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Integrated Algae Pond Systems (IAPS) are a derivation of the Oswald-designed Algal Integrated Wastewater Pond Systems (AIWPS®) and combine the use of anaerobic and aerobic bioprocesses to effect sewage treatment. IAPS technology was introduced to South Africa in 1996 and a pilot plant designed and commissioned at the Belmont Valley WWTW in Grahamstown. The system has been in continual use since implementation, and affords secondarily treated water for reclamation according to its design specifications, which most closely resemble those of the AIWPS Advanced Secondary Process. In this paper IAPS as a municipal sewage treatment technology is re-examined in relation to design and operation, the underpinning biochemistry of nutrient removal by algae is described, and a retrospective is provided on the demonstration system at the Belmont Valley WWTW. In addition to presenting details of the process flow, several shortcomings and/or oversights are highlighted and, in particular, the need for an appropriate tertiary treatment component. However, despite the use of IAPS for sewage treatment in many countries, this technology is still viewed with some scepticism. Thus, a major purpose of this overview is to provide a synthesis of available information on IAPS and an appraisal of its use for municipal sewage treatment. Keywords : advanced integrated wastewater pond system, integrated algae pond systems, wastewater, algae, nutrient removal, sewage

The efficiency of electrolytic treatment in reducing the Langelier saturation index (LSI) of the cooling water from a cooling tower of a textile industry was investigated. Sacrificial anodes were employed which prevent obnoxious chlorine generation. A series of batch experiments using stainless steel electrodes were conducted with 4 different current densities (5, 7, 10 and 15 A/m2) and 6 different electrolysis times (20, 30, 40, 50, 60 and 70 min). The use of 7 A/m2 for 50 min electrolysis time yielded a satisfactory efficiency in reducing the LSI index from 2.57 to zero, indicating that the treated water was of sufficient quality to be reused in the cooling process.

Polydiallyldimethylammonium chloride (polyDADMAC) is a water-soluble cationic polyelectrolyte used for water treatment. Its residues in treated water are contaminants as they react with chlorine to produce a carcinogenic compound. Commonly-used techniques for quantification of the polycation, such as colloidal and potentiometric titration as well as 1H NMR, have poor sensitivity and detection limits. This paper describes a more sensitive UV spectrophotometric method for quantitative determination of residual polyDADMAC in treated water, through formation of an ion pair with (4-hydroxy-1-napthylazo) benzene-sulphonic acid (dye). The ion pair, which is a colloidal solid material, was characterised by FTIR, 13C NMR and 1H NMR techniques. The colloid materials formed with different concentrations of polyDADMAC were dissolved in either N,N-dimethylformamide or 1,4-dioxane, followed by determination with UV spectrophotometry. The wavelength of maximum absorption (ëmax) was found to be dependent on the solvent used, with 1,4-dioxane showing a better linear range of 0.1–1.8 mg..-1 polyDADMAC. Varying the pH of the solutions had no significant effect on ëmax.

Microbial water quality is an essential aspect in the provision of potable water for domestic use. The provision of adequate amounts of safe water for domestic purposes has become difficult for most municipalities mandated to do so in Zimbabwe. Morton-Jaffray Treatment Plant supplies potable water to Harare City and areas surrounding Harare. This study investigated microbial water quality and the impact of microbial water quality related disasters in the area supplied by the Morton Jaffray Treatment Plant. Questionnaires were distributed to household owners in Harare who receive their water from the Municipality and those who use alternate water supplies. Candidates were randomly selected from their workplace. The raw water quality of Manyame River and its tributaries was assessed. Treated water in households was assessed for microbial quality using hydrogen sulphide test and heterotrophic bacteria plate count. Raw water sources were found to be contaminated by faecal matter. Household water sources tested negative for faecal contamination but positive for heterotrophic bacteria. CFU quantities ranged from 1 to 452 CFU/m. for all samples. The WHO guidelines for domestic water sources state that water used for domestic purposes should not be contain than 100 CFU/m.. Public perceptions of water quality ranged from eunsafef to ehighly contaminatedf. A decrease in the level of aesthetic appeal resulted in residents resorting to alternative sources such as wells and rivers for their domestic water. The current state of treated water was suitable for domestic use. Pathogen monitoring of domestic water is recommended using the hydrogen sulphide test and R2A agar test. Keywords : microbial water quality, faecal contamination, H 2 S strip test, R2A agar test

The purpose of this work is to evaluate the possibility of utilising an ultrafiltration process for the treatment of water from the dam in the Kabylia region of Algeria and, in particular, for the provision of drinking water to people living in dispersed small villages. The water quality was determined by measuring turbidity, and natural organic matter concentration. The results obtained with an ultrafiltration process indicate that this technique can considerably reduce suspended and organic matter. It also improves the bacteriological quality of the treated water. An economic evaluation for ultrafiltration of surface water is presented. The economic study was performed for a drinking water unit of 20 m3/h . It was found that the cost per m3 of treated water ($ 0.235/m3) obtained would not be excessively high for the states of the North African region. WaterSA Vol.27(2) 2001: 199-204

This paper investigates the best attainable treatability to which a water polluted with a technologically significant concentration of organic matter is treatable by different cation-active polyelectrolytes and their blends with mineral coagulants in comparison to that attainable by traditional hydrolysing coagulants. The negative influence of these reagents used as primary coagulants on the treated water quality is demonstrated in the case of Saulspoort Waterworks. WaterSA Vol.28(1) 2002: 69-82