Potential for potable water savings by combining the use of rainwater and greywater in houses in southern Brazil

Research on rainwater and greywater have been performed all over the world as a way of promoting potable water savings. The main objective of this article is to evaluate the potential for potable water savings by using rainwater and greywater in two houses in southern Brazil. An economic analysis is performed to evaluate the benefits of using rainwater and greywater either separately or together. Results indicate that the potential for potable water savings in both houses range from 33.8% (house B) to 36.6% (house A), considering that water for toilet flushing and washing machine does not need to be potable. By using rainwater, the potable water savings in house A would be 35.5% and in house B, 33.6%. When greywater is considered alone, potable water savings are lower, i.e., 30.4% in house A and 25.6% in house B. As for the use of rainwater and greywater combined, the potable water savings are 36.4% in house A and 33.8% in house B. The three systems that were investigated seem not to be cost effective as the payback periods were very high (above 17 years), but the greywater system was the most attractive one. The main conclusion that can be made from the research is that there needs to be government incentives in order to promote the use of rainwater or greywater in houses in southern Brazil.     

Rainwater tank capacity and potential for potable water savings by using rainwater in the residential sector of southeastern Brazil

Rainwater has been used in many countries as a way of minimising water availability problems. In Brazil, it has been reported that the potential for potable water savings by using rainwater may range from 48% to 100% depending on the geographic region. In southeastern Brazil, water availability is about 4500 m³ per capita per year, but it is predicted to be lower than 1000 m³ per capita per year from about 2100 onwards. The main objective of this article is to evaluate the potential for potable water savings by using rainwater in 195 cities located in southeastern Brazil. Rainwater tank sizes are also assessed for some cities in order to evaluate the ideal tank capacity as a function of potable water demand and rainwater demand. Results indicate that average potential for potable water savings range from 12% to 79% per year for the cities analysed. Ideal rainwater tank capacities for dwellings with low potable water demand range from about 2000 to 20,000 litres depending on rainwater demand. For dwellings with high potable water demand, ideal rainwater tank capacities range from about 3000 to 7000 litres. The main conclusion drawn from the research is that the average potential for potable water savings in southeastern Brazil is 41%. It was also concluded that rainwater tank capacity has to be determined for each location and dwelling as it depends strongly on potable water demand and rainwater demand.     

Role of environmental pollution in prevalence of antibiotic resistant bacteria in aquatic environment of river: case of Musi river,South India

Antibiotic resistance in clinical settings has been studied from last few decades but the possibility of development of antibiotic resistance at polluted environmental sites is also of concern. In developing countries, the major source of antibiotic contamination in surface water is improper disposal of effluents from industries, hospitals and domestic waste water treatment plants. The antibiotic pollution combined with other environmental pollution factors exerts selective pressure on environmental microbes, driving evolution and resulting in the spread of antibiotic resistance in a local to global scale. Present study aimed to determine the proliferation of ciprofloxacin resistant bacteria in aquatic environment of a river which is heavily impacted by industrial effluents. Correlation analyses were performed to evaluate the impact of anthropogenic factors. Statistical analysis evaluated the effect of fluoroquinolones, heavy metals, total organic carbon and total nitrogen on the levels of resistant culture in samples from the natural settings.     

Studies of the halogenation of dissolved organic material during the chlorination of saline cooling waters, using the model compound resorcinol

When resorcinol is chlorinated in seawater, the variety of reaction products formed is controlled by competing equilibria involving chlorination of the resorcinol and conversion of oxidising species to hypobromous acid by exchange with naturally occurring bromide. When bromide is present in a molar excess over added chlorine, chlorination of resorcinol is only favoured under high pH conditions; under more acid conditions however, bromination occurs at the expense of chlorination. Increasing chlorine levels leads to ring cleavage and the production of trihalomethanes (haloforms).     

