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Direct and indirect effects of wastewater use and herd environment on the occurrence of animal diseases and animal health in Pakistan Texto completo
2017
Elahi, Ehsan | Zhang, Liqin | Abid, Mohamed | Javed, Muhammad Tariq | Xinru, Han
The use of wastewater for rearing domestic animals is a common phenomenon in most of the developing countries like Pakistan that face a serious shortage of freshwater resources. However, most of the literature has only focused on the indirect effects of wastewater use on animal health or productivity, and literature on the direct effects of wastewater use is rare. Therefore, this study aims to investigate the direct and indirect effects of wastewater usage on the prevalence of animal diseases and animal health in Pakistan. The study is based on a household-level survey of 360 domestic water buffalo herds collected from 12 districts of Punjab Province, Pakistan. We tested the prevalence of the animal’s diseases, animal’s health, and wastewater-use preference with various econometric tools, such as the Poisson, negative binomial, and logistic regressions. The findings of the study show that the majority of the farmers use wastewater for buffalo bathing due to the shortage of freshwater resources. Results explore the prevalence of diseases such as clinical mastitis, tick infestation, and foot and mouth disease at the farm level significantly associated with buffalo bathing in the wastewater. Moreover, bathing in wastewater pre- and post-milking also plays a role in the occurrence of diseases. Particularly, if the buffalo’s access to wastewater for bathing is within 60 min after milking, the probability of the animals being exposed to mastitis is higher. Furthermore, on investigation, a number of factors are found, such as the distance to the water source, power shortage, groundwater availability, and the education of farmers that influence farmers’ behavior of letting their animals take a bath in wastewater. Moreover, the use of different preventive measures improves the animal’s health.
Mostrar más [+] Menos [-]Parasites and pollution: the effectiveness of tiny organisms in assessing the quality of aquatic ecosystems, with a focus on Africa Texto completo
2017
Gilbert, Beric Michael | Avenant-Oldewage, Annemariè
The aquatic environment represents the final repository for many human-generated pollutants associated with anthropogenic activities. The quality of natural freshwater systems is easily disrupted by the introduction of pollutants from urban, industrial and agricultural processes. To assess the extent of chemical perturbation and associated environmental degradation, physico-chemical parameters have been monitored in conjunction with biota in numerous biological monitoring protocols. Most studies incorporating organisms into such approaches have focussed on fish and macroinvertebrates. More recently, interest in the ecology of parasites in relation to environmental monitoring has indicated that these organisms are sensitive towards the quality of the macroenvironment. Variable responses towards exposure to pollution have been identified at the population and component community level of a number of parasites. Furthermore, such responses have been found to differ with the type of pollutant and the lifestyle of the parasite. Generally, endoparasite infection levels have been shown to become elevated in relation to poorer water quality conditions, while ectoparasites are more sensitive, and exposure to contaminated environments resulted in a decline in ectoparasite infections. Furthermore, endoparasites have been found to be suitable accumulation indicators for monitoring levels of several trace elements and metals in the environment. The ability of these organisms to accumulate metals has further been observed to be of benefit to the host, resulting in decreased somatic metal levels in infected hosts. These trends have similarly been found for host–parasite models in African freshwater environments, but such analyses are comparatively sparse compared to other countries. Recently, studies on diplozoids from two freshwater systems have indicated that exposure to poorer water quality resulted in decreased infections. In the Vaal River, the poor water quality resulted in the extinction of the parasite from a site below the Vaal River Barrage. Laboratory exposures have further indicated that oncomiracidia of Paradiplozoon ichthyoxanthon are sensitive to exposure to dissolved aluminium. Overall, parasites from African freshwater and marine ecosystems have merit as effect and accumulation indicators; however, more research is required to detail the effects of exposure on sensitive biological processes within these organisms.
Mostrar más [+] Menos [-]A novel biocoagulant agent from mushroom chitosan as water and wastewater therapy Texto completo
2017
Adnan, Oday | Abidin, ZurinaZ. | Idris, Azni | Kamarudin, Suryani | Al-Qubaisi, MothannaSadiq
A new commercial cationic polyelectrolyte chitosan (CM), obtained from the waste of mushroom production, was examined using models of water and wastewater namely kaolin and palm oil mill effluent (pome). As it is biocompatible, widely available, and economically feasible, chitosan mushroom has high potential to be a suitable replacement for alum. Also, it can be a promising alternative to chitosan obtained traditionally from Crustaceans due to its higher zeta potential and homogeneity based on the raw material required for its production. A wide range of coagulant dose (5–60 mg l⁻¹) and wastewater pH (2–12) were taken into account to find the optimal conditions of coagulation. The optimal doses are 10 and 20 mg l⁻¹ at best pH (11 and 3) when treated with kaolin and palm oil mill effluent, respectively, while 1200 mg l⁻¹ of alum was not enough to reach the efficiency of chitosan mushroom. On the other hand, the optimum dose of chitosan mushroom (20 mg l⁻¹) at pH 3 of pome produced (75, 73, and 98%) removal of chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS), respectively. The significant potential of chitosan mushroom was proved by zeta potential measurement. Indeed, it possesses the highest zeta potential (+70 mV) as compared to the traditional chitosan produced from crustaceans. In short, chitosan mushroom as a biocoagulant is eco-friendly and it enhances water quality that meets the requirements of environmental conservatives.
