratio examination below the limit of biodegradability (0.4). Contrarily, a positive trend was recorded for Orange II during the electro-Fenton reaction, with a BOD₅/COD ratio of 0.81 after 28 h of pretreatment.     

Biochemical Oxygen Demand Relationships in Typical Agricultural Effluents

Understanding the variables controlling biochemical oxygen demand (BOD) of effluents from agricultural systems is essential for predicting and managing the water quality risks associated with agricultural production. In this study, short- and long-term oxygen demand behaviors of waters from primarily agricultural sources and their relationships with other parameters were evaluated. A total of 46 water samples were generated from diverse organic sources commonly associated with agricultural activities and analyzed for BOD and other various water quality parameters. Short-term BOD (BOD₂ and BOD₅) were significantly correlated with total organic carbon (TOC), particulate organic carbon (POC), and dissolved organic carbon (DOC) (R ²?=?0.62–0.77, p?<?0.001), likewise to total nitrogen, total Kjeldahl nitrogen, and nitrite–nitrogen (NO₂–N) (R ²?=?0.40–0.55, p?<?0.001). Long-term BOD (BOD₆₀) was generally poorly correlated with these C and N fractions. Phosphate (PO₄–P) exhibited a positive and linear relationship with both short- and long-term BOD, whereas chloride (Cl) tended to inhibit oxygen demand. Multivariate combinations of each of TOC, POC, and DOC with NO₂–N, and Cl or PO₄–P improved the predictions of both short- and long-term BOD. The ultimate BOD (BOD_u) derived from the first-order kinetics was highly correlated with BOD₆₀ (R ²?=?0.81, p?<?0.001) whereas BOD₆₀ was correlated with BOD₅ (R ²?=?0.60, p?<?0.001). Overall the results indicated that C and N forms along with PO₄–P and Cl were the dominant factors controlling the oxygen demand behaviors of agricultural effluents.     

Biodegradability Improvement of Sulfamethazine Solutions by Means of an electro-Fenton Process

The main objective of this study was to examine the effect of an electro-Fenton pretreatment on the biodegradability of sulfamethazine-polluted solutions. The aim of the pretreatment was only to degrade this molecule in order to increase the biodegradability of the effluent and therefore allow a subsequent biological treatment. Preliminary tests showed the absence of biodegradability of the target compound. The degradation of sulfamethazine by electro-Fenton process was then examined using a carbon felt cathode and a platinum anode in an electrochemical reactor containing 1?L of solution. The influence of some experimental parameters such as initial concentration, temperature and current intensity on the degradation by electro-Fenton step has been investigated. In addition, the biodegradability of the solution after electrochemical pretreatment was examined and showed a Biological Oxygen Demand (BOD₅) on Chemical Oxygen Demand (COD) ratio above the limit of biodegradability, namely 0.4, for several experimental conditions. The feasibility of coupling an electro-Fenton pretreatment with a biological degradation of by-products in order to mineralize polluted solutions of sulfamethazine was confirmed.     

BOD/TOC correlations and their application to water quality evaluation

The error residual for TOC analysis is examined with the result that two BOD₅/TOC models are suggested, both of which use a multiplicative error structure. A comparison of these models with the historically-assumed linear BOD₅/TOC model is created for data collected from the City of Waterloo's Water Pollution Control Plant. The predictive capabilities of the derived BOD₅/TOC models are examined for interpolation and extrapolation potentials for augmenting water quality data information bases. Use of the models to reduce the statistical uncertainty associated with BOD measurements is considered.     

The Impact of Rainfall on Flows and Loadings at Georgia’s Wastewater Treatment Plants

An assessment of influent and effluent data from 24 wastewater treatment plants (WWTPs) in the state of Georgia with design capacities of 37,850 m³/d (10-mgd) or greater was undertaken. Twelve months of operating data from the 2003 calendar year were evaluated. The objectives of the study were to determine the effect of rainfall intensity on the volumetric flow rate to each WWTP and to determine the relationship between flow rate and the influent five-day, biochemical oxygen demand (BOD₅) and total suspended solids (TSS) concentrations. The relationships between rainfall intensity and influent BOD concentration, rainfall intensity and influent TSS concentration, influent BOD loading and effluent BOD concentration, and influent TSS loading and effluent TSS concentration were also evaluated. Moderate to strong correlations were observed between rainfall intensity and volumetric flow rate, volumetric flow rate and influent BOD and TSS concentrations, average monthly rainfall intensity and influent BOD and TSS concentrations, and between influent BOD and TSS loadings and effluent BOD and TSS concentrations. Weak correlations were observed for some of the relationships when applied to the complete data set however, stronger correlations were achieved by performing statistical analyses of variance and pooling subsets of the data. Peaking factors for flows and loadings were similar to those reported in the literature.     