新疆伊犁盆地南缘天然放射性水平评价

本文根据新疆伊犁盆地南缘1∶2.5万地面γ能谱测量中的铀、钍、钾含量数据,对新疆伊犁盆地南缘地表介质的天然放射性进行了研究和评价。测量结果显示,该地区地表介质中放射性核素²³⁸U、²³²Th和⁴⁰K的比活度,分别为6.14～2584.64 Bq/kg、2.86～105.63 Bq/kg、11.58～2190.83 Bq/kg。γ射线空气吸收剂量率均值为75.56 nGy/h,低于全国(81.50 nGy/h)和世界(80.00 nGy/h)的平均值;内、外照射指数和年有效剂量都在国家限量标准控制范围内。研究区局部放射性水平相对偏高,与含铀地层露头受自然动力和人类活动等作用下铀元素扩散有关;由于含铀地层露头规模有限,其对放射性环境的影响具有强度小、范围小、不均匀特征。     

Energy efficiency benchmarks and the performance of LEED rated buildings for Information Technology facilities in Bangalore, India

This paper provides a summary of an energy benchmarking study that uses performance data of a sample of Information Technology facilities in Bangalore. Information provided by the sample of occupiers was used to develop an Energy Performance Index (EPI) and an Annual Average hourly Energy Performance Index (AAhEPI), which takes into account the variations in operation hours and days for these facilities. The EPI and AAhEPI were modelled to identify the factors that influence energy efficiency. Employment density, size of facility, operating hours per week, type of chiller and age of facility were found to be significant factors in regression models with EPI and AAhEPI as dependent variables. Employment density, size of facility and operating hours per week were standardised and used in a separate regression analysis. Parameter estimates from this regression were used to normalize the EPI and AAhEPI for variance in the independent variables. Three benchmark ranges - the bottom third, middle third and top third - were developed for the two normalised indices. The normalised EPI and AAhEPI of LEED rated building, which were also part of the sample, indicate that, on average, LEED rated buildings outperform the other buildings.     

Radon measurement studies in workplace buildings of the Rawalpindi region and Islamabad Capital area, Pakistan

A survey concerning measurement of the indoor radon levels has been carried out in 105 workplaces of the Rawalpindi region and Islamabad Capital Territory using CR-39 based radon detectors. The main objective of this study was to assess the health hazard due to the indoor radon. CR-39 based NRPB type detectors were installed in offices/rooms located on first floors, ground floors and basements and were exposed to indoor radon for six months. The measured indoor radon concentration in the buildings surveyed ranged from 12 ± 5 to 293 ± 19 Bq m⁻³ with an overall mean value of 64 ± 32 Bq m⁻³. The highest mean radon concentration (113 ± 48 Bq m⁻³) was observed in the offices located in basements of the Rawalpindi city. The overall average annual effective dose in the studied workplaces was estimated to be 0.61 ± 0.30 mSv. The mean annual effective doses in basements, ground floor and first floor were found to be 0.87 ± 0.34 mSv, 0.55 ± 0.28 mSv, and 0.47 ± 0.29 mSv, respectively. These values are less than the action level recommended by International Commission on Radiological Protection.     

Occurrence and removal of pharmaceuticals and endocrine disruptors in South Korean surface, drinking, and waste waters

Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) was used to measure the concentrations of 14 pharmaceuticals, 6 hormones, 2 antibiotics, 3 personal care products (PCPs), and 1 flame retardant in surface waters and wastewater treatment plant effluents in South Korea. Tris (2-chloroethyl) phosphate (TCEP), iopromide, naproxen, carbamazepine, and caffeine were quite frequently observed (>80%) in both surface waters and effluents. The analytes of greatest concentration were iopromide, TCEP, sulfamethoxazole, and carbamazepine. However, the primary estrogen hormones, 17alpha-ethynylestradiol and 17beta-estradiol, were rarely detected, while estrone was detected in both surface water and wastewater effluent. The elimination of these chemicals during drinking water and wastewater treatment processes at full- and pilot-scale also was investigated. Conventional drinking water treatment methods were relatively inefficient for contaminant removal, while efficient removal (approximately equal to 99%) was achieved by granular activated carbon (GAC). In wastewater treatment processes, membrane bioreactors (MBR) showed limited target compound removal, but were effective at eliminating hormones and some pharmaceuticals (e.g., acetaminophen, ibuprofen, and caffeine). Membrane filtration processes using reverse osmosis (RO) and nanofiltration (NF) showed excellent removal (>95%) for all target analytes.     

