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Bioplastics are alternatives of conventional petroleum-based plastics. Bioplastics are polymers processed from renewable sources and are biodegradable. This study aims at conducting an environmental impact assessment of the bioprocessing of agricultural wastes into bioplastics compared to petro-plastics using an LCA approach. Bioplastics were produced from potato peels in laboratory. In a biochemical reaction under heating, starch was extracted from peels and glycerin, vinegar and water were added with a range of different ratios, which resulted in producing different samples of bio-based plastics. Nevertheless, the environmental impact of the bioplastics production process was evaluated and compared to petro-plastics. A life cycle analysis of bioplastics produced in laboratory and petro-plastics was conducted. The results are presented in the form of global warming potential, and other environmental impacts including acidification potential, eutrophication potential, freshwater ecotoxicity potential, human toxicity potential, and ozone layer depletion of producing bioplastics are compared to petro-plastics. The results show that the greenhouse gases (GHG) emissions, through the different experiments to produce bioplastics, range between 0.354 and 0.623 kg CO2 eq. per kg bioplastic compared to 2.37 kg CO2 eq. per kg polypropylene as a petro-plastic. The results also showed that there are no significant potential effects for the bioplastics produced from potato peels on different environmental impacts in comparison with poly-β-hydroxybutyric acid and polypropylene. Thus, the bioplastics produced from agricultural wastes can be manufactured in industrial scale to reduce the dependence on petroleum-based plastics. This in turn will mitigate GHG emissions and reduce the negative environmental impacts on climate change.

SummaryThe German government has adopted a law that requires sewage plants to go beyond the recovery of phosphorus from wastewater and to promote recycling. We argue that there is no physical global short‐ or mid‐term phosphorus scarcity. However, we also argue that there are legitimate reasons for policies such as those of Germany, including: precaution as a way to ensure future generations’ long‐term supply security, promotion of technologies for closed‐loop economics in a promising stage of technology development, and decrease in the current supply risk with a new resource pool.

Use of a pilot-scale fixed-film bioreactor was investigated for remediation of bromate contamination within groundwater. Bromate reduction with stoichiometric production of bromide was observed, providing supporting evidence for complete reduction of bromate with no production of stable intermediates. Reduction of 87-90% bromate from an influent concentration of 1.1 mg L(-1) was observed with retention times of 40-80 h. Lower retention times led to decreases in bromate reduction capability, with 11.5% removal at a 10 h retention time. Nitrate reduction of 76-99% from a 30.7 mg L(-1) as NO(3)(-) influent was observed at retention times of 10-80 h, although an increase in nitrite production to 2.7 mg L(-1) occurred with a 10 h retention time. Backwashing was not required, with the large plastic packing media able to accommodate biomass accumulation without decreases in operational efficiency. This study has provided proof of concept and demonstrated the potential of biological bromate reduction by fixed-film processes for remediation of a bromate contaminated groundwater source.

Abstract A small reverse osmoisis (RO) plant supplied by a photovoltaic (PV) power supply has been installed at the island of Gran Canaria. On behalf of this system the feasibility of small PV-RO systems (1 m3/d) is investigated. The RO-plant is described in detail concerning its technical specifications, its operation constraints and its energy demand. Furthermore the photovoltaic power supply is described in detail. With simulations it is shown how the system is designed to guarantee a reliability of more than 96% in the water supply. A brief economic analysis shows that the water production costs are still high (about 16 $/m3) but can be lowered in future.

