[en] An oligochaete reactor linked to an integrated oxidation ditch with vertical cycle (IODVC) was used to investigate the sludge reduction potential induced by worms. The presence of Tubificidae was observed in the worm reactor throughout the operational period after its inoculation, and Tubificidae was occasionally found in the IODVC. Free-swimming worms, Aeolosoma hemprichi, Nais elinguis, and Aulophorus furcatus, were found in both the IODVC and the worm reactor, but A. hemprichi was dominant. A. hemprichi reached its maximum, 322 and 339 Aeolosoma/mL mixed liquor on day 49 in the worm reactor and the IODVC, respectively. The presence of oligochaetes or the integration of worm reactor with the IODVC had little effect on sludge yield, but the worm growth was helpful for improving sludge settling characteristics. The average sludge yield and sludge volume index (SVI) in the IODVC were 0.33 kgSS/kgCOD_removed and 78 mL/g, respectively. The worm presence had little impact on effluent quality of the IODVC, but it caused phosphorus release into the effluent. The average COD, NH₄⁺-N, and SS concentrations in the effluent of the IODVC were 49.06, 12.82, and 58.25 mg/L, respectively. No total nitrogen (TN) release into the effluent of the IODVC occurred

[en] Highlights: • Direct chlorination of wastewater from hospital was be effective for disinfection. • Direct chlorination of wastewater from STP was also effective for disinfection. • Disinfection of six classes of AMRB by chlorination was clearly attained. • Disinfection of AMSB by chlorination was also clearly attained. • Notable change in bacterial community structure didn't occur by direct chlorination. Both hospital effluent and a model sewage treatment plant (STP) wastewater prepared by mixing STP influent and STP secondary effluent at a volume ratio of 1:9 were directly treated with chlorine for investigation of their effects on disinfection of antimicrobial-resistant bacteria (AMRB) and antimicrobial-susceptible bacteria (AMSB). The overall results indicate that the chlorine disinfection effectively inactivated the majority of AMRB and AMSB, expect for MRSA and Staphylococcus aureus in both wastewaters. No significant differences could further be observed in the taxonomic diversity of micro-organisms after the treatment. The degrees of disinfection given by the direct chlorination were comparable to those attained by combination of conventional activated sludge process and additional chlorine treatment at the STP. The results of this study evoked a recommendation to operate local chlorination treatment directly for the wastewater from medicinal facilities prior to its flow into the STP as sewage. Although additional disinfection treatment at the STP seems necessary to remove the recalcitrant MRSA and Staphylococcus aureus, the present study desirably contributes to a great reduction of the loads of STP and urgent prevention of spreading of infectious diseases in the present state.

[en] The purpose of this document is to provide detailed information regarding the operations and maintenance of the septic holding tank system at the 100-C Remedial Action Restroom Facility. Specific information provided in this document includes the type and frequency of required maintenance and failure response procedures

[en] Short communication

No abstract available

[en] Though the active sludge process represent, nowadays, the main reference system referring to installations for wastewater treatments, nevertheless systems that exploit the pure oxygen properties constitute an alternative method to the traditional cycle. The following essay is divided into two parts: the first one deals with the fundamental concepts related to the active sludge process and to the alternative system proposed, mentioned before, and includes a short account of the functional characteristics and a brief comparison with traditional methods; the second part represents the head corpus of the work and deals with the problems related to the safety with particular reference to the risk of an explosion meanwhile the process. Moreover, it's drawn attention to the fundamental role of security systems that, nowadays, get frequently used in such kind of installations. On this subject, furthermore, it's pointed out the great importance of the whole preliminary treatments in the planning phase, with particular reference to the processes used for stripping

[en] Initially, a literature review about the general behaviour of the biological decomposition of phenol by the activated-sludge system is presented, where discrepancies seem to appear among researchers due to different operation conditions Worked by them. The degradation velocity depends on phenol concentration in a high level and on the charge used because its potential toxicity. Experiments were carryon in a pilot plant, using a mixture of low molecular weight alcohols, highly biodegradable, with a solution of pure phenol, increasing the phenol concentration from 33 % to 60 % in relation to DQO. Charges of phenol between 0,2 and 0,8 g of phenol /day/litter were applied, the initial concentration of phenol was changed between 200- 2000 mg/L and hydraulic retention times between 0,9 and 1,5 days were handled. The results have shown that the phenol concentration in the downstream has an exponential behaviour with the charge of phenol applied. In general, high efficiency in phenol removability is presented, reaching phenol concentration below 0,2 mg/1 downstream, with an average of 1,5 days in THR and average charges between 0,5-0,6 g phenol/day/ litter and a micro organism relation feed (arm) of 0,4- 0,5 g DBO₅/day/g. SS

[en] Activated sludges from the wastewater treatment of an oil refinery were characterized in order to improve the biotreatment of soils contaminated with hydrocarbons. The objective was to evaluate whether such industrial wastes that are being sent to landfills could be used for any useful purposes. A sand pit soil that contained 416 mg PAHs/kg and a gas station soil containing 1 mg PAHs/kg were evaluated. The study showed that activated sludges contain high concentration of oil and grease. Activated sludges were also found to be a valuable source of nitrogen and adapted bacteria

[en] This study aimed to determine the types of bacteria exist in wastewater that contribute to generate electricity and simultaneously remove carbon and nitrogen. The method used was Fluorescence In Situ Hybridization (FISH) to detect the bacteria group while Polymerase Chain Reaction (PCR) was used to confirm the observation made using FISH. A biochemical identification using BIOLOG GEN III MICROPLATE^TM also was used . The samples were cultured on nutrient agar plate to identify the morphology of the bacteria. The result showed that 21 isolates from three different locations at the activated sludge treatment plant with six, eleven and four strains for raw sewage, aeration tank and returned activated sludge samples, respectively. Preliminary identification does not give a good match but only showed the existence of ammonia-oxidizing bacteria (FISH) and Kurtia Gibsoni (BIOLOG) from aeration tank : Bacillus sp (PCR) and Bacillus Pseudomycoides (BIOLOG) from returned activated sludge. The maximum power density generated using returned activated sludge was 9.053 mW/ cm², with 26.8 % COD removal and 40 % TKN removal (author)

[en] The adsorption behavior of Zn²⁺ in four different biological sludge systems, i.e. activated sludge, denitrification sludge, short-cut nitrification sludge, and anammox granules, was investigated. The results indicated that all sludge samples possessed considerable potential for Zn²⁺ adsorption. Short-cut nitrification sludge possessed the highest Zn²⁺ maximum adsorption capacity (q_m) of 36.4 mg g SS⁻¹, which was much higher than other sludges applied (12.8–14.7 mg g SS⁻¹). Besides, the adsorption rate for short-cut nitrification sludge was fastest among the four types of sludge after fitting with a pseudo-second-order rate equation. Comparing with the physicochemical properties of the four sludges, the soluble extracellular polymeric substances (EPS), especially soluble polysaccharide (PS), played a prior role in binding metal cations (i.e., Zn). The present study also showed that with less than 30% of Zn²⁺ trapped by EPS, 61.6–71.9% of Zn²⁺could be harvested directly by cells, indicating that the protecting capability by EPS was limited. Therefore, it is important to remove metal ions as early as possible if the activated sludge processes encountered high stress of heavy metal.