Studies of the halogenation of dissolved organic material during the chlorination of saline cooling waters,the model compounds resorcinol diacetate and resorcinol dimethyl ether

Chlorination of seawater containing resorcinol diacetate or resorcinol dimethyl ether results primarily in the formation of brominated products. At low chlorine concentrations (cf. model compound), ring substitution products dominate whilst at higher chlorine levels ring cleavage occurs and trihalomethanes are produced. Electrophilic chlorination of the model compounds in seawater therefore appears to be slower than the formation of HOBr by oxidation of naturally occurring bromide. The influence of solution acidity on the nature and extent of halogenation is described and reaction mechanisms postulated.     

Evaluation of a novel hybrid inorganic/organic polymer type material in the arsenic removal process from drinking water

The objective of this paper is the evaluation of a hybrid inorganic/organic polymer type material based on hydrated ferric oxide (HFO), in the adsorption process of arsenic oxyanions from contaminated waters used as drinking water. The study includes rapid small-scale column tests conducted in continuous flow operation in order to assess the arsenic removal capacity in various conditions. Thus it was evaluated the influence of some competing ions like silicate and phosphate on As(V) adsorption and the influence of feed water pH in the removal process of As(V) and As(III) species. Based on the As/pH variation in time at different feed water pH (5, 7 and 9), a possible sorption mechanism that fits the experimental data was suggested. The regeneration and re-use of the hybrid adsorbent was studied in the presence and in the absence of the contaminant ions. The novel hybrid material is very selective towards arsenic oxyanions even though the presence of silica and phosphate reduces the adsorption capacity.     

水在中国传统建筑环境中的生态应用

通过对水在中国传统建筑环境中的低技术生态应用手法的总结，以及对乡土建筑技术的再认识，探讨了“水”在现代建筑中生态运用的趋势，以最终实现创造舒适的人居环境的目标。     

Assessment of physical properties and pH of selected surface waters in the northern part of Western Siberia

One of the undisputed natural resources of Western Siberia is a countless number of surface waters. They can be found in the form of all sorts of lakes from the smallest thermokarst ones with a surface area of only 1 m² to large post-glacial lakes or high-mountain lakes. Besides, the world’s largest wetland is the peat bogs in the Western Siberia. Other equally impressive forms of surface waters are streams and rivers with the Ob River at the head making it the seventh largest river in the world. All these water bodies pose a tremendous challenge for research into their ecology.     

以生态环保安全的角度谈太原市排水规划

结合太原市总体规划中提出的将太原市建设为生态城市的规划目标,介绍了太原市排水体制采用近远期结合的规划方式,并详细的分析了排水规划,从而有效地保护水环境,促进水资源的开发利用。     

Occurrence of seven artificial sweeteners in the aquatic environment and precipitation of Tianjin,China

Seventy water samples, including wastewaters, tap waters, fresh surface waters, coastal waters, groundwaters, and precipitation samples, from Tianjin, China, were analyzed for seven commonly used artificial sweeteners (ASs). The concentrations of the investigated ASs were generally in the order of wastewater treatment plant (WWTP) influent > WWTP effluent > surface water > tap water > groundwater ≈ precipitation, while the composition profiles of ASs varied in different waters. Acesulfame, sucralose, cyclamate, and saccharin were consistently detected in surface waters and ranged from 50 ng/L to 0.12 mg/L, while acesulfame was the dominant AS in surface and tap waters. Aspartame was found in all of the surface waters at a concentration up to 0.21 μg/L, but was not found in groundwaters and tap waters. Neotame and neohesperidin dihydrochalcone were less frequently detected and the concentrations were low. The concentrations of the ASs in some of the surface waters were of the same order with those in the WWTP influents, but not with the effluents, indicating there are probably untreated discharges into the surface waters. The ASs were detected in precipitation samples with high frequency, and acesulfame, saccharin, and cyclamate were the predominant ASs, with concentrations ranging from 3.5 ng/L to 1.3 μg/L. A gross estimation revealed that precipitation may act as a source for saccharin and cyclamate in the surface environment of Tianjin city. Moreover, the presence of ASs in the atmosphere was primarily assessed by taking 4 air samples to evaluate their potential source in precipitation.     

