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Lead and Zinc Smelting Wastewater Treatment and Reclamation by Coagulation-Flocculation-Sedimentation, Ultrafiltration and Reverse Osmosis Technique
Issue:
Volume 6, Issue 4, December 2021
Pages:
94-105
Received:
26 August 2021
Accepted:
15 September 2021
Published:
30 September 2021
Abstract: The typical smelting wastewater is with characteristics of high concentration of TDS, conductivity, heavy metal ions, and low concentration of COD. The ultrafiltration (UF) and reverse osmosis (RO) is an attractive technology to reclaim and reuse this kind of wastewater. In this work, Coagulation-flocculation-sedimentation (CFS) and multi-media filter (MMF) was used as the pretreatment processes. UF, RO and concentration RO (CRO) processes was applied as the advanced treatment processes to reclaim the smelting wastewater. To enlarge the recovery of RO and CRO units, the influences of increasing the feed temperature by waste heat from the smelting plant and the feed pressure by change the operating frequency of the high pressure pumps were investigated. The optimize operation parameters of RO and CRO units were obtained. To understand the operation CIP cycle time of UF, RO and CRO membrane units in a long term operation, the trans-membrane pressure (TMP) and permeate flux difference were investigate. Good system operation stability, permeate flux recovery after CIP and qualified treated water were obtained in the recommend operation parameters. The results of this work can benefit to the designing of reclaiming the smelting wastewater by UF-RO-CRO approach within the Lead and Zinc smelting industrial application.
Abstract: The typical smelting wastewater is with characteristics of high concentration of TDS, conductivity, heavy metal ions, and low concentration of COD. The ultrafiltration (UF) and reverse osmosis (RO) is an attractive technology to reclaim and reuse this kind of wastewater. In this work, Coagulation-flocculation-sedimentation (CFS) and multi-media fil...
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Assessment of Some Pollutant Gases in Selected Cities in Crude Oil-Rich Delta State Nigeria
Ifezue Obianuju Appolonia,
Aiyesanmi Ademola Festus,
Ogunjobi Kehinde,
Sunday Oluwatoyin Michael
Issue:
Volume 6, Issue 4, December 2021
Pages:
106-113
Received:
18 August 2021
Accepted:
31 August 2021
Published:
5 October 2021
Abstract: Delta state is one of the petroleum-producing states in Nigeria where upstream and downstream exploration activities tend to pollute the environment. While soil and water pollution are regularly monitored, there is a dearth of information on the impact of exploration and related industries on air quality. This study investigated the levels of pollutant gases including ozone, nitrogen dioxide, sulphur dioxide, hydrogen sulphide and ammonia in ambient air samples selected cities (Warri, Ughelli, Sapele and Ugbenu) in Delta state, Nigeria. The concentration of the gases was determined using air sampling instruments equipped with appropriate sensors for selective to each gas. Meteorological parameters were also obtained concurrently during sampling. The results obtained showed that the average concentrations of SO2, H2S and NH3 were all below the National ambient air quality standard (NAAQS) and Federal ministry of environment (FMEnv) regulatory limits. However, the mean concentration of O3 and NO2 obtained exceeded the NAAQS and FMEnv regulatory limits of 0.007 ppm, 0.05 ppm and 0.04 ppm – 0.06 ppm respectively. Ugbenu, the control station did not record any value for the pollutant gases. This is as a result of non-availability of industrial activities that emit these pollutant gases in the area. There was a clear seasonal variation, with higher values recorded mostly in the dry season. The field data agreed with global model data on the pollutant gases. The information from this study provides information on the level of these pollutant gases and how the various industrial process may impact their concentration in this region.
Abstract: Delta state is one of the petroleum-producing states in Nigeria where upstream and downstream exploration activities tend to pollute the environment. While soil and water pollution are regularly monitored, there is a dearth of information on the impact of exploration and related industries on air quality. This study investigated the levels of pollu...
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Optimization of Selected Pyrolysis Parameters in Pyroligneous Acid Production Rate and Quality from Acacia Twigs
Baqe Sharu Doti,
Samwel Nyakach,
Jane Nyaanga,
Oscar Ingasia,
Daudi Nyaanga
Issue:
Volume 6, Issue 4, December 2021
Pages:
114-123
Received:
25 September 2021
Accepted:
12 October 2021
Published:
21 October 2021
Abstract: Biomass material is a renewable source of energy which are readily available and being produced in large quantities as most of it goes to waste. These materials can be recovered through pyrolysis process in order to produce usable products like biochar and pyroligneous acid. These products can be used as bio-fertilizer and bio-pesticides. The aim of this research was to optimize the selected pyrolysis parameters in pyroligneous acid production rate and quality from acacia twigs. The parameters varied were feedstock moisture content (10%, 15% and 20%), Pyrolysis residence time (90 minutes, 135 minutes and 180 minutes) and chimney inclination angle (30°, 45° and 60°). Smoke condensation system also known as heat exchanger was used for condensing the pyrolysis smoke in to pyroligneous acid. Response Surface Methodology technique by using Box-Behnken Design was used to develop a mathematical equation to predict the production rate and quality of the pyroligneous acid with respect to varied parameters which was later optimized to determine the optimal conditions for pyroligneous acid production rate and quality. The pyroligneous acid quality was based on its pH and density. The combined optimal conditions were 20% feedstock moisture content, 137.27 min pyrolysis residence time and 60° chimney inclination angle resulting to a density of 1.03 gcm-3, pH of 3.01 and production rate of 0.19 kg/min (26.08%). The mathematical equation developed had a composite desirability of 0.9663 for pyroligneous acid production rate at p-value ≤0.05 which made it viable. These research findings are of importance since pyrolysis of the biomass material will maintain a balance in the environment and also serve as a source of livelihood when the products are sold as bio-fertilizer or bio-pesticides.
