某有机化工企业危废仓库挥发性有机物的治理案例

来源广、浓度低、成分复杂的挥发性有机物(volatile organic compounds, VOCs)一直是大气污染防治的难点。以某化工企业危废仓库有机废气治理项目为例,设计采用"水洗+气雾分离+活性炭吸附"的组合工艺对危废仓库内的VOCs进行处理并达标排放。该工艺具有运行稳定,维护成本低等优点,可以为易产生低浓度、成分复杂的VOCs的化工企业原料仓库、危废仓库、污水处理站等提供切实可行、高效治理的参考依据。     

How to run biotransformations⿿At the optimal temperature control or isothermally? Mathematical assessment

The optimization of batch biotransformations has attracted attention in recent years because, in the face of growing competition, it is a natural choice for reducing production costs and improving product quality. However, in many cases the effects achieved as a result of optimization may be less valuable in comparison to those obtained when the process is carried out in possibly the simplest way. Hence, in the present paper a mathematical analysis was proposed to assess if application of the optimal temperature control (OTC) in biotransformations with deactivation of native enzyme is justified. At the same time a simple biotransformation process accomplished in the presence of a native enzyme undergoing deactivation independent of or dependent on substrate concentration was considered. The estimation has been done on the basis of the indicator expressed by a quotient of the process duration under time-optimal temperature control and that for isothermal conditions (IC). It has been found that application of the OTC is justified when the biotransformation process is characterized by a high value of the quotient of activation energies referring to enzyme deactivation and for enzymatic reaction which is running up to attain a high conversion and low final enzyme activity. Moreover, application of the OTC in biotransformations with a parallel enzyme deactivation enables significant reduction of process duration in comparison to those with deactivation independent of substrate concentration. Framework proposed here can be helpful for evaluation of economic aspects of the optimally controlled process.     

Developing multiple regression models from the manufacturer's ground-source heat pump catalogue data

The performance of ground-source heat pumps (GSHP), often expressed as Power drawn and/or the COP, depends on several operating parameters. Manufacturers usually publish such data in tables for certain discrete values of the operating fluid temperatures and flow rates conditions. In actual applications, such as in dynamic simulations of heat pump system integrated to buildings, there is a need to determine equipment performance under operating conditions other than those listed. This paper describes a simplified methodology for predicting the performance of GSHPs using multiple regression (MR) models as applicable to manufacturer data. We find that fitting second-order MR models with eight statistically significant x-variables from 36 observations appropriately selected in the manufacturer catalogue can predict the system global behavior with good accuracy. For the three studied GSHPs, the external prediction error of the MR models identified following the methodology are 0.2%, 0.9% and 1% for heating capacity (HC) predictions and 2.6%, 4.9% and 3.2% for COP predictions. No correlation is found between residuals and the response, thus validating the models. The operational approach appears to be a reliable tool to be integrated in dynamic simulation codes, as the method is applicable to any GSHP catalogue data.     

A population-based iterated greedy algorithm for the delimitation and zoning of rural settlements

In this paper we present a Population-Based Iterated Greedy (PBIG) algorithm for delimiting and zoning rural settlements. Each cadastral plots is allocated to a category (traditional–historical, common or none) considering restrictions such as the characteristics of the existing edifications and the building density. Since the problem has multiple solutions, heuristic search algorithms, as PBIG, are a good strategy to solve it. Besides the resolution of the problem according to the requirements of the laws, our work explores also new methods of delimitation. The comparison between both types of solutions can help to improve the current methodology. The algorithm, implemented using the Java programming language and integrated into an open-source GIS software, has been tested in rural settlements with different morphological characteristics, providing adjustable solutions to the specific needs of each rural settlement.     

Diet-derived vicilins detected in eggs laid by a double-mated female Callosobruchus maculatus originate from nuptial gifts donated by both male partners

The eggshell and the cement that attaches the eggs of the seed-beetle Callosobruchus maculatus to the seeds of cowpea (Vigna unguiculata) contain vicilins, the main storage protein found in seeds. These proteins are derived from both males and females, which originally sequester them during the larval phase from their seed hosts. In this test, females received vicilin from different males during mating as a seminal nuptial gift, and transmitted this sequestered blend of proteins to the eggs. The presence of vicilin in the cement and eggshell was demonstrated by light microscopy and Western blotting. Quantification using ELISA showed that the concentration of vicilin from seminal vesicles of a virgin male is approximately double that measured following the first copula to a virgin female, suggesting that the investment of vicilin by the males is very important. This is the first demonstration showing that at least two different males can make a direct contribution of a sequestered protein which is used in oogenesis.     

Multi-wheat-model ensemble responses to interannual climate variability

We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981–2010 grain yield, and we evaluate results against the interannual variability of growing season temperature, precipitation, and solar radiation. The amount of information used for calibration has only a minor effect on most models' climate response, and even small multi-model ensembles prove beneficial. Wheat model clusters reveal common characteristics of yield response to climate; however models rarely share the same cluster at all four sites indicating substantial independence. Only a weak relationship (R² ≤ 0.24) was found between the models' sensitivities to interannual temperature variability and their response to long-term warming, suggesting that additional processes differentiate climate change impacts from observed climate variability analogs and motivating continuing analysis and model development efforts.     