Long-term performance of bicarbonate-form anion exchange: removal of dissolved organic matter and bromide from the St. Johns River, FL, USA

The goal of this research was to evaluate the long-term performance of magnetic ion exchange (MIEX) treatment using bicarbonate as the mobile counter ion (i.e., MIEX-HCO₃) and sodium bicarbonate for regeneration. This work is important because there are many unknowns concerning the affinity and regeneration efficiency of bicarbonate-form anion exchange, whereas chloride-form anion exchange (i.e., MIEX-Cl resin) is well-studied. Raw water samples were collected approximately two times per month for one year from a single location on the St. Johns River (SJR), FL, USA. The SJR is characterized by high concentrations of dissolved organic carbon (DOC; 12-26 mg C/L) and bromide (550-1100 μg/L), and is being considered as an alternative drinking water supply. Jar tests were conducted using MIEX-HCO₃ resin, and MIEX-Cl resin was used as a baseline for comparison. The same batch of MIEX-HCO₃ and MIEX-Cl resin was used for the entire study, which was accomplished by regenerating the resins after each jar test in concentrated solutions of sodium bicarbonate and sodium chloride, respectively, and resulted in 21 regeneration cycles. Maximum removal efficiency was achieved with fresh MIEX-HCO₃ resin and virgin MIEX-Cl resin. Both forms of fresh/virgin MIEX resin also had the same affinity sequence with sulfate ≈ UV-absorbing substance > DOC > bromide. The removal efficiency of both forms of MIEX resin decreased as the number of regeneration cycles increased, with MIEX-HCO₃ resin showing 7-18% lower removals than MIEX-Cl resin after 21 regeneration cycles. The affinity sequence of regenerated MIEX-HCO₃ and MIEX-Cl resins differed from fresh resin with UV-absorbing substances > DOC > sulfate > bromide. Scanning electron microscopy and simulated MIEX-HCO₃ treatment under rapidly changing water quality were also used to improve the understanding of bicarbonate-form anion exchange. The major contribution of this research is a systematic study of the extended use of bicarbonate-form anion exchange resin in the context of affinity, regeneration efficiency, and changing water quality.     

Changing from intermittent to continuous water supply and its influence on service level benchmarks: a case study in the demonstration zone of Nagpur,India

A dearth in infrastructure and operations significantly reduces the expected benefits of safe drinking water provision. Intermittent water supplies are characterized by inefficient demand and supply management owing to operational inadequacies eventually causing physical deterioration of infrastructure and inconvenience to consumers, resulting in consumer dissatisfaction. Conversion from intermittent to continuous water supply was undertaken in a demonstration zone of Nagpur, India, with a population of about 150,000 people. Data related to the infrastructural, operational, managerial and financial capabilities were used to determine service level benchmarks (SLBs) — pre- and post-intervention — to quantify the improvement due to continuous water supply interventions. The post-intervention data analysis clearly indicated substantial improvement in post-intervention SLBs, consequently paving the way for the conversion of the water supply of the entire city to continuous mode.     

西秦岭泽库毛海-夏德日花岗岩年代学、地球化学及构造环境分析

研究区位于同德-泽库弧后盆地,岩浆活动以印支期中酸性岩浆岩为主。本研究利用LA-ICP-MS锆石U-Pb同位素测年方法获得毛海-夏德日花岗岩体年龄(236.39±0.96) Ma。该岩体具有富碱、富钾的特征,为高钾钙碱性系列;富集大离子亲石元素和轻稀土元素。综合前人研究成果,认为岩体属于Ⅰ型花岗岩,继承了早期岛弧火山岩的部分特征,与阿尼玛卿-勉略残余海盆在晚古生代末期向北俯冲消减有关。     

节能节水技术在建筑给排水中的应用分析

本文主要简单介绍了节能节水技术在建筑给排水中应用的重要性,通过对现阶段建筑用水中存在的问题的分析,探讨了节能节水技术在建筑给排水中的有效应用,以满足建筑用水的要求。