Oxygen Transfer and Industrial Wastewater Treatment Efficiency of a Vertically Moving Biofilm System

A vertically moving biofilm system (VMBS) was developed to treat wastewater. In this system, the biofilm grows on a biofilm module consisting of plastic media that is vertically and repeatedly moved up into the air and down into the water. The objectives of this study were to investigate the oxygen transfer efficiency and industrial wastewater treatment performance of the VMBS. The oxygen transfer coefficient (K _L a) depended on the movement frequency (n) of the biofilm module and was proportional to n ^1.67. K _L a values measured were within the range of 0.0001 to 0.0027 s^-1. The VMBS exhibited good carbonaceous removal when treating industrial wastewater produced in a factory manufacturing synthetic fibres. Removal efficiency of filtered chemical oxygen demand (COD) and biological oxygen demand (BOD₅) was up to 93.2 and 97.9%, respectively. The volumetric removal rates of filtered COD and BOD₅ reached 1320 g COD m^-3 day^-1 and 700 g BOD₅ m^-3 day^-1. The areal organic removal rates, based on the surface area of the biofilm substrata, were 16 g BOD₅ m^-2 day^-1 and 39 g COD m^-2 day^-1. No clogging occurred during the experiment. The mean areal biofilm mass increased with increasing the mean areal BOD₅ removal rate. The new biofilm process has such advantages as high carbonaceous oxidation, energy saving, simpleconstruction and easy operation for industrial wastewater treatment.     

Application of stabilization pond for purification of textile wastewater in Esfahan,Iran

Two experimental ponds, with an effective volume of 2 m3 each, were constructed in a workshop at the textile plants to investigate the potential for a stabilization pond for purification of textile wastewater. Parametric analysis of pH, temperature, turbidity suspended solids, total suspended solids, DO, BOD, COD, N, and algae was carried out on the influent and the effluent according to the procedures recommended by the standard methods (APHA, 1971). Considering the results obtained from tests after daily observations, the application of an oxidation pond for treatment of textile wastewaters in the winter time was not promising. The ponds had a little activity in aerobic condition. In other seasons the ponds were efficient and the removal of BOD, COD, and N was 81, 78, 72% respectively, with a loading rate of 7.950 g BOD m^?2 day^?1 and detention time of 20 days. The ponds were usually saturated and sometimes super-saturated with dissolved O₂. The experimental ponds were put to work in series for BOD, COD, and N removal observation. The removal did not improve compared with a single pond and algae concentration was noticeably reduced in the effluent.     

Impact of sanitary landfill on groundwater quality

This paper presents the results of monitoring the shallow groundwater quality around two municipal landfill sites in the Eastern Province of Saudi Arabia. Boreholes were installed at Dhahran and Juaymah sites upstream and downstream of the landfill. Twenty water samples were collected from each borehole and analyzed for various parameters mainly for BOD, COD, TOC, NH₃-N, TKN, sulphate, chloride, hardness and metals. The result of the analysis of water samples from Dhahran boreholes shows an increase in the concentration of pollutants in downstream groundwater over that observed in upstream boreholes. The average concentration of BOD₅, COD and TOC in the samples obtained from the downstream borehole was found to be 6.5, 23.5, and 34.3 mg L^?1, respectively. On the other hand, the mean concentration of the same parameters in upstream monitoring wells was found to be less than 2.4, 11.5, and 10.0 mg L^?1, respectively. The ammonia-N and organic-N in the downstream wells were 0.37 and 0.29 mg L^?1, respectively, whereas, in upstream wells they were 0.11 and 0.15 mg L^?1, respectively. At Juaymah, the average concentration of BOD and TOC in groundwater samples obtained from upstream boreholes were less than 3.0 and 7.2 mg L^?1, respectively, while the concentration of the same parameters in downstream well samples were above 5.0 and 35.0 mg L^?1, respectively. A similar trend of increment of ammonia-N, organic-N, phosphate, sulfate and metals in downstream samples was observed. Since the water from these shallow aquifers at both places is not being used for human consumptions or for any other commercial purpose, therefore, the minor increase in pollutants concentration at downstream level is not of a great concern.     

