Phytoremediation Potential of Some Macrophytes from a Car Wash Stream in Buea, South Western Cameroon

Phytoremediation is a cheap and environmentally friendly technique in which green plants in situ are used to clean the soil, sediments and water of heavy metals. This study investigated the phytoremediation potential of six naturally occurring macrophytes from Nange (a stream in Buea municipality where cars have been driven into and washed for over 20 years). Plant samples were collected before and after car wash, then analysed for copper, zinc, lead and cadmium accumulation. There was an increase in concentration of all the four heavy metals in water after carwash point, with Zn having the highest concentration (0.27 mg/L). Mean concentration of the heavy metals in the water showed that Zn and Pb had the highest concentrations (0.24 mg/L each) while the least concentration was obtained in Cu (0.12 mg/kg). Heavy metal concentrations in the sediments were higher after car wash point than before. Cadmium had the highest concentration (5.58 mg/kg) while Cu had the least (0.75 mg/kg). Ludwigia peruviana had the highest BAFs for all the heavy metals (22.95 for Cu, 33.41 for Zn, 21.79 for Pb and 7.85 for Cd). Species with the leasts were: Anubias barteri for Cu (7.16), Polygonum persicaria for Zn (14.28), Rorippa nasturtium-aquaticum for Pb (11.60) and Vallisneria spiralis for Cd (1.98). L. peruviana had the highest BAC values (Cu = 10.11, Zn = 14.73, Pb = 11.39, Cd = 3.85) and BCF values (Cu = 12.84, Zn = 18.67, Pb = 10.40, Cd = 4.00). A. barteri had the highest TF (Cu = 1.49, Zn = 1.27, Cd = 1.99) except for Pb where both A. barteri and L. peruviana each had a TF of 1.10. While all the six plants were found to be good accumulators of the heavy metals, L. peruviana showed remarkable efficiency indicating that the species is a good candidate for cleaning such environments.

An Assessment of Authorized Car Wash Site Suitability Using a GIS-Based Modeling in Khartoum City, Sudan

The goal of this study is to assess the ability of existing car washing stations in Khartoum City using an ArcMap suitability modeling tool. Methods: In Khartoum, an increasing number of vehicle wash stations were opened every day. The main criteria are street, the slope, the hospitals, the police station, and the school, which have been used to build a model of suitability based on weight overlay in ArcGIS 10.4. The findings revealed two evaluation tendencies. One tendency involves business centers that are located on main roads but are adjacent to residential areas, while another involves business centers that have rezoned residential plots without consideration for ideal site requirements for the environment. There are locations that would be appropriate for vehicle wash centers, according to the final suitability map. On a scale of 1 to 5, less than 30% of the study area is considered suitable for a new car wash regarding class 5. On the other hand, significant areas are available for car wash development in the second value of suitability 4, but as second-ranked suitability. The assessment was accomplished by comparing the final suitability map of car washing centers to the layers which represented them.

Evaluation of Filter Material for Treatment of Different Types of Wastewater

This paper presents an evaluation of the suitability of a mixed absorbent based on peat and carbon-containing ash for treatment of wastewaters, such as wastewater from professional car washes, landfill leachate and stormwater. This mixture is very attractive, since it is a low-cost material which has a capability to simultaneously remove inorganic as well as organic pollutants. Since any filter material eventually needs to be replaced either due to saturation of pollutants or reduced infiltration capacity, it is important that the residual can be handled at low cost and that the environment will be not impaired. The tested mixture, used in filter beds, showed low leaching values and high simultaneous removal efficiency of metals as Cu, Cd and Pb, non-polar organic compounds such as PCBs. Polar organic compounds as phenols were also efficiently removed by microbial and/or chemical degradation in the studied treatment plants with the filter bed acted as a biofilter. Filter material used for three years in a full-scale plant for leachate treatment and four years in treatment plants for wastewater from car washes, had sufficiently high energy content indicating that energy recovery is a good alternative for handling after its usage. Results show that the presented filter material is excellent for both small scale applications (e.g. treatment systems for car wash wastewater with capacity between 250 - 3000 m3 per year) as well as large-scale applications (e.g. filter systems for landfill leachates with capacity above 30,000 m3 per year).