Mostrar más [+] Menos [-]Removal of DDE by exploiting the alcoho-phobic interactions Texto completo
2017
Köse, Kazım | Köse, Dursun Ali
DDE (1,1-bis-(4-chlorophenyl)-2,2-dichloroethene), which is a commonly used pesticides in agriculture, has harmful effects on human health. Therefore, the removal of this substance from the drinking water and the soil is essential. Since DDT (1,1″-(2,2,2-Trichloroethane-1,1-diyl) bis(4-chlorobenzene)) is derivation of DDE, the presence of DDT can be monitored by the detection of DDE present in the environment. Herein, we report on the development of aspartic acid-incorporated poly(2-hydroxyethyl methacrylate-L-aspartic acid) [poly(HEMA-MAsp)] cryogel for the removal of DDE from aqueous solutions for the first time in the literature. The synthesized cryogels were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), an N₂ adsorption method, elemental analysis, and swelling test. The separation experiments were carried out via a batch system to get the optimum adsorption conditions including pH, interaction time, initial DDE concentration, and temperature. The desorption and the reusability results revealed that there was no significant decrease in the DDE adsorption capacity of the cryogels after five adsorption-desorption cycles. The maximum DDE adsorption capacity of poly(HEMA-MAsp) cryogels was found to be 31.51 mg DDE/g polymer for 50 mg DDE/L solution.
Mostrar más [+] Menos [-]Climate change mitigation: comparative assessment of Malaysian and ASEAN scenarios Texto completo
2017
Rasiah, Rajah | Ahmed, Adeel | Al-Amin, Abul Quasem | Chenayah, Santha
This paper analyses empirically the optimal climate change mitigation policy of Malaysia with the business as usual scenario of ASEAN to compare their environmental and economic consequences over the period 2010–2110. A downscaling empirical dynamic model is constructed using a dual multidisciplinary framework combining economic, earth science, and ecological variables to analyse the long-run consequences. The model takes account of climatic variables, including carbon cycle, carbon emission, climatic damage, carbon control, carbon concentration, and temperature. The results indicate that without optimal climate policy and action, the cumulative cost of climate damage for Malaysia and ASEAN as a whole over the period 2010–2110 would be MYR40.1 trillion and MYR151.0 trillion, respectively. Under the optimal policy, the cumulative cost of climatic damage for Malaysia would fall to MYR5.3 trillion over the 100 years. Also, the additional economic output of Malaysia will rise from MYR2.1 billion in 2010 to MYR3.6 billion in 2050 and MYR5.5 billion in 2110 under the optimal climate change mitigation scenario. The additional economic output for ASEAN would fall from MYR8.1 billion in 2010 to MYR3.2 billion in 2050 before rising again slightly to MYR4.7 billion in 2110 in the business as usual ASEAN scenario.
Mostrar más [+] Menos [-]Hydrodehalogenation of hexachloro- and hexabromobenzene by metallic calcium in ethanol, in the presence of Rh/C catalyst Texto completo
2017
Katayama, Yumi | Aoyagi, Mitsuru | Matsumoto, Takuya | Harada, Hiroyuki | Simion, Alina M. | Egashira, Naoyoshi | Mitoma, Yoshiharu | Simion, Cristian
Both hexachlorobenzene and hexabromobenzene were successfully hydrodehalogenated to the monohalogenated derivative and ultimately to benzene (which was subsequently reduced to cyclohexane) using a mixture of metallic Ca, ethanol, and Rh/C, by simple stirring in diethyl ether, at room or mild temperature (60 °C). Various experiments were performed in order to assess the role of the solvent and Rh/C catalyst, as well as for elucidating the reaction pathway.
Mostrar más [+] Menos [-]Total and settling velocity-fractionated pollution potential of sewer sediments in Jiaxing, China Texto completo
2017
Zhou, Yongchao | Zhang, Ping | Zhang, Yiping | Li, Jin | Zhang, Tuqiao | Yu, Tingchao
Sewer sediments and their associated contaminant released along with wet-weather discharges pose potential pollution risks to environment. This paper presents total characteristics of sediments collected from Jiaxing, China. Size distribution and concentrations of volatile solids (VS) and four metals (Pb, Cu, Zn, Cr) of sediment samples from seven land use categories were analyzed. Then, the sediment samples were graded five fractions according to its settling velocity through the custom-built settling velocity-grading device. Sediment mass and pollution load distribution based on settling velocity were also assessed. The results show that there are relatively high level of heavy metal load in the sediment of separated storm drainage systems in Jiaxing, especially for the catchment of residential area (RA), road of developed area (RDA), and industrial area (IA). Although grain size follows a trend of increasing along with settling velocity, the methods of settling velocity grading are meaningful for stormwater treatment facilities with precipitation. For all land use categories, the pollution concentrations of the three lower settling velocity-fractionated sediment are relatively consistent and higher than others. Combined with mass distribution, the pollution percentage of fraction with different velocities for seven land use categories were also evaluated. Based on it, the statistical conclusion of design target settling velocity to different pollution load removal rates are drawn, which is helpful to guide design of on-site precipitation separation facilities.