Impact of Land Use and Urban Runoff on the Contamination of the Sarno River Basin in Southwestern Italy

A study was conducted to determine the contaminantlevel of the Sarno River basin, a small creek located insouthwestern Italy. Six sampling site locations were selected tocoincide with two previous studies conducted in 1975 and 1985 toprovide a basis for comparison. For each location, twelve sampleswere collected over the period October 1997–September 1998.Results indicated a degradation in river water quality, especiallynear the mouth. This was reflected by a dissolved oxygenconcentration of about 0.8 mg L^-1 near the urban areas ofScafati, Pompei and Castellamare of Stabia. At the same locations,BOD₅ and COD values were two to five times higher than theallowable regulatory maximum levels, respectively. About 4 kmfrom the headwaters, the average oxygen concentration was 4.7 mgL^-1, BOD₅ values were close to the standard limit (37 vs 40 mg L^-1), and COD values were above the standard limits(252 vs 160 mg L^-1). Highest concentrations were detectedduring peak tomato production. During this time, settleable solidswere also elevated, two to six times the regulatory standard.Coliform bacteria densities were found in excess of the standardlimits at all sites. Near the head of the river, mean fecalcoliform (22,571 MPN mL^-1) and streptococci densities (14,214 MPN mL^-1) surpassed the regulatory level of 120 and 20 MPN mL^-1, respectively, reflecting the input from the urbansettings of Sarno and agricultural fields. The heavy metaldissolved concentrations were low at all sampling sites. Most ofthe analyzed contaminants increased when comparend with 1985data. BOD₅ increased 5 to 10 times at sites near the urbansettings of Scafati, Pompei and Castellamare di Stabia, whereasCOD increases were twofold at all sites. A decline of chromiumlevels was observed due to the recent effective treatment ofwaste water from the tanning plants.     

A Novel High Capacity Biofilm Reactor System for Treatment of Domestic Sewage

A lab-scale novel biofilm reactor system, Ultra-Compact Biofilm Reactor (UCBR), was studied to investigate its performance and operational characteristics for domestic sewage treatment. The reactor was operated at four different hydraulic retention times, namely, 90, 60, 30 and 15 min. The operating ranges of volumetric loading rates in terms of COD, BOD₅, NH⁺ ₄-N and TKN were 5.6-62.1 kg COD/m³ d, 2.6-32.5 BOD₅/m³ d, 0.6-3.2 kg NH⁺ ₄-N/m³ d and 0.82-6.2 kg TKN/m³ d, respectively. The COD, BOD₅ and NH⁺ ₄-N removal efficiencies at 90-min hydraulic retention time (HRT) and 60-min HRT could exceed 80%, 90% and 99%, respectively. The corresponding maximum biomass concentrations were 12.0 g/L and 15.0 g/L at 90-min HRT and 60-min HRT, respectively. At 30-min HRT, the biomass concentration increased to a maximum of 24.0 g/L. However, COD and BOD₅ removal efficiencies decreased to 75% and 80%, respectively, while the NH⁺ ₄-N nitrification efficiency decreased to only 25% to 30%. These observations suggested that high biomass concentration alone was not sufficient to provide a high removal capacity in a UCBR. Further reduction in HRT to 15 min led to an excessive biomass decline from 22.5 g/L to 4.0 g/L. On the whole, the UCBR was able to sustain COD removal and NH⁺ ₄-N conversion of up to 5.96-18.70 kg COD/m³ d and 0.73-1.00 kg NH⁺ ₄-N/m³ d, respectively.     

宿州市沱河段水质时间变化及影响因素研究

通过对宿州市沱河段沿岸实地调查,以沱河东关闸断面为采样点,分时段采集样品,并以沱河东关闸断面2004-2009年的连续监测资料为基础,对水质污染物主要指标进行了分析。监测的水质指标包括溶解氧(DO)、生化需氧量(BOD)、化学需氧量(COD)、氨氮(NH₃-N)、总氮(TN)、总磷(TP)。采用单因子评价,基于直观图解、线性趋势分析和季节性Kendall检验法,探究了沱河水质污染的年内及年际变化趋势,并分析影响水质变化的主要因素,提出了相关保护对策。结果表明:(1)年内水质变化显著,DO,NH₃-N和TP在冬季含量偏高,TN和COD在春、秋季含量较高,BOD在夏季含量偏高。(2)年际变化方面,BOD,NH₃-N和TN均呈显著下降趋势,COD呈不明显下降趋势,DO和TP无明显变化趋势。总体来说,宿州市沱河段水质状况处于不断改善之中。     