Abstract: Biomass material is a renewable source of energy which are readily available and being produced in large quantities as most of it goes to waste. These materials can be recovered through pyrolysis process in order to produce usable products like biochar and pyroligneous acid. These products can be used as bio-fertilizer and bio-pesticides. The aim o...
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Production of Bio-methane Gas as Renewable Energy Source - A Review
Rasha Jame,
Omaymah Alaysuy,
Noha Omer,
Nada Mofadi Alatawi,
Mawia Hassan Elsaim
Issue:
Volume 6, Issue 4, December 2021
Pages:
124-130
Received:
9 September 2021
Accepted:
22 November 2021
Published:
29 November 2021
Abstract: The present review aims to provide an up-to-date summary of bio-methane (CH4) gas production, which use as is a renewable energy source. Burned bio-methane gas used for water heating, space heating, drying, or cooking. CH4 is also used in an automotive to produce both heat and electricity. The bio-methane gas is produced by anaerobic digestion (AD) technology of food waste, agricultural waste, municipal waste, green waste, manure, and sewage. AD technolog is promising technology; having the potential to convert several bio-masses into bio-gas rich with methane gas, which is alternative to fossil fuels. The hydrolysis, acidogenesis, acetogenesis, and methanogenesis are essential steps of AD process. The steps are proceeding by different kind of bacteria such as, acidogenic, acetogenic, and methanogenic bacteria. An effective process to increase the productivity of an anaerobic digestion process by combining it with a microbial electrosynthesis system (MES) was developed. Percentage compositions of CH4 from anaerobic digestion of a different feedstock were between 50% - 84%. The various physical, chemical, physiochemical and, biological pretreatments methods were applied to break the complex biomass into easily digested components. The AD system has many advantages, like low energy consumption, low nutrient and chemical requirement, improved sanitation, pathogens reduction, reduction of disease transmission, greenhouse emissions and nitrous oxide emissions reduction, etc. And some of the anaerobic digestion disadvantages are a long start-up, high buffer requirements for pH controlling, higher sensitivity of microorganisms to pH and temperature, etc. More advantages and disadvantages are discussed in this review. In the future, will be solutions to problems that limits production yield.
Abstract: The present review aims to provide an up-to-date summary of bio-methane (CH4) gas production, which use as is a renewable energy source. Burned bio-methane gas used for water heating, space heating, drying, or cooking. CH4 is also used in an automotive to produce both heat and electricity. The bio-methane gas is produced by anaerobic digestion (AD)...
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A Comprehensive Review of Biomethanation of Urban Food Waste in Nairobi City County, Kenya
Hope Baxter Chamdimba,
Isaiah Omosa,
Simon Mdondo Wandera
Issue:
Volume 6, Issue 4, December 2021
Pages:
131-144
Received:
16 November 2021
Accepted:
16 December 2021
Published:
29 December 2021
Abstract: Organic waste in Nairobi City County accounts for 58-63% of the municipal solid waste generated. Food waste is at the center of urban waste management in the city as it accounts for 64% of the recoverable material. The city is estimated to have a food waste generation per capita of 6.1 kilogram per year, which accumulates to 29.4 thousand tons yearly. It transpires that upstream activities of the food supply chain, mainly production, postharvest loss, processing and distribution are the major food waste hotspots, accounting for 95% of the food waste in developing countries. Additionally, downstream activities of the food supply chain show that hotels, restaurants and super markets are the most important food waste hotspots. Such food waste hotspots should become the primary targets for resource recovery in a circular economy. Currently, the exploitation of food waste for animal feed and composting is growing in Nairobi City County, which signifies that food waste is becoming a valuable urban resource that can be traded, thus creating employment. However, the application of food waste for energy recovery through anaerobic digestion is limited in the city due to lack of source separation of municipal solid waste. On average, food waste has a biomethane potential of 508.45 ml CH4 /g VS. This implies that 29.4 thousand tons of food waste generated in Nairobi City County has the potential to yield 10.5 million m3 of methane, and will demand a digestion volume of 4,299 m3. Using global case studies of electricity generation from biogas, it is estimated that food waste in the city potentially yields 1.38 MW of electricity. In addition, about 26.1 thousand tons of bioslurry can be recovered from the digestion of food waste, which can be used for urban agriculture. Regardless of the liquefied petroleum gas enjoying a tax exemption, biogas at 32.78 USD per gigajoule of delivered energy demonstrates to be more economical, and this can be enhanced by upgrading it. The removal of liquefied petroleum gas from tax-exempt goods through the Finance Act 2020, and an addition of 16% value added tax on the fuel by Kenya Revenue Authority that became effective on 1st July, 2021 favors biofuels such as methane. However, long term realization of methane generation potential in NCC demands the adoption and implementation of more friendly biofuels policies and regulatory frameworks in the country.
Abstract: Organic waste in Nairobi City County accounts for 58-63% of the municipal solid waste generated. Food waste is at the center of urban waste management in the city as it accounts for 64% of the recoverable material. The city is estimated to have a food waste generation per capita of 6.1 kilogram per year, which accumulates to 29.4 thousand tons year...
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