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Established approaches for the management of contaminants include things like membrane separation, ion exchange, precipitation, transformation and biosorption. Of all of these technologies, biosorption has lots of features that include low running expenditures, very effective detoxification of toxicants at low levels, low quantity of removal components as well as does not require nutrient needs as with bacterial-based remediation, theaforementioned being restricted to the existence of heavy metals and other toxicants. The biosorption of BDE-3 on spent black tea was successfully fitted to three models—pseudo-1st, pseudo-2nd and Elovich. Statistical analysis based on root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), accuracy factor (AF), bias factor (BF), corrected AICc Bayesian Information Criterion (BIC), (Akaike Information Criterion) and Hannan–Quinn information criterion (HQC) showed that the pseudo-second order model is the best model giving valuable parameters such as the equilibrium sorption capacity qe and the pseudo-second-order rate constant, k2, which can be further utilized in isothermal modelling analysis. Further analysis is needed to provide proof for the chemisorption mechanism usually tied to this kinetic.

Several models are available to model the effect of temperature on the growth rate of microorganism on substrates. One of the models is Arrhenius and is very popular due to it having few parameters. An apparent activation energy based on the Arrhenius plot on the growth on acrylamide by Pseudomonas sp. strain DRYJ7 on acrylamide is reported for the first time. The bacterium was grown in minimal salts media supplemented with 1000 mg/L of acrylamide as a nitrogen source and glucose as the carbon source. The plot of ln m (specific growth rate) against 1/T for growth on acrylamide was carried out spanning the range of temperature from 10 to 35 oC. Regression analysis from 10–20 oC results in an activation energy of 14.96 kJ mol-1. A relative 10 ˚C increase in the surrounding temperature, usually results in doubling the reaction rate, with corresponding Q10 value of 1.8, which is the approximate value for a number of biological reactions. The Q10 values, determined from the Arrhenius plot of 2.17 and a theta value of 1.03 obtained in this work, are within the normal range for many biological values. This is the first time that values for the activation energy, Q10 and theta for the growth of a bacterium on acrylamide is reported.

Existing techniques for the treatment of pollutants include membrane separation, ion exchange, precipitation, and transformation and biosorption. Of all this technology, biosorption has several positive aspects which include low operating expenses, very efficient detoxification of toxicants at low concentrations, low amount of disposal materials and does not need nutrient requirements as in bacterial-based remediation, the latter of which is limited by the presence of heavy metals and other toxicants. The reduction of copper by Durvillaea antarctica, an alga that lives as south as the Antarctic region can be an efficient and low-cost tool for remediation of copper. In this study, the kinetics of copper biosorption is modelled according to the pseudo-first order, pseudo-second order and Elovich models. Statistical analysis based on root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), bias factor (BF), accuracy factor (AF) and corrected AICc (Akaike Information Criterion) showed that the pseudo-second order model is the best model. Kinetic analysis using the pseudo-second order model at 0.15 mM copper gave a value of equilibrium sorption capacity qe of 0.150 mmol g-1 (95% confidence interval from 0.149 to 0.151) and a value of the pseudo-second-order rate constant, k2 of 8.605 (95% confidence interval from 7.016 to 10.194).

Glyphosate is a heavily usage herbicide in Malaysia. It inhibits amino acids synthesis in plants and microorganisms with the latter inhibition makes it difficult to find biodegradation microorganism as a bioremediation agent for this pesticide. One candidate for bioremediation is biosorption that has several positive aspects which include low operating expenses, very efficient detoxification of toxicants at low concentrations, low amount of disposal materials and does not need nutrient requirements as in bacterial-based remediation, the latter of which is limited by the presence of heavy metals and other toxicants. The biosorption of glyphosate on palm oil fronds activated carbon can be an efficient and low-cost tool for remediation of glyphosate. The absorption kinetics data of biosorption isotherm on the biosorption of glyphosate on oil palm fronds activated carbon were analyzed using modelled according to various models ranging from one to five parameters models such as Henry, Langmuir, Dubinin-Radushkevich, Freundlich, BET, Toth, Sips, Fritz-Schlunder IV, Baudu and Fritz-Schlunder V, and fitted using non-linear regression. Only the Henry, Langmuir, Freundlich, BET and Toth models can fit the data. Statistical analysis based on root-mean-square error (RMSE), adjusted coefficient of determination (adjR2), bias factor (BF), accuracy factor (AF), corrected AICc (Akaike Information Criterion) showed that the Langmuir model is the best model. The calculated Langmuir parameters bL value of 0.002 L/mg (95% confidence interval from 0.001 to 0.004) and qmL value of 255.5 mg/g (95% confidence interval from 160.90 to 350.11).

An affinity chromatography column to purify AChE was developed using procainamide as the ligand coupled with the epoxy activated Sephacryl-S1000 as the modified matrix. From this study, the procainamide matrix was found to be capable of binding acetylcholinesterase (AChE) from the brain of Pangasius pangasius efficiently, with percentage of yield of approximately 51.97% and a purification fold of 7.52. The value for Michaelis-Menten (Km app) was 0.1265 mM and maximal velocity (Vmax app) of the partially purified enzyme was 0.6981 µmol/min/mg, with a substrate specificity in the sequence of— acetylthiocholine iodide (ATC) > propinylcholine iodide (PTC) > butyrylcholine iodide (BTC). This strongly suggest that using this column, AChE can be purified successfully and efficiently. SDS-PAGE indicated a reduced band intensity, indicating that the procainamide-based affinity chromatography column produces acceptable partially purified enzyme adequate for the application in the rapid detection of carbamate and organophosphate (OP) at the large scale.

Probit analysis is generally employed in the studies of toxicology, to determine the concentration of toxicant causing 50% mortality or LC50 value. The response of an organism is generally binomial and is typically sigmoidal in property. The Probit value can be calculated by hand or can be calculated through the use of a computer via software, the latter utilising the maximum likelihood method which is a more precise estimation of the parameters. When a published result failed to produce the 95% confidence interval, the results can be re-evaluated using software including SPSS. In this study, the LC50 value of the effect of ferrous sulphate to the fish Catla catla is re-evaluated using the Probit modelling exercise via the SPSS software, which gave an LC50 value of 8.271 p.p.m., with a 95% confidence interval from 7.353 to 9.189 p.p.m. The sub lethal concentration (SLC) for ferrous sulphate, which is one fourth of the LC50 value was 2.06 p.p.m