The phosphate (P) fertilizer industry generates a highly hazardous and acidic wastewater. The present study reports the evaluation of an integrated precipitation and Enhanced Biological Phosphorus Removal (EBPR) process for the treatment of fertilizer plant wastewater and effluent detoxification, assessed by microtoxicity and seed germination tests. Effluent samples were collected from a local P fertilizer industry and were characterized by their high fluoride and P content. First, the samples were pre‐treated by precipitation of P and fluoride ions using hydrated lime. The resulting low‐fluoride and phosphorus effluent was then treated with the EBPR process to monitor the simultaneous removal of carbon, nitrogen, and phosphorus. Phosphorus removal included a two‐stage anaerobic/aerobic system operating under continuous flow. Pre‐treated wastewater was added to the activated sludge and operated for 160 days in the reactor. The operating strategy included increasing the organic loading rate from 0.3 to 1.2 g chemical oxygen demand (COD)/L day. The stable and high removal rates of COD, NH4+‐N, and PO43−‐P were then recorded. The mean concentrations of the influent were approximately 3600 mg COD/L, 60 mg N/L and 14 mg P/L, which corresponded to removal efficiencies of approximately 98%, 86%, and 92%, respectively. The microtoxicity of the treated wastewater was then monitored by LUMIStox and its phytotoxicity was investigated on cress, tomato, wheat, maize, ryegrass, and alfalfa seed germination. LUMIStox tests showed that treatment allowed a significant toxicity removal. Moreover, the untreated wastewater inhibited the species germination even when diluted 10 times, whereas a positive effect of treated wastewater was noticed. © 2013 American Institute of Chemical Engineers Environ Prog, 33: 463–471, 2014

Mercury (Hg) represents a growing environmental and health major concern. It originates from natural sources and mainly from anthropogenic processes and it is widely distributed in the natural media. According to the last Global Mercury Assessment (2013), annual global emissions from both sources were estimated to be from 5,000 to 8,000 metric tons per year. Among the different mercury species released to the environment, methylmercury (MeHg) is considered as the most toxic form due to its ability to bioaccumulate, being then threatening even at very low concentrations.Its presence depends onHg(II) bioavailability and global amount.This explains the urgent need to ensure a continuous Hg(II) monitoring. Many efforts have been made in order to develop reliable systems able to deliver quick data and to comply with low detection limits, in accordance with the threshold value delivered by the World Health Organization (1µg L-1/ 5 nM). Spectroscopic techniques such as CV-AFS and CV-AAS are routinely used for Hg(II) determination. Although these methods can afford good sensitivity and low concentrations determination, they require sample preparation step, complex procedures and expensive material, which limits their use for on-site measurements. In this context, electrochemical sensors present excellent candidates for in situ Hg(II) trace analysis, taking in account their numerous advantages compared to spectroscopic techniques: easier handling, simple procedure, low energy consuming, low cost material and portability. In this work, we will propose a new electrochemical approach aiming to conceive and optimize an electrochemical Hg(II) sensor. The method consists in the functionalization of a glassy carbon electrode (GC) with gold nanoparticles (AuNPs) and Diazonium Salts. The main idea is to combine the interesting properties of both AuNPs and Diazonium salts. AuNPs were chosen for their electrocatalytic effect, large surface area, mass transport enhancement and for the strong affinity to mercury which will improve the sensor sensitivity. On the other hand, diazonium salts are used to improve the sensor stability by anchoring the AuNPs to the GC surface. First, nanometricorganic layer were grafted of the polished GC surface, by electrochemical reduction of 1.5 mM4-thiophenol diazonium (SH) using Constant Potential Electrolysis (CPE) in 0.1 M HCl solution at -0.55 V for 300 seconds. Electrochemical characterization performed by Cyclic Voltammetry (CV) and redox probes (ferricyanide and hexaamineruthenium(III)) revealed a total suppression of the signal, confirming the formation of a continuous blocking layer. This was confirmed by Atomic Force Microscopy (AFM)used to estimate the layer thickness, which was found to be 4 nm. Second, AuNPs were electrodeposited, for the first time, onto the diazonium multilayer by CPE in NaNO3 solution containing 0.25 mM HAuCl4for 300 seconds. Once more, redox probes were used to characterize the resulting interface and a total signal restauration and enhancement was observed after AuNPs electrodeposition, which highlights the effective AuNPs onto the organic layers. Field emission gun scanning microscopy (FEG-SEM) was used to provided further evidence and to quantify particle size and density of the AuNPs deposits. Both size and density are dependent on the CPE duration. Small homogeneous AuNPs with 27±3 nm average diameter and 158 NPs/µm2density were observed when the CPE was carried out during 300 seconds, while larger particles with 63±6 nm average diameter and lower density (63 NPs/µm2) were obtained when a longer CPE duration (600 seconds) is used. Finally, AuNPs were activated by cyclic voltammetry in H2SO4 prior to Hg(II) detection in order to homogenize the surface and to rearrange the crystallographic plans of the AuNPs. Herein, the well-known gold oxides reduction peak was observed and used to calculate the electroactive surface area (ESA) of the functionlized electrode. The electrochemical response of the final generated GC/SH/AuNPs interface towards Hg(II) was recorded by Square Wave Anodic Stripping Voltammetry (SWASV) in 0.01 M HCl solution containing different amounts of Hg(II). The SWASV procedure consists on the Hg(II) preconcentration at the electrode surface followed by the preconcentrated Hg(0) reoxidation in Hg(II). Under optimized conditions, and for a preconcentration time of 300 seconds, a well-defined peak, corresponding to Hg(0) reoxidation, was observed around 0.5 V/ECS. The sensor showed a linearity range from 1 up to 10 nM and allowed to reach picomolar level. The stability in HCl, phosphate buffer and air was also studied over several weeks: Once a week, the activation procedure was performed and followed by Hg(II) determination in order to evaluate the analytical performances of the sensor over time. Finally, Hg(II) detection assays were conducted in natural water samples collected from different sampling points. Figure 1

