Characterization of Phosphate-Free Detergent Powders Incorporated with Palm C16 Methyl Ester Sulfonate (C16MES) and Linear Alkyl Benzene Sulfonic Acid (LABSA)

Laboratory and pilot scale investigations were carried out on phosphate-free detergent (PFD) formulations comprising binary anionic surfactants of C16 palm methyl ester sulfonates (C16MES) and linear alkyl benzene sulfonic acid (LABSA) with the aim of maximizing the incorporation of C16MES into low density detergent powders without compromising the detergency and other significant properties. Initial laboratory experiments revealed that the detergent powder resulting from C16MES/LABSA with a 50:50 ratio and pH 7–8 has acceptable detergency stability over 1 week of accelerated ageing test at 50 °C and 85 % relative humidity. Subsequent experiments were carried out in a 5-kg/h-capacity pilot spray dryer using PFD formulations of C16MES/LABSA over the whole range of weight ratios under the same pH of 7–8. The concentration of the detergent slurry and cleaning performance (detergency, foaming ability and wetting power) of the resulting spray dried detergent powder (SDDP) were evaluated. C16MES/LABSA in a 40:60 ratio was selected as the ideal formulation based on its optimum detergent slurry concentration and comparable cleaning performance against the control formulation. Further environmental tests have confirmed that SDDP obtained from the ideal formulation is readily biodegradable (60 % in 13 days) and exhibits low eco-toxicity properties (LC₅₀ of 11.3 mg/L).     

Performance of an up-flow anaerobic stage reactor (UASR) in the treatment of pharmaceutical wastewater containing macrolide antibiotics

The performance of an up-flow anaerobic stage reactor (UASR) treating pharmaceutical wastewater containing macrolide antibiotics was investigated. Specifically, it was determined whether a UASR could be used as pre-treatment system at an existing pharmaceutical production plant to reduce the antibiotics in the trade effluent. Accordingly, a UASR was developed with an active reactor volume of 11 L being divided into four 2.75 L stages. Each stage of the reactor was an up-flow sludge blanket reactor and had a 3-phase separator baffle to retain biomass. The reactor was fed with real pharmaceutical wastewater containing Tylosin and Avilamycin antibiotics and operated with step-wise increases in the reactor organic loading rate (OLR) from 0.43 to 3.73 kg chemical oxygen demand (COD) m(-3)d(-1), and then reduced to 1.86, over 279 days. The process performance of the reactor was characterised in terms of its COD removal, Tylosin reduction, pH, VFA production, methane yield and sludge washout. At a total hydraulic retention time (HRT) of 4 d and OLR of 1.86 kg COD m(-3)d(-1), COD reduction was 70-75%, suggesting the biomass had acclimated to the antibiotics. Furthermore, an average of 95% Tylosin reduction was achieved in the UASR, indicating that this antibiotic could be degraded efficiently in the anaerobic reactor system. In addition, the influence of elevated Tylosin concentrations on the UASR process performance was studied using additions of Tylosin phosphate concentrate. Results showed similar efficiency for COD removal when Tylosin was present at concentrations ranging from 0 to 400 mgL(-1) (mean removal over this range was 93%), however, at Tylosin concentrations of 600 and 800 mgL(-1) there was a slight decline in treatment efficiency at 85% and 75% removal, respectively.     

Efficiency of carbon sorbents in mitigating polar herbicides leaching from tropical soil

Clean Technologies and Environmental Policy - Imidazolinones are a group of herbicides with high potential of leaching and long half-lives that are posing a threat to water resources’ quality...     

Review on fermentative biohydrogen production from water hyacinth,wheat straw and rice straw with focus on recent perspectives

Hydrogen (H₂) is often considered as the best option to store energy coming from renewable sources. Hydrogen production from lignocellulosic biomass via fermentation offers low cost and environmental friendly method in terms of energy balance and provides a sustainable pathway for utilization of huge amount of unused biomass. In this regard, special attention on potential of different lignocellulosic biomass is required. In this paper, the fermentative hydrogen production from three carbohydrates-rich biomass: water hyacinth, wheat straw and rice straw is comprehensively reviewed. In other point of view, usage of H₂ has a 10% growth annually that will reach to 8–10% of total energy in 2025. Furthermore, research on recent trends of fermentative hydrogen production is crucial and vital. However, the majority of the published researches in the last decade confirmed that some challenges exists which are the process optimization, effecting parameters and commercialization aspects.