猪场废水厌氧消化液后处理技术研究及工程应用

猪场废水经过厌氧消化后，可生化性变差，BOD₅/COD仅为0.19，并且碳、氮倒置，比例严重失调，给后续好氧处理带来很大困难。采用序批式活性污泥法(SBR)工艺直接处理厌氧消化液，污染物的去除效果很差，COD仅去除8.31%，NH₃-N去除78.7％。通过改善厌氧消化液的可生化性和培养高效脱氮菌种等措施，COD、NH₃-N去除率改善显著，COD、BOD₅与SS的去除分别达到89.6%～93.4%、97.9%，95.6%，特别是对NH₃-N，达到了99%以上去除效率。将实验室结果应用于实际工程，也取得了好的效果，工程上SBR系统对猪场废水厌氧消化液的COD去除90%左右，出水COD基本上在300 mg/L以下。NH₃-N去除率大于99%，出水NH₃-N小于10 mg/L。BOD₅去除率大于98%，出水BOD₅小于20 mg/L。TN去除率大于90%。     

Heritability Estimates of Winter Hardiness in White Clover Based on Field and Laboratory Experiments

For testing of winter hardiness and to obtain estimates of heritability (h²) for this character, field experiments are the most common method. In order to develop a supplement to the field method, artificial freezing to test for freezing hardiness in the laboratory has been carried out. The purpose of the present study was to compare estimates of broad sense heritability (h² _b) for winter hardiness in white clover (Trifolium repens L.) based on an experiment in the field, and freezing hardiness based on a laboratory test. The plant material consisted of six local populations with origins between ca. 61°- and 70° northern Latitude. The northern related populations Nos. 06 and 22 showed the best winter hardiness in the field, while the more southern related population No. 38 showed the best freezing hardiness in the laboratory. The field data was generally more variable than the laboratory data. In the field, h² _b     

Application of an Air Ionization Device Using an Atmospheric Pressure Corona Discharge Process for Water Purification

Pesticides presently being discharged into the aquatic environment are not only toxic but also only partially biodegradable, they are not easily removed by conventional water treatment plants. Air ionization devices using an atmospheric pressure corona discharge process show great promise in improving degradation of chemical and biological contaminants in water purification plants. In order to assess the effectiveness of this air ionization apparatus, laboratory scale degradation experiments were carried out systematically in a bubble column reactor containing a variety of pesticides such as triazines, carbamates, phenyl urea derivates and chlorophenols relative to the addition of humic acid and inorganic chemicals as well as to pH variation. Chemical oxygen demand (COD) decreased with air ionization treatment and the rate of the biological oxygen demand related to this (BOD/COD) showed improved pesticide biodegradability. Changes in water toxicity were monitored by Daphnia- and Luminescence Bacteria tests. This novel water treatment process is shown to be a potent oxidation technique for persistent organic pollutants such as pesticides.     

Kinetic and Thermodynamic Studies of Chlorinated Organic Compound Degradation by Siderite-Activated Peroxide and Persulfate

The efficacy of two oxidant systems, iron-activated hydrogen peroxide (H₂O₂) and iron-activated hydrogen peroxide coupled with persulfate (S₂O₈ ^2?), was investigated for treatment of two chlorinated organic compounds, trichloroethene (TCE) and 1,2-dichloroethane (DCA). Batch tests were conducted at multiple temperatures (10–50 °C) to investigate degradation kinetics and reaction thermodynamics. The influence of an inorganic salt, dihydrogen phosphate ion (H₂PO₄ ^?), on oxidative degradation was also examined. The degradation of TCE was promoted in both systems, with greater degradation observed for higher temperatures. The inhibition effect of H₂PO₄ ^? on the degradation of TCE increased with increasing temperature for the iron-activated H₂O₂ system but decreased for the iron-activated hydrogen peroxide-persulfate system. DCA degradation was limited in the iron-activated hydrogen peroxide system. Conversely, significant DCA degradation (87% in 48 h at 20 °C) occurred in the iron-activated hydrogen peroxide-persulfate system, indicating the crucial role of sulfate radical (SO₄ ^??) from persulfate on the oxidative degradation of DCA. The activation energy values varied from 37.7 to 72.9 kJ/mol, depending on the different reactants. Overall, the binary hydrogen peroxide-persulfate oxidant system exhibited better performance than hydrogen peroxide alone for TCE and DCA degradation.     