Abstract Continuous bio-methanization of an energy crop, namely the beet silage, was investigated in this laboratory-scale work as mono-substrate, using a mesophilic biogas digester controlled by a fuzzy logic control (FLC) technique and without using any supplementing or buffering agent, despite the low pH of the substrate around 3.80. The temperature, pH, redox potential (ORP), daily biogas production and composition of digester biogas were continuously measured online. During the operation, the hydraulic retention time (HRT) varied between 24.8 and 9 days, as the organic loading rate (OLR) ranged from 2.6 to 4.7 g L −1 d −1 . The average pH, specific gas production rate (spec. GPR) and volumetric gas production rate (vol. GPR) were determined to be 7.12, 0.31 L g VS −1 d −1 and 1.084 L L −1 d −1 , respectively. The average methane (CH 4 ) content of digester biogas was about 56%. The FLC technique, which was developed at HAW Hamburg for anaerobic conversion of acidic energy crops to methane, determined the daily feeding volume (∼ OLR/HRT) for the biogas digester, depending on the feedback from online pH and methane measurements, and on the calculation of the spec. GPR. The spec. GPR was calculated by the corrected daily biogas production. Through online monitoring of pH, biogas production rate and composition, and by use of the FLC technique, the acidic beet silage could continuously be converted to biogas, without using manure or any other kind of buffering or supplementing agent(s). The lab-scale anaerobic biogas digester performed stable and safe, without encountering any problems of instability, as indicated by an adequate amount of buffering capacity, a VFA content below 0.5 g L −1 and a neutral pH range throughout the study.

Many cosmetic products are available in spray form. Even though the principal targets of these products are the skin and hair, spraying leads to the partitioning of the product between the target and the surrounding air. In the previous COLIPA study (Hall et al., 2007) the daily use of deodorant/antiperspirant (Deo/AP) in spray form was quantified in terms of the amount of product dispensed from the spray can, without specifically quantifying the product fraction reaching the skin during use. Results of the present study provide this additional information, necessary for a reliable safety assessment of sprayed Deo/AP products. In a novel experimental approach the information obtained from real-life movement analysis (automated motion imaging) of volunteers using their own products was integrated with the aerosol cloud sampling data obtained from the same products, leading to the computation of the product deposited on the skin. The 90th percentile values, expressed as percent deposition relative to the can weight loss after spraying, are 23.5% and 11.4% for ethanol-based and non-ethanol-based products, respectively. Additionally, the study has generated data on the skin area covered by the products, spray duration time, spray angle and spray distance from the skin.

Abstract Water management has a major impact in the solid polymer fuel cell on overall system power, cost and efficiency. Single cell and stack performance may be adversely affected by the formation of liquid water, the dilution of reactant gases by water vapour, or by the dehydration of the solid polymer membrane. Peak fuel cell power is achieved typically at current densities at which performance is limited by mass transport. Improved water management at higher current densities not only increases peak power and efficiency but changes the profile of the power curve resulting in improved stability near the peak power operating point. Fuel cell water management can be accomplished by a number of approaches which include system design, stack operating conditions, stack hardware and membrane electrode assembly design. A number of these techniques have been successfully applied to both single cells and stacks. However, the options available for water management have to be assessed from an overall engineered system point of view.