A Theme‐Based Seminar on Environmental Sustainability Improves Participant Satisfaction in an Undergraduate Summer Research Program

We analyzed seven years of pre‐program and post‐program survey data to evaluate the Clarkson University Research Experience for Undergraduates (REU) Site Program in Environmental Science and Engineering, and evaluated whether our program was successful at meeting the intended outcome of increasing participants' likelihood of attending graduate school and pursuing a career in science or engineering research or education. We also evaluated how participant satisfaction in the program changed with the addition of a weekly seminar on environmental sustainability that was intended to improve participants' understanding of the societal value of their research projects. Participant satisfaction in the Clarkson REU Program was high, and increased after the addition of the sustainability seminar. Participants' intention to attend graduate or professional school increased after participating in the program, but their intention to pursue a career in science or engineering research declined. Over 60 percent of participants eventually attended graduate or professional school.     

Effect of method of preparation on properties of temperature and pH-sensitive gels: Chemical crosslinking versus irradiation with e-beam

Two problems that have impeded a broader application of polyelectrolytic smart polymers are their low speed of response and their faulty behavior in the presence of salts. To contribute to the solution of those problems we prepared two series of gels based on N-isopropylacrylamide (NIPAAm) containing ampholytic units using chemical crosslinking methods and electron beam irradiation. In the first method, the gels prepared contain NIPAAm, N-N′-dimethylaminoethylmethacrylate (DMAEM) and a methacrylate of the ortho-, meta- or para-benzoic acid, respectively, to impart amphoteric behavior. They were crosslinked using N-N′-methylenebisacrylamide (BIS) as crosslinker by standard free-radical techniques. In the second method aqueous solutions containing mixtures of polyNIPAAm and charge balanced copolymers of DMAEM with the methacrylates of the ortho-, meta- and para-benzoic acid, respectively, prepared previously, were irradiated by e-beam. Both series were characterized by DSC, mechanical compression and swelling–shrinking tests in deionized water, buffers solutions at different pH-values and in water having different salt concentrations. The results show that the gels prepared by irradiation have a swelling degree up to four times higher than that of the gels prepared by chemical crosslinking, furthermore, their shrinking velocity is up to twenty times higher than that of gels prepared by chemical crosslinking. The results also showed that the gels prepared by chemical crosslinking using monomers show only polyelectrolyte behavior, while those prepared by e-beam irradiation of polymer solutions show in fact amphoteric behavior; while all gels retained their temperature sensitivity between 32 and 39 °C.     

Photoheterotrophic growth of purple non-sulfur bacteria on Tris Acetate Phosphate Yeast extract (TAPY) medium and its hydrogen productivity in light under nitrogen deprivation

In this study, an active photoheterotrophic growth of purple non-sulfur bacteria (PNSB) on Tris Acetate Phosphate Yeast extract (TAPY) medium is reported. TAPY medium is a modified TAP medium supplemented with filter sterilized yeast extract (0.3 g L⁻¹) and vitamin B12. Heterotrophic growth of PNSB on nitrogen replete TAPY medium in dark could be obtained but much slower than that in light where cells could grow but without formation of pigments. The medium showed high potency for hydrogen production under nitrogen deprivation in light by Rhodobacter sphaeroides DSM 5864. Through using TAPY medium, 1 mole of acetate provided as glacial acetic acid produced 0.819 mole of hydrogen gas by R. sphaeroides on nitrogen deprived TAPY medium (initial pH 7 adjusted by HCl) with a maximum H₂ production rate of (0.669 mmol H₂ h⁻¹ L⁻¹) obtained at 42 h after start of fermentation. Repeated-batch hydrogen production could be achieved with high efficiency for three cycles by supplementing the nitrogen deprived culture with filter sterilized sodium acetate at the end of the log hydrogen production phase of each cycle. The medium was also applicable for photoheterotrophic growth in light and heterotrophic growth in dark of other PNSB namely Rhodobacter capsulatus JCM-21090 and Rhodospirillum rubrum DSM 467. Although R. rubrum could actively grow on TAPY medium under nitrogen deprivation in light, it was the lowest in hydrogen production compared to R. sphaeroides and R. capsulatus. The active growth of R. rubrum on nitrogen deprived TAPY medium suggests its possible use for producing biodegradable plastic polymers better than hydrogen. The results suggest that it's possible to use TAPY medium for growth and producing variable bioproducts by PNSB in future studies and applications. The repeated-batch hydrogen production by R. sphaeroides on nitrogen deprived TAPY medium is promising for large-scale applications of hydrogen production industry by only sequential supply with sodium acetate to the culture for three rounds of batch fermentation. This is the first report in using TAPY medium for growth and hydrogen production by PNSB.