The Effects of Hydraulic and Organic Loadings on the Performance of a Full-Scale Facultative Pond in a Temperate Climate Region (Argentine Patagonia)

This work focuses on the performance of a primary facultative pond, in a full-scale waste stabilization pond system, located in a temperate climate region (average air temperature in winter, 7.7°C; spring and autumn, 14.0°C; and summer, 19.9°C) in Puerto Madryn city??Argentine Patagonia (42°45??S; 65°05??W). Experimental work was conducted for 43?months in seven sampling points. During the experimental time frame, the influent flow rate increased from 12,000 to 15,500?m³/day; the surface organic loading ranged from 55 to 68?kg BOD₅/ha·day and the theoretical retention time decreased from 31 to 24?days. The results indicate that a primary facultative pond performing in this region, to keep predominant facultative conditions and acceptable filtered biochemical oxygen demand (BOD₅) removal, should be loaded with an organic loading rate of up to 60?kg BOD₅/ha·day. The flow and organic loading increase affected the ammonium removal process, extending the period time in which ammonium removal was less than 50% and nitrate was not detectable; at first, this period occurred during winter strictly and then covered part of autumn and part of spring, too. Ammonium removal was clearly temperature dependent and directly related to chlorophyll a and nitrate concentrations (i.e. higher ammonia removals were reported under summer conditions when chlorophyll a and nitrate concentrations were higher), but was not linked with high pH values. The ammonium volatilization as a predominant removal process could be discarded, while ammonium nitrification?Cdenitrification and algal nitrogen uptake seems to be the dominant mechanisms.     

BOD,COD and TOC studies of petroleum base cutting fluids

The biological oxidation criteria of 21 oil-in-water metal working lubricants have been examined using classical Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) analyses. The O₂ required by unacclimated sewage microorganisms ranged from 14 000 to 297 000 mg O₂ l^?1 lubricant. Based on the initial COD and/or TOC, the extent of biological oxidation ranged from 1.6 to 35.0% over the five day test period.     

Characteristics of Nitrous Oxide (N2O) Emissions from Intermittently-Aerated Sequencing Batch Reactors Treating the Separated Liquid Fraction of Anaerobically Digested Pig Manure

In this study, the N₂O emission from an intermittently aerated sequencing batch reactor (IASBR-1) treating the separated liquid fraction of anaerobically digested pig manure (SLAP) was investigated. The wastewater had chemical oxygen demand (COD) concentrations of 11,540?±?860?mg?l^?1, 5-day biochemical oxygen demand (BOD₅) concentrations of 2,900?±?200?mg?l^?1and total nitrogen concentrations of 4,041?±?59?mg?l^?1, with low COD:N ratios (2.9, on average) and BOD₅:N ratios (0.72, on average). Synthetic wastewater, simulating the SLAP with similar COD and nitrogen concentrations but with higher BOD₅ concentrations of up to 11,500?±?100?mg?l^?1, was treated in another identical reactor (IASBR-2) to compare the effects of carbon source on nutrient removals and N₂O emissions. In steady-state, soluble N₂O accumulated in the non-aeration periods, with the highest N₂O concentrations measured at the end of the non-aeration periods. There was a significant reduction in N₂O concentrations during the aeration periods with reductions occurring immediately on commencement of aeration. The mean N₂O emissions in an operational cycle were 253.6 and 205.3?mg for IASBR-1 and IASBR-2, respectively. During the non-aeration periods, only 8.3% and 8.4% of total N₂O emissions occurred in IASBR-1 and IASBR-2, respectively; while during the aeration periods, 91.7% and 91.6% of N₂O emissions took place in IASBR-1 and IASBR-2, respectively. The mean specific N₂O generation rates were 0.010 and 0.005?mg (g VSS·min)^?1 in the aeration periods, 0.024 and 0.021?mg (g VSS·min)^?1 in the non-aeration periods for IASBR-1 and IABSR-2, respectively. Mean nitrogen removal via N₂O emissions was 15.6% and 10.1% for IASBR-1 and IASBR-2, respectively. The IASBR-1 with low influent BOD₅ concentrations emitted and generated more N₂O.     

Innovative Technology of COD and BOD Reduction from Coffee Processing Wastewater Using Avocado Seed Carbon (ASC)

The study estimated the efficiency of Avocado seed carbon (ASC) for chemical oxygen demand (COD) and biochemical oxygen demand (BOD) reduction from coffee processing wastewater. It was performed under batch mode conditions to investigate the optimum operating conditions and efficiency for COD and BOD reduction with ASC compared with commercial activated carbon (CAC). Adsorption isotherm study was also performed and it was found that the values of regression coefficient (r ²), adsorption capacity (k), and adsorption intensity (1/n) for COD and BOD reduction with ASC were comparable to those of CAC. Under optimum operating conditions, the maximum percentage reduction of COD and BOD concentration using ASC was 98.28% and 99.19%, respectively and with CAC was 99.12% and 99.45%, respectively and hence adsorption capacity of ASC is comparable with that of CAC. Thus, this technique may be a good option for treatment of domestic wastewater.