Mostrar más [+] Menos [-]Thermochemical conversion of waste tyres—a review Texto completo
2017
Labaki, Madona | Jeguirim, Mejdi
A review of the energy recovery from waste tyres is presented and focuses on the three thermochemical processes used to valorise waste tyres: pyrolysis, gasification, and combustion/incineration. After recalling the chemical composition of tyres, the thermogravimetric behaviours of tyres or their components under different atmospheres are described. Different kinetic studies on the thermochemical processes are treated. Then, the three processes were investigated, with a particular attention given to the gasification, due to the information unavailability on this process. Pyrolysis is a thermochemical conversion to produce a hydrocarbon rich gas mixture, condensable liquids or tars, and a carbon-rich solid residue. Gasification is a form of pyrolysis, carried out at higher temperatures and under given atmosphere (air, steam, oxygen, carbon dioxide, etc.) in order to yield mainly low molecular weight gaseous products. Combustion is a process that needs a fuel and an oxidizer with an ignition system to produce heat and/or steam. The effects of various process parameters such as temperature, heating rate, residence time, catalyst addition, etc. on the energy efficiency and the products yields and characteristics are mainly reviewed. These thermochemical processes are considered to be the more attractive and practicable methods for recovering energy and material from waste tyres. For the future, they are the main promising issue to treat and valorise used tyres. However, efforts should be done in developing more efficient technical systems.
Mostrar más [+] Menos [-]A brief review and evaluation of earthworm biomarkers in soil pollution assessment Texto completo
2017
Shi, Zhiming | Tang, Zhiwen | Wang, Congying
Earthworm biomarker response to pollutants has been widely investigated in the assessment of soil pollution. However, whether and how the earthworm biomarker-approach can be actually applied to soil pollution assessment is still a controversial issue. This review is concerned about the following points: 1. Despite much debate, biomarker is valuable to ecotoxicology and biomarker approach has been properly used in different fields. Earthworm biomarker might be used in different scenarios such as large-scale soil pollution survey and soil pollution risk assessment. Compared with physicochemical analysis, they can provide more comprehensive and straightforward information about soil pollution at low cost. 2. Although many earthworm species from different ecological categories have been tested, Eisenia fetida/andrei is commonly used. Many earthworm biomarkers have been screened from the molecular to the individual level, while only a few biomarkers, such as avoidance behavior and lysosomal membrane stability, have been focused on. Other aspects of the experimental design were critically reviewed. 3. More studies should focus on determining the reliability of various earthworm biomarkers in soil pollution assessment in future research. Besides, establishing a database of a basal level of each biomarker, exploring biomarker response in different region/section/part of earthworm, and other issues are also proposed. 4. A set of research guideline for earthworm biomarker studies was recommended, and the suitability of several earthworm biomarkers was briefly evaluated with respect to their application in soil pollution assessment. This review will help to promote further studies and practical application of earthworm biomarker in soil pollution assessment.
Mostrar más [+] Menos [-]Adsorptive properties of alluvial soil for arsenic(V) and its potential for protection of the shallow groundwater among Changsha, Zhuzhou, and Xiangtan cities, China Texto completo
2017
Chen, Hongwei | Mei, Jinhua | Luo, Yueping | Qiu, Anni | Wang, Huan
The study area is among Changsha, Zhuzhou, and Xiangtan cities, which was under agricultural use and natural conditions about 10 years ago and now is becoming part of the metropolis because of the urban expansion. This study aims to investigate the mechanisms and capabilities of the local alluvial soil layer for protecting the local shallow groundwater from arsenic pollution by field surveys and batch experiments. The field surveys showed that there was an acidic tendency of the groundwater, and phosphate, nitrate, and arsenic in the groundwater significantly increased comparing to their reference values. It indicates that the disturbance of the former agricultural land due to the change of land use may be responsible for these changes. From the experimental results, the maximum adsorption capacity of the soil for As(V) was as low as 0.334 mg/g, and lower As(V) adsorption capacities were obtained at higher As(V) concentration, higher pH, and lower temperature. The presence of H₂PO₄ ⁻ and SiO₃ ²⁻ posed negative, while HCO₃ ⁻ slight positive, and SO₄ ²⁻, NO₃ ⁻ and Cl⁻ negligible influences on the As(V) adsorption. The surface-derived organic matter played a negative role in the adsorption process, and low specific surface area influenced adsorption capacity of the soil. The study reveals that the local soil layer shows poor potential for protection of the local shallow groundwater from As(V) pollution, and the change trends of the groundwater environments due to more intensive anthropogenic activities will further weaken this potential and increase the risk of the groundwater contamination.
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